diff --git a/src/filters/rclabw b/src/filters/rclabw
index ffb88658..52fcbcb5 100755
--- a/src/filters/rclabw
+++ b/src/filters/rclabw
@@ -84,7 +84,7 @@ umask 77
 
 checkcmds xsltproc
 
-xsltproc - $infile <<EOF
+xsltproc - "$infile" <<EOF
 <?xml version="1.0"?>
 <xsl:stylesheet version="1.0"
   xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
diff --git a/src/filters/rclaptosidman b/src/filters/rclaptosidman
index 56164190..14e50a5b 100755
--- a/src/filters/rclaptosidman
+++ b/src/filters/rclaptosidman
@@ -86,7 +86,7 @@ checkcmds sed
 # Delete everything from <div id="menu"> to <div id="main-page">
 # This prints an additional blank line at top which does not matter
 sed -n -e '1,/<div id="menu">/{x;p' -e '}' \
-    -e '/<div id="main-page">/,$p' < $infile
+    -e '/<div id="main-page">/,$p' < "$infile"
 
 # exit normally
 exit 0
diff --git a/src/filters/rcldjvu b/src/filters/rcldjvu
index 414956dd..93210a71 100755
--- a/src/filters/rcldjvu
+++ b/src/filters/rcldjvu
@@ -114,7 +114,7 @@ else
 fi
 tmplink=$ttdir/rcldjvu_tmp$$.djvu
 rm -f $tmplink
-ln -s $infile $tmplink || exit 1
+ln -s "$infile" $tmplink || exit 1
 
 cleanup()
 {
diff --git a/src/filters/rcldoc b/src/filters/rcldoc
index 305019b1..9dd96e32 100755
--- a/src/filters/rcldoc
+++ b/src/filters/rcldoc
@@ -145,6 +145,6 @@ END {
 # seem to be an issue with our brave html input handler...
 if test $? -eq 1 ; then
     if iscmd wvWare ; then
-	wvWare --nographics --charset=utf-8 $infile
+	wvWare --nographics --charset=utf-8 "$infile"
     fi
 fi
diff --git a/src/filters/rclfb2 b/src/filters/rclfb2
index d3274564..892e7c0f 100755
--- a/src/filters/rclfb2
+++ b/src/filters/rclfb2
@@ -79,7 +79,7 @@ umask 77
 
 checkcmds xsltproc
 
-xsltproc - $infile <<EOF
+xsltproc - "$infile" <<EOF
 <?xml version="1.0"?>
 <xsl:stylesheet version="1.0"
   xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
diff --git a/src/filters/rclgaim b/src/filters/rclgaim
index e18cc346..97e90ff2 100755
--- a/src/filters/rclgaim
+++ b/src/filters/rclgaim
@@ -138,7 +138,7 @@ NR == 1 {
 END {
     printf("</body></html>\n")
 }
-' < $infile
+' < "$infile"
 
 # exit normally
 exit 0
diff --git a/src/filters/rclkwd b/src/filters/rclkwd
index 08ea7467..a12a7430 100755
--- a/src/filters/rclkwd
+++ b/src/filters/rclkwd
@@ -107,7 +107,7 @@ cleanup()
 trap cleanup EXIT HUP QUIT INT TERM
 
 # Old kwd files are gzip/tar archibes. Newer ones are zip archives.
-if file $infile | grep -qi gzip ; then
+if file "$infile" | grep -qi gzip ; then
    # Unzip the input file and change to the unzipped directory
    gunzip < "$infile" | (cd $tmpdir/rclkwdtmp;tar xf -)
 else
diff --git a/src/filters/rcllyx b/src/filters/rcllyx
index b914dd39..49f41201 100755
--- a/src/filters/rcllyx
+++ b/src/filters/rcllyx
@@ -128,7 +128,7 @@ trap cleanup EXIT HUP QUIT INT TERM
 workdir=$tmpdir/rcllyxtmp
 case "$infile" in
  */*) ;;
- *) infile=`pwd`/$infile;;
+ *) infile=`pwd`/"$infile";;
 esac
 
 binfile=`basename "$infile"`
diff --git a/src/filters/rclpurple b/src/filters/rclpurple
index 38576e07..39a8a784 100755
--- a/src/filters/rclpurple
+++ b/src/filters/rclpurple
@@ -137,7 +137,7 @@ NR == 1 {
 END {
     printf("</body></html>\n")
 }
-' < $infile
+' < "$infile"
 
 # exit normally
 exit 0
diff --git a/src/filters/rclscribus b/src/filters/rclscribus
index a99b9e7c..6bc2b75c 100755
--- a/src/filters/rclscribus
+++ b/src/filters/rclscribus
@@ -106,7 +106,7 @@ sedjoinprog=':a
 #P;D'
 
 # Extract description title author and keywords
-description=`sed -e "$sedjoinprog" < $infile | \
+description=`sed -e "$sedjoinprog" < "$infile" | \
 awk '
 /<DOCUMENT / {
     if (match($0, " COMMENTS=\"[^\"]+")) { 
@@ -117,7 +117,7 @@ awk '
 }
 '`
 
-title=`sed -e "$sedjoinprog" < $infile | \
+title=`sed -e "$sedjoinprog" < "$infile" | \
 awk '
 /<DOCUMENT / {
     if (match($0, " TITLE=\"[^\"]+")) { 
@@ -128,7 +128,7 @@ awk '
 }
 '`
 
-author=`sed -e "$sedjoinprog" < $infile | \
+author=`sed -e "$sedjoinprog" < "$infile" | \
 awk '
 /<DOCUMENT / {
     if (match($0, " AUTHOR=\"[^\"]+")) { 
@@ -139,7 +139,7 @@ awk '
 }
 '`
 
-keywords=`sed -e "$sedjoinprog" < $infile | \
+keywords=`sed -e "$sedjoinprog" < "$infile" | \
 awk '
 /<DOCUMENT / {
     if (match($0, " KEYWORDS=\"[^\"]+")) { 
@@ -165,7 +165,7 @@ cat <<EOF
 EOF
 
 
-sed -e ':a' -e '/[^>] *$/N; s/\n/ /; ta' < $infile | \
+sed -e ':a' -e '/[^>] *$/N; s/\n/ /; ta' < "$infile" | \
 awk '
 /<ITEXT / {
     if (match($0, " CH=\"[^\"]+")) { 
diff --git a/src/filters/rclsiduxman b/src/filters/rclsiduxman
index 747b9088..b9bbe723 100755
--- a/src/filters/rclsiduxman
+++ b/src/filters/rclsiduxman
@@ -86,7 +86,7 @@ checkcmds sed
 # Delete everything from <div id="menu"> to <div id="main-page">
 # This prints an additional blank line at top which does not matter
 sed -n -e '1,/<div id="menu">/{x;p' -e '}' \
-    -e '/<div id="main-page">/,$p' < $infile
+    -e '/<div id="main-page">/,$p' < "$infile"
 
 # exit normally
 exit 0
diff --git a/src/filters/rclsvg b/src/filters/rclsvg
index 82278f51..361c9bba5 100755
--- a/src/filters/rclsvg
+++ b/src/filters/rclsvg
@@ -79,7 +79,7 @@ umask 77
 
 checkcmds xsltproc
 
-xsltproc - $infile <<EOF
+xsltproc - "$infile" <<EOF
 <?xml version="1.0"?>
 <xsl:stylesheet version="1.0"
   xmlns:xsl="http://www.w3.org/1999/XSL/Transform"