Howto add colors support for less

This howto explain how to add synthaxic coloration support for less with lessfilter and enscript.

1 - Install enscript

You can :

• Install enscript from sources : http://ftp.gnu.org/pub/gnu/enscript/enscript-1.6.1.tar.gz
• Install enscript package : "apt-get install enscript" for debian

2 - Install extra languages support

You can add support for extra languages (ruby, eiffel, ...). For this, you need to copy the file language.st in your ~/.enscript directory. Here is language files that are not included with enscript

• Eiffel programming language
• Ruby programming language

3 - Create a .lessfilter file

You can copy this file to ~/.lessfilter. Don't forget to add execution right to this file (this is a shell script).

#!/bin/sh
case "$1" in
    *.e)
 enscript --color --language=ansi --highlight=eiffel -o - -q "$1"
 ;;
    *akefile | *akefile.in | *akefile.am)
 enscript --color --language=ansi --highlight=makefile -o - -q "$1"
 ;;
    *.cc | *.C | *.hh | *.hxx | *.cpp | *.hpp | *.yy | *.ll)
 enscript --color --language=ansi --highlight=cpp -o - -q "$1"
 ;;
    *.c | *.h | *.y | *.l | *.php)
 enscript --color --language=ansi --highlight=c -o - -q "$1"
 ;;
    *.sh)
 enscript --color --language=ansi --highlight=sh -o - -q "$1"
 ;;
    *.tex)
 enscript --color --language=ansi --highlight=tex -o - -q "$1"
 ;;
    *.el)
 enscript --color --language=ansi --highlight=elisp -o - -q "$1"
 ;;
    *.pl | *.pm)
 enscript --color --language=ansi --highlight=perl -o - -q "$1"
 ;;
    *.ada | *.ads | *.adb)
 enscript --color --language=ansi --highlight=ada -o - -q "$1"
 ;;
    *.m | *.mi)
 enscript --color --language=ansi --highlight=objc -o - -q "$1"
 ;;
    *.idl)
 enscript --color --language=ansi --highlight=idl -o - -q "$1"
 ;;
    *.inf)
 enscript --color --language=ansi --highlight=inf -o - -q "$1"
 ;;
    *.awk)
 enscript --color --language=ansi --highlight=awk -o - -q "$1"
 ;;
    *.bash)
 enscript --color --language=ansi --highlight=bash -o - -q "$1"
 ;;
    *.csh)
 enscript --color --language=ansi --highlight=csh -o - -q "$1"
 ;;
    *.ksh)
 enscript --color --language=ansi --highlight=ksh -o - -q "$1"
 ;;
    *.sql)
 enscript --color --language=ansi --highlight=sql -o - -q "$1"
 ;;
    *.pas | *.dpk | *.pce)
 enscript --color --language=ansi --highlight=delphi -o - -q "$1"
 ;;
    *.java)
 enscript --color --language=ansi --highlight=java -o - -q "$1"
 ;;
    *.f | *.for | *.FOR | *.F | *.fpp | *.FPP)
 enscript --color --language=ansi --highlight=fortran -o - -q "$1"
 ;;
    *.lhs | *.hs)
 enscript --color --language=ansi --highlight=haskell -o - -q "$1"
 ;;
    *.m4)
 enscript --color --language=ansi --highlight=m4 -o - -q "$1"
 ;;
    *.js)
 enscript --color --language=ansi --highlight=javascript -o - -q "$1"
 ;;
    *.vhdl)
 enscript --color --language=ansi --highlight=vhdl -o - -q "$1"
 ;;
    *.vrml)
 enscript --color --language=ansi --highlight=vrml -o - -q "$1"
 ;;
    Changelog)
 enscript --color --language=ansi --highlight=changelog -o - -q "$1"
 ;;
    *.html | *.htm)
 html2text "$1"
 ;;
    *.ps | *.pdf)
 pstotext "$1"
 ;;
    *.patch.gz | *.diff.gz)
 gunzip -c "$1" | enscript --color --language=ansi --highlight=diff -o - -q -
 ;;
    *.patch | *.diff)
 enscript --color --language=ansi --highlight=diff -o - -q "$1"
 ;;
    *) # We don't handle this format.
 exit 1
 ;;
esac
# No further processing by lesspipe necessary
exit 0

4 - export some variables

you can add them in your .bashrc, .zshrc, ...

export LESS='--RAW-CONTROL-CHARS --tabs=8 -r'
export LESSOPEN='| /usr/bin/lesspipe %s'
export LESSCLOSE='/usr/bin/lesspipe %s %s'

If you are using tcsh or an other c-shell, the correct synthax is :

setenv LESS '--RAW-CONTROL-CHARS --tabs=8 -r'
setenv LESSOPEN '| /usr/bin/lesspipe %s'
setenv LESSCLOSE '/usr/bin/lesspipe %s %s'

Have fun.