/usr/bin/gfs-highlight is in gerris 20131206+dfsg-17.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 | #!/bin/sh
wiki="http:\/\/gfs.sf.net\/wiki\/index.php"
title=""
css="darcs.css"
path="/usr/share/gerris"
usage()
{
	cat <<EOF
Usage: gfs-highlight [OPTIONS] < input.gfs > output.html
Syntax highlighting/hypertext linking of Gerris simulation files.
Options:
	[--title=TITLE] sets the page title
	[--css=FILE]    sets the CSS stylesheet filename
        [--comments]    include comment block at the start
        [--bold]        use bold instead of links
        [--help]        displays this message and exits
EOF
	exit $1
}
comment=0
bold=0
while test $# -gt 0; do
  case "$1" in
  -*=*) optarg=`echo "$1" | sed 's/[-_a-zA-Z0-9]*=//'` ;;
  *) optarg= ;;
  esac
  case $1 in
    --title=*)
      title=$optarg
      ;;
    --css=*)
      css=$optarg
      ;;
    --comment)
      comment=1
      ;;
    --bold)
      bold=1
      ;;
    --help)
      usage 0 1>&2
      ;;
    *)
      usage 0 1>&2
      ;;
  esac
  shift
done
if test "x$title" = "x"; then :
cat <<EOF
<tt class="gfs">
EOF
else
cat <<EOF
<html>
<head>
<title>$title</title>
<link rel="stylesheet" type="text/css" href="$css">
</head>
<body><tt class="gfs">
EOF
fi
file=`mktemp gfs-highlight.XXXXXX`
ln -s -f $path/gfs.lang $file
awk -v comment=$comment 'BEGIN{ infile=comment } {
       if ($2 == "Generated" && $3 == "files:") {
         infile = 1; 
         while ($1 == "#") getline; 
         print $0; 
       }
       else if (infile) 
         print $0;
       else if ($5 == "GfsGEdge") {
         infile = 1;
         print $0;
       }
     }' | \
source-highlight --lang-def=$file --out-format=html-css | \
(
if test $bold = "1"; then
    sed "s/\"classname\">\(Gfs\)\{0,1\}\([a-zA-Z0-9_]*\)<\/span>/"classname"><b>\1\2<\/b><\/span>/g"
else
    sed "s/\"classname\">\(Gfs\)\{0,1\}\([a-zA-Z0-9_]*\)<\/span>/"classname"><a href=\"$wiki\/Gfs\2\">\1\2<\/a><\/span>/g"
fi
)
rm -f $file
if test "x$title" = "x"; then :
cat <<EOF
</tt>
EOF
else
cat <<EOF
</tt></body>
</html>
EOF
fi
 |