Get colors in 'less'' command

Question

when I read a file in Linux with the command 'less' or 'more', how can I get the content in colors?

Answer 1

You can utilize the power of pygmentize with less - automatically! (No need to pipe by hand.)

Write a file ~/.lessfilter

#!/bin/sh
case "$1" in
    *.awk|*.groff|*.java|*.js|*.m4|*.php|*.pl|*.pm|*.pod|*.sh|\
    *.ad[asb]|*.asm|*.inc|*.[ch]|*.[ch]pp|*.[ch]xx|*.cc|*.hh|\
    *.lsp|*.l|*.pas|*.p|*.xml|*.xps|*.xsl|*.axp|*.ppd|*.pov|\
    *.diff|*.patch|*.py|*.rb|*.sql|*.ebuild|*.eclass)
        pygmentize -f 256 "$1";;
    .bashrc|.bash_aliases|.bash_environment)
        pygmentize -f 256 -l sh "$1"
        ;;
    *)
        grep "#\!/bin/bash" "$1" > /dev/null
        if [ "$?" -eq "0" ]; then
            pygmentize -f 256 -l sh "$1"
        else
            exit 1
        fi
esac

exit 0

In your .bashrc add

export LESS='-R'
export LESSOPEN='|~/.lessfilter %s'

Tested on debian.

The idea comes from here Using Pygments with less.

Answer 2

Try the following:

less -R

Answer 3

I got the answer in another post: Less and Grep - Color

When you simply run grep --color it implies grep --color=auto which detects whether the output is a terminal and if so enables colors. However, when it detects a pipe it disables coloring. The following command:

grep --color=always -R "search string" * | less

Will always enable coloring and override the automatic detection, and you will get the color highlighting in less.

Warning: Don't put --color=always as an alias, it break things sometimes. That's why there is an --color=auto option.

Answer 4

Use VIM as a syntax highlighting pager.

Answer 5

You didn't say what this color should mean, e.g. what should the colors be for a text file?

If what you want is syntax highlighting for source code, you need a source code highlighter. I sometimes use pygmentize like this

pygmentize file.cpp | less

or

pygmentize file.cpp | more

There are other highlighters around.

This is pretty fast. If you don't mind firing up vim there is a read-only mode that can give you syntax highlighting if you have it in vim.

view file.cpp

or alternatively see churnd's answer.

Answer 6

To expand upon captaincomic's answer, you can make it work for most if not all of your scripts that don't have extensions by changing the .lessfilter file around just a bit:

#!/bin/sh
    case "$1" in
    *.awk|*.groff|*.java|*.js|*.m4|*.php|*.pl|*.pm|*.pod|*.sh|\
    *.ad[asb]|*.asm|*.inc|*.[ch]|*.[ch]pp|*.[ch]xx|*.cc|*.hh|\
    *.lsp|*.l|*.pas|*.p|*.xml|*.xps|*.xsl|*.axp|*.ppd|*.pov|\
    *.diff|*.patch|*.py|*.rb|*.sql|*.ebuild|*.eclass)
        pygmentize -f 256 "$1";;
    .bashrc|.bash_aliases|.bash_environment)
        pygmentize -f 256 -l sh "$1"
        ;;
    *)
        scriptExec=$(head -1 "$1" |grep "^#\!" |awk -F" " '{print $1}')
        scriptExecStatus=$?
        if [ "$scriptExecStatus" -eq "0" ]; then
            lexer=$(echo $scriptExec |awk -F/ '{print $NF}')
            pygmentize -f 256 -l $lexer "$1"
        else
            exit 1
        fi
esac

exit 0

You'd still need to add the two variables to .bashrc:

export LESS='-R'
export LESSOPEN='|~/.lessfilter %s'

And you'll still need to make .lessfilter executable:

$ chmod 700 ~/.lessfilter

Also I wanted to add that under debian the pygments package is called python-pygments. I had trouble locating it at first because the obvious misspelling of "pigments" as "pygments" wasn't enough of a hint to me that it was a package that might be prefixed with "python-" by the package manager.

Answer 7

pygmentize supports the -g option to automatically guess the lexer to be used which is useful for files read from STDIN without checking any extension type.

Using that, you only need to set the following 2 exports in your .bashrc without any additional scripts:

export LESS='-R'
export LESSOPEN='|pygmentize -g %s'