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==================
Recoll user manual
==================
:Author: Jean-Francois Dockes
.. _RCL.INTRODUCTION:
Introduction
============
This document introduces full text search notions and describes the
installation and use of the RCL application. It is updated for RCL
RCLVERSION.
RCL was for a long time dedicated to Unix-like systems. It was only
lately (2015) ported to MS-Windows. Many references in this manual,
especially file locations, are specific to Unix, and not valid on WIN,
where some described features are also not available. The manual will be
progressively updated. Until this happens, on WIN, most references to
shared files can be translated by looking under the Recoll installation
directory (esp. the ``Share`` subdirectory). The user configuration is
stored by default under ``AppData/Local/Recoll`` inside the user
directory, along with the index itself.
.. _RCL.INTRODUCTION.TRYIT:
Giving it a try
---------------
If you do not like reading manuals (who does?) but wish to give RCL a
try, just `install <#RCL.INSTALL.BINARY>`__ the application and start
the ``recoll`` graphical user interface (GUI), which will ask permission
to index your home directory, allowing you to search immediately after
indexing completes.
Do not do this if your home directory contains a huge number of
documents and you do not want to wait or are very short on disk space.
In this case, you may first want to customize the
`configuration <#RCL.INDEXING.CONFIG>`__ to restrict the indexed area
(shortcut: from the ``recoll`` GUI go to: Preferences > Indexing
configuration, then adjust the Top directories section).
On Unix/Linux, you may need to install the appropriate `supporting
applications <#RCL.INSTALL.EXTERNAL>`__ for document types that need
them (for example antiword for Microsoft Word files). The RCL for WIN
package is self-contained and includes most useful auxiliary programs.
.. _RCL.INTRODUCTION.SEARCH:
Full text search
----------------
RCL is a full text search application, which means that it finds your
data by content rather than by external attributes (like the file name).
You specify words (terms) which should or should not appear in the text
you are looking for, and receive in return a list of matching documents,
ordered so that the most *relevant* documents will appear first.
You do not need to remember in what file or email message you stored a
given piece of information. You just ask for related terms, and the tool
will return a list of documents where these terms are prominent, in a
similar way to Internet search engines.
Full text search applications try to determine which documents are most
relevant to the search terms you provide. Computer algorithms for
determining relevance can be very complex, and in general are inferior
to the power of the human mind to rapidly determine relevance. The
quality of relevance guessing is probably the most important aspect when
evaluating a search application. RCL relies on the XAP probabilistic
information retrieval library to determine relevance.
In many cases, you are looking for all the forms of a word, including
plurals, different tenses for a verb, or terms derived from the same
root or *stem* (example: floor, floors, floored, flooring...). Queries
are usually automatically expanded to all such related terms (words that
reduce to the same stem). This can be prevented for searching for a
specific form.
Stemming, by itself, does not accommodate for misspellings or phonetic
searches. A full text search application may also support this form of
approximation. For example, a search for aliterattion returning no
result might propose alliteration, alteration, alterations, or
altercation as possible replacement terms. RCL bases its suggestions on
the actual index contents, so that suggestions may be made for words
which would not appear in a standard dictionary.
.. _RCL.INTRODUCTION.RECOLL:
Recoll overview
---------------
RCL uses the `XAP <http://www.xapian.org>`__ information retrieval
library as its storage and retrieval engine. XAP is a very mature
package using `a sophisticated probabilistic ranking
model <http://www.xapian.org/docs/intro_ir.html>`__.
The XAP library manages an index database which describes where terms
appear in your document files. It efficiently processes the complex
queries which are produced by the RCL query expansion mechanism, and is
in charge of the all-important relevance computation task.
RCL provides the mechanisms and interface to get data into and out of
the index. This includes translating the many possible document formats
into pure text, handling term variations (using XAP stemmers), and
spelling approximations (using the aspell speller), interpreting user
queries and presenting results.
In a shorter way, RCL does the dirty footwork, XAP deals with the
intelligent parts of the process.
The XAP index can be big (roughly the size of the original document
set), but it is not a document archive. RCL can only display documents
that still exist at the place from which they were indexed. (Actually,
there is a way to reconstruct a document from the information in the
index, but only the pure text is saved, possibly without punctuation and
capitalization, depending on RCL version).
RCL stores all internal data in Unicode UTF-8 format, and it can index
files of many types with different character sets, encodings, and
languages into the same index. It can process documents embedded inside
other documents (for example a pdf document stored inside a Zip archive
sent as an email attachment...), down to an arbitrary depth.
Stemming is the process by which RCL reduces words to their radicals so
that searching does not depend, for example, on a word being singular or
plural (floor, floors), or on a verb tense (flooring, floored). Because
the mechanisms used for stemming depend on the specific grammatical
rules for each language, there is a separate XAP stemmer module for most
common languages where stemming makes sense.
RCL stores the unstemmed versions of terms in the main index and uses
auxiliary databases for term expansion (one for each stemming language),
which means that you can switch stemming languages between searches, or
add a language without needing a full reindex.
Storing documents written in different languages in the same index is
possible, and commonly done. In this situation, you can specify several
stemming languages for the index.
RCL currently makes no attempt at automatic language recognition, which
means that the stemmer will sometimes be applied to terms from other
languages with potentially strange results. In practise, even if this
introduces possibilities of confusion, this approach has been proven
quite useful, and it is much less cumbersome than separating your
documents according to what language they are written in.
By default, RCL strips most accents and diacritics from terms, and
converts them to lower case before either storing them in the index or
searching for them. As a consequence, it is impossible to search for a
particular capitalization of a term (``US`` / ``us``), or to
discriminate two terms based on diacritics (``sake`` / ``saké``,
``mate`` / ``maté``).
RCL can optionally store the raw terms, without accent stripping or case
conversion. In this configuration, default searches will behave as
before, but it is possible to perform searches sensitive to case and
diacritics. This is described in more detail in the section about `index
case and diacritics sensitivity <#RCL.INDEXING.CONFIG.SENS>`__.
RCL has many parameters which define exactly what to index, and how to
classify and decode the source documents. These are kept in
`configuration files <#RCL.INDEXING.CONFIG>`__. A default configuration
is copied into a standard location (usually something like
``/usr/share/recoll/examples``) during installation. The default values
set by the configuration files in this directory may be overridden by
values set inside your personal configuration, found by default in the
``.recoll`` sub-directory of your home directory. The default
configuration will index your home directory with default parameters and
should be sufficient for giving RCL a try, but you may want to adjust it
later, which can be done either by editing the text files or by using
configuration menus in the ``recoll`` GUI. Some other parameters
affecting only the ``recoll`` GUI are stored in the standard location
defined by Qt.
The `indexing process <#RCL.INDEXING.PERIODIC.EXEC>`__ is started
automatically (after asking permission), the first time you execute the
``recoll`` GUI. Indexing can also be performed by executing the
``recollindex`` command. RCL indexing is multithreaded by default when
appropriate hardware resources are available, and can perform in
parallel multiple tasks for text extraction, segmentation and index
updates.
`Searches <#RCL.SEARCH>`__ are usually performed inside the ``recoll``
GUI, which has many options to help you find what you are looking for.
However, there are other ways to perform RCL searches:
- A `command line interface <#RCL.SEARCH.COMMANDLINE>`__.
- A `Pythonprogramming interface <#RCL.PROGRAM.PYTHONAPI>`__
- A `KDE KIO slave module <#RCL.SEARCH.KIO>`__.
- A Ubuntu Unity
`Scope <https://www.lesbonscomptes.com/recoll/download.html>`__
module.
- A Gnome Shell `Search
Provider <https://www.lesbonscomptes.com/recoll/download.html>`__.
- A `WEB interface <https://github.com/koniu/recoll-webui>`__.
.. _RCL.INDEXING:
Indexing
========
.. _RCL.INDEXING.INTRODUCTION:
Introduction
------------
Indexing is the process by which the set of documents is analyzed and
the data entered into the database. RCL indexing is normally
incremental: documents will only be processed if they have been modified
since the last run. On the first execution, all documents will need
processing. A full index build can be forced later by specifying an
option to the indexing command (``recollindex`` ``-z`` or ``-Z``).
``recollindex`` skips files which caused an error during a previous
pass. This is a performance optimization, and a new behaviour in version
1.21 (failed files were always retried by previous versions). The
command line option ``-k`` can be set to retry failed files, for example
after updating an input handler.
The following sections give an overview of different aspects of the
indexing processes and configuration, with links to detailed sections.
Depending on your data, temporary files may be needed during indexing,
some of them possibly quite big. You can use the RECOLL_TMPDIR or TMPDIR
environment variables to determine where they are created (the default
is to use ``/tmp``). Using TMPDIR has the nice property that it may also
be taken into account by auxiliary commands executed by ``recollindex``.
.. _RCL.INDEXING.INTRODUCTION.MODES:
Indexing modes
~~~~~~~~~~~~~~
RCL indexing can be performed along two main modes:
- `Periodic (or batch) indexing: <#RCL.INDEXING.PERIODIC>`__\ **.**
``recollindex`` is executed at discrete times. The typical usage is
to have a nightly run `programmed <#RCL.INDEXING.PERIODIC.AUTOMAT>`__
into your ``cron`` file.
- `Real time indexing: <#RCL.INDEXING.MONITOR>`__\ **.**
``recollindex`` runs permanently as a daemon and uses a file system
alteration monitor (e.g. inotify) to detect file changes. New or
updated files are indexed at once.
The choice between the two methods is mostly a matter of preference, and
they can be combined by setting up multiple indexes (ie: use periodic
indexing on a big documentation directory, and real time indexing on a
small home directory). Monitoring a big file system tree can consume
significant system resources.
With RCL 1.24 and newer, it is also possible to set up an index so that
only a subset of the tree will be monitored and the rest will be covered
by batch/incremental indexing. (See the details in the `Real time
indexing <#RCL.INDEXING.MONITOR>`__ section.
The choice of method and the parameters used can be configured from the
``recoll`` GUI: Preferences > Indexing schedule
The GUI File menu also has entries to start or stop the current indexing
operation. Stopping indexing is performed by killing the ``recollindex``
process, which will checkpoint its state and exit. A later restart of
indexing will mostly resume from where things stopped (the file tree
walk has to be restarted from the beginning).
When the real time indexer is running, two operations are available from
the menu: 'Stop' and 'Trigger incremental pass'. When no indexing is
running, you have a choice of updating the index or rebuilding it (the
first choice only processes changed files, the second one zeroes the
index before starting so that all files are processed).
.. _RCL.INDEXING.INTRODUCTION.CONFIG:
Configurations, multiple indexes
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
RCL supports defining multiple indexes, each defined by its own
`configuration directory <#RCL.INDEXING.CONFIG>`__, in which several
configuration files describe what should be indexed and how.
A default personal configuration directory (``$HOME/.recoll/``) is
created when a RCL program is first executed. This configuration is the
one used for indexing and querying when no specific configuration is
specified.
All configuration parameters have defaults, defined in system-wide
files. Without further customisation, the default configuration will
process your complete home directory, with a reasonable set of defaults.
It can be changed to process a different area of the file system, select
files in different ways, and many other things.
In some cases, it may be useful to create additional configuration
directories, for example, to separate personal and shared indexes, or to
take advantage of the organization of your data to improve search
precision.
A plausible usage scenario for the multiple index feature would be for a
system administrator to set up a central index for shared data, that you
choose to search or not in addition to your personal data. Of course,
there are other possibilities. for example, there are many cases where
you know the subset of files that should be searched, and where
narrowing the search can improve the results. You can achieve
approximately the same effect with the directory filter in advanced
search, but multiple indexes may have better performance and may be
worth the trouble in some cases.
A more advanced use case would be to use multiple index to improve
indexing performance, by updating several indexes in parallel (using
multiple CPU cores and disks, or possibly several machines), and then
merging them, or querying them in parallel.
A specific configuration can be selected by setting the RECOLL_CONFDIR
environment variable, or giving the ``-c`` option to any of the RCL
commands.
When creating or updating indexes, the different configurations are
entirely independant (no parameters are ever shared between
configurations when indexing). The ``recollindex`` program always works
on a single index.
When querying, multiple indexes can be accessed concurrently, either
from the GUI or the command line. When doing this, there is always one
main configuration, from which both configuration and index data are
used. Only the index data from the additional indexes is used (their
configuration parameters are ignored).
The behaviour of index update and query regarding multiple
configurations is important and sometimes confusing, so it will be
rephrased here: for index generation, multiple configurations are
totally independant from each other. When querying, configuration and
data are used from the main index (the one designated by ``-c`` or
RECOLL_CONFDIR), and only the data from the additional indexes is used.
This implies that some parameters should be consistent among the
configurations for indexes which are to be used together.
See the section about `configuring multiple
indexes <#RCL.INDEXING.CONFIG.MULTIPLE>`__ for more detail
Document types
~~~~~~~~~~~~~~
RCL knows about quite a few different document types. The parameters for
document types recognition and processing are set in `configuration
files <#RCL.INDEXING.CONFIG>`__.
Most file types, like HTML or word processing files, only hold one
document. Some file types, like email folders or zip archives, can hold
many individually indexed documents, which may themselves be compound
ones. Such hierarchies can go quite deep, and RCL can process, for
example, a LibreOffice document stored as an attachment to an email
message inside an email folder archived in a zip file...
``recollindex`` processes plain text, HTML, OpenDocument
(Open/LibreOffice), email formats, and a few others internally.
Other file types (ie: postscript, pdf, ms-word, rtf ...) need external
applications for preprocessing. The list is in the
`installation <#RCL.INSTALL.EXTERNAL>`__ section. After every indexing
operation, RCL updates a list of commands that would be needed for
indexing existing files types. This list can be displayed by selecting
the menu option File > Show Missing Helpers in the ``recoll`` GUI. It is
stored in the ``missing`` text file inside the configuration directory.
By default, RCL will try to index any file type that it has a way to
read. This is sometimes not desirable, and there are ways to either
exclude some types, or on the contrary define a positive list of types
to be indexed. In the latter case, any type not in the list will be
ignored.
Excluding files by name can be done by adding wildcard name patterns to
the `skippedNames <#RCL.INSTALL.CONFIG.RECOLLCONF.SKIPPEDNAMES>`__ list,
which can be done from the GUI Index configuration menu. Excluding by
type can be done by setting the
`excludedmimetypes <#RCL.INSTALL.CONFIG.RECOLLCONF.EXCLUDEDMIMETYPES>`__
list in the configuration file (1.20 and later). This can be redefined
for subdirectories.
You can also define an exclusive list of MIME types to be indexed (no
others will be indexed), by settting the
`indexedmimetypes <#RCL.INSTALL.CONFIG.RECOLLCONF.INDEXEDMIMETYPES>`__
configuration variable. Example:
::
indexedmimetypes = text/html application/pdf
It is possible to redefine this parameter for subdirectories. Example:
::
[/path/to/my/dir]
indexedmimetypes = application/pdf
(When using sections like this, don't forget that they remain in effect
until the end of the file or another section indicator).
``excludedmimetypes`` or ``indexedmimetypes``, can be set either by
editing the `configuration file
(``recoll.conf``) <#RCL.INSTALL.CONFIG.RECOLLCONF>`__ for the index, or
by using the GUI index configuration tool.
**Note**
When editing the ``indexedmimetypes`` or ``excludedmimetypes`` lists,
you should use the MIME values listed in the ``mimemap`` file or in
Recoll result lists in preference to ``file -i`` output: there are a
number of differences. The ``file -i`` output should only be used for
files without extensions, or for which the extension is not listed in
``mimemap``
Indexing failures
~~~~~~~~~~~~~~~~~
Indexing may fail for some documents, for a number of reasons: a helper
program may be missing, the document may be corrupt, we may fail to
uncompress a file because no file system space is available, etc.
RCL versions prior to 1.21 always retried to index files which had
previously caused an error. This guaranteed that anything that may have
become indexable (for example because a helper had been installed) would
be indexed. However this was bad for performance because some indexing
failures may be quite costly (for example failing to uncompress a big
file because of insufficient disk space).
The indexer in RCL versions 1.21 and later does not retry failed files
by default. Retrying will only occur if an explicit option (``-k``) is
set on the ``recollindex`` command line, or if a script executed when
``recollindex`` starts up says so. The script is defined by a
configuration variable (``checkneedretryindexscript``), and makes a
rather lame attempt at deciding if a helper command may have been
installed, by checking if any of the common ``bin`` directories have
changed.
Recovery
~~~~~~~~
In the rare case where the index becomes corrupted (which can signal
itself by weird search results or crashes), the index files need to be
erased before restarting a clean indexing pass. Just delete the
``xapiandb`` directory (see `next section <#RCL.INDEXING.STORAGE>`__),
or, alternatively, start the next ``recollindex`` with the ``-z``
option, which will reset the database before indexing. The difference
between the two methods is that the second will not change the current
index format, which may be undesirable if a newer format is supported by
the XAP version.
.. _RCL.INDEXING.STORAGE:
Index storage
-------------
The default location for the index data is the ``xapiandb`` subdirectory
of the RCL configuration directory, typically
``$HOME/.recoll/xapiandb/``. This can be changed via two different
methods (with different purposes):
1. For a given configuration directory, you can specify a non-default
storage location for the index by setting the ``dbdir`` parameter in
the configuration file (see the `configuration
section <#RCL.INSTALL.CONFIG.RECOLLCONF>`__). This method would
mainly be of use if you wanted to keep the configuration directory in
its default location, but desired another location for the index,
typically out of disk occupation or performance concerns.
2. You can specify a different configuration directory by setting the
RECOLL_CONFDIR environment variable, or using the ``-c`` option to
the RCL commands. This method would typically be used to index
different areas of the file system to different indexes. For example,
if you were to issue the following command:
::
recoll -c ~/.indexes-email
Then RCL would use configuration files stored in
``~/.indexes-email/`` and, (unless specified otherwise in
``recoll.conf``) would look for the index in
``~/.indexes-email/xapiandb/``.
Using multiple configuration directories and `configuration
options <#RCL.INSTALL.CONFIG.RECOLLCONF>`__ allows you to tailor
multiple configurations and indexes to handle whatever subset of the
available data you wish to make searchable.
The size of the index is determined by the size of the set of documents,
but the ratio can vary a lot. For a typical mixed set of documents, the
index size will often be close to the data set size. In specific cases
(a set of compressed mbox files for example), the index can become much
bigger than the documents. It may also be much smaller if the documents
contain a lot of images or other non-indexed data (an extreme example
being a set of mp3 files where only the tags would be indexed).
Of course, images, sound and video do not increase the index size, which
means that in most cases, the space used by the index will be negligible
against the total amount of data on the computer.
The index data directory (``xapiandb``) only contains data that can be
completely rebuilt by an index run (as long as the original documents
exist), and it can always be destroyed safely.
.. _RCL.INDEXING.STORAGE.FORMAT:
XAP index formats
~~~~~~~~~~~~~~~~~
XAP versions usually support several formats for index storage. A given
major XAP version will have a current format, used to create new
indexes, and will also support the format from the previous major
version.
XAP will not convert automatically an existing index from the older
format to the newer one. If you want to upgrade to the new format, or if
a very old index needs to be converted because its format is not
supported any more, you will have to explicitly delete the old index
(typically ``~/.recoll/xapiandb``), then run a normal indexing command.
Using ``recollindex`` option ``-z`` would not work in this situation.
.. _RCL.INDEXING.STORAGE.SECURITY:
Security aspects
~~~~~~~~~~~~~~~~
The RCL index does not hold complete copies of the indexed documents (it
almost does after version 1.24). But it does hold enough data to allow
for an almost complete reconstruction. If confidential data is indexed,
access to the database directory should be restricted.
RCL will create the configuration directory with a mode of 0700 (access
by owner only). As the index data directory is by default a
sub-directory of the configuration directory, this should result in
appropriate protection.
If you use another setup, you should think of the kind of protection you
need for your index, set the directory and files access modes
appropriately, and also maybe adjust the ``umask`` used during index
updates.
.. _RCL.INDEXING.STORAGE.BIG:
Special considerations for big indexes
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This only needs concern you if your index is going to be bigger than
around 5 GBytes. Beyond 10 GBytes, it becomes a serious issue. Most
people have much smaller indexes. For reference, 5 GBytes would be
around 2000 bibles, a lot of text. If you have a huge text dataset
(remember: images don't count, the text content of PDFs is typically
less than 5% of the file size), read on.
The amount of writing performed by Xapian during index creation is not
linear with the index size (it is somewhere between linear and
quadratic). For big indexes this becomes a performance issue, and may
even be an SSD disk wear issue.
The problem can be mitigated by observing the following rules:
- Partition the data set and create several indexes of reasonable size
rather than a huge one. These indexes can then be queried in parallel
(using the RCL external indexes facility), or merged using
``xapian-compact``.
- Have a lot of RAM available and set the ``idxflushmb`` RCL
configuration parameter as high as you can without swapping
(experimentation will be needed). 200 would be a minimum in this
context.
- Use Xapian 1.4.10 or newer, as this version brought a significant
improvement in the amount of writes.
.. _RCL.INDEXING.CONFIG:
Index configuration
-------------------
Variables set inside the `RCL configuration
files <#RCL.INSTALL.CONFIG>`__ control which areas of the file system
are indexed, and how files are processed. These variables can be set
either by editing the text files or by using the `dialogs in the
``recoll`` GUI <#RCL.INDEXING.CONFIG.GUI>`__.
The first time you start ``recoll``, you will be asked whether or not
you would like it to build the index. If you want to adjust the
configuration before indexing, just click Cancel at this point, which
will get you into the configuration interface. If you exit at this
point, ``recoll`` will have created a ``~/.recoll`` directory containing
empty configuration files, which you can edit by hand.
The configuration is documented inside the `installation
chapter <#RCL.INSTALL.CONFIG>`__ of this document, or in the recoll.conf
5 man page, but the most current information will most likely be the
comments inside the sample file. The most immediately useful variable is
probably ```topdirs`` <#RCL.INSTALL.CONFIG.RECOLLCONF.TOPDIRS>`__, which
determines what subtrees and files get indexed.
The applications needed to index file types other than text, HTML or
email (ie: pdf, postscript, ms-word...) are described in the `external
packages section <#RCL.INSTALL.EXTERNAL>`__.
As of Recoll 1.18 there are two incompatible types of Recoll indexes,
depending on the treatment of character case and diacritics. A `further
section <#RCL.INDEXING.CONFIG.SENS>`__ describes the two types in more
detail.
.. _RCL.INDEXING.CONFIG.MULTIPLE:
Multiple indexes
~~~~~~~~~~~~~~~~
Multiple RCL indexes can be created by using several configuration
directories which are typically set to index different areas of the file
system. A specific index can be selected for updating or searching,
using the RECOLL_CONFDIR environment variable or the ``-c`` option to
``recoll`` and ``recollindex``.
Index configuration parameters can be set either by using a text editor
on the files, or, for most parameters, by using the ``recoll`` index
configuration GUI. In the latter case, the configuration directory for
which parameters are modified is the one which was selected by
RECOLL_CONFDIR or the ``-c`` parameter, and there is no way to switch
configurations within the GUI.
As a remainder from a previous section, a ``recollindex`` program
instance can only update one specific index, and it will only use
parameters from a single configuration (no parameters are ever shared
between configurations when indexing). All the query methods
(``recoll``, ``recollq``, the Python API, etc.) operate with a main
configuration, from which both configuration and index data are used,
but can also query data from multiple additional indexes. Only the index
data from the latter is used, their configuration parameters are
ignored.
When searching, the current main index (defined by RECOLL_CONFDIR or
``-c``) is always active. If this is undesirable, you can set up your
base configuration to index an empty directory.
If a set of multiple indexes are to be used together for searches, some
configuration parameters must be consistent among the set. These are
parameters which need to be the same when indexing and searching. As the
parameters come from the main configuration when searching, they need to
be compatible with what was set when creating the other indexes (which
came from their respective configuration directories).
Most importantly, all indexes to be queried concurrently must have the
same option concerning character case and diacritics stripping, but
there are other constraints. Most of the relevant parameters are
described in the `linked
section <#RCL.INSTALL.CONFIG.RECOLLCONF.TERMS>`__.
The different search interfaces (GUI, command line, ...) have different
methods to define the set of indexes to be used, see the appropriate
section.
At the moment, using multiple configurations implies a small level of
command line usage. Additional configuration directories (beyond
``~/.recoll``) must be created by hand (``mkdir`` or such), the GUI will
not do it. This is to avoid mistakenly creating additional directories
when an argument is mistyped. Also, the GUI or the indexer must be
launched with a specific option or environment to work on the right
configuration.
To be more practical, here follows a few examples of the commands need
to create, configure, update, and query an additional index.
Initially creating the configuration and index:
::
mkdir /path/to/my/new/config
Configuring the new index can be done from the ``recoll`` GUI, launched
from the command line to pass the ``-c`` option (you could create a
desktop file to do it for you), and then using the GUI index
configuration tool to set up the index.
::
recoll -c /path/to/my/new/config
Alternatively, you can just start a text editor on the main
configuration file ```recoll.conf`` <#RCL.INSTALL.CONFIG.RECOLLCONF>`__.
Creating and updating the index can be done from the command line:
::
recollindex -c /path/to/my/new/config
or from the File menu of a GUI launched with the same option
(``recoll``, see above).
The same GUI would also let you set up batch indexing for the new index.
Real time indexing can only be set up from the GUI for the default index
(the menu entry will be inactive if the GUI was started with a
non-default ``-c`` option).
The new index can be queried alone with
::
recoll -c /path/to/my/new/config
Or, in parallel with the default index, by starting ``recoll`` without a
``-c`` option, and using the Preferences > External Index Dialog menu.
.. _RCL.INDEXING.CONFIG.SENS:
Index case and diacritics sensitivity
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
As of RCL version 1.18 you have a choice of building an index with terms
stripped of character case and diacritics, or one with raw terms. For a
source term of ``Résumé``, the former will store ``resume``, the latter
``Résumé``.
Each type of index allows performing searches insensitive to case and
diacritics: with a raw index, the user entry will be expanded to match
all case and diacritics variations present in the index. With a stripped
index, the search term will be stripped before searching.
A raw index allows for another possibility which a stripped index cannot
offer: using case and diacritics to discriminate between terms,
returning different results when searching for ``US`` and ``us`` or
``resume`` and ``résumé``. Read the `section about search case and
diacritics sensitivity <#RCL.SEARCH.CASEDIAC>`__ for more details.
The type of index to be created is controlled by the ``indexStripChars``
configuration variable which can only be changed by editing the
configuration file. Any change implies an index reset (not automated by
RCL), and all indexes in a search must be set in the same way (again,
not checked by RCL).
If the ``indexStripChars`` is not set, RCL 1.18 creates a stripped index
by default, for compatibility with previous versions.
As a cost for added capability, a raw index will be slightly bigger than
a stripped one (around 10%). Also, searches will be more complex, so
probably slightly slower, and the feature is still young, so that a
certain amount of weirdness cannot be excluded.
One of the most adverse consequence of using a raw index is that some
phrase and proximity searches may become impossible: because each term
needs to be expanded, and all combinations searched for, the
multiplicative expansion may become unmanageable.
.. _RCL.INDEXING.CONFIG.THREADS:
Indexing threads configuration
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The RCL indexing process ``recollindex`` can use multiple threads to
speed up indexing on multiprocessor systems. The work done to index
files is divided in several stages and some of the stages can be
executed by multiple threads. The stages are:
1. File system walking: this is always performed by the main thread.
2. File conversion and data extraction.
3. Text processing (splitting, stemming, etc.).
4. XAP index update.
You can also read a `longer
document <http://www.recoll.org/idxthreads/threadingRecoll.html>`__
about the transformation of RCL indexing to multithreading.
The threads configuration is controlled by two configuration file
parameters.
``thrQSizes``
This variable defines the job input queues configuration. There are
three possible queues for stages 2, 3 and 4, and this parameter
should give the queue depth for each stage (three integer values). If
a value of -1 is used for a given stage, no queue is used, and the
thread will go on performing the next stage. In practise, deep queues
have not been shown to increase performance. A value of 0 for the
first queue tells RCL to perform autoconfiguration (no need for
anything else in this case, thrTCounts is not used) - this is the
default configuration.
``thrTCounts``
This defines the number of threads used for each stage. If a value of
-1 is used for one of the queue depths, the corresponding thread
count is ignored. It makes no sense to use a value other than 1 for
the last stage because updating the XAP index is necessarily
single-threaded (and protected by a mutex).
..
**Note**
If the first value in ``thrQSizes`` is 0, ``thrTCounts`` is ignored.
The following example would use three queues (of depth 2), and 4 threads
for converting source documents, 2 for processing their text, and one to
update the index. This was tested to be the best configuration on the
test system (quadri-processor with multiple disks).
::
thrQSizes = 2 2 2
thrTCounts = 4 2 1
The following example would use a single queue, and the complete
processing for each document would be performed by a single thread
(several documents will still be processed in parallel in most cases).
The threads will use mutual exclusion when entering the index update
stage. In practise the performance would be close to the precedent case
in general, but worse in certain cases (e.g. a Zip archive would be
performed purely sequentially), so the previous approach is preferred.
YMMV... The 2 last values for thrTCounts are ignored.
::
thrQSizes = 2 -1 -1
thrTCounts = 6 1 1
The following example would disable multithreading. Indexing will be
performed by a single thread.
::
thrQSizes = -1 -1 -1
.. _RCL.INDEXING.CONFIG.GUI:
The index configuration GUI
~~~~~~~~~~~~~~~~~~~~~~~~~~~
Most parameters for a given index configuration can be set from a
``recoll`` GUI running on this configuration (either as default, or by
setting RECOLL_CONFDIR or the ``-c`` option.)
The interface is started from the Preferences > Index Configuration menu
entry. It is divided in four tabs, Global parameters, Local parameters,
Web history (which is explained in the next section) and Search
parameters.
The Global parameters tab allows setting global variables, like the
lists of top directories, skipped paths, or stemming languages.
The Local parameters tab allows setting variables that can be redefined
for subdirectories. This second tab has an initially empty list of
customisation directories, to which you can add. The variables are then
set for the currently selected directory (or at the top level if the
empty line is selected).
The Search parameters section defines parameters which are used at query
time, but are global to an index and affect all search tools, not only
the GUI.
The meaning for most entries in the interface is self-evident and
documented by a ``ToolTip`` popup on the text label. For more detail,
you will need to refer to the `configuration
section <#RCL.INSTALL.CONFIG>`__ of this guide.
The configuration tool normally respects the comments and most of the
formatting inside the configuration file, so that it is quite possible
to use it on hand-edited files, which you might nevertheless want to
backup first...
.. _RCL.INDEXING.WEBQUEUE:
Indexing the WEB pages which you wisit.
---------------------------------------
With the help of a Firefox extension, RCL can index the Internet pages
that you visit. The extension has a long history: it was initially
designed for the Beagle indexer, then adapted to RCL and the Firefox XUL
API. A new version of the addon has been written to work with the
WebExtensions API, which is the only one supported after Firefox version
57.
The extension works by copying visited WEB pages to an indexing queue
directory, which RCL then processes, indexing the data, storing it into
a local cache, then removing the file from the queue.
Because the WebExtensions API introduces more constraints to what
extensions can do, the new version works with one more step: the files
are first created in the browser default downloads location (typically
``$HOME/Downloads`` ), then moved by a script in the old queue location.
The script is automatically executed by the RCL indexer versions 1.23.5
and newer. It could conceivably be executed independantly to make the
new browser extension compatible with an older RCL version (the script
is named ``recoll-we-move-files.py``).
**Note**
For the WebExtensions-based version to work, it is necessary to set
the ``webdownloadsdir`` value in the configuration if it was changed
from the default ``$HOME/Downloads`` in the browser preferences.
The visited WEB pages indexing feature can be enabled on the RCL side
from the GUI Index configuration panel, or by editing the configuration
file (set ``processwebqueue`` to 1).
A current pointer to the extension can be found, along with up-to-date
instructions, on the `Recoll wiki <&FAQS;IndexWebHistory>`__.
A copy of the indexed WEB pages is retained by Recoll in a local cache
(from which previews can be fetched). The cache size can be adjusted
from the Index configuration / Web history panel. Once the maximum size
is reached, old pages are purged - both from the cache and the index -
to make room for new ones, so you need to explicitly archive in some
other place the pages that you want to keep indefinitely.
.. _RCL.INDEXING.EXTATTR:
Extended attributes data
------------------------
User extended attributes are named pieces of information that most
modern file systems can attach to any file.
RCL versions 1.19 and later process extended attributes as document
fields by default. For older versions, this has to be activated at build
time.
A `freedesktop
standard <http://www.freedesktop.org/wiki/CommonExtendedAttributes>`__
defines a few special attributes, which are handled as such by RCL:
mime_type
If set, this overrides any other determination of the file MIME type.
charset
If set, this defines the file character set (mostly useful for plain
text files).
By default, other attributes are handled as RCL fields. On Linux, the
``user`` prefix is removed from the name. This can be configured more
precisely inside the ```fields`` configuration
file <#RCL.INSTALL.CONFIG.FIELDS>`__.
.. _RCL.INDEXING.EXTTAGS:
Importing external tags
-----------------------
During indexing, it is possible to import metadata for each file by
executing commands. For example, this could extract user tag data for
the file and store it in a field for indexing.
See the `section about the ``metadatacmds``
field <#RCL.INSTALL.CONFIG.RECOLLCONF.METADATACMDS>`__ in the main
configuration chapter for a description of the configuration syntax.
As an example, if you would want RCL to use tags managed by tmsu, you
would add the following to the configuration file:
::
[/some/area/of/the/fs]
metadatacmds = ; tags = tmsu tags %f
..
**Note**
Depending on the tmsu version, you may need/want to add options like
``--database=/some/db``.
You may want to restrict this processing to a subset of the directory
tree, because it may slow down indexing a bit
(``[some/area/of/the/fs]``).
Note the initial semi-colon after the equal sign.
In the example above, the output of ``tmsu`` is used to set a field
named ``tags``. The field name is arbitrary and could be ``tmsu`` or
``myfield`` just the same, but ``tags`` is an alias for the standard RCL
``keywords`` field, and the ``tmsu`` output will just augment its
contents. This will avoid the need to extend the `field
configuration <#RCL.PROGRAM.FIELDS>`__.
Once re-indexing is performed (you'll need to force the file reindexing,
RCL will not detect the need by itself), you will be able to search from
the query language, through any of its aliases:
``tags:some/alternate/values`` or ``tags:all,these,values`` (the compact
field search syntax is supported for recoll 1.20 and later. For older
versions, you would need to repeat the ``tags:`` specifier for each
term, e.g. ``tags:some OR tags:alternate``).
You should be aware that tags changes will not be detected by the
indexer if the file itself did not change. One possible workaround would
be to update the file ``ctime`` when you modify the tags, which would be
consistent with how extended attributes function. A pair of ``chmod``
commands could accomplish this, or a ``touch -a`` . Alternatively, just
couple the tag update with a ``recollindex -e -i filename.``
.. _RCL.INDEXING.PDF:
The PDF input handler
---------------------
The PDF format is very important for scientific and technical
documentation, and document archival. It has extensive facilities for
storing metadata along with the document, and these facilities are
actually used in the real world.
In consequence, the ``rclpdf.py`` PDF input handler has more complex
capabilities than most others, and it is also more configurable.
Specifically, ``rclpdf.py`` can automatically use tesseract to perform
OCR if the document text is empty, it can be configured to extract
specific metadata tags from an XMP packet, and to extract PDF
attachments.
.. _RCL.INDEXING.PDF.OCR:
OCR with Tesseract
~~~~~~~~~~~~~~~~~~
If both tesseract and ``pdftoppm`` (generally from the poppler-utils
package) are installed, the PDF handler may attempt OCR on PDF files
with no text content. This is controlled by the
`pdfocr <#RCL.INSTALL.CONFIG.RECOLLCONF.PDFOCR>`__ configuration
variable, which is false by default because OCR is very slow.
The choice of language is very important for successfull OCR. Recoll has
currently no way to determine this from the document itself. You can set
the language to use through the contents of a ``.ocrpdflang`` text file
in the same directory as the PDF document, or through the
RECOLL_TESSERACT_LANG environment variable, or through the contents of
an ``ocrpdf`` text file inside the configuration directory. If none of
the above are used, RCL will try to guess the language from the NLS
environment.
.. _RCL.INDEXING.PDF.XMP:
XMP fields extraction
~~~~~~~~~~~~~~~~~~~~~
The ``rclpdf.py`` script in RCL version 1.23.2 and later can extract XMP
metadata fields by executing the ``pdfinfo`` command (usually found with
poppler-utils). This is controlled by the
`pdfextrameta <#RCL.INSTALL.CONFIG.RECOLLCONF.PDFEXTRAMETA>`__
configuration variable, which specifies which tags to extract and,
possibly, how to rename them.
The `pdfextrametafix <#RCL.INSTALL.CONFIG.RECOLLCONF.PDFEXTRAMETAFIX>`__
variable can be used to designate a file with Python code to edit the
metadata fields (available for RCL 1.23.3 and later. 1.23.2 has
equivalent code inside the handler script). Example:
::
import sys
import re
class MetaFixer(object):
def __init__(self):
pass
def metafix(self, nm, txt):
if nm == 'bibtex:pages':
txt = re.sub(r'--', '-', txt)
elif nm == 'someothername':
# do something else
pass
elif nm == 'stillanother':
# etc.
pass
return txt
def wrapup(self, metaheaders):
pass
If the 'metafix()' method is defined, it is called for each metadata
field. A new MetaFixer object is created for each PDF document (so the
object can keep state for, for example, eliminating duplicate values).
If the 'wrapup()' method is defined, it is called at the end of XMP
fields processing with the whole metadata as parameter, as an array of
'(nm, val)' pairs, allowing an alternate approach for editing or
adding/deleting fields.
.. _RCL.INDEXING.PDF.ATTACH:
PDF attachment indexing
~~~~~~~~~~~~~~~~~~~~~~~
If pdftk is installed, and if the the
`pdfattach <#RCL.INSTALL.CONFIG.RECOLLCONF.PDFATTACH>`__ configuration
variable is set, the PDF input handler will try to extract PDF
attachements for indexing as sub-documents of the PDF file. This is
disabled by default, because it slows down PDF indexing a bit even if
not one attachment is ever found (PDF attachments are uncommon in my
experience).
.. _RCL.INDEXING.PERIODIC:
Periodic indexing
-----------------
.. _RCL.INDEXING.PERIODIC.EXEC:
Running indexing
~~~~~~~~~~~~~~~~
Indexing is always performed by the ``recollindex`` program, which can
be started either from the command line or from the File menu in the
``recoll`` GUI program. When started from the GUI, the indexing will run
on the same configuration ``recoll`` was started on. When started from
the command line, ``recollindex`` will use the RECOLL_CONFDIR variable
or accept a ``-c`` confdir option to specify a non-default configuration
directory.
If the ``recoll`` program finds no index when it starts, it will
automatically start indexing (except if canceled).
The ``recollindex`` indexing process can be interrupted by sending an
interrupt (Ctrl-C, SIGINT) or terminate (SIGTERM) signal. Some time may
elapse before the process exits, because it needs to properly flush and
close the index. This can also be done from the ``recoll`` GUI File >
Stop Indexing menu entry.
After such an interruption, the index will be somewhat inconsistent
because some operations which are normally performed at the end of the
indexing pass will have been skipped (for example, the stemming and
spelling databases will be inexistant or out of date). You just need to
restart indexing at a later time to restore consistency. The indexing
will restart at the interruption point (the full file tree will be
traversed, but files that were indexed up to the interruption and for
which the index is still up to date will not need to be reindexed).
``recollindex`` has a number of other options which are described in its
man page. Only a few will be described here.
Option ``-z`` will reset the index when starting. This is almost the
same as destroying the index files (the nuance is that the XAP format
version will not be changed).
Option ``-Z`` will force the update of all documents without resetting
the index first. This will not have the "clean start" aspect of ``-z``,
but the advantage is that the index will remain available for querying
while it is rebuilt, which can be a significant advantage if it is very
big (some installations need days for a full index rebuild).
Option ``-k`` will force retrying files which previously failed to be
indexed, for example because of a missing helper program.
Of special interest also, maybe, are the ``-i`` and ``-f`` options.
``-i`` allows indexing an explicit list of files (given as command line
parameters or read on ``stdin``). ``-f`` tells ``recollindex`` to ignore
file selection parameters from the configuration. Together, these
options allow building a custom file selection process for some area of
the file system, by adding the top directory to the ``skippedPaths``
list and using an appropriate file selection method to build the file
list to be fed to ``recollindex`` ``-if``. Trivial example:
::
find . -name indexable.txt -print | recollindex -if
``recollindex`` ``-i`` will not descend into subdirectories specified as
parameters, but just add them as index entries. It is up to the external
file selection method to build the complete file list.
.. _RCL.INDEXING.PERIODIC.AUTOMAT:
Using ``cron`` to automate indexing
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The most common way to set up indexing is to have a cron task execute it
every night. For example the following ``crontab`` entry would do it
every day at 3:30AM (supposing ``recollindex`` is in your PATH):
::
30 3 * * * recollindex > /some/tmp/dir/recolltrace 2>&1
Or, using ``anacron``:
::
1 15 su mylogin -c "recollindex recollindex > /tmp/rcltraceme 2>&1"
As of version 1.17 the RCL GUI has dialogs to manage ``crontab`` entries
for ``recollindex``. You can reach them from the Preferences > Indexing
Schedule menu. They only work with the good old ``cron``, and do not
give access to all features of ``cron`` scheduling.
The usual command to edit your ``crontab`` is ``crontab`` ``-e`` (which
will usually start the ``vi`` editor to edit the file). You may have
more sophisticated tools available on your system.
Please be aware that there may be differences between your usual
interactive command line environment and the one seen by crontab
commands. Especially the PATH variable may be of concern. Please check
the crontab manual pages about possible issues.
.. _RCL.INDEXING.MONITOR:
Real time indexing
------------------
Real time monitoring/indexing is performed by starting the
``recollindex`` ``-m`` command. With this option, ``recollindex`` will
detach from the terminal and become a daemon, permanently monitoring
file changes and updating the index.
While it is convenient that data is indexed in real time, repeated
indexing can generate a significant load on the system when files such
as email folders change. Also, monitoring large file trees by itself
significantly taxes system resources. You probably do not want to enable
it if your system is short on resources. Periodic indexing is adequate
in most cases.
As of RCL 1.24, you can set the
`monitordirs <#RCL.INSTALL.CONFIG.RECOLLCONF.MONITORDIRS>`__
configuration variable to specify that only a subset of your indexed
files will be monitored for instant indexing. In this situation, an
incremental pass on the full tree can be triggered by either restarting
the indexer, or just running ``recollindex``, which will notify the
running process. The ``recoll`` GUI also has a menu entry for this.
.. _RCL.INDEXING.MONITOR.START:
Real time indexing: automatic daemon start
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Under KDE, Gnome and some other desktop environments, the daemon can
automatically started when you log in, by creating a desktop file inside
the ``~/.config/autostart`` directory. This can be done for you by the
RCL GUI. Use the Preferences->Indexing Schedule menu.
With older X11 setups, starting the daemon is normally performed as part
of the user session script.
The ``rclmon.sh`` script can be used to easily start and stop the
daemon. It can be found in the ``examples`` directory (typically
``/usr/local/[share/]recoll/examples``).
For example, my out of fashion xdm-based session has a ``.xsession``
script with the following lines at the end:
::
recollconf=$HOME/.recoll-home
recolldata=/usr/local/share/recoll
RECOLL_CONFDIR=$recollconf $recolldata/examples/rclmon.sh start
fvwm
The indexing daemon gets started, then the window manager, for which the
session waits.
By default the indexing daemon will monitor the state of the X11
session, and exit when it finishes, it is not necessary to kill it
explicitly. (The X11 server monitoring can be disabled with option
``-x`` to ``recollindex``).
If you use the daemon completely out of an X11 session, you need to add
option ``-x`` to disable X11 session monitoring (else the daemon will
not start).
.. _RCL.INDEXING.MONITOR.DETAILS:
Real time indexing: miscellaneous details
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
By default, the messages from the indexing daemon will be sent to the
same file as those from the interactive commands (``logfilename``). You
may want to change this by setting the ``daemlogfilename`` and
``daemloglevel`` configuration parameters. Also the log file will only
be truncated when the daemon starts. If the daemon runs permanently, the
log file may grow quite big, depending on the log level.
When building RCL, the real time indexing support can be customised
during package `configuration <#RCL.INSTALL.BUILDING>`__ with the
``--with[out]-fam`` or ``--with[out]-inotify`` options. The default is
currently to include inotify monitoring on systems that support it, and,
as of RCL 1.17, gamin support on FreeBSD.
**Note**
On Linux systems, monitoring a big tree may need increasing the
resources available to inotify, which are normally defined in
``/etc/sysctl.conf``.
::
### inotify
#
# cat /proc/sys/fs/inotify/max_queued_events - 16384
# cat /proc/sys/fs/inotify/max_user_instances - 128
# cat /proc/sys/fs/inotify/max_user_watches - 16384
#
# -- Change to:
#
fs.inotify.max_queued_events=32768
fs.inotify.max_user_instances=256
fs.inotify.max_user_watches=32768
Especially, you will need to trim your tree or adjust the
``max_user_watches`` value if indexing exits with a message about
errno ``ENOSPC`` (28) from ``inotify_add_watch``.
..
**Note**
When using the real time monitor, it may happen that some files need
to be indexed, but change so often that they impose an excessive load
for the system.
RCL provides a configuration option to specify the minimum time
before which a file, specified by a wildcard pattern, cannot be
reindexed. See the ``mondelaypatterns`` parameter in the
`configuration section <#RCL.INSTALL.CONFIG.RECOLLCONF.MISC>`__.
.. _RCL.SEARCH:
Searching
=========
.. _RCL.SEARCH.GUI:
Searching with the Qt graphical user interface
----------------------------------------------
The ``recoll`` program provides the main user interface for searching.
It is based on the Qt library.
``recoll`` has two search modes:
- Simple search (the default, on the main screen) has a single entry
field where you can enter multiple words.
- Advanced search (a panel accessed through the Tools menu or the
toolbox bar icon) has multiple entry fields, which you may use to
build a logical condition, with additional filtering on file type,
location in the file system, modification date, and size.
In most cases, you can enter the terms as you think them, even if they
contain embedded punctuation or other non-textual characters. For
example, RCL can handle things like email addresses, or arbitrary cut
and paste from another text window, punctation and all.
The main case where you should enter text differently from how it is
printed is for east-asian languages (Chinese, Japanese, Korean). Words
composed of single or multiple characters should be entered separated by
white space in this case (they would typically be printed without white
space).
Some searches can be quite complex, and you may want to re-use them
later, perhaps with some tweaking. RCL versions 1.21 and later can save
and restore searches, using XML files. See `Saving and restoring
queries <#RCL.SEARCH.SAVING>`__.
.. _RCL.SEARCH.GUI.SIMPLE:
Simple search
~~~~~~~~~~~~~
Start the ``recoll`` program.
Possibly choose a search mode: Any term, All terms, File name or Query
language.
Enter search term(s) in the text field at the top of the window.
Click the Search button or hit the Enter key to start the search.
The initial default search mode is Query language. Without special
directives, this will look for documents containing all of the search
terms (the ones with more terms will get better scores), just like the
All terms mode. Any term will search for documents where at least one of
the terms appear.
The Query Language features are described in `a separate
section <#RCL.SEARCH.LANG>`__.
All search modes allow terms to be expanded with wildcards characters
(``*``, ``?``, ``[]``). See the `section about
wildcards <#RCL.SEARCH.WILDCARDS>`__ for more details.
The File name search mode will specifically look for file names. The
point of having a separate file name search is that wild card expansion
can be performed more efficiently on a small subset of the index
(allowing wild cards on the left of terms without excessive penality).
Things to know:
- White space in the entry should match white space in the file name,
and is not treated specially.
- The search is insensitive to character case and accents,
independantly of the type of index.
- An entry without any wild card character and not capitalized will be
prepended and appended with '*' (ie: etc -> \*etc*, but Etc -> etc).
- If you have a big index (many files), excessively generic fragments
may result in inefficient searches.
In all modes except File name, you can search for exact phrases
(adjacent words in a given order) by enclosing the input inside double
quotes. Ex: ``"virtual reality"``.
When using a stripped index (the default), character case has no
influence on search, except that you can disable stem expansion for any
term by capitalizing it. Ie: a search for ``floor`` will also normally
look for ``flooring``, ``floored``, etc., but a search for ``Floor``
will only look for ``floor``, in any character case. Stemming can also
be disabled globally in the preferences. When using a raw index, `the
rules are a bit more complicated <#RCL.SEARCH.CASEDIAC>`__.
RCL remembers the last few searches that you performed. You can directly
access the search history by clicking the clock button on the right of
the search entry, while the latter is empty. Otherwise, the history is
used for entry completion (see next). Only the search texts are
remembered, not the mode (all/any/file name).
While text is entered in the search area, ``recoll`` will display
possible completions, filtered from the history and the index search
terms. This can be disabled with a GUI Preferences option.
Double-clicking on a word in the result list or a preview window will
insert it into the simple search entry field.
You can cut and paste any text into an All terms or Any term search
field, punctuation, newlines and all - except for wildcard characters
(single ``?`` characters are ok). RCL will process it and produce a
meaningful search. This is what most differentiates this mode from the
Query Language mode, where you have to care about the syntax.
You can use the `Tools > Advanced search <#RCL.SEARCH.GUI.COMPLEX>`__
dialog for more complex searches.
.. _RCL.SEARCH.GUI.RESLIST:
The default result list
~~~~~~~~~~~~~~~~~~~~~~~
After starting a search, a list of results will instantly be displayed
in the main list window.
By default, the document list is presented in order of relevance (how
well the system estimates that the document matches the query). You can
sort the result by ascending or descending date by using the vertical
arrows in the toolbar.
Clicking on the ``Preview`` link for an entry will open an internal
preview window for the document. Further ``Preview`` clicks for the same
search will open tabs in the existing preview window. You can use
Shift+Click to force the creation of another preview window, which may
be useful to view the documents side by side. (You can also browse
successive results in a single preview window by typing
Shift+ArrowUp/Down in the window).
Clicking the ``Open`` link will start an external viewer for the
document. By default, RCL lets the desktop choose the appropriate
application for most document types (there is a short list of
exceptions, see further). If you prefer to completely customize the
choice of applications, you can uncheck the Use desktop preferences
option in the GUI preferences dialog, and click the Choose editor
applications button to adjust the predefined RCL choices. The tool
accepts multiple selections of MIME types (e.g. to set up the editor for
the dozens of office file types).
Even when Use desktop preferences is checked, there is a small list of
exceptions, for MIME types where the RCL choice should override the
desktop one. These are applications which are well integrated with RCL,
especially evince for viewing PDF and Postscript files because of its
support for opening the document at a specific page and passing a search
string as an argument. Of course, you can edit the list (in the GUI
preferences) if you would prefer to lose the functionality and use the
standard desktop tool.
You may also change the choice of applications by editing the
```mimeview`` <#RCL.INSTALL.CONFIG.MIMEVIEW>`__ configuration file if
you find this more convenient.
Each result entry also has a right-click menu with an Open With entry.
This lets you choose an application from the list of those which
registered with the desktop for the document MIME type.
The ``Preview`` and ``Open`` edit links may not be present for all
entries, meaning that RCL has no configured way to preview a given file
type (which was indexed by name only), or no configured external editor
for the file type. This can sometimes be adjusted simply by tweaking the
```mimemap`` <#RCL.INSTALL.CONFIG.MIMEMAP>`__ and
```mimeview`` <#RCL.INSTALL.CONFIG.MIMEVIEW>`__ configuration files (the
latter can be modified with the user preferences dialog).
The format of the result list entries is entirely configurable by using
the preference dialog to `edit an HTML
fragment <#RCL.SEARCH.GUI.CUSTOM.RESLIST>`__.
You can click on the ``Query details`` link at the top of the results
page to see the query actually performed, after stem expansion and other
processing.
Double-clicking on any word inside the result list or a preview window
will insert it into the simple search text.
The result list is divided into pages (the size of which you can change
in the preferences). Use the arrow buttons in the toolbar or the links
at the bottom of the page to browse the results.
.. _RCL.SEARCH.GUI.RESLIST.SUGGS:
No results: the spelling suggestions
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
When a search yields no result, and if the aspell dictionary is
configured, RCL will try to check for misspellings among the query
terms, and will propose lists of replacements. Clicking on one of the
suggestions will replace the word and restart the search. You can hold
any of the modifier keys (Ctrl, Shift, etc.) while clicking if you would
rather stay on the suggestion screen because several terms need
replacement.
.. _RCL.SEARCH.GUI.RESULTLIST.MENU:
The result list right-click menu
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Apart from the preview and edit links, you can display a pop-up menu by
right-clicking over a paragraph in the result list. This menu has the
following entries:
- Preview
- Open
- Open With
- Run Script
- Copy File Name
- Copy Url
- Save to File
- Find similar
- Preview Parent document
- Open Parent document
- Open Snippets Window
The Preview and Open entries do the same thing as the corresponding
links.
Open With lets you open the document with one of the applications
claiming to be able to handle its MIME type (the information comes from
the ``.desktop`` files in ``/usr/share/applications``).
Run Script allows starting an arbitrary command on the result file. It
will only appear for results which are top-level files. See
`further <#RCL.SEARCH.GUI.RUNSCRIPT>`__ for a more detailed description.
The Copy File Name and Copy Url copy the relevant data to the clipboard,
for later pasting.
Save to File allows saving the contents of a result document to a chosen
file. This entry will only appear if the document does not correspond to
an existing file, but is a subdocument inside such a file (ie: an email
attachment). It is especially useful to extract attachments with no
associated editor.
The Open/Preview Parent document entries allow working with the higher
level document (e.g. the email message an attachment comes from). RCL is
sometimes not totally accurate as to what it can or can't do in this
area. For example the Parent entry will also appear for an email which
is part of an mbox folder file, but you can't actually visualize the
mbox (there will be an error dialog if you try).
If the document is a top-level file, Open Parent will start the default
file manager on the enclosing filesystem directory.
The Find similar entry will select a number of relevant term from the
current document and enter them into the simple search field. You can
then start a simple search, with a good chance of finding documents
related to the current result. I can't remember a single instance where
this function was actually useful to me...
The Open Snippets Window entry will only appear for documents which
support page breaks (typically PDF, Postscript, DVI). The snippets
window lists extracts from the document, taken around search terms
occurrences, along with the corresponding page number, as links which
can be used to start the native viewer on the appropriate page. If the
viewer supports it, its search function will also be primed with one of
the search terms.
.. _RCL.SEARCH.GUI.RESTABLE:
The result table
~~~~~~~~~~~~~~~~
In RCL 1.15 and newer, the results can be displayed in spreadsheet-like
fashion. You can switch to this presentation by clicking the table-like
icon in the toolbar (this is a toggle, click again to restore the list).
Clicking on the column headers will allow sorting by the values in the
column. You can click again to invert the order, and use the header
right-click menu to reset sorting to the default relevance order (you
can also use the sort-by-date arrows to do this).
Both the list and the table display the same underlying results. The
sort order set from the table is still active if you switch back to the
list mode. You can click twice on a date sort arrow to reset it from
there.
The header right-click menu allows adding or deleting columns. The
columns can be resized, and their order can be changed (by dragging).
All the changes are recorded when you quit ``recoll``
Hovering over a table row will update the detail area at the bottom of
the window with the corresponding values. You can click the row to
freeze the display. The bottom area is equivalent to a result list
paragraph, with links for starting a preview or a native application,
and an equivalent right-click menu. Typing Esc (the Escape key) will
unfreeze the display.
.. _RCL.SEARCH.GUI.RUNSCRIPT:
Running arbitrary commands on result files (1.20 and later)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Apart from the Open and Open With operations, which allow starting an
application on a result document (or a temporary copy), based on its
MIME type, it is also possible to run arbitrary commands on results
which are top-level files, using the Run Script entry in the results
pop-up menu.
The commands which will appear in the Run Script submenu must be defined
by ``.desktop`` files inside the ``scripts`` subdirectory of the current
configuration directory.
Here follows an example of a ``.desktop`` file, which could be named for
example, ``~/.recoll/scripts/myscript.desktop`` (the exact file name
inside the directory is irrelevant):
::
[Desktop Entry]
Type=Application
Name=MyFirstScript
Exec=/home/me/bin/tryscript %F
MimeType=*/*
The ``Name`` attribute defines the label which will appear inside the
Run Script menu. The ``Exec`` attribute defines the program to be run,
which does not need to actually be a script, of course. The ``MimeType``
attribute is not used, but needs to exist.
The commands defined this way can also be used from links inside the
`result paragraph <#RCL.SEARCH.GUI.CUSTOM.RESLIST.PARA>`__.
As an example, it might make sense to write a script which would move
the document to the trash and purge it from the RCL index.
.. _RCL.SEARCH.GUI.THUMBNAILS:
Displaying thumbnails
~~~~~~~~~~~~~~~~~~~~~
The default format for the result list entries and the detail area of
the result table display an icon for each result document. The icon is
either a generic one determined from the MIME type, or a thumbnail of
the document appearance. Thumbnails are only displayed if found in the
standard freedesktop location, where they would typically have been
created by a file manager.
Recoll has no capability to create thumbnails. A relatively simple trick
is to use the Open parent document/folder entry in the result list popup
menu. This should open a file manager window on the containing
directory, which should in turn create the thumbnails (depending on your
settings). Restarting the search should then display the thumbnails.
There are also `some pointers about thumbnail
generation <&FAQS;ResultsThumbnails.wiki>`__ on the RCL wiki.
.. _RCL.SEARCH.GUI.PREVIEW:
The preview window
~~~~~~~~~~~~~~~~~~
The preview window opens when you first click a ``Preview`` link inside
the result list.
Subsequent preview requests for a given search open new tabs in the
existing window (except if you hold the Shift key while clicking which
will open a new window for side by side viewing).
Starting another search and requesting a preview will create a new
preview window. The old one stays open until you close it.
You can close a preview tab by typing Ctrl-W (Ctrl + W) in the window.
Closing the last tab for a window will also close the window.
Of course you can also close a preview window by using the window
manager button in the top of the frame.
You can display successive or previous documents from the result list
inside a preview tab by typing Shift+Down or Shift+Up (Down and Up are
the arrow keys).
A right-click menu in the text area allows switching between displaying
the main text or the contents of fields associated to the document (ie:
author, abtract, etc.). This is especially useful in cases where the
term match did not occur in the main text but in one of the fields. In
the case of images, you can switch between three displays: the image
itself, the image metadata as extracted by ``exiftool`` and the fields,
which is the metadata stored in the index.
You can print the current preview window contents by typing Ctrl-P (Ctrl
+ P) in the window text.
.. _RCL.SEARCH.GUI.PREVIEW.SEARCH:
Searching inside the preview
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The preview window has an internal search capability, mostly controlled
by the panel at the bottom of the window, which works in two modes: as a
classical editor incremental search, where we look for the text entered
in the entry zone, or as a way to walk the matches between the document
and the RCL query that found it.
Incremental text search
The preview tabs have an internal incremental search function. You
initiate the search either by typing a / (slash) or CTL-F inside the
text area or by clicking into the Search for: text field and entering
the search string. You can then use the Next and Previous buttons to
find the next/previous occurrence. You can also type F3 inside the
text area to get to the next occurrence.
If you have a search string entered and you use Ctrl-Up/Ctrl-Down to
browse the results, the search is initiated for each successive
document. If the string is found, the cursor will be positioned at
the first occurrence of the search string.
Walking the match lists
If the entry area is empty when you click the Next or Previous
buttons, the editor will be scrolled to show the next match to any
search term (the next highlighted zone). If you select a search group
from the dropdown list and click Next or Previous, the match list for
this group will be walked. This is not the same as a text search,
because the occurences will include non-exact matches (as caused by
stemming or wildcards). The search will revert to the text mode as
soon as you edit the entry area.
.. _RCL.SEARCH.GUI.FRAGBUTS:
The Query Fragments window
~~~~~~~~~~~~~~~~~~~~~~~~~~
Selecting the Tools > Query Fragments menu entry will open a window with
radio- and check-buttons which can be used to activate query language
fragments for filtering the current query. This can be useful if you
have frequent reusable selectors, for example, filtering on alternate
directories, or searching just one category of files, not covered by the
standard category selectors.
The contents of the window are entirely customizable, and defined by the
contents of the ``fragbuts.xml`` file inside the configuration
directory. The sample file distributed with RCL (which you should be
able to find under ``/usr/share/recoll/examples/fragbuts.xml``),
contains an example which filters the results from the WEB history.
Here follows an example:
::
<?xml version="1.0" encoding="UTF-8"?>
<fragbuts version="1.0">
<radiobuttons>
<fragbut>
<label>Include Web Results</label>
<frag></frag>
</fragbut>
<fragbut>
<label>Exclude Web Results</label>
<frag>-rclbes:BGL</frag>
</fragbut>
<fragbut>
<label>Only Web Results</label>
<frag>rclbes:BGL</frag>
</fragbut>
</radiobuttons>
<buttons>
<fragbut>
<label>Year 2010</label>
<frag>date:2010-01-01/2010-12-31</frag>
</fragbut>
<fragbut>
<label>My Great Directory Only</label>
<frag>dir:/my/great/directory</frag>
</fragbut>
</buttons>
</fragbuts>
Each ``radiobuttons`` or ``buttons`` section defines a line of
checkbuttons or radiobuttons inside the window. Any number of buttons
can be selected, but the radiobuttons in a line are exclusive.
Each ``fragbut`` section defines the label for a button, and the Query
Language fragment which will be added (as an AND filter) before
performing the query if the button is active.
This feature is new in RCL 1.20, and will probably be refined depending
on user feedback.
.. _RCL.SEARCH.GUI.COMPLEX:
Complex/advanced search
~~~~~~~~~~~~~~~~~~~~~~~
The advanced search dialog helps you build more complex queries without
memorizing the search language constructs. It can be opened through the
Tools menu or through the main toolbar.
RCL keeps a history of searches. See `Advanced search
history <#RCL.SEARCH.GUI.COMPLEX.HISTORY>`__.
The dialog has two tabs:
1. The first tab lets you specify terms to search for, and permits
specifying multiple clauses which are combined to build the search.
2. The second tab lets filter the results according to file size, date
of modification, MIME type, or location.
Click on the Start Search button in the advanced search dialog, or type
Enter in any text field to start the search. The button in the main
window always performs a simple search.
Click on the ``Show query details`` link at the top of the result page
to see the query expansion.
.. _RCL.SEARCH.GUI.COMPLEX.TERMS:
Avanced search: the "find" tab
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
This part of the dialog lets you constructc a query by combining
multiple clauses of different types. Each entry field is configurable
for the following modes:
- All terms.
- Any term.
- None of the terms.
- Phrase (exact terms in order within an adjustable window).
- Proximity (terms in any order within an adjustable window).
- Filename search.
Additional entry fields can be created by clicking the Add clause
button.
When searching, the non-empty clauses will be combined either with an
AND or an OR conjunction, depending on the choice made on the left (All
clauses or Any clause).
Entries of all types except "Phrase" and "Near" accept a mix of single
words and phrases enclosed in double quotes. Stemming and wildcard
expansion will be performed as for simple search.
**Phrases and Proximity searches.**
These two clauses work in similar ways, with the difference that
proximity searches do not impose an order on the words. In both cases,
an adjustable number (slack) of non-matched words may be accepted
between the searched ones (use the counter on the left to adjust this
count). For phrases, the default count is zero (exact match). For
proximity it is ten (meaning that two search terms, would be matched if
found within a window of twelve words). Examples: a phrase search for
``quick fox`` with a slack of 0 will match ``quick fox`` but not
``quick brown fox``. With a slack of 1 it will match the latter, but not
``fox quick``. A proximity search for ``quick fox`` with the default
slack will match the latter, and also
``a fox is a cunning and quick animal``.
.. _RCL.SEARCH.GUI.COMPLEX.FILTER:
Avanced search: the "filter" tab
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
This part of the dialog has several sections which allow filtering the
results of a search according to a number of criteria
- The first section allows filtering by dates of last modification. You
can specify both a minimum and a maximum date. The initial values are
set according to the oldest and newest documents found in the index.
- The next section allows filtering the results by file size. There are
two entries for minimum and maximum size. Enter decimal numbers. You
can use suffix multipliers: ``k/K``, ``m/M``, ``g/G``, ``t/T`` for
1E3, 1E6, 1E9, 1E12 respectively.
- The next section allows filtering the results by their MIME types, or
MIME categories (ie: media/text/message/etc.).
You can transfer the types between two boxes, to define which will be
included or excluded by the search.
The state of the file type selection can be saved as the default (the
file type filter will not be activated at program start-up, but the
lists will be in the restored state).
- The bottom section allows restricting the search results to a
sub-tree of the indexed area. You can use the Invert checkbox to
search for files not in the sub-tree instead. If you use directory
filtering often and on big subsets of the file system, you may think
of setting up multiple indexes instead, as the performance may be
better.
You can use relative/partial paths for filtering. Ie, entering
``dirA/dirB`` would match either ``/dir1/dirA/dirB/myfile1`` or
``/dir2/dirA/dirB/someother/myfile2``.
.. _RCL.SEARCH.GUI.COMPLEX.HISTORY:
Avanced search history
^^^^^^^^^^^^^^^^^^^^^^
The advanced search tool memorizes the last 100 searches performed. You
can walk the saved searches by using the up and down arrow keys while
the keyboard focus belongs to the advanced search dialog.
The complex search history can be erased, along with the one for simple
search, by selecting the File > Erase Search History menu entry.
.. _RCL.SEARCH.GUI.TERMEXPLORER:
The term explorer tool
~~~~~~~~~~~~~~~~~~~~~~
RCL automatically manages the expansion of search terms to their
derivatives (ie: plural/singular, verb inflections). But there are other
cases where the exact search term is not known. For example, you may not
remember the exact spelling, or only know the beginning of the name.
The search will only propose replacement terms with spelling variations
when no matching document were found. In some cases, both proper
spellings and mispellings are present in the index, and it may be
interesting to look for them explicitely.
The term explorer tool (started from the toolbar icon or from the Term
explorer entry of the Tools menu) can be used to search the full index
terms list. It has three modes of operations:
Wildcard
In this mode of operation, you can enter a search string with
shell-like wildcards (*, ?, []). ie: xapi\* would display all index
terms beginning with xapi. (More about wildcards
`here <#RCL.SEARCH.WILDCARDS>`__ ).
Regular expression
This mode will accept a regular expression as input. Example:
word[0-9]+. The expression is implicitely anchored at the beginning.
Ie: press will match pression but not expression. You can use .*press
to match the latter, but be aware that this will cause a full index
term list scan, which can be quite long.
Stem expansion
This mode will perform the usual stem expansion normally done as part
user input processing. As such it is probably mostly useful to
demonstrate the process.
Spelling/Phonetic
In this mode, you enter the term as you think it is spelled, and RCL
will do its best to find index terms that sound like your entry. This
mode uses the Aspell spelling application, which must be installed on
your system for things to work (if your documents contain non-ascii
characters, RCL needs an aspell version newer than 0.60 for UTF-8
support). The language which is used to build the dictionary out of
the index terms (which is done at the end of an indexing pass) is the
one defined by your NLS environment. Weird things will probably
happen if languages are mixed up.
Note that in cases where RCL does not know the beginning of the string
to search for (ie a wildcard expression like \*coll), the expansion can
take quite a long time because the full index term list will have to be
processed. The expansion is currently limited at 10000 results for
wildcards and regular expressions. It is possible to change the limit in
the configuration file.
Double-clicking on a term in the result list will insert it into the
simple search entry field. You can also cut/paste between the result
list and any entry field (the end of lines will be taken care of).
.. _RCL.SEARCH.GUI.MULTIDB:
Multiple indexes
~~~~~~~~~~~~~~~~
See the section describing `the use of multiple
indexes <#RCL.INDEXING.CONFIG.MULTIPLE>`__ for generalities. Only the
aspects concerning the ``recoll`` GUI are described here.
A ``recoll`` program instance is always associated with a specific
index, which is the one to be updated when requested from the File menu,
but it can use any number of RCL indexes for searching. The external
indexes can be selected through the external indexes tab in the
preferences dialog.
Index selection is performed in two phases. A set of all usable indexes
must first be defined, and then the subset of indexes to be used for
searching. These parameters are retained across program executions
(there are kept separately for each RCL configuration). The set of all
indexes is usually quite stable, while the active ones might typically
be adjusted quite frequently.
The main index (defined by RECOLL_CONFDIR) is always active. If this is
undesirable, you can set up your base configuration to index an empty
directory.
When adding a new index to the set, you can select either a RCL
configuration directory, or directly a XAP index directory. In the first
case, the XAP index directory will be obtained from the selected
configuration.
As building the set of all indexes can be a little tedious when done
through the user interface, you can use the RECOLL_EXTRA_DBS environment
variable to provide an initial set. This might typically be set up by a
system administrator so that every user does not have to do it. The
variable should define a colon-separated list of index directories, ie:
::
export RECOLL_EXTRA_DBS=/some/place/xapiandb:/some/other/db
Another environment variable, RECOLL_ACTIVE_EXTRA_DBS allows adding to
the active list of indexes. This variable was suggested and implemented
by a RCL user. It is mostly useful if you use scripts to mount external
volumes with RCL indexes. By using RECOLL_EXTRA_DBS and
RECOLL_ACTIVE_EXTRA_DBS, you can add and activate the index for the
mounted volume when starting ``recoll``.
RECOLL_ACTIVE_EXTRA_DBS is available for RCL versions 1.17.2 and later.
A change was made in the same update so that ``recoll`` will
automatically deactivate unreachable indexes when starting up.
.. _RCL.SEARCH.GUI.HISTORY:
Document history
~~~~~~~~~~~~~~~~
Documents that you actually view (with the internal preview or an
external tool) are entered into the document history, which is
remembered.
You can display the history list by using the Tools/Doc History menu
entry.
You can erase the document history by using the Erase document history
entry in the File menu.
.. _RCL.SEARCH.GUI.SORT:
Sorting search results and collapsing duplicates
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The documents in a result list are normally sorted in order of
relevance. It is possible to specify a different sort order, either by
using the vertical arrows in the GUI toolbox to sort by date, or
switching to the result table display and clicking on any header. The
sort order chosen inside the result table remains active if you switch
back to the result list, until you click one of the vertical arrows,
until both are unchecked (you are back to sort by relevance).
Sort parameters are remembered between program invocations, but result
sorting is normally always inactive when the program starts. It is
possible to keep the sorting activation state between program
invocations by checking the Remember sort activation state option in the
preferences.
It is also possible to hide duplicate entries inside the result list
(documents with the exact same contents as the displayed one). The test
of identity is based on an MD5 hash of the document container, not only
of the text contents (so that ie, a text document with an image added
will not be a duplicate of the text only). Duplicates hiding is
controlled by an entry in the GUI configuration dialog, and is off by
default.
As of release 1.19, when a result document does have undisplayed
duplicates, a ``Dups`` link will be shown with the result list entry.
Clicking the link will display the paths (URLs + ipaths) for the
duplicate entries.
.. _RCL.SEARCH.GUI.TIPS:
Search tips, shortcuts
~~~~~~~~~~~~~~~~~~~~~~
.. _RCL.SEARCH.GUI.TIPS.TERMS:
Terms and search expansion
^^^^^^^^^^^^^^^^^^^^^^^^^^
**Term completion.**
Typing Esc Space in the simple search entry field while entering a word
will either complete the current word if its beginning matches a unique
term in the index, or open a window to propose a list of completions.
**Picking up new terms from result or preview text.**
Double-clicking on a word in the result list or in a preview window will
copy it to the simple search entry field.
**Wildcards.**
Wildcards can be used inside search terms in all forms of searches.
`More about wildcards <#RCL.SEARCH.WILDCARDS>`__.
**Automatic suffixes.**
Words like ``odt`` or ``ods`` can be automatically turned into query
language ``ext:xxx`` clauses. This can be enabled in the Search
preferences panel in the GUI.
**Disabling stem expansion.**
Entering a capitalized word in any search field will prevent stem
expansion (no search for ``gardening`` if you enter ``Garden`` instead
of ``garden``). This is the only case where character case should make a
difference for a RCL search. You can also disable stem expansion or
change the stemming language in the preferences.
**Finding related documents.**
Selecting the Find similar documents entry in the result list paragraph
right-click menu will select a set of "interesting" terms from the
current result, and insert them into the simple search entry field. You
can then possibly edit the list and start a search to find documents
which may be apparented to the current result.
**File names.**
File names are added as terms during indexing, and you can specify them
as ordinary terms in normal search fields (RCL used to index all
directories in the file path as terms. This has been abandoned as it did
not seem really useful). Alternatively, you can use the specific file
name search which will *only* look for file names, and may be faster
than the generic search especially when using wildcards.
.. _RCL.SEARCH.GUI.TIPS.PHRASES:
Working with phrases and proximity
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
**Phrases and Proximity searches.**
A phrase can be looked for by enclosing it in double quotes. Example:
``"user manual"`` will look only for occurrences of ``user`` immediately
followed by ``manual``. You can use the This phrase field of the
advanced search dialog to the same effect. Phrases can be entered along
simple terms in all simple or advanced search entry fields (except This
exact phrase).
**AutoPhrases.**
This option can be set in the preferences dialog. If it is set, a phrase
will be automatically built and added to simple searches when looking
for ``Any terms``. This will not change radically the results, but will
give a relevance boost to the results where the search terms appear as a
phrase. Ie: searching for ``virtual reality`` will still find all
documents where either ``virtual`` or ``reality`` or both appear, but
those which contain ``virtual reality`` should appear sooner in the
list.
Phrase searches can strongly slow down a query if most of the terms in
the phrase are common. This is why the ``autophrase`` option is off by
default for RCL versions before 1.17. As of version 1.17, ``autophrase``
is on by default, but very common terms will be removed from the
constructed phrase. The removal threshold can be adjusted from the
search preferences.
**Phrases and abbreviations.**
As of RCL version 1.17, dotted abbreviations like ``I.B.M.`` are also
automatically indexed as a word without the dots: ``IBM``. Searching for
the word inside a phrase (ie: ``"the IBM company"``) will only match the
dotted abrreviation if you increase the phrase slack (using the advanced
search panel control, or the ``o`` query language modifier). Literal
occurences of the word will be matched normally.
.. _RCL.SEARCH.GUI.TIPS.MISC:
Others
^^^^^^
**Using fields.**
You can use the `query language <#RCL.SEARCH.LANG>`__ and field
specifications to only search certain parts of documents. This can be
especially helpful with email, for example only searching emails from a
specific originator: ``search tips from:helpfulgui``
**Ajusting the result table columns.**
When displaying results in table mode, you can use a right click on the
table headers to activate a pop-up menu which will let you adjust what
columns are displayed. You can drag the column headers to adjust their
order. You can click them to sort by the field displayed in the column.
You can also save the result list in CSV format.
**Changing the GUI geometry.**
It is possible to configure the GUI in wide form factor by dragging the
toolbars to one of the sides (their location is remembered between
sessions), and moving the category filters to a menu (can be set in the
Preferences > GUI configuration > User interface panel).
**Query explanation.**
You can get an exact description of what the query looked for, including
stem expansion, and Boolean operators used, by clicking on the result
list header.
**Advanced search history.**
As of RCL 1.18, you can display any of the last 100 complex searches
performed by using the up and down arrow keys while the advanced search
panel is active.
**Browsing the result list inside a preview window.**
Entering Shift-Down or Shift-Up (Shift + an arrow key) in a preview
window will display the next or the previous document from the result
list. Any secondary search currently active will be executed on the new
document.
**Scrolling the result list from the keyboard.**
You can use PageUp and PageDown to scroll the result list, Shift+Home to
go back to the first page. These work even while the focus is in the
search entry.
**Result table: moving the focus to the table.**
You can use Ctrl-r to move the focus from the search entry to the table,
and then use the arrow keys to change the current row. Ctrl-Shift-s
returns to the search.
**Result table: open / preview.**
With the focus in the result table, you can use Ctrl-o to open the
document from the current row, Ctrl-Shift-o to open the document and
close ``recoll``, Ctrl-d to preview the document.
**Editing a new search while the focus is not in the search entry.**
You can use the Ctrl-Shift-S shortcut to return the cursor to the search
entry (and select the current search text), while the focus is anywhere
in the main window.
**Forced opening of a preview window.**
You can use Shift+Click on a result list ``Preview`` link to force the
creation of a preview window instead of a new tab in the existing one.
**Closing previews.**
Entering Ctrl-W in a tab will close it (and, for the last tab, close the
preview window). Entering Esc will close the preview window and all its
tabs.
**Printing previews.**
Entering Ctrl-P in a preview window will print the currently displayed
text.
**Quitting.**
Entering Ctrl-Q almost anywhere will close the application.
.. _RCL.SEARCH.SAVING:
Saving and restoring queries (1.21 and later)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Both simple and advanced query dialogs save recent history, but the
amount is limited: old queries will eventually be forgotten. Also,
important queries may be difficult to find among others. This is why
both types of queries can also be explicitely saved to files, from the
GUI menus: File > Save last query / Load last query
The default location for saved queries is a subdirectory of the current
configuration directory, but saved queries are ordinary files and can be
written or moved anywhere.
Some of the saved query parameters are part of the preferences (e.g.
``autophrase`` or the active external indexes), and may differ when the
query is loaded from the time it was saved. In this case, RCL will warn
of the differences, but will not change the user preferences.
.. _RCL.SEARCH.GUI.CUSTOM:
Customizing the search interface
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
You can customize some aspects of the search interface by using the GUI
configuration entry in the Preferences menu.
There are several tabs in the dialog, dealing with the interface itself,
the parameters used for searching and returning results, and what
indexes are searched.
**User interface parameters:.**
- Highlight color for query terms: Terms from the user query are
highlighted in the result list samples and the preview window. The
color can be chosen here. Any Qt color string should work (ie
``red``, ``#ff0000``). The default is ``blue``.
- Style sheet: The name of a Qt style sheet text file which is applied
to the whole Recoll application on startup. The default value is
empty, but there is a skeleton style sheet (``recoll.qss``) inside
the ``/usr/share/recoll/examples`` directory. Using a style sheet,
you can change most ``recoll`` graphical parameters: colors, fonts,
etc. See the sample file for a few simple examples.
You should be aware that parameters (e.g.: the background color) set
inside the RCL GUI style sheet will override global system
preferences, with possible strange side effects: for example if you
set the foreground to a light color and the background to a dark one
in the desktop preferences, but only the background is set inside the
RCL style sheet, and it is light too, then text will appear
light-on-light inside the RCL GUI.
- Maximum text size highlighted for preview Inserting highlights on
search term inside the text before inserting it in the preview window
involves quite a lot of processing, and can be disabled over the
given text size to speed up loading.
- Prefer HTML to plain text for preview if set, Recoll will display
HTML as such inside the preview window. If this causes problems with
the Qt HTML display, you can uncheck it to display the plain text
version instead.
- Activate links in preview if set, Recoll will turn HTTP links found
inside plain text into proper HTML anchors, and clicking a link
inside a preview window will start the default browser on the link
target.
- Plain text to HTML line style: when displaying plain text inside the
preview window, RCL tries to preserve some of the original text line
breaks and indentation. It can either use PRE HTML tags, which will
well preserve the indentation but will force horizontal scrolling for
long lines, or use BR tags to break at the original line breaks,
which will let the editor introduce other line breaks according to
the window width, but will lose some of the original indentation. The
third option has been available in recent releases and is probably
now the best one: use PRE tags with line wrapping.
- Choose editor application: this opens a dialog which allows you to
select the application to be used to open each MIME type. The default
is to use the ``xdg-open`` utility, but you can use this dialog to
override it, setting exceptions for MIME types that will still be
opened according to RCL preferences. This is useful for passing
parameters like page numbers or search strings to applications that
support them (e.g. evince). This cannot be done with ``xdg-open``
which only supports passing one parameter.
- Disable Qt autocompletion in search entry: this will disable the
completion popup. Il will only appear, and display the full history,
either if you enter only white space in the search area, or if you
click the clock button on the right of the area.
- Document filter choice style: this will let you choose if the
document categories are displayed as a list or a set of buttons, or a
menu.
- Start with simple search mode: this lets you choose the value of the
simple search type on program startup. Either a fixed value (e.g.
``Query Language``, or the value in use when the program last exited.
- Start with advanced search dialog open: If you use this dialog
frequently, checking the entries will get it to open when recoll
starts.
- Remember sort activation state if set, Recoll will remember the sort
tool stat between invocations. It normally starts with sorting
disabled.
**Result list parameters:.**
- Number of results in a result page
- Result list font: There is quite a lot of information shown in the
result list, and you may want to customize the font and/or font size.
The rest of the fonts used by RCL are determined by your generic Qt
config (try the ``qtconfig`` command).
- Edit result list paragraph format string: allows you to change the
presentation of each result list entry. See the `result list
customisation section <#RCL.SEARCH.GUI.CUSTOM.RESLIST>`__.
- Edit result page HTML header insert: allows you to define text
inserted at the end of the result page HTML header. More detail in
the `result list customisation
section <#RCL.SEARCH.GUI.CUSTOM.RESLIST>`__.
- Date format: allows specifying the format used for displaying dates
inside the result list. This should be specified as an strftime()
string (man strftime).
- Abstract snippet separator: for synthetic abstracts built from index
data, which are usually made of several snippets from different parts
of the document, this defines the snippet separator, an ellipsis by
default.
**Search parameters:.**
- Hide duplicate results: decides if result list entries are shown for
identical documents found in different places.
- Stemming language: stemming obviously depends on the document's
language. This listbox will let you chose among the stemming
databases which were built during indexing (this is set in the `main
configuration file <#RCL.INSTALL.CONFIG.RECOLLCONF>`__), or later
added with ``recollindex -s`` (See the recollindex manual). Stemming
languages which are dynamically added will be deleted at the next
indexing pass unless they are also added in the configuration file.
- Automatically add phrase to simple searches: a phrase will be
automatically built and added to simple searches when looking for
``Any terms``. This will give a relevance boost to the results where
the search terms appear as a phrase (consecutive and in order).
- Autophrase term frequency threshold percentage: very frequent terms
should not be included in automatic phrase searches for performance
reasons. The parameter defines the cutoff percentage (percentage of
the documents where the term appears).
- Replace abstracts from documents: this decides if we should
synthesize and display an abstract in place of an explicit abstract
found within the document itself.
- Dynamically build abstracts: this decides if RCL tries to build
document abstracts (lists of *snippets*) when displaying the result
list. Abstracts are constructed by taking context from the document
information, around the search terms.
- Synthetic abstract size: adjust to taste...
- Synthetic abstract context words: how many words should be displayed
around each term occurrence.
- Query language magic file name suffixes: a list of words which
automatically get turned into ``ext:xxx`` file name suffix clauses
when starting a query language query (e.g.: ``doc xls xlsx...``).
This will save some typing for people who use file types a lot when
querying.
**External indexes:.**
This panel will let you browse for additional indexes that you may want
to search. External indexes are designated by their database directory
(ie: ``/home/someothergui/.recoll/xapiandb``,
``/usr/local/recollglobal/xapiandb``).
Once entered, the indexes will appear in the External indexes list, and
you can chose which ones you want to use at any moment by checking or
unchecking their entries.
Your main database (the one the current configuration indexes to), is
always implicitly active. If this is not desirable, you can set up your
configuration so that it indexes, for example, an empty directory. An
alternative indexer may also need to implement a way of purging the
index from stale data,
.. _RCL.SEARCH.GUI.CUSTOM.RESLIST:
The result list format
^^^^^^^^^^^^^^^^^^^^^^
Newer versions of Recoll (from 1.17) normally use WebKit HTML widgets
for the result list and the `snippets
window <#RCL.SEARCH.GUI.RESULTLIST.MENU.SNIPPETS>`__ (this may be
disabled at build time). Total customisation is possible with full
support for CSS and Javascript. Conversely, there are limits to what you
can do with the older Qt QTextBrowser, but still, it is possible to
decide what data each result will contain, and how it will be displayed.
The result list presentation can be exhaustively customized by adjusting
two elements:
- The paragraph format
- HTML code inside the header section. For versions 1.21 and later,
this is also used for the `snippets
window <#RCL.SEARCH.GUI.RESULTLIST.MENU.SNIPPETS>`__.
The paragraph format and the header fragment can be edited from the
Result list tab of the GUI configuration.
The header fragment is used both for the result list and the snippets
window. The snippets list is a table and has a ``snippets`` class
attribute. Each paragraph in the result list is a table, with class
``respar``, but this can be changed by editing the paragraph format.
There are a few examples on the `page about customising the result
list <http://www.recoll.org/custom.html>`__ on the RCL web site.
.. _RCL.SEARCH.GUI.CUSTOM.RESLIST.PARA:
The paragraph format
''''''''''''''''''''
This is an arbitrary HTML string where the following printf-like ``%``
substitutions will be performed:
- **%A.**
Abstract
- **%D.**
Date
- **%I.**
Icon image name. This is normally determined from the MIME type. The
associations are defined inside the ```mimeconf`` configuration
file <#RCL.INSTALL.CONFIG.MIMECONF>`__. If a thumbnail for the file
is found at the standard Freedesktop location, this will be displayed
instead.
- **%K.**
Keywords (if any)
- **%L.**
Precooked Preview, Edit, and possibly Snippets links
- **%M.**
MIME type
- **%N.**
result Number inside the result page
- **%P.**
Parent folder Url. In the case of an embedded document, this is the
parent folder for the top level container file.
- **%R.**
Relevance percentage
- **%S.**
Size information
- **%T.**
Title or Filename if not set.
- **%t.**
Title or empty.
- **%(filename).**
File name.
- **%U.**
Url
The format of the Preview, Edit, and Snippets links is
``<a href="P%N">``, ``<a href="E%N">`` and ``<a href="A%N">`` where
docnum (%N) expands to the document number inside the result page).
A link target defined as ``"F%N"`` will open the document corresponding
to the ``%P`` parent folder expansion, usually creating a file manager
window on the folder where the container file resides. E.g.:
::
<a href="F%N">%P</a>
A link target defined as ``R%N|scriptname`` will run the corresponding
script on the result file (if the document is embedded, the script will
be started on the top-level parent). See the `section about defining
scripts <#RCL.SEARCH.GUI.RUNSCRIPT>`__.
In addition to the predefined values above, all strings like
``%(fieldname)`` will be replaced by the value of the field named
``fieldname`` for this document. Only stored fields can be accessed in
this way, the value of indexed but not stored fields is not known at
this point in the search process (see `field
configuration <#RCL.PROGRAM.FIELDS>`__). There are currently very few
fields stored by default, apart from the values above (only ``author``
and ``filename``), so this feature will need some custom local
configuration to be useful. An example candidate would be the
``recipient`` field which is generated by the message input handlers.
The default value for the paragraph format string is:
::
"<table class=\"respar\">\n"
"<tr>\n"
"<td><a href='%U'><img src='%I' width='64'></a></td>\n"
"<td>%L &nbsp;<i>%S</i> &nbsp;&nbsp;<b>%T</b><br>\n"
"<span style='white-space:nowrap'><i>%M</i>&nbsp;%D</span>&nbsp;&nbsp;&nbsp; <i>%U</i>&nbsp;%i<br>\n"
"%A %K</td>\n"
"</tr></table>\n"
You may, for example, try the following for a more web-like experience:
::
<u><b><a href="P%N">%T</a></b></u><br>
%A<font color=#008000>%U - %S</font> - %L
Note that the P%N link in the above paragraph makes the title a preview
link. Or the clean looking:
::
<img src="%I" align="left">%L <font color="#900000">%R</font>
&nbsp;&nbsp;<b>%T&</b><br>%S&nbsp;
<font color="#808080"><i>%U</i></font>
<table bgcolor="#e0e0e0">
<tr><td><div>%A</div></td></tr>
</table>%K
These samples, and some others are `on the web site, with pictures to
show how they look. <http://www.recoll.org/custom.html>`__
It is also possible to `define the value of the snippet separator inside
the abstract section <#RCL.SEARCH.GUI.CUSTOM.ABSSEP>`__.
.. _RCL.SEARCH.KIO:
Searching with the KDE KIO slave
--------------------------------
.. _RCL.SEARCH.KIO.INTRO:
What's this
~~~~~~~~~~~
The RCL KIO slave allows performing a RCL search by entering an
appropriate URL in a KDE open dialog, or with an HTML-based interface
displayed in ``Konqueror``.
The HTML-based interface is similar to the Qt-based interface, but
slightly less powerful for now. Its advantage is that you can perform
your search while staying fully within the KDE framework: drag and drop
from the result list works normally and you have your normal choice of
applications for opening files.
The alternative interface uses a directory view of search results. Due
to limitations in the current KIO slave interface, it is currently not
obviously useful (to me).
The interface is described in more detail inside a help file which you
can access by entering ``recoll:/`` inside the ``konqueror`` URL line
(this works only if the recoll KIO slave has been previously installed).
The instructions for building this module are located in the source
tree. See: ``kde/kio/recoll/00README.txt``. Some Linux distributions do
package the kio-recoll module, so check before diving into the build
process, maybe it's already out there ready for one-click installation.
.. _RCL.SEARCH.KIO.SEARCHABLEDOCS:
Searchable documents
~~~~~~~~~~~~~~~~~~~~
As a sample application, the RCL KIO slave could allow preparing a set
of HTML documents (for example a manual) so that they become their own
search interface inside ``konqueror``.
This can be done by either explicitly inserting
``<a href="recoll://...">`` links around some document areas, or
automatically by adding a very small javascript program to the
documents, like the following example, which would initiate a search by
double-clicking any term:
::
<script language="JavaScript">
function recollsearch() {
var t = document.getSelection();
window.location.href = 'recoll://search/query?qtp=a&p=0&q=' +
encodeURIComponent(t);
}
</script>
....
<body ondblclick="recollsearch()">
.. _RCL.SEARCH.COMMANDLINE:
Searching on the command line
-----------------------------
There are several ways to obtain search results as a text stream,
without a graphical interface:
- By passing option ``-t`` to the ``recoll`` program, or by calling it
as ``recollq`` (through a link).
- By using the ``recollq`` program.
- By writing a custom Python program, using the `Recoll Python
API <#RCL.PROGRAM.PYTHONAPI>`__.
The first two methods work in the same way and accept/need the same
arguments (except for the additional ``-t`` to ``recoll``). The query to
be executed is specified as command line arguments.
``recollq`` is not built by default. You can use the ``Makefile`` in the
``query`` directory to build it. This is a very simple program, and if
you can program a little c++, you may find it useful to taylor its
output format to your needs. Not that recollq is only really useful on
systems where the Qt libraries (or even the X11 ones) are not available.
Otherwise, just use ``recoll -t``, which takes the exact same parameters
and options which are described for ``recollq``
``recollq`` has a man page (not installed by default, look in the
``doc/man`` directory). The Usage string is as follows:
::
recollq: usage:
-P: Show the date span for all the documents present in the index
[-o|-a|-f] [-q] <query string>
Runs a recoll query and displays result lines.
Default: will interpret the argument(s) as a xesam query string
query may be like:
implicit AND, Exclusion, field spec: t1 -t2 title:t3
OR has priority: t1 OR t2 t3 OR t4 means (t1 OR t2) AND (t3 OR t4)
Phrase: "t1 t2" (needs additional quoting on cmd line)
-o Emulate the GUI simple search in ANY TERM mode
-a Emulate the GUI simple search in ALL TERMS mode
-f Emulate the GUI simple search in filename mode
-q is just ignored (compatibility with the recoll GUI command line)
Common options:
-c <configdir> : specify config directory, overriding $RECOLL_CONFDIR
-d also dump file contents
-n [first-]<cnt> define the result slice. The default value for [first]
is 0. Without the option, the default max count is 2000.
Use n=0 for no limit
-b : basic. Just output urls, no mime types or titles
-Q : no result lines, just the processed query and result count
-m : dump the whole document meta[] array for each result
-A : output the document abstracts
-S fld : sort by field <fld>
-s stemlang : set stemming language to use (must exist in index...)
Use -s "" to turn off stem expansion
-D : sort descending
-i <dbdir> : additional index, several can be given
-e use url encoding (%xx) for urls
-F <field name list> : output exactly these fields for each result.
The field values are encoded in base64, output in one line and
separated by one space character. This is the recommended format
for use by other programs. Use a normal query with option -m to
see the field names.
Sample execution:
::
recollq 'ilur -nautique mime:text/html'
Recoll query: ((((ilur:(wqf=11) OR ilurs) AND_NOT (nautique:(wqf=11)
OR nautiques OR nautiqu OR nautiquement)) FILTER Ttext/html))
4 results
text/html [file:///Users/uncrypted-dockes/projets/bateaux/ilur/comptes.html] [comptes.html] 18593 bytes
text/html [file:///Users/uncrypted-dockes/projets/nautique/webnautique/articles/ilur1/index.html] [Constructio...
text/html [file:///Users/uncrypted-dockes/projets/pagepers/index.html] [psxtcl/writemime/recoll]...
text/html [file:///Users/uncrypted-dockes/projets/bateaux/ilur/factEtCie/recu-chasse-maree....
.. _RCL.SEARCH.SYNONYMS:
Using Synonyms (1.22)
---------------------
**Term synonyms:.**
there are a number of ways to use term synonyms for searching text:
- At index creation time, they can be used to alter the indexed terms,
either increasing or decreasing their number, by expanding the
original terms to all synonyms, or by reducing all synonym terms to a
canonical one.
- At query time, they can be used to match texts containing terms which
are synonyms of the ones specified by the user, either by expanding
the query for all synonyms, or by reducing the user entry to
canonical terms (the latter only works if the corresponding
processing has been performed while creating the index).
RCL only uses synonyms at query time. A user query term which part of a
synonym group will be optionally expanded into an ``OR`` query for all
terms in the group.
Synonym groups are defined inside ordinary text files. Each line in the
file defines a group.
Example:
::
hi hello "good morning"
# not sure about "au revoir" though. Is this english ?
bye goodbye "see you" \
"au revoir"
As usual, lines beginning with a ``#`` are comments, empty lines are
ignored, and lines can be continued by ending them with a backslash.
Multi-word synonyms are supported, but be aware that these will generate
phrase queries, which may degrade performance and will disable stemming
expansion for the phrase terms.
The synonyms file can be specified in the Search parameters tab of the
GUI configuration Preferences menu entry, or as an option for
command-line searches.
Once the file is defined, the use of synonyms can be enabled or disabled
directly from the Preferences menu.
The synonyms are searched for matches with user terms after the latter
are stem-expanded, but the contents of the synonyms file itself is not
subjected to stem expansion. This means that a match will not be found
if the form present in the synonyms file is not present anywhere in the
document set.
The synonyms function is probably not going to help you find your
letters to Mr. Smith. It is best used for domain-specific searches. For
example, it was initially suggested by a user performing searches among
historical documents: the synonyms file would contains nicknames and
aliases for each of the persons of interest.
.. _RCL.SEARCH.PTRANS:
Path translations
-----------------
In some cases, the document paths stored inside the index do not match
the actual ones, so that document previews and accesses will fail. This
can occur in a number of circumstances:
- When using multiple indexes it is a relatively common occurrence that
some will actually reside on a remote volume, for exemple mounted via
NFS. In this case, the paths used to access the documents on the
local machine are not necessarily the same than the ones used while
indexing on the remote machine. For example, ``/home/me`` may have
been used as a ``topdirs`` elements while indexing, but the directory
might be mounted as ``/net/server/home/me`` on the local machine.
- The case may also occur with removable disks. It is perfectly
possible to configure an index to live with the documents on the
removable disk, but it may happen that the disk is not mounted at the
same place so that the documents paths from the index are invalid.
- As a last exemple, one could imagine that a big directory has been
moved, but that it is currently inconvenient to run the indexer.
RCL has a facility for rewriting access paths when extracting the data
from the index. The translations can be defined for the main index and
for any additional query index.
The path translation facility will be useful whenever the documents
paths seen by the indexer are not the same as the ones which should be
used at query time.
In the above NFS example, RCL could be instructed to rewrite any
``file:///home/me`` URL from the index to
``file:///net/server/home/me``, allowing accesses from the client.
The translations are defined in the
```ptrans`` <#RCL.INSTALL.CONFIG.PTRANS>`__ configuration file, which
can be edited by hand or from the GUI external indexes configuration
dialog: Preferences > External index dialog, then click the Paths
translations button on the right below the index list.
**Note**
Due to a current bug, the GUI must be restarted after changing the
``ptrans`` values (even when they were changed from the GUI).
.. _RCL.SEARCH.LANG:
The query language
------------------
The query language processor is activated in the GUI simple search entry
when the search mode selector is set to Query Language. It can also be
used with the KIO slave or the command line search. It broadly has the
same capabilities as the complex search interface in the GUI.
The language was based on the now defunct
`Xesam <http://www.xesam.org/main/XesamUserSearchLanguage95>`__ user
search language specification.
If the results of a query language search puzzle you and you doubt what
has been actually searched for, you can use the GUI ``Show Query`` link
at the top of the result list to check the exact query which was finally
executed by Xapian.
Here follows a sample request that we are going to explain:
::
author:"john doe" Beatles OR Lennon Live OR Unplugged -potatoes
This would search for all documents with John Doe appearing as a phrase
in the author field (exactly what this is would depend on the document
type, ie: the ``From:`` header, for an email message), and containing
either beatles or lennon and either live or unplugged but not potatoes
(in any part of the document).
An element is composed of an optional field specification, and a value,
separated by a colon (the field separator is the last colon in the
element). Examples: Eugenie, author:balzac, dc:title:grandet
dc:title:"eugenie grandet"
The colon, if present, means "contains". Xesam defines other relations,
which are mostly unsupported for now (except in special cases, described
further down).
All elements in the search entry are normally combined with an implicit
AND. It is possible to specify that elements be OR'ed instead, as in
Beatles ``OR`` Lennon. The ``OR`` must be entered literally (capitals),
and it has priority over the AND associations: word1 word2 ``OR`` word3
means word1 AND (word2 ``OR`` word3) not (word1 AND word2) ``OR`` word3.
RCL versions 1.21 and later, allow using parentheses to group elements,
which will sometimes make things clearer, and may allow expressing
combinations which would have been difficult otherwise.
An element preceded by a ``-`` specifies a term that should *not*
appear.
As usual, words inside quotes define a phrase (the order of words is
significant), so that title:"prejudice pride" is not the same as
title:prejudice title:pride, and is unlikely to find a result.
Words inside phrases and capitalized words are not stem-expanded.
Wildcards may be used anywhere inside a term. Specifying a wild-card on
the left of a term can produce a very slow search (or even an incorrect
one if the expansion is truncated because of excessive size). Also see
`More about wildcards <#RCL.SEARCH.WILDCARDS>`__.
To save you some typing, recent RCL versions (1.20 and later) interpret
a comma-separated list of terms as an AND list inside the field. Use
slash characters ('/') for an OR list. No white space is allowed. So
::
author:john,lennon
will search for documents with ``john`` and ``lennon`` inside the
``author`` field (in any order), and
::
author:john/ringo
would search for ``john`` or ``ringo``.
Modifiers can be set on a double-quote value, for example to specify a
proximity search (unordered). See `the modifier
section <#RCL.SEARCH.LANG.MODIFIERS>`__. No space must separate the
final double-quote and the modifiers value, e.g. "two one"po10
RCL currently manages the following default fields:
- ``title``, ``subject`` or ``caption`` are synonyms which specify data
to be searched for in the document title or subject.
- ``author`` or ``from`` for searching the documents originators.
- ``recipient`` or ``to`` for searching the documents recipients.
- ``keyword`` for searching the document-specified keywords (few
documents actually have any).
- ``filename`` for the document's file name. This is not necessarily
set for all documents: internal documents contained inside a compound
one (for example an EPUB section) do not inherit the container file
name any more, this was replaced by an explicit field (see next).
Sub-documents can still have a specific ``filename``, if it is
implied by the document format, for example the attachment file name
for an email attachment.
- ``containerfilename``. This is set for all documents, both top-level
and contained sub-documents, and is always the name of the filesystem
directory entry which contains the data. The terms from this field
can only be matched by an explicit field specification (as opposed to
terms from ``filename`` which are also indexed as general document
content). This avoids getting matches for all the sub-documents when
searching for the container file name.
- ``ext`` specifies the file name extension (Ex: ``ext:html``)
RCL 1.20 and later have a way to specify aliases for the field names,
which will save typing, for example by aliasing ``filename`` to fn or
``containerfilename`` to cfn. See the `section about the ``fields``
file <#RCL.INSTALL.CONFIG.FIELDS>`__.
The document input handlers used while indexing have the possibility to
create other fields with arbitrary names, and aliases may be defined in
the configuration, so that the exact field search possibilities may be
different for you if someone took care of the customisation.
The field syntax also supports a few field-like, but special, criteria:
- ``dir`` for filtering the results on file location (Ex:
``dir:/home/me/somedir``). ``-dir`` also works to find results not in
the specified directory (release >= 1.15.8). Tilde expansion will be
performed as usual (except for a bug in versions 1.19 to 1.19.11p1).
Wildcards will be expanded, but please `have a
look <#RCL.SEARCH.WILDCARDS.PATH>`__ at an important limitation of
wildcards in path filters.
Relative paths also make sense, for example, ``dir:share/doc`` would
match either ``/usr/share/doc`` or ``/usr/local/share/doc``
Several ``dir`` clauses can be specified, both positive and negative.
For example the following makes sense:
::
dir:recoll dir:src -dir:utils -dir:common
This would select results which have both ``recoll`` and ``src`` in
the path (in any order), and which have not either ``utils`` or
``common``.
You can also use ``OR`` conjunctions with ``dir:`` clauses.
A special aspect of ``dir`` clauses is that the values in the index
are not transcoded to UTF-8, and never lower-cased or unaccented, but
stored as binary. This means that you need to enter the values in the
exact lower or upper case, and that searches for names with
diacritics may sometimes be impossible because of character set
conversion issues. Non-ASCII UNIX file paths are an unending source
of trouble and are best avoided.
You need to use double-quotes around the path value if it contains
space characters.
- ``size`` for filtering the results on file size. Example:
``size<10000``. You can use ``<``, ``>`` or ``=`` as operators. You
can specify a range like the following: ``size>100 size<1000``. The
usual ``k/K, m/M, g/G, t/T`` can be used as (decimal) multipliers.
Ex: ``size>1k`` to search for files bigger than 1000 bytes.
- ``date`` for searching or filtering on dates. The syntax for the
argument is based on the ISO8601 standard for dates and time
intervals. Only dates are supported, no times. The general syntax is
2 elements separated by a ``/`` character. Each element can be a date
or a period of time. Periods are specified as
``P``\ n\ ``Y``\ n\ ``M``\ n\ ``D``. The n numbers are the respective
numbers of years, months or days, any of which may be missing. Dates
are specified as YYYY-MM-DD. The days and months parts may be
missing. If the ``/`` is present but an element is missing, the
missing element is interpreted as the lowest or highest date in the
index. Examples:
- ``2001-03-01/2002-05-01`` the basic syntax for an interval of
dates.
- ``2001-03-01/P1Y2M`` the same specified with a period.
- ``2001/`` from the beginning of 2001 to the latest date in the
index.
- ``2001`` the whole year of 2001
- ``P2D/`` means 2 days ago up to now if there are no documents with
dates in the future.
- ``/2003`` all documents from 2003 or older.
Periods can also be specified with small letters (ie: p2y).
- ``mime`` or ``format`` for specifying the MIME type. These clauses
are processed besides the normal Boolean logic of the search.
Multiple values will be OR'ed (instead of the normal AND). You can
specify types to be excluded, with the usual ``-``, and use
wildcards. Example: mime:text/\* -mime:text/plain Specifying an
explicit boolean operator before a ``mime`` specification is not
supported and will produce strange results.
- ``type`` or ``rclcat`` for specifying the category (as in
text/media/presentation/etc.). The classification of MIME types in
categories is defined in the RCL configuration (``mimeconf``), and
can be modified or extended. The default category names are those
which permit filtering results in the main GUI screen. Categories are
OR'ed like MIME types above, and can be negated with ``-``.
..
**Note**
``mime``, ``rclcat``, ``size`` and ``date`` criteria always affect
the whole query (they are applied as a final filter), even if set
with other terms inside a parenthese.
**Note**
``mime`` (or the equivalent ``rclcat``) is the *only* field with an
``OR`` default. You do need to use ``OR`` with ``ext`` terms for
example.
.. _RCL.SEARCH.LANG.RANGES:
Range clauses
~~~~~~~~~~~~~
RCL 1.24 and later support range clauses on fields which have been
configured to support it. No default field uses them currently, so this
paragraph is only interesting if you modified the fields configuration
and possibly use a custom input handler.
A range clause looks like one of the following:
::
myfield:small..big
myfield:small..
myfield:..big
The nature of the clause is indicated by the two dots ``..``, and the
effect is to filter the results for which the myfield value is in the
possibly open-ended interval.
See the section about the ```fields`` configuration
file <#RCL.INSTALL.CONFIG.FIELDS>`__ for the details of configuring a
field for range searches (list them in the [values] section).
.. _RCL.SEARCH.LANG.MODIFIERS:
Modifiers
~~~~~~~~~
Some characters are recognized as search modifiers when found
immediately after the closing double quote of a phrase, as in
``"some term"modifierchars``. The actual "phrase" can be a single term
of course. Supported modifiers:
- ``l`` can be used to turn off stemming (mostly makes sense with ``p``
because stemming is off by default for phrases).
- ``s`` can be used to turn off synonym expansion, if a synonyms file
is in place (only for RCL 1.22 and later).
- ``o`` can be used to specify a "slack" for phrase and proximity
searches: the number of additional terms that may be found between
the specified ones. If ``o`` is followed by an integer number, this
is the slack, else the default is 10.
- ``p`` can be used to turn the default phrase search into a proximity
one (unordered). Example: ``"order any in"p``
- ``C`` will turn on case sensitivity (if the index supports it).
- ``D`` will turn on diacritics sensitivity (if the index supports it).
- A weight can be specified for a query element by specifying a decimal
value at the start of the modifiers. Example: ``"Important"2.5``.
.. _RCL.SEARCH.CASEDIAC:
Search case and diacritics sensitivity
--------------------------------------
For RCL versions 1.18 and later, and *when working with a raw index*
(not the default), searches can be sensitive to character case and
diacritics. How this happens is controlled by configuration variables
and what search data is entered.
The general default is that searches entered without upper-case or
accented characters are insensitive to case and diacritics. An entry of
``resume`` will match any of ``Resume``, ``RESUME``, ``résumé``,
``Résumé`` etc.
Two configuration variables can automate switching on sensitivity (they
were documented but actually did nothing until RCL 1.22):
autodiacsens
If this is set, search sensitivity to diacritics will be turned on as
soon as an accented character exists in a search term. When the
variable is set to true, ``resume`` will start a
diacritics-unsensitive search, but ``résumé`` will be matched
exactly. The default value is *false*.
autocasesens
If this is set, search sensitivity to character case will be turned
on as soon as an upper-case character exists in a search term *except
for the first one*. When the variable is set to true, ``us`` or
``Us`` will start a diacritics-unsensitive search, but ``US`` will be
matched exactly. The default value is *true* (contrary to
``autodiacsens``).
As in the past, capitalizing the first letter of a word will turn off
its stem expansion and have no effect on case-sensitivity.
You can also explicitely activate case and diacritics sensitivity by
using modifiers with the query language. ``C`` will make the term
case-sensitive, and ``D`` will make it diacritics-sensitive. Examples:
::
"us"C
will search for the term ``us`` exactly (``Us`` will not be a match).
::
"resume"D
will search for the term ``resume`` exactly (``résumé`` will not be a
match).
When either case or diacritics sensitivity is activated, stem expansion
is turned off. Having both does not make much sense.
.. _RCL.SEARCH.ANCHORWILD:
Anchored searches and wildcards
-------------------------------
Some special characters are interpreted by RCL in search strings to
expand or specialize the search. Wildcards expand a root term in
controlled ways. Anchor characters can restrict a search to succeed only
if the match is found at or near the beginning of the document or one of
its fields.
.. _RCL.SEARCH.WILDCARDS:
More about wildcards
~~~~~~~~~~~~~~~~~~~~
All words entered in RCL search fields will be processed for wildcard
expansion before the request is finally executed.
The wildcard characters are:
- ``*`` which matches 0 or more characters.
- ``?`` which matches a single character.
- ``[]`` which allow defining sets of characters to be matched (ex:
``[``\ ``abc``\ ``]`` matches a single character which may be 'a' or
'b' or 'c', ``[``\ ``0-9``\ ``]`` matches any number.
You should be aware of a few things when using wildcards.
- Using a wildcard character at the beginning of a word can make for a
slow search because RCL will have to scan the whole index term list
to find the matches. However, this is much less a problem for field
searches, and queries like author:*@domain.com can sometimes be very
useful.
- For RCL version 18 only, when working with a raw index (preserving
character case and diacritics), the literal part of a wildcard
expression will be matched exactly for case and diacritics. This is
not true any more for versions 19 and later.
- Using a ``*`` at the end of a word can produce more matches than you
would think, and strange search results. You can use the `term
explorer <#RCL.SEARCH.GUI.TERMEXPLORER>`__ tool to check what
completions exist for a given term. You can also see exactly what
search was performed by clicking on the link at the top of the result
list. In general, for natural language terms, stem expansion will
produce better results than an ending ``*`` (stem expansion is turned
off when any wildcard character appears in the term).
.. _RCL.SEARCH.WILDCARDS.PATH:
Wildcards and path filtering
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Due to the way that RCL processes wildcards inside ``dir`` path
filtering clauses, they will have a multiplicative effect on the query
size. A clause containg wildcards in several paths elements, like, for
example, ``dir:``/home/me/*/*/docdir, will almost certainly fail if your
indexed tree is of any realistic size.
Depending on the case, you may be able to work around the issue by
specifying the paths elements more narrowly, with a constant prefix, or
by using 2 separate ``dir:`` clauses instead of multiple wildcards, as
in ``dir:``/home/me ``dir:``\ docdir. The latter query is not equivalent
to the initial one because it does not specify a number of directory
levels, but that's the best we can do (and it may be actually more
useful in some cases).
.. _RCL.SEARCH.ANCHOR:
Anchored searches
~~~~~~~~~~~~~~~~~
Two characters are used to specify that a search hit should occur at the
beginning or at the end of the text. ``^`` at the beginning of a term or
phrase constrains the search to happen at the start, ``$`` at the end
force it to happen at the end.
As this function is implemented as a phrase search it is possible to
specify a maximum distance at which the hit should occur, either through
the controls of the advanced search panel, or using the query language,
for example, as in:
::
"^someterm"o10
which would force ``someterm`` to be found within 10 terms of the start
of the text. This can be combined with a field search as in
``somefield:"^someterm"o10`` or ``somefield:someterm$``.
This feature can also be used with an actual phrase search, but in this
case, the distance applies to the whole phrase and anchor, so that, for
example, ``bla bla my unexpected term`` at the beginning of the text
would be a match for ``"^my term"o5``.
Anchored searches can be very useful for searches inside somewhat
structured documents like scientific articles, in case explicit metadata
has not been supplied (a most frequent case), for example for looking
for matches inside the abstract or the list of authors (which occur at
the top of the document).
.. _RCL.SEARCH.DESKTOP:
Desktop integration
-------------------
Being independant of the desktop type has its drawbacks: RCL desktop
integration is minimal. However there are a few tools available:
- The KDE KIO Slave was described in a `previous
section <#RCL.SEARCH.KIO>`__.
- If you use a recent version of Ubuntu Linux, you may find the `Ubuntu
Unity Lens <&FAQS;UnityLens>`__ module useful.
- There is also an independantly developed `Krunner
plugin <http://kde-apps.org/content/show.php/recollrunner?content=128203>`__.
Here follow a few other things that may help.
.. _RCL.SEARCH.SHORTCUT:
Hotkeying recoll
~~~~~~~~~~~~~~~~
It is surprisingly convenient to be able to show or hide the RCL GUI
with a single keystroke. Recoll comes with a small Python script, based
on the libwnck window manager interface library, which will allow you to
do just this. The detailed instructions are on `this wiki
page <&FAQS;HotRecoll>`__.
.. _RCL.KICKER-APPLET:
The KDE Kicker Recoll applet
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This is probably obsolete now. Anyway:
The RCL source tree contains the source code to the recoll_applet, a
small application derived from the find_applet. This can be used to add
a small RCL launcher to the KDE panel.
The applet is not automatically built with the main RCL programs, nor is
it included with the main source distribution (because the KDE build
boilerplate makes it relatively big). You can download its source from
the recoll.org download page. Use the omnipotent
``configure;make;make install`` incantation to build and install.
You can then add the applet to the panel by right-clicking the panel and
choosing the Add applet entry.
The recoll_applet has a small text window where you can type a RCL query
(in query language form), and an icon which can be used to restrict the
search to certain types of files. It is quite primitive, and launches a
new recoll GUI instance every time (even if it is already running). You
may find it useful anyway.
.. _RCL.REMOVABLE:
Removable volumes
=================
RCL used to have no support for indexing removable volumes (portable
disks, USB keys, etc.). Recent versions have improved the situation and
support indexing removable volumes in two different ways:
- By storing a volume index on the volume itself (RCL 1.24).
- By indexing the volume in the main, fixed, index, and ensuring that
the volume data is not purged if the indexing runs while the volume
is mounted. (RCL 1.25.2).
.. _RCL.REMOVABLE.MAIN:
Indexing removable volumes in the main index
--------------------------------------------
As of version 1.25.2, RCL has a simple way to ensure that the index data
for an absent volume will not be purged: the volume mount point must be
a member of the ``topdirs`` list, and the mount directory must be empty
(when the volume is not mounted). If ``recollindex`` finds that one of
the ``topdirs`` is empty when starting up, any existing data for the
tree will be preserved by the indexing pass (no purge for this area).
.. _RCL.REMOVABLE.SELF:
Self contained volumes
----------------------
As of RCL 1.24, it has become easy to build self-contained datasets
including a RCL configuration directory and index together with the
indexed documents, and to move such a dataset around (for example
copying it to an USB drive), without having to adjust the configuration
for querying the index.
**Note**
This is a query-time feature only. The index must only be updated in
its original location. If an update is necessary in a different
location, the index must be reset.
To make a long story short, here follows a script to create a RCL
configuration and index under a given directory (given as single
parameter). The resulting data set (files + recoll directory) can later
to be moved to a CDROM or thumb drive. Longer explanations come after
the script.
::
#!/bin/sh
fatal()
{
echo $*;exit 1
}
usage()
{
fatal "Usage: init-recoll-volume.sh <top-directory>"
}
test $# = 1 || usage
topdir=$1
test -d "$topdir" || fatal $topdir should be a directory
confdir="$topdir/recoll-config"
test ! -d "$confdir" || fatal $confdir should not exist
mkdir "$confdir"
cd "$topdir"
topdir=`pwd`
cd "$confdir"
confdir=`pwd`
(echo topdirs = '"'$topdir'"'; \
echo orgidxconfdir = $topdir/recoll-config) > "$confdir/recoll.conf"
recollindex -c "$confdir"
The examples below will assume that you have a dataset under
``/home/me/mydata/``, with the index configuration and data stored
inside ``/home/me/mydata/recoll-confdir``.
In order to be able to run queries after the dataset has been moved, you
must ensure the following:
- The main configuration file must define the
`orgidxconfdir <#RCL.INSTALL.CONFIG.RECOLLCONF.ORGIDXCONFDIR>`__
variable to be the original location of the configuration directory
(``orgidxconfdir=/home/me/mydata/recoll-confdir`` must be set inside
``/home/me/mydata/recoll-confdir/recoll.conf`` in the example above).
- The configuration directory must exist with the documents, somewhere
under the directory which will be moved. E.g. if you are moving
``/home/me/mydata`` around, the configuration directory must exist
somewhere below this point, for example
``/home/me/mydata/recoll-confdir``, or
``/home/me/mydata/sub/recoll-confdir``.
- You should keep the default locations for the index elements (they
are relative to the configuration directory by default). Only the
paths referring to the documents themselves (e.g. ``topdirs`` values)
should be absolute (in general, they are only used when indexing
anyway).
Only the first point needs an explicit user action, the RCL defaults are
compatible with the second one, and the third is natural.
If, after the move, the configuration directory needs to be copied out
of the dataset (for example because the thumb drive is too slow), you
can set the
`curidxconfdir <#RCL.INSTALL.CONFIG.RECOLLCONF.CURIDXCONFDIR>`__,
variable inside the copied configuration to define the location of the
moved one. For example if ``/home/me/mydata`` is now mounted onto
``/media/me/somelabel``, but the configuration directory and index has
been copied to ``/tmp/tempconfig``, you would set ``curidxconfdir`` to
``/media/me/somelabel/recoll-confdir`` inside
``/tmp/tempconfig/recoll.conf``. ``orgidxconfdir`` would still be
``/home/me/mydata/recoll-confdir`` in the original and the copy.
If you are regularly copying the configuration out of the dataset, it
will be useful to write a script to automate the procedure. This can't
really be done inside RCL because there are probably many possible
variants. One example would be to copy the configuration to make it
writable, but keep the index data on the medium because it is too big -
in this case, the script would also need to set ``dbdir`` in the copied
configuration.
The same set of modifications (RCL 1.24) has also made it possible to
run queries from a readonly configuration directory (with slightly
reduced function of course, such as not recording the query history).
.. _RCL.PROGRAM:
Programming interface
=====================
RCL has an Application Programming Interface, usable both for indexing
and searching, currently accessible from the Python language.
Another less radical way to extend the application is to write input
handlers for new types of documents.
The processing of metadata attributes for documents (``fields``) is
highly configurable.
.. _RCL.PROGRAM.FILTERS:
Writing a document input handler
--------------------------------
**Note**
The small programs or pieces of code which handle the processing of
the different document types for RCL used to be called ``filters``,
which is still reflected in the name of the directory which holds
them and many configuration variables. They were named this way
because one of their primary functions is to filter out the
formatting directives and keep the text content. However these
modules may have other behaviours, and the term ``input handler`` is
now progressively substituted in the documentation. ``filter`` is
still used in many places though.
RCL input handlers cooperate to translate from the multitude of input
document formats, simple ones as opendocument, acrobat, or compound ones
such as Zip or Email, into the final RCL indexing input format, which is
plain text (in many cases the processing pipeline has an intermediary
HTML step, which may be used for better previewing presentation). Most
input handlers are executable programs or scripts. A few handlers are
coded in C++ and live inside ``recollindex``. This latter kind will not
be described here.
There are currently (since version 1.13) two kinds of external
executable input handlers:
- Simple ``exec`` handlers run once and exit. They can be bare programs
like ``antiword``, or scripts using other programs. They are very
simple to write, because they just need to print the converted
document to the standard output. Their output can be plain text or
HTML. HTML is usually preferred because it can store metadata fields
and it allows preserving some of the formatting for the GUI preview.
However, these handlers have limitations:
- They can only process one document per file.
- The output MIME type must be known and fixed.
- The character encoding, if relevant, must be known and fixed (or
possibly just depending on location).
- Multiple ``execm`` handlers can process multiple files (sparing the
process startup time which can be very significant), or multiple
documents per file (e.g.: for archives or multi-chapter
publications). They communicate with the indexer through a simple
protocol, but are nevertheless a bit more complicated than the older
kind. Most of the new handlers are written in Python (exception:
``rclimg`` which is written in Perl because ``exiftool`` has no real
Python equivalent). The Python handlers use common modules to factor
out the boilerplate, which can make them very simple in favorable
cases. The subdocuments output by these handlers can be directly
indexable (text or HTML), or they can be other simple or compound
documents that will need to be processed by another handler.
In both cases, handlers deal with regular file system files, and can
process either a single document, or a linear list of documents in each
file. RCL is responsible for performing up to date checks, deal with
more complex embedding and other upper level issues.
A simple handler returning a document in ``text/plain`` format, can
transfer no metadata to the indexer. Generic metadata, like document
size or modification date, will be gathered and stored by the indexer.
Handlers that produce ``text/html`` format can return an arbitrary
amount of metadata inside HTML ``meta`` tags. These will be processed
according to the directives found in the ```fields`` configuration
file <#RCL.PROGRAM.FIELDS>`__.
The handlers that can handle multiple documents per file return a single
piece of data to identify each document inside the file. This piece of
data, called an ``ipath`` will be sent back by RCL to extract the
document at query time, for previewing, or for creating a temporary file
to be opened by a viewer. These handlers can also return metadata either
as HTML ``meta`` tags, or as named data through the communication
protocol.
The following section describes the simple handlers, and the next one
gives a few explanations about the ``execm`` ones. You could conceivably
write a simple handler with only the elements in the manual. This will
not be the case for the other ones, for which you will have to look at
the code.
.. _RCL.PROGRAM.FILTERS.SIMPLE:
Simple input handlers
~~~~~~~~~~~~~~~~~~~~~
RCL simple handlers are usually shell-scripts, but this is in no way
necessary. Extracting the text from the native format is the difficult
part. Outputting the format expected by RCL is trivial. Happily enough,
most document formats have translators or text extractors which can be
called from the handler. In some cases the output of the translating
program is completely appropriate, and no intermediate shell-script is
needed.
Input handlers are called with a single argument which is the source
file name. They should output the result to stdout.
When writing a handler, you should decide if it will output plain text
or HTML. Plain text is simpler, but you will not be able to add metadata
or vary the output character encoding (this will be defined in a
configuration file). Additionally, some formatting may be easier to
preserve when previewing HTML. Actually the deciding factor is metadata:
RCL has a way to `extract metadata from the HTML header and use it for
field searches. <#RCL.PROGRAM.FILTERS.HTML>`__.
The RECOLL_FILTER_FORPREVIEW environment variable (values ``yes``,
``no``) tells the handler if the operation is for indexing or
previewing. Some handlers use this to output a slightly different
format, for example stripping uninteresting repeated keywords (ie:
``Subject:`` for email) when indexing. This is not essential.
You should look at one of the simple handlers, for example ``rclps`` for
a starting point.
Don't forget to make your handler executable before testing !
.. _RCL.PROGRAM.FILTERS.MULTIPLE:
"Multiple" handlers
~~~~~~~~~~~~~~~~~~~
If you can program and want to write an ``execm`` handler, it should not
be too difficult to make sense of one of the existing handlers.
The existing handlers differ in the amount of helper code which they are
using:
- ``rclimg`` is written in Perl and handles the execm protocol all by
itself (showing how trivial it is).
- All the Python handlers share at least the ``rclexecm.py`` module,
which handles the communication. Have a look at, for example,
``rclzip`` for a handler which uses ``rclexecm.py`` directly.
- Most Python handlers which process single-document files by executing
another command are further abstracted by using the ``rclexec1.py``
module. See for example ``rclrtf.py`` for a simple one, or
``rcldoc.py`` for a slightly more complicated one (possibly executing
several commands).
- Handlers which extract text from an XML document by using an XSLT
style sheet are now executed inside ``recollindex``, with only the
style sheet stored in the ``filters/`` directory. These can use a
single style sheet (e.g. ``abiword.xsl``), or two sheets for the data
and metadata (e.g. ``opendoc-body.xsl`` and ``opendoc-meta.xsl``).
The ``mimeconf`` configuration file defines how the sheets are used,
have a look. Before the C++ import, the xsl-based handlers used a
common module ``rclgenxslt.py``, it is still around but unused. The
handler for OpenXML presentations is still the Python version because
the format did not fit with what the C++ code does. It would be a
good base for another similar issue.
There is a sample trivial handler based on ``rclexecm.py``, with many
comments, not actually used by RCL. It would index a text file as one
document per line. Look for ``rcltxtlines.py`` in the ``src/filters``
directory in the online RCL `Git
repository <https://opensourceprojects.eu/p/recoll1/>`__ (the sample not
in the distributed release at the moment).
You can also have a look at the slightly more complex ``rclzip`` which
uses Zip file paths as identifiers (``ipath``).
``execm`` handlers sometimes need to make a choice for the nature of the
``ipath`` elements that they use in communication with the indexer. Here
are a few guidelines:
- Use ASCII or UTF-8 (if the identifier is an integer print it, for
example, like printf %d would do).
- If at all possible, the data should make some kind of sense when
printed to a log file to help with debugging.
- RCL uses a colon (``:``) as a separator to store a complex path
internally (for deeper embedding). Colons inside the ``ipath``
elements output by a handler will be escaped, but would be a bad
choice as a handler-specific separator (mostly, again, for debugging
issues).
In any case, the main goal is that it should be easy for the handler to
extract the target document, given the file name and the ``ipath``
element.
``execm`` handlers will also produce a document with a null ``ipath``
element. Depending on the type of document, this may have some
associated data (e.g. the body of an email message), or none (typical
for an archive file). If it is empty, this document will be useful
anyway for some operations, as the parent of the actual data documents.
.. _RCL.PROGRAM.FILTERS.ASSOCIATION:
Telling RCL about the handler
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
There are two elements that link a file to the handler which should
process it: the association of file to MIME type and the association of
a MIME type with a handler.
The association of files to MIME types is mostly based on name suffixes.
The types are defined inside the ```mimemap``
file <#RCL.INSTALL.CONFIG.MIMEMAP>`__. Example:
::
.doc = application/msword
If no suffix association is found for the file name, RCL will try to
execute a system command (typically ``file -i`` or ``xdg-mime``) to
determine a MIME type.
The second element is the association of MIME types to handlers in the
```mimeconf`` file <#RCL.INSTALL.CONFIG.MIMECONF>`__. A sample will
probably be better than a long explanation:
::
[index]
application/msword = exec antiword -t -i 1 -m UTF-8;\
mimetype = text/plain ; charset=utf-8
application/ogg = exec rclogg
text/rtf = exec unrtf --nopict --html; charset=iso-8859-1; mimetype=text/html
application/x-chm = execm rclchm
The fragment specifies that:
- ``application/msword`` files are processed by executing the
``antiword`` program, which outputs ``text/plain`` encoded in
``utf-8``.
- ``application/ogg`` files are processed by the ``rclogg`` script,
with default output type (``text/html``, with encoding specified in
the header, or ``utf-8`` by default).
- ``text/rtf`` is processed by ``unrtf``, which outputs ``text/html``.
The ``iso-8859-1`` encoding is specified because it is not the
``utf-8`` default, and not output by ``unrtf`` in the HTML header
section.
- ``application/x-chm`` is processed by a persistant handler. This is
determined by the ``execm`` keyword.
.. _RCL.PROGRAM.FILTERS.HTML:
Input handler output
~~~~~~~~~~~~~~~~~~~~
Both the simple and persistent input handlers can return any MIME type
to Recoll, which will further process the data according to the MIME
configuration.
Most input filters filters produce either ``text/plain`` or
``text/html`` data. There are exceptions, for example, filters which
process archive file (``zip``, ``tar``, etc.) will usually return the
documents as they are found, without processing them further.
There is nothing to say about ``text/plain`` output, except that its
character encoding should be consistent with what is specified in the
``mimeconf`` file.
For filters producing HTML, the output could be very minimal like the
following example:
::
<html>
<head>
<meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
</head>
<body>
Some text content
</body>
</html>
You should take care to escape some characters inside the text by
transforming them into appropriate entities. At the very minimum,
"``&``" should be transformed into "``&amp;``", "``<``" should be
transformed into "``&lt;``". This is not always properly done by
external helper programs which output HTML, and of course never by those
which output plain text.
When encapsulating plain text in an HTML body, the display of a preview
may be improved by enclosing the text inside ``<pre>`` tags.
The character set needs to be specified in the header. It does not need
to be UTF-8 (RCL will take care of translating it), but it must be
accurate for good results.
RCL will process ``meta`` tags inside the header as possible document
fields candidates. Documents fields can be processed by the indexer in
different ways, for searching or displaying inside query results. This
is described in a `following section. <#RCL.PROGRAM.FIELDS>`__
By default, the indexer will process the standard header fields if they
are present: ``title``, ``meta/description``, and ``meta/keywords`` are
both indexed and stored for query-time display.
A predefined non-standard ``meta`` tag will also be processed by RCL
without further configuration: if a ``date`` tag is present and has the
right format, it will be used as the document date (for display and
sorting), in preference to the file modification date. The date format
should be as follows:
::
<meta name="date" content="YYYY-mm-dd HH:MM:SS">
or
<meta name="date" content="YYYY-mm-ddTHH:MM:SS">
Example:
::
<meta name="date" content="2013-02-24 17:50:00">
Input handlers also have the possibility to "invent" field names. This
should also be output as meta tags:
::
<meta name="somefield" content="Some textual data" />
You can embed HTML markup inside the content of custom fields, for
improving the display inside result lists. In this case, add a (wildly
non-standard) ``markup`` attribute to tell RCL that the value is HTML
and should not be escaped for display.
::
<meta name="somefield" markup="html" content="Some <i>textual</i> data" />
As written above, the processing of fields is described in a `further
section <#RCL.PROGRAM.FIELDS>`__.
Persistent filters can use another, probably simpler, method to produce
metadata, by calling the ``setfield()`` helper method. This avoids the
necessity to produce HTML, and any issue with HTML quoting. See, for
example, ``rclaudio`` in RCL 1.23 and later for an example of handler
which outputs ``text/plain`` and uses ``setfield()`` to produce
metadata.
.. _RCL.PROGRAM.FILTERS.PAGES:
Page numbers
~~~~~~~~~~~~
The indexer will interpret ``^L`` characters in the handler output as
indicating page breaks, and will record them. At query time, this allows
starting a viewer on the right page for a hit or a snippet. Currently,
only the PDF, Postscript and DVI handlers generate page breaks.
.. _RCL.PROGRAM.FIELDS:
Field data processing
---------------------
``Fields`` are named pieces of information in or about documents, like
``title``, ``author``, ``abstract``.
The field values for documents can appear in several ways during
indexing: either output by input handlers as ``meta`` fields in the HTML
header section, or extracted from file extended attributes, or added as
attributes of the ``Doc`` object when using the API, or again
synthetized internally by RCL.
The RCL query language allows searching for text in a specific field.
RCL defines a number of default fields. Additional ones can be output by
handlers, and described in the ``fields`` configuration file.
Fields can be:
- ``indexed``, meaning that their terms are separately stored in
inverted lists (with a specific prefix), and that a field-specific
search is possible.
- ``stored``, meaning that their value is recorded in the index data
record for the document, and can be returned and displayed with
search results.
A field can be either or both indexed and stored. This and other aspects
of fields handling is defined inside the ``fields`` configuration file.
Some fields may also designated as supporting range queries, meaning
that the results may be selected for an interval of its values. See the
`configuration section <#RCL.INSTALL.CONFIG.FIELDS>`__ for more details.
The sequence of events for field processing is as follows:
- During indexing, ``recollindex`` scans all ``meta`` fields in HTML
documents (most document types are transformed into HTML at some
point). It compares the name for each element to the configuration
defining what should be done with fields (the ``fields`` file)
- If the name for the ``meta`` element matches one for a field that
should be indexed, the contents are processed and the terms are
entered into the index with the prefix defined in the ``fields``
file.
- If the name for the ``meta`` element matches one for a field that
should be stored, the content of the element is stored with the
document data record, from which it can be extracted and displayed at
query time.
- At query time, if a field search is performed, the index prefix is
computed and the match is only performed against appropriately
prefixed terms in the index.
- At query time, the field can be displayed inside the result list by
using the appropriate directive in the definition of the `result list
paragraph format <#RCL.SEARCH.GUI.CUSTOM.RESLIST>`__. All fields are
displayed on the fields screen of the preview window (which you can
reach through the right-click menu). This is independant of the fact
that the search which produced the results used the field or not.
You can find more information in the `section about the ``fields``
file <#RCL.INSTALL.CONFIG.FIELDS>`__, or in comments inside the file.
You can also have a look at the `example in the FAQs
area <&FAQS;HandleCustomField>`__, detailing how one could add a *page
count* field to pdf documents for displaying inside result lists.
.. _RCL.PROGRAM.PYTHONAPI:
Python API
----------
.. _RCL.PROGRAM.PYTHONAPI.INTRO:
Introduction
~~~~~~~~~~~~
The RCL Python programming interface can be used both for searching and
for creating/updating an index. Bindings exist for Python2 and Python3.
The search interface is used in a number of active projects: the RCL
Gnome Shell Search Provider, the RCL Web UI, and the upmpdcli UPnP Media
Server, in addition to many small scripts.
The index update section of the API may be used to create and update RCL
indexes on specific configurations (separate from the ones created by
``recollindex``). The resulting databases can be queried alone, or in
conjunction with regular ones, through the GUI or any of the query
interfaces.
The search API is modeled along the Python database API specification.
There were two major changes along RCL versions:
- The basis for the RCL API changed from Python database API version
1.0 (RCL versions up to 1.18.1), to version 2.0 (RCL 1.18.2 and
later).
- The ``recoll`` module became a package (with an internal ``recoll``
module) as of RCL version 1.19, in order to add more functions. For
existing code, this only changes the way the interface must be
imported.
We will describe the new API and package structure here. A paragraph at
the end of this section will explain a few differences and ways to write
code compatible with both versions.
The ``recoll`` package now contains two modules:
- The ``recoll`` module contains functions and classes used to query
(or update) the index.
- The ``rclextract`` module contains functions and classes used at
query time to access document data.
There is a good chance that your system repository has packages for the
Recoll Python API, sometimes in a package separate from the main one
(maybe named something like python-recoll). Else refer to the `Building
from source chapter <#RCL.INSTALL.BUILDING>`__.
As an introduction, the following small sample will run a query and list
the title and url for each of the results. It would work with RCL 1.19
and later. The ``python/samples`` source directory contains several
examples of Python programming with RCL, exercising the extension more
completely, and especially its data extraction features.
::
#!/usr/bin/env python
from recoll import recoll
db = recoll.connect()
query = db.query()
nres = query.execute("some query")
results = query.fetchmany(20)
for doc in results:
print("%s %s" % (doc.url, doc.title))
You can also take a look at the source for the `Recoll
WebUI <https://opensourceprojects.eu/p/recollwebui/code/ci/78ddb20787b2a894b5e4661a8d5502c4511cf71e/tree/>`__,
the `upmpdcli local media
server <https://opensourceprojects.eu/p/upmpdcli/code/ci/c8c8e75bd181ad9db2df14da05934e53ca867a06/tree/src/mediaserver/cdplugins/uprcl/uprclfolders.py>`__,
or the `Gnome Shell Search
Provider <https://opensourceprojects.eu/p/recollgssp/code/ci/3f120108e099f9d687306c0be61593994326d52d/tree/gssp-recoll.py>`__.
.. _RCL.PROGRAM.PYTHONAPI.ELEMENTS:
Interface elements
~~~~~~~~~~~~~~~~~~
A few elements in the interface are specific and and need an
explanation.
ipath
This data value (set as a field in the Doc object) is stored, along
with the URL, but not indexed by RCL. Its contents are not
interpreted by the index layer, and its use is up to the application.
For example, the RCL file system indexer uses the ``ipath`` to store
the part of the document access path internal to (possibly
imbricated) container documents. ``ipath`` in this case is a vector
of access elements (e.g, the first part could be a path inside a zip
file to an archive member which happens to be an mbox file, the
second element would be the message sequential number inside the mbox
etc.). ``url`` and ``ipath`` are returned in every search result and
define the access to the original document. ``ipath`` is empty for
top-level document/files (e.g. a PDF document which is a filesystem
file). The RCL GUI knows about the structure of the ``ipath`` values
used by the filesystem indexer, and uses it for such functions as
opening the parent of a given document.
udi
An ``udi`` (unique document identifier) identifies a document.
Because of limitations inside the index engine, it is restricted in
length (to 200 bytes), which is why a regular URI cannot be used. The
structure and contents of the ``udi`` is defined by the application
and opaque to the index engine. For example, the internal file system
indexer uses the complete document path (file path + internal path),
truncated to length, the suppressed part being replaced by a hash
value. The ``udi`` is not explicit in the query interface (it is used
"under the hood" by the ``rclextract`` module), but it is an explicit
element of the update interface.
parent_udi
If this attribute is set on a document when entering it in the index,
it designates its physical container document. In a multilevel
hierarchy, this may not be the immediate parent. ``parent_udi`` is
optional, but its use by an indexer may simplify index maintenance,
as RCL will automatically delete all children defined by
``parent_udi == udi`` when the document designated by ``udi`` is
destroyed. e.g. if a ``Zip`` archive contains entries which are
themselves containers, like ``mbox`` files, all the subdocuments
inside the ``Zip`` file (mbox, messages, message attachments, etc.)
would have the same ``parent_udi``, matching the ``udi`` for the
``Zip`` file, and all would be destroyed when the ``Zip`` file
(identified by its ``udi``) is removed from the index. The standard
filesystem indexer uses ``parent_udi``.
Stored and indexed fields
The ```fields`` file <#RCL.INSTALL.CONFIG.FIELDS>`__ inside the RCL
configuration defines which document fields are either ``indexed``
(searchable), ``stored`` (retrievable with search results), or both.
Apart from a few standard/internal fields, only the ``stored`` fields
are retrievable through the Python search interface.
.. _RCL.PROGRAM.PYTHONAPI.SEARCH:
Python search interface
~~~~~~~~~~~~~~~~~~~~~~~
.. _RCL.PROGRAM.PYTHONAPI.RECOLL:
The recoll module
^^^^^^^^^^^^^^^^^
The ``connect()`` function connects to one or several RCL index(es) and
returns a ``Db`` object.
This call initializes the recoll module, and it should always be
performed before any other call or object creation.
- ``confdir`` may specify a configuration directory. The usual defaults
apply.
- ``extra_dbs`` is a list of additional indexes (Xapian directories).
- ``writable`` decides if we can index new data through this
connection.
A Db object is created by a ``connect()`` call and holds a connection to
a Recoll index.
Db.close()
Closes the connection. You can't do anything with the ``Db`` object
after this.
Db.query(), Db.cursor()
These aliases return a blank ``Query`` object for this index.
Db.setAbstractParams(maxchars, contextwords)
Set the parameters used to build snippets (sets of keywords in
context text fragments). ``maxchars`` defines the maximum total size
of the abstract. ``contextwords`` defines how many terms are shown
around the keyword.
Db.termMatch(match_type, expr, field='', maxlen=-1, casesens=False, diacsens=False, lang='english')
Expand an expression against the index term list. Performs the basic
function from the GUI term explorer tool. ``match_type`` can be
either of ``wildcard``, ``regexp`` or ``stem``. Returns a list of
terms expanded from the input expression.
A ``Query`` object (equivalent to a cursor in the Python DB API) is
created by a ``Db.query()`` call. It is used to execute index searches.
Query.sortby(fieldname, ascending=True)
Sort results by fieldname, in ascending or descending order. Must be
called before executing the search.
Query.execute(query_string, stemming=1, stemlang="english", fetchtext=False)
Starts a search for query_string, a RCL search language string. If
the index stores the document texts and ``fetchtext`` is True, store
the document extracted text in ``doc.text``.
Query.executesd(SearchData, fetchtext=False)
Starts a search for the query defined by the SearchData object. If
the index stores the document texts and ``fetchtext`` is True, store
the document extracted text in ``doc.text``.
Query.fetchmany(size=query.arraysize)
Fetches the next ``Doc`` objects in the current search results, and
returns them as an array of the required size, which is by default
the value of the ``arraysize`` data member.
Query.fetchone()
Fetches the next ``Doc`` object from the current search results.
Generates a StopIteration exception if there are no results left.
Query.close()
Closes the query. The object is unusable after the call.
Query.scroll(value, mode='relative')
Adjusts the position in the current result set. ``mode`` can be
``relative`` or ``absolute``.
Query.getgroups()
Retrieves the expanded query terms as a list of pairs. Meaningful
only after executexx In each pair, the first entry is a list of user
terms (of size one for simple terms, or more for group and phrase
clauses), the second a list of query terms as derived from the user
terms and used in the Xapian Query.
Query.getxquery()
Return the Xapian query description as a Unicode string. Meaningful
only after executexx.
Query.highlight(text, ishtml = 0, methods = object)
Will insert <span "class=rclmatch">, </span> tags around the match
areas in the input text and return the modified text. ``ishtml`` can
be set to indicate that the input text is HTML and that HTML special
characters should not be escaped. ``methods`` if set should be an
object with methods startMatch(i) and endMatch() which will be called
for each match and should return a begin and end tag
Query.makedocabstract(doc, methods = object))
Create a snippets abstract for ``doc`` (a ``Doc`` object) by
selecting text around the match terms. If methods is set, will also
perform highlighting. See the highlight method.
Query.__iter__() and Query.next()
So that things like ``for doc in query:`` will work.
Query.arraysize
Default number of records processed by fetchmany (r/w).
Query.rowcount
Number of records returned by the last execute.
Query.rownumber
Next index to be fetched from results. Normally increments after each
fetchone() call, but can be set/reset before the call to effect
seeking (equivalent to using ``scroll()``). Starts at 0.
A ``Doc`` object contains index data for a given document. The data is
extracted from the index when searching, or set by the indexer program
when updating. The Doc object has many attributes to be read or set by
its user. It mostly matches the Rcl::Doc C++ object. Some of the
attributes are predefined, but, especially when indexing, others can be
set, the name of which will be processed as field names by the indexing
configuration. Inputs can be specified as Unicode or strings. Outputs
are Unicode objects. All dates are specified as Unix timestamps, printed
as strings. Please refer to the ``rcldb/rcldoc.cpp`` C++ file for a full
description of the predefined attributes. Here follows a short list.
- ``url`` the document URL but see also ``getbinurl()``
- ``ipath`` the document ``ipath`` for embedded documents.
- ``fbytes, dbytes`` the document file and text sizes.
- ``fmtime, dmtime`` the document file and document times.
- ``xdocid`` the document Xapian document ID. This is useful if you
want to access the document through a direct Xapian operation.
- ``mtype`` the document MIME type.
- Fields stored by default: ``author``, ``filename``, ``keywords``,
``recipient``
At query time, only the fields that are defined as ``stored`` either by
default or in the ``fields`` configuration file will be meaningful in
the ``Doc`` object. The document processed text may be present or not,
depending if the index stores the text at all, and if it does, on the
``fetchtext`` query execute option. See also the ``rclextract`` module
for accessing document contents.
get(key), [] operator
Retrieve the named document attribute. You can also use
``getattr(doc, key)`` or ``doc.key``.
doc.key = value
Set the the named document attribute. You can also use
``setattr(doc, key, value)``.
getbinurl()
Retrieve the URL in byte array format (no transcoding), for use as
parameter to a system call.
setbinurl(url)
Set the URL in byte array format (no transcoding).
items()
Return a dictionary of doc object keys/values
keys()
list of doc object keys (attribute names).
A ``SearchData`` object allows building a query by combining clauses,
for execution by ``Query.executesd()``. It can be used in replacement of
the query language approach. The interface is going to change a little,
so no detailed doc for now...
addclause(type='and'|'or'|'excl'|'phrase'|'near'|'sub', qstring=string, slack=0, field='', stemming=1, subSearch=SearchData)
.. _RCL.PROGRAM.PYTHONAPI.RCLEXTRACT:
The rclextract module
^^^^^^^^^^^^^^^^^^^^^
Prior to RCL 1.25, index queries could not provide document content
because it was never stored. RCL 1.25 and later usually store the
document text, which can be optionally retrieved when running a query
(see ``query.execute()`` above - the result is always plain text).
The ``rclextract`` module can give access to the original document and
to the document text content (if not stored by the index, or to access
an HTML version of the text). Acessing the original document is
particularly useful if it is embedded (e.g. an email attachment).
You need to import the ``recoll`` module before the ``rclextract``
module.
Extractor(doc)
An ``Extractor`` object is built from a ``Doc`` object, output from a
query.
Extractor.textextract(ipath)
Extract document defined by ipath and return a ``Doc`` object. The
``doc.text`` field has the document text converted to either
text/plain or text/html according to ``doc.mimetype``. The typical
use would be as follows:
::
from recoll import recoll, rclextract
qdoc = query.fetchone()
extractor = recoll.Extractor(qdoc)
doc = extractor.textextract(qdoc.ipath)
# use doc.text, e.g. for previewing
Passing ``qdoc.ipath`` to ``textextract()`` is redundant, but
reflects the fact that the ``Extractor`` object actually has the
capability to access the other entries in a compound document.
Extractor.idoctofile(ipath, targetmtype, outfile='')
Extracts document into an output file, which can be given explicitly
or will be created as a temporary file to be deleted by the caller.
Typical use:
::
from recoll import recoll, rclextract
qdoc = query.fetchone()
extractor = recoll.Extractor(qdoc)
filename = extractor.idoctofile(qdoc.ipath, qdoc.mimetype)
In all cases the output is a copy, even if the requested document is
a regular system file, which may be wasteful in some cases. If you
want to avoid this, you can test for a simple file document as
follows:
::
not doc.ipath and (not "rclbes" in doc.keys() or doc["rclbes"] == "FS")
.. _RCL.PROGRAM.PYTHONAPI.SEARCH.EXAMPLE:
Search API usage example
^^^^^^^^^^^^^^^^^^^^^^^^
The following sample would query the index with a user language string.
See the ``python/samples`` directory inside the RCL source for other
examples. The ``recollgui`` subdirectory has a very embryonic GUI which
demonstrates the highlighting and data extraction functions.
::
#!/usr/bin/env python
from recoll import recoll
db = recoll.connect()
db.setAbstractParams(maxchars=80, contextwords=4)
query = db.query()
nres = query.execute("some user question")
print "Result count: ", nres
if nres > 5:
nres = 5
for i in range(nres):
doc = query.fetchone()
print "Result #%d" % (query.rownumber,)
for k in ("title", "size"):
print k, ":", getattr(doc, k).encode('utf-8')
abs = db.makeDocAbstract(doc, query).encode('utf-8')
print abs
print
.. _RCL.PROGRAM.PYTHONAPI.UPDATE:
Creating Python external indexers
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The update API can be used to create an index from data which is not
accessible to the regular RCL indexer, or structured to present
difficulties to the RCL input handlers.
An indexer created using this API will be have equivalent work to do as
the the Recoll file system indexer: look for modified documents, extract
their text, call the API for indexing it, take care of purging the index
out of data from documents which do not exist in the document store any
more.
The data for such an external indexer should be stored in an index
separate from any used by the RCL internal file system indexer. The
reason is that the main document indexer purge pass (removal of deleted
documents) would also remove all the documents belonging to the external
indexer, as they were not seen during the filesystem walk. The main
indexer documents would also probably be a problem for the external
indexer own purge operation.
While there would be ways to enable multiple foreign indexers to
cooperate on a single index, it is just simpler to use separate ones,
and use the multiple index access capabilities of the query interface,
if needed.
There are two parts in the update interface:
- Methods inside the ``recoll`` module allow inserting data into the
index, to make it accessible by the normal query interface.
- An interface based on scripts execution is defined to allow either
the GUI or the ``rclextract`` module to access original document data
for previewing or editing.
.. _RCL.PROGRAM.PYTHONAPI.UPDATE.UPDATE:
Python update interface
^^^^^^^^^^^^^^^^^^^^^^^
The update methods are part of the ``recoll`` module described above.
The connect() method is used with a ``writable=true`` parameter to
obtain a writable ``Db`` object. The following ``Db`` object methods are
then available.
addOrUpdate(udi, doc, parent_udi=None)
Add or update index data for a given document The ``udi`` string must
define a unique id for the document. It is an opaque interface
element and not interpreted inside Recoll. ``doc`` is a ``Doc``
object, created from the data to be indexed (the main text should be
in ``doc.text``). If ``parent_udi`` is set, this is a unique
identifier for the top-level container (e.g. for the filesystem
indexer, this would be the one which is an actual file).
delete(udi)
Purge index from all data for ``udi``, and all documents (if any)
which have a matrching ``parent_udi``.
needUpdate(udi, sig)
Test if the index needs to be updated for the document identified by
``udi``. If this call is to be used, the ``doc.sig`` field should
contain a signature value when calling ``addOrUpdate()``. The
``needUpdate()`` call then compares its parameter value with the
stored ``sig`` for ``udi``. ``sig`` is an opaque value, compared as a
string.
The filesystem indexer uses a concatenation of the decimal string
values for file size and update time, but a hash of the contents
could also be used.
As a side effect, if the return value is false (the index is up to
date), the call will set the existence flag for the document (and any
subdocument defined by its ``parent_udi``), so that a later
``purge()`` call will preserve them).
The use of ``needUpdate()`` and ``purge()`` is optional, and the
indexer may use another method for checking the need to reindex or to
delete stale entries.
purge()
Delete all documents that were not touched during the just finished
indexing pass (since open-for-write). These are the documents for the
needUpdate() call was not performed, indicating that they no longer
exist in the primary storage system.
.. _RCL.PROGRAM.PYTHONAPI.UPDATE.ACCESS:
Query data access for external indexers (1.23)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
RCL has internal methods to access document data for its internal
(filesystem) indexer. An external indexer needs to provide data access
methods if it needs integration with the GUI (e.g. preview function), or
support for the ``rclextract`` module.
The index data and the access method are linked by the ``rclbes``
(recoll backend storage) ``Doc`` field. You should set this to a short
string value identifying your indexer (e.g. the filesystem indexer uses
either "FS" or an empty value, the Web history indexer uses "BGL").
The link is actually performed inside a ``backends`` configuration file
(stored in the configuration directory). This defines commands to
execute to access data from the specified indexer. Example, for the mbox
indexing sample found in the Recoll source (which sets
``rclbes="MBOX"``):
::
[MBOX]
fetch = /path/to/recoll/src/python/samples/rclmbox.py fetch
makesig = path/to/recoll/src/python/samples/rclmbox.py makesig
``fetch`` and ``makesig`` define two commands to execute to respectively
retrieve the document text and compute the document signature (the
example implementation uses the same script with different first
parameters to perform both operations).
The scripts are called with three additional arguments: ``udi``,
``url``, ``ipath``, stored with the document when it was indexed, and
may use any or all to perform the requested operation. The caller
expects the result data on ``stdout``.
.. _RCL.PROGRAM.PYTHONAPI.UPDATE.SAMPLES:
External indexer samples
^^^^^^^^^^^^^^^^^^^^^^^^
The Recoll source tree has two samples of external indexers in the
``src/python/samples`` directory. The more interesting one is
``rclmbox.py`` which indexes a directory containing ``mbox`` folder
files. It exercises most features in the update interface, and has a
data access interface.
See the comments inside the file for more information.
.. _RCL.PROGRAM.PYTHONAPI.COMPAT:
Package compatibility with the previous version
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The following code fragments can be used to ensure that code can run
with both the old and the new API (as long as it does not use the new
abilities of the new API of course).
Adapting to the new package structure:
::
try:
from recoll import recoll
from recoll import rclextract
hasextract = True
except:
import recoll
hasextract = False
Adapting to the change of nature of the ``next`` ``Query`` member. The
same test can be used to choose to use the ``scroll()`` method (new) or
set the ``next`` value (old).
::
rownum = query.next if type(query.next) == int else \
query.rownumber
.. _RCL.INSTALL:
Installation and configuration
==============================
.. _RCL.INSTALL.BINARY:
Installing a binary copy
------------------------
RCL binary copies are always distributed as regular packages for your
system. They can be obtained either through the system's normal software
distribution framework (e.g. Debian/Ubuntu apt, FreeBSD ports, etc.), or
from some type of "backports" repository providing versions newer than
the standard ones, or found on the RCL WEB site in some cases. The most
up-to-date information about Recoll packages can usually be found on the
`Recoll WEB site downloads page <http://www.recoll.org/download.html>`__
There used to exist another form of binary install, as pre-compiled
source trees, but these are just less convenient than the packages and
don't exist any more.
The package management tools will usually automatically deal with hard
dependancies for packages obtained from a proper package repository. You
will have to deal with them by hand for downloaded packages (for
example, when ``dpkg`` complains about missing dependancies).
In all cases, you will have to check or install `supporting
applications <#RCL.INSTALL.EXTERNAL>`__ for the file types that you want
to index beyond those that are natively processed by RCL (text, HTML,
email files, and a few others).
You should also maybe have a look at the `configuration
section <#RCL.INSTALL.CONFIG>`__ (but this may not be necessary for a
quick test with default parameters). Most parameters can be more
conveniently set from the GUI interface.
.. _RCL.INSTALL.EXTERNAL:
Supporting packages
-------------------
**Note**
The WIN installation of RCL is self-contained, and only needs Python
2.7 to be externally installed. WIN users can skip this section.
RCL uses external applications to index some file types. You need to
install them for the file types that you wish to have indexed (these are
run-time optional dependencies. None is needed for building or running
RCL except for indexing their specific file type).
After an indexing pass, the commands that were found missing can be
displayed from the ``recoll`` File menu. The list is stored in the
``missing`` text file inside the configuration directory.
A list of common file types which need external commands follows. Many
of the handlers need the ``iconv`` command, which is not always listed
as a dependancy.
Please note that, due to the relatively dynamic nature of this
information, the most up to date version is now kept on RCLAPPS along
with links to the home pages or best source/patches pages, and misc
tips. The list below is not updated often and may be quite stale.
For many Linux distributions, most of the commands listed can be
installed from the package repositories. However, the packages are
sometimes outdated, or not the best version for RCL, so you should take
a look at RCLAPPS if a file type is important to you.
As of RCL release 1.14, a number of XML-based formats that were handled
by ad hoc handler code now use the ``xsltproc`` command, which usually
comes with libxslt. These are: abiword, fb2 (ebooks), kword, openoffice,
svg.
Now for the list:
- Openoffice files need ``unzip`` and ``xsltproc``.
- PDF files need ``pdftotext`` which is part of Poppler (usually comes
with the ``poppler-utils`` package). Avoid the original one from
Xpdf.
- Postscript files need ``pstotext``. The original version has an issue
with shell character in file names, which is corrected in recent
packages. See RCLAPPS for more detail.
- MS Word needs ``antiword``. It is also useful to have ``wvWare``
installed as it may be be used as a fallback for some files which
``antiword`` does not handle.
- MS Excel and PowerPoint are processed by internal ``Python``
handlers.
- MS Open XML (docx) needs ``xsltproc``.
- Wordperfect files need ``wpd2html`` from the libwpd (or libwpd-tools
on Ubuntu) package.
- RTF files need ``unrtf``, which, in its older versions, has much
trouble with non-western character sets. Many Linux distributions
carry outdated ``unrtf`` versions. Check RCLAPPS for details.
- TeX files need ``untex`` or ``detex``. Check RCLAPPS for sources if
it's not packaged for your distribution.
- dvi files need ``dvips``.
- djvu files need ``djvutxt`` and ``djvused`` from the DjVuLibre
package.
- Audio files: RCL releases 1.14 and later use a single Python handler
based on mutagen for all audio file types.
- Pictures: RCL uses the Exiftool Perl package to extract tag
information. Most image file formats are supported. Note that there
may not be much interest in indexing the technical tags (image size,
aperture, etc.). This is only of interest if you store personal tags
or textual descriptions inside the image files.
- chm: files in Microsoft help format need Python and the pychm module
(which needs chmlib).
- ICS: up to RCL 1.13, iCalendar files need Python and the icalendar
module. icalendar is not needed for newer versions, which use
internal code.
- Zip archives need Python (and the standard zipfile module).
- Rar archives need Python, the rarfile Python module and the ``unrar``
utility.
- Midi karaoke files need Python and the `Midi
module <http://pypi.python.org/pypi/midi/0.2.1>`__
- Konqueror webarchive format with Python (uses the Tarfile module).
- Mimehtml web archive format (support based on the email handler,
which introduces some mild weirdness, but still usable).
Text, HTML, email folders, and Scribus files are processed internally.
Lyx is used to index Lyx files. Many handlers need ``iconv`` and the
standard ``sed`` and ``awk``.
.. _RCL.INSTALL.BUILDING:
Building from source
--------------------
.. _RCL.INSTALL.BUILDING.PREREQS:
Prerequisites
~~~~~~~~~~~~~
The following prerequisites are described in broad terms and not as
specific package names (which will depend on the exact platform). The
dependancies should be available as packages on most common Unix
derivatives, and it should be quite uncommon that you would have to
build one of them.
The shopping list:
- The ``autoconf``, ``automake`` and ``libtool`` triad. Only
``autoconf`` is needed for RCL 1.21 and earlier.
- C++ compiler. Recent versions require C++11 compatibility (1.23 and
later).
- ``bison`` command (for RCL 1.21 and later).
- ``xsltproc`` command. For building the documentation (for RCL 1.21
and later). This sometimes comes with the libxslt package. And also
the Docbook XML and style sheet files.
- Development files for `Xapian core <http://www.xapian.org>`__.
**Important**
If you are building Xapian for an older CPU (before Pentium 4 or
Athlon 64), you need to add the ``--disable-sse`` flag to the
configure command. Else all Xapian application will crash with an
``illegal instruction`` error.
- Development files for `Qt 4 or Qt
5 <http://qt-project.org/downloads>`__. RCL 1.15.9 was the last
version to support Qt 3. If you do not want to install or build the
Qt Webkit module, RCL has a configuration option to disable its use
(see further in the configuration section).
- Development files for X11 and zlib.
- Development files for Python (or use ``--disable-python-module``).
- You may also need
`libiconv <http://www.gnu.org/software/libiconv/>`__. On Linux
systems, the iconv interface is part of libc and you should not need
to do anything special.
Check the `RCL download page <http://www.recoll.org/download.html>`__
for up to date version information.
.. _RCL.INSTALL.BUILDING.BUILDING:
Building
~~~~~~~~
RCL has been built on Linux, FreeBSD, Mac OS X, and Solaris, most
versions after 2005 should be ok, maybe some older ones too (Solaris 8
is ok). If you build on another system, and need to modify things, `I
would very much welcome patches <mailto:jfd@recoll.org>`__.
**Configure options:.**
- ``--without-aspell`` will disable the code for phonetic matching of
search terms.
- ``--with-fam`` or ``--with-inotify`` will enable the code for real
time indexing. Inotify support is enabled by default on recent Linux
systems.
- ``--with-qzeitgeist`` will enable sending Zeitgeist events about the
visited search results, and needs the qzeitgeist package.
- ``--disable-webkit`` is available from version 1.17 to implement the
result list with a Qt QTextBrowser instead of a WebKit widget if you
do not or can't depend on the latter.
- ``--disable-idxthreads`` is available from version 1.19 to suppress
multithreading inside the indexing process. You can also use the
run-time configuration to restrict ``recollindex`` to using a single
thread, but the compile-time option may disable a few more unused
locks. This only applies to the use of multithreading for the core
index processing (data input). The RCL monitor mode always uses at
least two threads of execution.
- ``--disable-python-module`` will avoid building the Python module.
- ``--disable-xattr`` will prevent fetching data from file extended
attributes. Beyond a few standard attributes, fetching extended
attributes data can only be useful is some application stores data in
there, and also needs some simple configuration (see comments in the
``fields`` configuration file).
- ``--enable-camelcase`` will enable splitting camelCase words. This is
not enabled by default as it has the unfortunate side-effect of
making some phrase searches quite confusing: ie, ``"MySQL manual"``
would be matched by ``"MySQL manual"`` and ``"my sql manual"`` but
not ``"mysql manual"`` (only inside phrase searches).
- ``--with-file-command`` Specify the version of the 'file' command to
use (ie: --with-file-command=/usr/local/bin/file). Can be useful to
enable the gnu version on systems where the native one is bad.
- ``--disable-qtgui`` Disable the Qt interface. Will allow building the
indexer and the command line search program in absence of a Qt
environment.
- ``--disable-x11mon`` Disable X11 connection monitoring inside
recollindex. Together with --disable-qtgui, this allows building
recoll without Qt and X11.
- ``--disable-userdoc`` will avoid building the user manual. This
avoids having to install the Docbook XML/XSL files and the TeX
toolchain used for translating the manual to PDF.
- ``--disable-pic`` (RCL versions up to 1.21 only) will compile RCL
with position-dependant code. This is incompatible with building the
KIO or the Python or PHP extensions, but might yield very marginally
faster code.
- Of course the usual autoconf ``configure`` options, like ``--prefix``
apply.
Normal procedure (for source extracted from a tar distribution):
::
cd recoll-xxx
./configure
make
(practices usual hardship-repelling invocations)
When building from source cloned from the git repository, you also need
to install autoconf, automake, and libtool and you must execute
``sh autogen.sh`` in the top source directory before running
``configure``.
.. _RCL.INSTALL.BUILDING.INSTALL:
Installing
~~~~~~~~~~
Use ``make install`` in the root of the source tree. This will copy the
commands to ``prefix/bin`` and the sample configuration files, scripts
and other shared data to ``prefix/share/recoll``.
.. _RCL.INSTALL.BUILDING.PYTHON:
Python API package
~~~~~~~~~~~~~~~~~~
The Python interface can be found in the source tree, under the
``python/recoll`` directory.
As of RCL 1.19, the module can be compiled for Python3.
The normal RCL build procedure (see above) installs the API package for
the default system version (python) along with the main code. The
package for other Python versions (e.g. python3 if the system default is
python2) must be explicitely built and installed.
The ``python/recoll/`` directory contains the usual ``setup.py``. After
configuring and building the main RCL code, you can use the script to
build and install the Python module:
::
cd recoll-xxx/python/recoll
pythonX setup.py build
sudo pythonX setup.py install
.. _RCL.INSTALL.BUILDING.SOLARIS:
Building on Solaris
~~~~~~~~~~~~~~~~~~~
We did not test building the GUI on Solaris for recent versions. You
will need at least Qt 4.4. There are some hints on `an old web site
page <http://www.recoll.org/download-1.14.html>`__, they may still be
valid.
Someone did test the 1.19 indexer and Python module build, they do work,
with a few minor glitches. Be sure to use GNU ``make`` and ``install``.
.. _RCL.INSTALL.CONFIG:
Configuration overview
----------------------
Most of the parameters specific to the ``recoll`` GUI are set through
the Preferences menu and stored in the standard Qt place
(``$HOME/.config/Recoll.org/recoll.conf``). You probably do not want to
edit this by hand.
RCL indexing options are set inside text configuration files located in
a configuration directory. There can be several such directories, each
of which defines the parameters for one index.
The configuration files can be edited by hand or through the Index
configuration dialog (Preferences menu). The GUI tool will try to
respect your formatting and comments as much as possible, so it is quite
possible to use both approaches on the same configuration.
The most accurate documentation for the configuration parameters is
given by comments inside the default files, and we will just give a
general overview here.
For each index, there are at least two sets of configuration files.
System-wide configuration files are kept in a directory named like
``/usr/share/recoll/examples``, and define default values, shared by all
indexes. For each index, a parallel set of files defines the customized
parameters.
The default location of the customized configuration is the ``.recoll``
directory in your home. Most people will only use this directory.
This location can be changed, or others can be added with the
RECOLL_CONFDIR environment variable or the ``-c`` option parameter to
``recoll`` and ``recollindex``.
In addition (as of RCL version 1.19.7), it is possible to specify two
additional configuration directories which will be stacked before and
after the user configuration directory. These are defined by the
RECOLL_CONFTOP and RECOLL_CONFMID environment variables. Values from
configuration files inside the top directory will override user ones,
values from configuration files inside the middle directory will
override system ones and be overriden by user ones. These two variables
may be of use to applications which augment RCL functionality, and need
to add configuration data without disturbing the user's files. Please
note that the two, currently single, values will probably be interpreted
as colon-separated lists in the future: do not use colon characters
inside the directory paths.
If the ``.recoll`` directory does not exist when ``recoll`` or
``recollindex`` are started, it will be created with a set of empty
configuration files. ``recoll`` will give you a chance to edit the
configuration file before starting indexing. ``recollindex`` will
proceed immediately. To avoid mistakes, the automatic directory creation
will only occur for the default location, not if ``-c`` or
RECOLL_CONFDIR were used (in the latter cases, you will have to create
the directory).
All configuration files share the same format. For example, a short
extract of the main configuration file might look as follows:
::
# Space-separated list of files and directories to index.
topdirs = ~/docs /usr/share/doc
[~/somedirectory-with-utf8-txt-files]
defaultcharset = utf-8
There are three kinds of lines:
- Comment (starts with *#*) or empty.
- Parameter affectation (*name = value*).
- Section definition ([*somedirname*]).
Long lines can be broken by ending each incomplete part with a backslash
(``\``).
Depending on the type of configuration file, section definitions either
separate groups of parameters or allow redefining some parameters for a
directory sub-tree. They stay in effect until another section
definition, or the end of file, is encountered. Some of the parameters
used for indexing are looked up hierarchically from the current
directory location upwards. Not all parameters can be meaningfully
redefined, this is specified for each in the next section.
**Important**
Global parameters *must not* be defined in a directory subsection,
else they will not be found at all by the RCL code, which looks for
them at the top level (e.g. ``skippedPaths``).
When found at the beginning of a file path, the tilde character (~) is
expanded to the name of the user's home directory, as a shell would do.
Some parameters are lists of strings. White space is used for
separation. List elements with embedded spaces can be quoted using
double-quotes. Double quotes inside these elements can be escaped with a
backslash.
No value inside a configuration file can contain a newline character.
Long lines can be continued by escaping the physical newline with
backslash, even inside quoted strings.
::
astringlist = "some string \
with spaces"
thesame = "some string with spaces"
Parameters which are not part of string lists can't be quoted, and
leading and trailing space characters are stripped before the value is
used.
**Encoding issues.**
Most of the configuration parameters are plain ASCII. Two particular
sets of values may cause encoding issues:
- File path parameters may contain non-ascii characters and should use
the exact same byte values as found in the file system directory.
Usually, this means that the configuration file should use the system
default locale encoding.
- The unac_except_trans parameter should be encoded in UTF-8. If your
system locale is not UTF-8, and you need to also specify non-ascii
file paths, this poses a difficulty because common text editors
cannot handle multiple encodings in a single file. In this relatively
unlikely case, you can edit the configuration file as two separate
text files with appropriate encodings, and concatenate them to create
the complete configuration.
.. _RCL.INSTALL.CONFIG.ENVIR:
Environment variables
~~~~~~~~~~~~~~~~~~~~~
``RECOLL_CONFDIR``
Defines the main configuration directory.
``RECOLL_TMPDIR, TMPDIR``
Locations for temporary files, in this order of priority. The default
if none of these is set is to use ``/tmp``. Big temporary files may
be created during indexing, mostly for decompressing, and also for
processing, e.g. email attachments.
``RECOLL_CONFTOP, RECOLL_CONFMID``
Allow adding configuration directories with priorities below and
above the user directory (see above the Configuration overview
section for details).
``RECOLL_EXTRA_DBS, RECOLL_ACTIVE_EXTRA_DBS``
Help for setting up external indexes. See `this
paragraph <#RCL.SEARCH.GUI.MULTIDB>`__ for explanations.
``RECOLL_DATADIR``
Defines replacement for the default location of Recoll data files,
normally found in, e.g., ``/usr/share/recoll``).
``RECOLL_FILTERSDIR``
Defines replacement for the default location of Recoll filters,
normally found in, e.g., ``/usr/share/recoll/filters``).
``ASPELL_PROG``
``aspell`` program to use for creating the spelling dictionary. The
result has to be compatible with the ``libaspell`` which RCL is
using.
``VARNAME``
Blabla
.. _RCL.INSTALL.CONFIG.RECOLLCONF:
Recoll main configuration file, recoll.conf
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.. _RCL.INSTALL.CONFIG.RECOLLCONF.WHATDOCS:
Parameters affecting what documents we index
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
``topdirs``
Space-separated list of files or directories to recursively index.
Default to ~ (indexes $HOME). You can use symbolic links in the list,
they will be followed, independantly of the value of the followLinks
variable.
``monitordirs``
Space-separated list of files or directories to monitor for updates.
When running the real-time indexer, this allows monitoring only a
subset of the whole indexed area. The elements must be included in
the tree defined by the 'topdirs' members.
``skippedNames``
Files and directories which should be ignored. White space separated
list of wildcard patterns (simple ones, not paths, must contain no /
), which will be tested against file and directory names. The list in
the default configuration does not exclude hidden directories (names
beginning with a dot), which means that it may index quite a few
things that you do not want. On the other hand, email user agents
like Thunderbird usually store messages in hidden directories, and
you probably want this indexed. One possible solution is to have ".*"
in "skippedNames", and add things like "~/.thunderbird"
"~/.evolution" to "topdirs". Not even the file names are indexed for
patterns in this list, see the "noContentSuffixes" variable for an
alternative approach which indexes the file names. Can be redefined
for any subtree.
``skippedNames-``
List of name endings to remove from the default skippedNames list.
``skippedNames+``
List of name endings to add to the default skippedNames list.
``noContentSuffixes``
List of name endings (not necessarily dot-separated suffixes) for
which we don't try MIME type identification, and don't uncompress or
index content. Only the names will be indexed. This complements the
now obsoleted recoll_noindex list from the mimemap file, which will
go away in a future release (the move from mimemap to recoll.conf
allows editing the list through the GUI). This is different from
skippedNames because these are name ending matches only (not wildcard
patterns), and the file name itself gets indexed normally. This can
be redefined for subdirectories.
``noContentSuffixes-``
List of name endings to remove from the default noContentSuffixes
list.
``noContentSuffixes+``
List of name endings to add to the default noContentSuffixes list.
``skippedPaths``
Absolute paths we should not go into. Space-separated list of
wildcard expressions for absolute filesystem paths. Must be defined
at the top level of the configuration file, not in a subsection. Can
contain files and directories. The database and configuration
directories will automatically be added. The expressions are matched
using 'fnmatch(3)' with the FNM_PATHNAME flag set by default. This
means that '/' characters must be matched explicitely. You can set
'skippedPathsFnmPathname' to 0 to disable the use of FNM_PATHNAME
(meaning that '/*/dir3' will match '/dir1/dir2/dir3'). The default
value contains the usual mount point for removable media to remind
you that it is a bad idea to have Recoll work on these (esp. with the
monitor: media gets indexed on mount, all data gets erased on
unmount). Explicitely adding '/media/xxx' to the 'topdirs' variable
will override this.
``skippedPathsFnmPathname``
Set to 0 to override use of FNM_PATHNAME for matching skipped paths.
``nowalkfn``
File name which will cause its parent directory to be skipped. Any
directory containing a file with this name will be skipped as if it
was part of the skippedPaths list. Ex: .recoll-noindex
``daemSkippedPaths``
skippedPaths equivalent specific to real time indexing. This enables
having parts of the tree which are initially indexed but not
monitored. If daemSkippedPaths is not set, the daemon uses
skippedPaths.
``zipUseSkippedNames``
Use skippedNames inside Zip archives. Fetched directly by the rclzip
handler. Skip the patterns defined by skippedNames inside Zip
archives. Can be redefined for subdirectories. See
https://www.lesbonscomptes.com/recoll/faqsandhowtos/FilteringOutZipArchiveMembers.html
``zipSkippedNames``
Space-separated list of wildcard expressions for names that should be
ignored inside zip archives. This is used directly by the zip
handler. If zipUseSkippedNames is not set, zipSkippedNames defines
the patterns to be skipped inside archives. If zipUseSkippedNames is
set, the two lists are concatenated and used. Can be redefined for
subdirectories. See
https://www.lesbonscomptes.com/recoll/faqsandhowtos/FilteringOutZipArchiveMembers.html
``followLinks``
Follow symbolic links during indexing. The default is to ignore
symbolic links to avoid multiple indexing of linked files. No effort
is made to avoid duplication when this option is set to true. This
option can be set individually for each of the 'topdirs' members by
using sections. It can not be changed below the 'topdirs' level.
Links in the 'topdirs' list itself are always followed.
``indexedmimetypes``
Restrictive list of indexed mime types. Normally not set (in which
case all supported types are indexed). If it is set, only the types
from the list will have their contents indexed. The names will be
indexed anyway if indexallfilenames is set (default). MIME type names
should be taken from the mimemap file (the values may be different
from xdg-mime or file -i output in some cases). Can be redefined for
subtrees.
``excludedmimetypes``
List of excluded MIME types. Lets you exclude some types from
indexing. MIME type names should be taken from the mimemap file (the
values may be different from xdg-mime or file -i output in some
cases) Can be redefined for subtrees.
``nomd5types``
Don't compute md5 for these types. md5 checksums are used only for
deduplicating results, and can be very expensive to compute on
multimedia or other big files. This list lets you turn off md5
computation for selected types. It is global (no redefinition for
subtrees). At the moment, it only has an effect for external handlers
(exec and execm). The file types can be specified by listing either
MIME types (e.g. audio/mpeg) or handler names (e.g. rclaudio).
``compressedfilemaxkbs``
Size limit for compressed files. We need to decompress these in a
temporary directory for identification, which can be wasteful in some
cases. Limit the waste. Negative means no limit. 0 results in no
processing of any compressed file. Default 50 MB.
``textfilemaxmbs``
Size limit for text files. Mostly for skipping monster logs. Default
20 MB.
``indexallfilenames``
Index the file names of unprocessed files Index the names of files
the contents of which we don't index because of an excluded or
unsupported MIME type.
``usesystemfilecommand``
Use a system command for file MIME type guessing as a final step in
file type identification This is generally useful, but will usually
cause the indexing of many bogus 'text' files. See
'systemfilecommand' for the command used.
``systemfilecommand``
Command used to guess MIME types if the internal methods fails This
should be a "file -i" workalike. The file path will be added as a
last parameter to the command line. 'xdg-mime' works better than the
traditional 'file' command, and is now the configured default (with a
hard-coded fallback to 'file')
``processwebqueue``
Decide if we process the Web queue. The queue is a directory where
the Recoll Web browser plugins create the copies of visited pages.
``textfilepagekbs``
Page size for text files. If this is set, text/plain files will be
divided into documents of approximately this size. Will reduce memory
usage at index time and help with loading data in the preview window
at query time. Particularly useful with very big files, such as
application or system logs. Also see textfilemaxmbs and
compressedfilemaxkbs.
``membermaxkbs``
Size limit for archive members. This is passed to the filters in the
environment as RECOLL_FILTER_MAXMEMBERKB.
.. _RCL.INSTALL.CONFIG.RECOLLCONF.TERMS:
Parameters affecting how we generate terms and organize the index
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
``indexStripChars``
Decide if we store character case and diacritics in the index. If we
do, searches sensitive to case and diacritics can be performed, but
the index will be bigger, and some marginal weirdness may sometimes
occur. The default is a stripped index. When using multiple indexes
for a search, this parameter must be defined identically for all.
Changing the value implies an index reset.
``indexStoreDocText``
Decide if we store the documents' text content in the index. Storing
the text allows extracting snippets from it at query time, instead of
building them from index position data. Newer Xapian index formats
have rendered our use of positions list unacceptably slow in some
cases. The last Xapian index format with good performance for the old
method is Chert, which is default for 1.2, still supported but not
default in 1.4 and will be dropped in 1.6. The stored document text
is translated from its original format to UTF-8 plain text, but not
stripped of upper-case, diacritics, or punctuation signs. Storing it
increases the index size by 10-20% typically, but also allows for
nicer snippets, so it may be worth enabling it even if not strictly
needed for performance if you can afford the space. The variable only
has an effect when creating an index, meaning that the xapiandb
directory must not exist yet. Its exact effect depends on the Xapian
version. For Xapian 1.4, if the variable is set to 0, the Chert
format will be used, and the text will not be stored. If the variable
is 1, Glass will be used, and the text stored. For Xapian 1.2, and
for versions after 1.5 and newer, the index format is always the
default, but the variable controls if the text is stored or not, and
the abstract generation method. With Xapian 1.5 and later, and the
variable set to 0, abstract generation may be very slow, but this
setting may still be useful to save space if you do not use abstract
generation at all.
``nonumbers``
Decides if terms will be generated for numbers. For example "123",
"1.5e6", 192.168.1.4, would not be indexed if nonumbers is set
("value123" would still be). Numbers are often quite interesting to
search for, and this should probably not be set except for special
situations, ie, scientific documents with huge amounts of numbers in
them, where setting nonumbers will reduce the index size. This can
only be set for a whole index, not for a subtree.
``dehyphenate``
Determines if we index 'coworker' also when the input is 'co-worker'.
This is new in version 1.22, and on by default. Setting the variable
to off allows restoring the previous behaviour.
``backslashasletter``
Process backslash as normal letter This may make sense for people
wanting to index TeX commands as such but is not of much general use.
``maxtermlength``
Maximum term length. Words longer than this will be discarded. The
default is 40 and used to be hard-coded, but it can now be adjusted.
You need an index reset if you change the value.
``nocjk``
Decides if specific East Asian (Chinese Korean Japanese)
characters/word splitting is turned off. This will save a small
amount of CPU if you have no CJK documents. If your document base
does include such text but you are not interested in searching it,
setting nocjk may be a significant time and space saver.
``cjkngramlen``
This lets you adjust the size of n-grams used for indexing CJK text.
The default value of 2 is probably appropriate in most cases. A value
of 3 would allow more precision and efficiency on longer words, but
the index will be approximately twice as large.
``indexstemminglanguages``
Languages for which to create stemming expansion data. Stemmer names
can be found by executing 'recollindex -l', or this can also be set
from a list in the GUI.
``defaultcharset``
Default character set. This is used for files which do not contain a
character set definition (e.g.: text/plain). Values found inside
files, e.g. a 'charset' tag in HTML documents, will override it. If
this is not set, the default character set is the one defined by the
NLS environment ($LC_ALL, $LC_CTYPE, $LANG), or ultimately iso-8859-1
(cp-1252 in fact). If for some reason you want a general default
which does not match your LANG and is not 8859-1, use this variable.
This can be redefined for any sub-directory.
``unac_except_trans``
A list of characters, encoded in UTF-8, which should be handled
specially when converting text to unaccented lowercase. For example,
in Swedish, the letter a with diaeresis has full alphabet citizenship
and should not be turned into an a. Each element in the
space-separated list has the special character as first element and
the translation following. The handling of both the lowercase and
upper-case versions of a character should be specified, as
appartenance to the list will turn-off both standard accent and case
processing. The value is global and affects both indexing and
querying. Examples: Swedish: unac_except_trans = ää Ää öö Öö üü Üü
ßss œoe Œoe æae Æae ffff fifi flfl åå Åå . German: unac_except_trans =
ää Ää öö Öö üü Üü ßss œoe Œoe æae Æae ffff fifi flfl In French, you
probably want to decompose oe and ae and nobody would type a German ß
unac_except_trans = ßss œoe Œoe æae Æae ffff fifi flfl . The default for
all until someone protests follows. These decompositions are not
performed by unac, but it is unlikely that someone would type the
composed forms in a search. unac_except_trans = ßss œoe Œoe æae Æae
ffff fifi flfl
``maildefcharset``
Overrides the default character set for email messages which don't
specify one. This is mainly useful for readpst (libpst) dumps, which
are utf-8 but do not say so.
``localfields``
Set fields on all files (usually of a specific fs area). Syntax is
the usual: name = value ; attr1 = val1 ; [...] value is empty so this
needs an initial semi-colon. This is useful, e.g., for setting the
rclaptg field for application selection inside mimeview.
``testmodifusemtime``
Use mtime instead of ctime to test if a file has been modified. The
time is used in addition to the size, which is always used. Setting
this can reduce re-indexing on systems where extended attributes are
used (by some other application), but not indexed, because changing
extended attributes only affects ctime. Notes: - This may prevent
detection of change in some marginal file rename cases (the target
would need to have the same size and mtime). - You should probably
also set noxattrfields to 1 in this case, except if you still prefer
to perform xattr indexing, for example if the local file update
pattern makes it of value (as in general, there is a risk for pure
extended attributes updates without file modification to go
undetected). Perform a full index reset after changing this.
``noxattrfields``
Disable extended attributes conversion to metadata fields. This
probably needs to be set if testmodifusemtime is set.
``metadatacmds``
Define commands to gather external metadata, e.g. tmsu tags. There
can be several entries, separated by semi-colons, each defining which
field name the data goes into and the command to use. Don't forget
the initial semi-colon. All the field names must be different. You
can use aliases in the "field" file if necessary. As a not too pretty
hack conceded to convenience, any field name beginning with
"rclmulti" will be taken as an indication that the command returns
multiple field values inside a text blob formatted as a recoll
configuration file ("fieldname = fieldvalue" lines). The rclmultixx
name will be ignored, and field names and values will be parsed from
the data. Example: metadatacmds = ; tags = tmsu tags %f; rclmulti1 =
cmdOutputsConf %f
.. _RCL.INSTALL.CONFIG.RECOLLCONF.STORE:
Parameters affecting where and how we store things
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
``cachedir``
Top directory for Recoll data. Recoll data directories are normally
located relative to the configuration directory (e.g.
~/.recoll/xapiandb, ~/.recoll/mboxcache). If 'cachedir' is set, the
directories are stored under the specified value instead (e.g. if
cachedir is ~/.cache/recoll, the default dbdir would be
~/.cache/recoll/xapiandb). This affects dbdir, webcachedir,
mboxcachedir, aspellDicDir, which can still be individually specified
to override cachedir. Note that if you have multiple configurations,
each must have a different cachedir, there is no automatic
computation of a subpath under cachedir.
``maxfsoccuppc``
Maximum file system occupation over which we stop indexing. The value
is a percentage, corresponding to what the "Capacity" df output
column shows. The default value is 0, meaning no checking.
``dbdir``
Xapian database directory location. This will be created on first
indexing. If the value is not an absolute path, it will be
interpreted as relative to cachedir if set, or the configuration
directory (-c argument or $RECOLL_CONFDIR). If nothing is specified,
the default is then ~/.recoll/xapiandb/
``idxstatusfile``
Name of the scratch file where the indexer process updates its
status. Default: idxstatus.txt inside the configuration directory.
``mboxcachedir``
Directory location for storing mbox message offsets cache files. This
is normally 'mboxcache' under cachedir if set, or else under the
configuration directory, but it may be useful to share a directory
between different configurations.
``mboxcacheminmbs``
Minimum mbox file size over which we cache the offsets. There is
really no sense in caching offsets for small files. The default is 5
MB.
``webcachedir``
Directory where we store the archived web pages. This is only used by
the web history indexing code Default: cachedir/webcache if cachedir
is set, else $RECOLL_CONFDIR/webcache
``webcachemaxmbs``
Maximum size in MB of the Web archive. This is only used by the web
history indexing code. Default: 40 MB. Reducing the size will not
physically truncate the file.
``webqueuedir``
The path to the Web indexing queue. This used to be hard-coded in the
old plugin as ~/.recollweb/ToIndex so there would be no need or
possibility to change it, but the WebExtensions plugin now downloads
the files to the user Downloads directory, and a script moves them to
webqueuedir. The script reads this value from the config so it has
become possible to change it.
``webdownloadsdir``
The path to browser downloads directory. This is where the new
browser add-on extension has to create the files. They are then moved
by a script to webqueuedir.
``aspellDicDir``
Aspell dictionary storage directory location. The aspell dictionary
(aspdict.(lang).rws) is normally stored in the directory specified by
cachedir if set, or under the configuration directory.
``filtersdir``
Directory location for executable input handlers. If
RECOLL_FILTERSDIR is set in the environment, we use it instead.
Defaults to $prefix/share/recoll/filters. Can be redefined for
subdirectories.
``iconsdir``
Directory location for icons. The only reason to change this would be
if you want to change the icons displayed in the result list.
Defaults to $prefix/share/recoll/images
.. _RCL.INSTALL.CONFIG.RECOLLCONF.PERFS:
Parameters affecting indexing performance and resource usage
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
``idxflushmb``
Threshold (megabytes of new data) where we flush from memory to disk
index. Setting this allows some control over memory usage by the
indexer process. A value of 0 means no explicit flushing, which lets
Xapian perform its own thing, meaning flushing every
$XAPIAN_FLUSH_THRESHOLD documents created, modified or deleted: as
memory usage depends on average document size, not only document
count, the Xapian approach is is not very useful, and you should let
Recoll manage the flushes. The program compiled value is 0. The
configured default value (from this file) is now 50 MB, and should be
ok in many cases. You can set it as low as 10 to conserve memory, but
if you are looking for maximum speed, you may want to experiment with
values between 20 and 200. In my experience, values beyond this are
always counterproductive. If you find otherwise, please drop me a
note.
``filtermaxseconds``
Maximum external filter execution time in seconds. Default 1200
(20mn). Set to 0 for no limit. This is mainly to avoid infinite loops
in postscript files (loop.ps)
``filtermaxmbytes``
Maximum virtual memory space for filter processes
(setrlimit(RLIMIT_AS)), in megabytes. Note that this includes any
mapped libs (there is no reliable Linux way to limit the data space
only), so we need to be a bit generous here. Anything over 2000 will
be ignored on 32 bits machines.
``thrQSizes``
Stage input queues configuration. There are three internal queues in
the indexing pipeline stages (file data extraction, terms generation,
index update). This parameter defines the queue depths for each stage
(three integer values). If a value of -1 is given for a given stage,
no queue is used, and the thread will go on performing the next
stage. In practise, deep queues have not been shown to increase
performance. Default: a value of 0 for the first queue tells Recoll
to perform autoconfiguration based on the detected number of CPUs (no
need for the two other values in this case). Use thrQSizes = -1 -1 -1
to disable multithreading entirely.
``thrTCounts``
Number of threads used for each indexing stage. The three stages are:
file data extraction, terms generation, index update). The use of the
counts is also controlled by some special values in thrQSizes: if the
first queue depth is 0, all counts are ignored (autoconfigured); if a
value of -1 is used for a queue depth, the corresponding thread count
is ignored. It makes no sense to use a value other than 1 for the
last stage because updating the Xapian index is necessarily
single-threaded (and protected by a mutex).
.. _RCL.INSTALL.CONFIG.RECOLLCONF.MISC:
Miscellaneous parameters
^^^^^^^^^^^^^^^^^^^^^^^^
``loglevel``
Log file verbosity 1-6. A value of 2 will print only errors and
warnings. 3 will print information like document updates, 4 is quite
verbose and 6 very verbose.
``logfilename``
Log file destination. Use 'stderr' (default) to write to the console.
``idxloglevel``
Override loglevel for the indexer.
``idxlogfilename``
Override logfilename for the indexer.
``daemloglevel``
Override loglevel for the indexer in real time mode. The default is
to use the idx... values if set, else the log... values.
``daemlogfilename``
Override logfilename for the indexer in real time mode. The default
is to use the idx... values if set, else the log... values.
``orgidxconfdir``
Original location of the configuration directory. This is used
exclusively for movable datasets. Locating the configuration
directory inside the directory tree makes it possible to provide
automatic query time path translations once the data set has moved
(for example, because it has been mounted on another location).
``curidxconfdir``
Current location of the configuration directory. Complement
orgidxconfdir for movable datasets. This should be used if the
configuration directory has been copied from the dataset to another
location, either because the dataset is readonly and an r/w copy is
desired, or for performance reasons. This records the original moved
location before copy, to allow path translation computations. For
example if a dataset originally indexed as '/home/me/mydata/config'
has been mounted to '/media/me/mydata', and the GUI is running from a
copied configuration, orgidxconfdir would be
'/home/me/mydata/config', and curidxconfdir (as set in the copied
configuration) would be '/media/me/mydata/config'.
``idxrundir``
Indexing process current directory. The input handlers sometimes
leave temporary files in the current directory, so it makes sense to
have recollindex chdir to some temporary directory. If the value is
empty, the current directory is not changed. If the value is
(literal) tmp, we use the temporary directory as set by the
environment (RECOLL_TMPDIR else TMPDIR else /tmp). If the value is an
absolute path to a directory, we go there.
``checkneedretryindexscript``
Script used to heuristically check if we need to retry indexing files
which previously failed. The default script checks the modified dates
on /usr/bin and /usr/local/bin. A relative path will be looked up in
the filters dirs, then in the path. Use an absolute path to do
otherwise.
``recollhelperpath``
Additional places to search for helper executables. This is only used
on Windows for now.
``idxabsmlen``
Length of abstracts we store while indexing. Recoll stores an
abstract for each indexed file. The text can come from an actual
'abstract' section in the document or will just be the beginning of
the document. It is stored in the index so that it can be displayed
inside the result lists without decoding the original file. The
idxabsmlen parameter defines the size of the stored abstract. The
default value is 250 bytes. The search interface gives you the choice
to display this stored text or a synthetic abstract built by
extracting text around the search terms. If you always prefer the
synthetic abstract, you can reduce this value and save a little
space.
``idxmetastoredlen``
Truncation length of stored metadata fields. This does not affect
indexing (the whole field is processed anyway), just the amount of
data stored in the index for the purpose of displaying fields inside
result lists or previews. The default value is 150 bytes which may be
too low if you have custom fields.
``idxtexttruncatelen``
Truncation length for all document texts. Only index the beginning of
documents. This is not recommended except if you are sure that the
interesting keywords are at the top and have severe disk space
issues.
``aspellLanguage``
Language definitions to use when creating the aspell dictionary. The
value must match a set of aspell language definition files. You can
type "aspell dicts" to see a list The default if this is not set is
to use the NLS environment to guess the value.
``aspellAddCreateParam``
Additional option and parameter to aspell dictionary creation
command. Some aspell packages may need an additional option (e.g. on
Debian Jessie: --local-data-dir=/usr/lib/aspell). See Debian bug
772415.
``aspellKeepStderr``
Set this to have a look at aspell dictionary creation errors. There
are always many, so this is mostly for debugging.
``noaspell``
Disable aspell use. The aspell dictionary generation takes time, and
some combinations of aspell version, language, and local terms,
result in aspell crashing, so it sometimes makes sense to just
disable the thing.
``monauxinterval``
Auxiliary database update interval. The real time indexer only
updates the auxiliary databases (stemdb, aspell) periodically,
because it would be too costly to do it for every document change.
The default period is one hour.
``monixinterval``
Minimum interval (seconds) between processings of the indexing queue.
The real time indexer does not process each event when it comes in,
but lets the queue accumulate, to diminish overhead and to aggregate
multiple events affecting the same file. Default 30 S.
``mondelaypatterns``
Timing parameters for the real time indexing. Definitions for files
which get a longer delay before reindexing is allowed. This is for
fast-changing files, that should only be reindexed once in a while. A
list of wildcardPattern:seconds pairs. The patterns are matched with
fnmatch(pattern, path, 0) You can quote entries containing white
space with double quotes (quote the whole entry, not the pattern).
The default is empty. Example: mondelaypatterns = \*.log:20 "*with
spaces.*:30"
``monioniceclass``
ionice class for the real time indexing process On platforms where
this is supported. The default value is 3.
``monioniceclassdata``
ionice class parameter for the real time indexing process. On
platforms where this is supported. The default is empty.
.. _RCL.INSTALL.CONFIG.RECOLLCONF.QUERY:
Query-time parameters (no impact on the index)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
``autodiacsens``
auto-trigger diacritics sensitivity (raw index only). IF the index is
not stripped, decide if we automatically trigger diacritics
sensitivity if the search term has accented characters (not in
unac_except_trans). Else you need to use the query language and the
"D" modifier to specify diacritics sensitivity. Default is no.
``autocasesens``
auto-trigger case sensitivity (raw index only). IF the index is not
stripped (see indexStripChars), decide if we automatically trigger
character case sensitivity if the search term has upper-case
characters in any but the first position. Else you need to use the
query language and the "C" modifier to specify character-case
sensitivity. Default is yes.
``maxTermExpand``
Maximum query expansion count for a single term (e.g.: when using
wildcards). This only affects queries, not indexing. We used to not
limit this at all (except for filenames where the limit was too low
at 1000), but it is unreasonable with a big index. Default 10000.
``maxXapianClauses``
Maximum number of clauses we add to a single Xapian query. This only
affects queries, not indexing. In some cases, the result of term
expansion can be multiplicative, and we want to avoid eating all the
memory. Default 50000.
``snippetMaxPosWalk``
Maximum number of positions we walk while populating a snippet for
the result list. The default of 1,000,000 may be insufficient for
very big documents, the consequence would be snippets with possibly
meaning-altering missing words.
.. _RCL.INSTALL.CONFIG.RECOLLCONF.PDF:
Parameters for the PDF input script
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
``pdfocr``
Attempt OCR of PDF files with no text content if both tesseract and
pdftoppm are installed. The default is off because OCR is so very
slow.
``pdfocrlang``
Language to assume for PDF OCR. This is very important for having a
reasonable rate of errors with tesseract. This can also be set
through a configuration variable or directory-local parameters. See
the rclpdf.py script.
``pdfattach``
Enable PDF attachment extraction by executing pdftk (if available).
This is normally disabled, because it does slow down PDF indexing a
bit even if not one attachment is ever found.
``pdfextrameta``
Extract text from selected XMP metadata tags. This is a
space-separated list of qualified XMP tag names. Each element can
also include a translation to a Recoll field name, separated by a '|'
character. If the second element is absent, the tag name is used as
the Recoll field names. You will also need to add specifications to
the 'fields' file to direct processing of the extracted data.
``pdfextrametafix``
Define name of XMP field editing script. This defines the name of a
script to be loaded for editing XMP field values. The script should
define a 'MetaFixer' class with a metafix() method which will be
called with the qualified tag name and value of each selected field,
for editing or erasing. A new instance is created for each document,
so that the object can keep state for, e.g. eliminating duplicate
values.
.. _RCL.INSTALL.CONFIG.RECOLLCONF.SPECLOCATIONS:
Parameters set for specific locations
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
``mhmboxquirks``
Enable thunderbird/mozilla-seamonkey mbox format quirks Set this for
the directory where the email mbox files are stored.
.. _RCL.INSTALL.CONFIG.FIELDS:
The fields file
~~~~~~~~~~~~~~~
This file contains information about dynamic fields handling in RCL.
Some very basic fields have hard-wired behaviour, and, mostly, you
should not change the original data inside the ``fields`` file. But you
can create custom fields fitting your data and handle them just like
they were native ones.
The ``fields`` file has several sections, which each define an aspect of
fields processing. Quite often, you'll have to modify several sections
to obtain the desired behaviour.
We will only give a short description here, you should refer to the
comments inside the default file for more detailed information.
Field names should be lowercase alphabetic ASCII.
[prefixes]
A field becomes indexed (searchable) by having a prefix defined in
this section. There is a more complete explanation of what prefixes
are in used by a standard recoll installation. In a nutshell:
extension prefixes should be all caps, begin with XY, and short. E.g.
XYMFLD.
[values]
Fields listed in this section will be stored as XAP ``values`` inside
the index. This makes them available for range queries, allowing to
filter results according to the field value. This feature currently
supports string and integer data. See the comments in the file for
more detail
[stored]
A field becomes stored (displayable inside results) by having its
name listed in this section (typically with an empty value).
[aliases]
This section defines lists of synonyms for the canonical names used
inside the ``[prefixes]`` and ``[stored]`` sections
[queryaliases]
This section also defines aliases for the canonic field names, with
the difference that the substitution will only be used at query time,
avoiding any possibility that the value would pick-up random metadata
from documents.
handler-specific sections
Some input handlers may need specific configuration for handling
fields. Only the email message handler currently has such a section
(named ``[mail]``). It allows indexing arbitrary email headers in
addition to the ones indexed by default. Other such sections may
appear in the future.
Here follows a small example of a personal ``fields`` file. This would
extract a specific email header and use it as a searchable field, with
data displayable inside result lists. (Side note: as the email handler
does no decoding on the values, only plain ascii headers can be indexed,
and only the first occurrence will be used for headers that occur
several times).
::
[prefixes]
# Index mailmytag contents (with the given prefix)
mailmytag = XMTAG
[stored]
# Store mailmytag inside the document data record (so that it can be
# displayed - as %(mailmytag) - in result lists).
mailmytag =
[queryaliases]
filename = fn
containerfilename = cfn
[mail]
# Extract the X-My-Tag mail header, and use it internally with the
# mailmytag field name
x-my-tag = mailmytag
.. _RCL.INSTALL.CONFIG.FIELDS.XATTR:
Extended attributes in the fields file
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
RCL versions 1.19 and later process user extended file attributes as
documents fields by default.
Attributes are processed as fields of the same name, after removing the
``user`` prefix on Linux.
The ``[xattrtofields]`` section of the ``fields`` file allows specifying
translations from extended attributes names to RCL field names. An empty
translation disables use of the corresponding attribute data.
.. _RCL.INSTALL.CONFIG.MIMEMAP:
The mimemap file
~~~~~~~~~~~~~~~~
``mimemap`` specifies the file name extension to MIME type mappings.
For file names without an extension, or with an unknown one, a system
command (``file`` ``-i``, or ``xdg-mime``) will be executed to determine
the MIME type (this can be switched off, or the command changed inside
the main configuration file).
All extension values in ``mimemap`` must be entered in lower case. File
names extensions are lower-cased for comparison during indexing, meaning
that an upper case ``mimemap`` entry will never be matched.
The mappings can be specified on a per-subtree basis, which may be
useful in some cases. Example: okular notes have a ``.xml`` extension
but should be handled specially, which is possible because they are
usually all located in one place. Example:
::
[~/.kde/share/apps/okular/docdata]
.xml = application/x-okular-notes
The ``recoll_noindex`` ``mimemap`` variable has been moved to
``recoll.conf`` and renamed to ``noContentSuffixes``, while keeping the
same function, as of RCL version 1.21. For older RCL versions, see the
documentation for ``noContentSuffixes`` but use ``recoll_noindex`` in
``mimemap``.
.. _RCL.INSTALL.CONFIG.MIMECONF:
The mimeconf file
~~~~~~~~~~~~~~~~~
The main purpose of the ``mimeconf`` file is to specify how the
different MIME types are handled for indexing. This is done in the
``[index]`` section, which should not be modified casually. See the
comments in the file.
The file also contains other definitions which affect the query language
and the GUI, and which, in retrospect, should have been stored
elsewhere.
The ``[icons]`` section allows you to change the icons which are
displayed by the ``recoll`` GUI in the result lists (the values are the
basenames of the ``png`` images inside the ``iconsdir`` directory (which
is itself defined in ``recoll.conf``).
The ``[categories]`` section defines the groupings of MIME types into
``categories`` as used when adding an ``rclcat`` clause to a `query
language <#RCL.SEARCH.LANG>`__ query. ``rclcat`` clauses are also used
by the default ``guifilters`` buttons in the GUI (see next).
The filter controls appear at the top of the ``recoll`` GUI, either as
checkboxes just above the result list, or as a dropbox in the tool area.
By default, they are labeled: ``media``, ``message``, ``other``,
``presentation``, ``spreadsheet`` and ``text``, and each maps to a
document category. This is determined in the ``[guifilters]`` section,
where each control is defined by a variable naming a query language
fragment.
A simple exemple will hopefully make things clearer.
::
[guifilters]
Big Books = dir:"~/My Books" size>10K
My Docs = dir:"~/My Documents"
Small Books = dir:"~/My Books" size<10K
System Docs = dir:/usr/share/doc
The above definition would create four filter checkboxes, labelled
``Big Books``, ``My Docs``, etc.
The text after the equal sign must be a valid query language fragment,
and, when the button is checked, it will be combined with the rest of
the query with an AND conjunction.
Any name text before a colon character will be erased in the display,
but used for sorting. You can use this to display the checkboxes in any
order you like. For exemple, the following would do exactly the same as
above, but ordering the checkboxes in the reverse order.
::
[guifilters]
d:Big Books = dir:"~/My Books" size>10K
c:My Docs = dir:"~/My Documents"
b:Small Books = dir:"~/My Books" size<10K
a:System Docs = dir:/usr/share/doc
As you may have guessed, The default ``[guifilters]`` section looks
like:
::
[guifilters]
text = rclcat:text
spreadsheet = rclcat:spreadsheet
presentation = rclcat:presentation
media = rclcat:media
message = rclcat:message
other = rclcat:other
.. _RCL.INSTALL.CONFIG.MIMEVIEW:
The mimeview file
~~~~~~~~~~~~~~~~~
``mimeview`` specifies which programs are started when you click on an
Open link in a result list. Ie: HTML is normally displayed using
firefox, but you may prefer Konqueror, your openoffice.org program might
be named ``oofice`` instead of ``openoffice`` etc.
Changes to this file can be done by direct editing, or through the
``recoll`` GUI preferences dialog.
If Use desktop preferences to choose document editor is checked in the
RCL GUI preferences, all ``mimeview`` entries will be ignored except the
one labelled ``application/x-all`` (which is set to use ``xdg-open`` by
default).
In this case, the ``xallexcepts`` top level variable defines a list of
MIME type exceptions which will be processed according to the local
entries instead of being passed to the desktop. This is so that specific
RCL options such as a page number or a search string can be passed to
applications that support them, such as the evince viewer.
As for the other configuration files, the normal usage is to have a
``mimeview`` inside your own configuration directory, with just the
non-default entries, which will override those from the central
configuration file.
All viewer definition entries must be placed under a ``[view]`` section.
The keys in the file are normally MIME types. You can add an application
tag to specialize the choice for an area of the filesystem (using a
``localfields`` specification in ``mimeconf``). The syntax for the key
is mimetype\ ``|``\ tag
The ``nouncompforviewmts`` entry, (placed at the top level, outside of
the ``[view]`` section), holds a list of MIME types that should not be
uncompressed before starting the viewer (if they are found compressed,
ie: mydoc.doc.gz).
The right side of each assignment holds a command to be executed for
opening the file. The following substitutions are performed:
- **%D.**
Document date
- **%f.**
File name. This may be the name of a temporary file if it was
necessary to create one (ie: to extract a subdocument from a
container).
- **%i.**
Internal path, for subdocuments of containers. The format depends on
the container type. If this appears in the command line, RCL will not
create a temporary file to extract the subdocument, expecting the
called application (possibly a script) to be able to handle it.
- **%M.**
MIME type
- **%p.**
Page index. Only significant for a subset of document types,
currently only PDF, Postscript and DVI files. Can be used to start
the editor at the right page for a match or snippet.
- **%s.**
Search term. The value will only be set for documents with indexed
page numbers (ie: PDF). The value will be one of the matched search
terms. It would allow pre-setting the value in the "Find" entry
inside Evince for example, for easy highlighting of the term.
- **%u.**
Url.
In addition to the predefined values above, all strings like
``%(fieldname)`` will be replaced by the value of the field named
``fieldname`` for the document. This could be used in combination with
field customisation to help with opening the document.
.. _RCL.INSTALL.CONFIG.PTRANS:
The ``ptrans`` file
~~~~~~~~~~~~~~~~~~~
``ptrans`` specifies query-time path translations. These can be useful
in `multiple cases <#RCL.SEARCH.PTRANS>`__.
The file has a section for any index which needs translations, either
the main one or additional query indexes. The sections are named with
the XAP index directory names. No slash character should exist at the
end of the paths (all comparisons are textual). An exemple should make
things sufficiently clear
::
[/home/me/.recoll/xapiandb]
/this/directory/moved = /to/this/place
[/path/to/additional/xapiandb]
/server/volume1/docdir = /net/server/volume1/docdir
/server/volume2/docdir = /net/server/volume2/docdir
.. _RCL.INSTALL.CONFIG.EXAMPLES:
Examples of configuration adjustments
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.. _RCL.INSTALL.CONFIG.EXAMPLES.ADDVIEW:
Adding an external viewer for an non-indexed type
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Imagine that you have some kind of file which does not have indexable
content, but for which you would like to have a functional Open link in
the result list (when found by file name). The file names end in .blob
and can be displayed by application blobviewer.
You need two entries in the configuration files for this to work:
- In ``$RECOLL_CONFDIR/mimemap`` (typically ``~/.recoll/mimemap``), add
the following line:
::
.blob = application/x-blobapp
Note that the MIME type is made up here, and you could call it
diesel/oil just the same.
- In ``$RECOLL_CONFDIR/mimeview`` under the ``[view]`` section, add:
::
application/x-blobapp = blobviewer %f
We are supposing that blobviewer wants a file name parameter here,
you would use ``%u`` if it liked URLs better.
If you just wanted to change the application used by RCL to display a
MIME type which it already knows, you would just need to edit
``mimeview``. The entries you add in your personal file override those
in the central configuration, which you do not need to alter.
``mimeview`` can also be modified from the Gui.
.. _RCL.INSTALL.CONFIG.EXAMPLES.ADDINDEX:
Adding indexing support for a new file type
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Let us now imagine that the above .blob files actually contain indexable
text and that you know how to extract it with a command line program.
Getting RCL to index the files is easy. You need to perform the above
alteration, and also to add data to the ``mimeconf`` file (typically in
``~/.recoll/mimeconf``):
- Under the ``[index]`` section, add the following line (more about the
rclblob indexing script later):
::
application/x-blobapp = exec rclblob
Or if the files are mostly text and you don't need to process them
for indexing:
::
application/x-blobapp = internal text/plain
- Under the ``[icons]`` section, you should choose an icon to be
displayed for the files inside the result lists. Icons are normally
64x64 pixels PNG files which live in ``/usr/share/recoll/images``.
- Under the ``[categories]`` section, you should add the MIME type
where it makes sense (you can also create a category). Categories may
be used for filtering in advanced search.
The rclblob handler should be an executable program or script which
exists inside ``/usr/share/recoll/filters``. It will be given a file
name as argument and should output the text or html contents on the
standard output.
The `filter programming <#RCL.PROGRAM.FILTERS>`__ section describes in
more detail how to write an input handler.
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