Syntax highlighting/colorizing cat

Question

Is there a method to colorize the output of cat, the way grep does.

For grep, in most consoles it displays a colored output highlighting the searched keywords. Otherwise, you can force it by calling grep --color Is there a generic way to color the output of any program according to your personal choice.

From what I understand, the program itself is not responsible for the colors. It is the shell.

I am using the default shell in FreeBSD 5.2.1 which looks like it has never seen colors since epoch.

Answer 1

I'd recommend pygmentize from the python package python-pygments. You may want to define the following handy alias (unless you use ccat from the ccrypt package).

alias ccat='pygmentize -g'

And if you want line numbers:

alias ccat='pygmentize -g -O style=colorful,linenos=1'

Answer 2

Options:

pygmentize is good. I have an alias:

alias c='pygmentize -g'

but highlight is another widely available alternative is

alias cats='highlight -O ansi --force'

Installation:

You may have to install pygments using one of these:

sudo apt install python-pygments
sudo pip install pygments
sudo easy_install Pygments #for Mac user

and for highlight package which is easily available on all distributions

sudo apt install highlight
sudo yum install highlight

• Bitbucket repo: https://bitbucket.org/birkenfeld/pygments-main
• GitHub mirror: https://github.com/sglyon/pygments

In Action:

I'm attaching shots for both down below for a good comparison in highlightings

Here is pygmentize in action:

and this is highlight:

Answer 3

From late April 2018 onwards:

Bat - A cat(1) clone with syntax highlighting and Git integration.

The project is a cat clone with support for colors and customizations written in Rust. It offers not only syntax highlighting with multiple themes, but also Git integration. As described in the documentation:

bat tries to achieve the following goals:

• Provide beautiful, advanced syntax highlighting
• Integrate with Git to show file modifications
• Be a drop-in replacement for (POSIX) cat
• Offer a user-friendly command-line interface

It is, needless to say, much faster than pygmentize and does not choke when confronted with large files.

Source code and binary releases + installation instructions can be found in the Github repository, as well as a comparison to alternative programs.

Answer 4

vimcat is single-file (shell script) and works good:

http://www.vim.org/scripts/script.php?script_id=4325

Last update is from December 2013. Hint: you can force file type recognition by vimcat -c "set ft=<type>".

Answer 5

The tool you're looking for is probably supercat (here's a quick introduction published by Linux Journal).

I realize that this answer is late, and that it doesn't fully meet the OP requirements. So I'm adding it just for reference (it could be useful for other people looking for how to colorize text file output).

Answer 6

cat with syntax highlighting is simply out of scope. cat is not meant for that. If you just want to have the entire content of some file coloured in some way (with the same colour for the whole file), you can make use of terminal escape sequences to control the color.

Here's a sample script that will choose the colour based on the file type (you can use something like this instead of invoking cat directly):

#!/bin/bash
fileType="$(file "$1" | grep -o 'text')"
if [ "$fileType" == 'text' ]; then
    echo -en "\033[1m"
else
    echo -en "\033[31m"
fi
cat $1
echo -en "\033[0m"

The above (on a terminal that supports those escape sequences) will print any text file as 'bold', and will print any binary file as red. You can use strings instead of cat for printing binary files and you can enhance the logic to make it suit your needs.

Answer 7

There are colorized versions of cat (their names are hard to google, unless you append pager and github or cat replacement).

• bat [rust] https://github.com/sharkdp/bat (actively maintained)
• ccat [golang] https://github.com/jingweno/ccat/

Both bat and ccat are native binaries and are almost as fast as /bin/cat unlike Python-based solutions, such as pygmentize.

installing bat

• MacOS: brew install bat
• Linux: apt install bat
• Windows: choco install bat
• Binaries: https://github.com/sharkdp/bat/releases
• Build from source: cargo install --locked bat (requires cargo, the rust build tools)

see steps for more OS's at https://github.com/sharkdp/bat#on-ubuntu-using-apt

Installing ccat

• get the binaries for Linux/Windows/macOS and copy ccat for example to /usr/local/bin.
• Mac: brew install ccat

If there is no binary for your platform (e.g. raspberry pi, etc) then you can install from source (requires the golang environment):

go get -u github.com/jingweno/ccat

Aliasing to cat

The ootb configuration of bat shows line numbers and does paging which I didn't need so I aliased it to disable the feature I didn't want:

Add in your ~/.bashrc (~/.zshrc, etc..):

alias cat="bat --paging=never -pp --style='plain' --theme=TwoDark $*"

For ccat:

alias cat="ccat $*"

In cases when you need the plain cat you can still invoke it by the absolute path:

/bin/cat /etc/hosts

Answer 8

The best way and the easiest way to do it if you have vim in your machine is to use vimcat which comes with vimpager program.

1. Install vimpage with git clone git://github.com/rkitover/vimpager cd vimpager sudo make install

2. Run vimcat:

   vimcat index.html

Answer 9

source-highlight

Maybe it's possible to find interesting source-highlight released under GNU: a package different from highlight.

Excerpt from apt-cache show source-highlight:

Description-en: convert source code to syntax highlighted document.
This program, given a source file, produces a document with syntax highlighting.
It supports syntax highlighting for over 100 file formats ...
For output, the following formats are supported: HTML, XHTML, LaTeX, Texinfo, ANSI color escape sequences, and DocBook

I did some alias (Cat and PCat, see below) and this is their output

You can install on Debian based with

sudo apt-get install source-highlight

and add it as alias e.g. in your .bash_aliases with something like the line below.

alias Cat='source-highlight --out-format=esc -o STDOUT -i'  
Cat myfile.c # or myfile.xml ...

Or you can do a similar alias (without the -iat the end to have the possibility to pipe in)

alias PCat='source-highlight --out-format=esc -o STDOUT '
tail myfile.sh | PCat     # Note the absence of the `-i`

Among the options that it's possible to read from man source-highlight the -s underlines that is possible to select, or force, the highlighting by command line or to leave to the program this duty:

-s, --src-lang=STRING source language (use --lang-list to get the complete list). If not specified, the source language will be guessed from the file extension.

--lang-list list all the supported language and associated language definition file

Answer 10

From what I understand, the binary itself is not responsible for the colors. It is the shell.

That't not correct. Terminal just interprets the color codes that is output to the terminal. Depending on its capability it can ignore certain formatting/coloring codes.

From man page it does not seem cat supports coloring its output. Even if it were to support coloring like grep what should it color in the text file? Syntax highlighting required knowledge of underlying language which is not in the scope of simple utility like cat.

You can try more powerful editors like vim,emacs, gedit etc on unix platform if seeing the code highlighted is your goal.

Answer 11

bat precisely does that and can be aliased to cat alias cat='bat'

Answer 12

On OSX simply do brew install ccat.

https://github.com/jingweno/ccat. Like cat but displays content with syntax highlighting. Built in Go.

Answer 13

Old question, just answering for the record to provide the solution I ended up using. Perhaps this is a bit hacky (probably not the original intent of the parameter), but:

alias cgrep='grep -C 9000'

cat whatever | cgrep 'snozzberries'

..grep -C N will provide N lines of context above and below the found item. If it's larger than the input, the whole input is included. In this case, we just make sure it's larger than any typical terminal output we'll want to look at manually, which is generally what you're looking to do if highlighting.

EDIT : However, this solution suggested below by Beni Cherniavsky-Paskin is superior -- it matches (and highlights) either the word you're looking for or the beginning of the line (not highlightable). The net result is exactly what you want.

cat whatever | egrep 'snozzberries|$'

That's the new best solution I've seen for that problem, thanks Beni.

Answer 14

In this question https://superuser.com/questions/602294/is-there-colorizer-utility-that-can-take-command-output-and-colorize-it-accordin grcat/grc tool was recommended as alternative to supercat.

Man of grc and of grcat; it is part of grc package (sources):

grc - frontend for generic colouriser grcat(1)

grcat - read from standard input, colourise it and write to standard output

Answer 15

I have written the small script to perform the colourization using pygmentize.

colorize_via_pygmentize() {
    if [ ! -x "$(which pygmentize)" ]; then
        echo "package \'Pygments\' is not installed!"
        return -1
    fi

    if [ $# -eq 0 ]; then
        pygmentize -g $@
    fi

    for FNAME in $@
    do
        filename=$(basename "$FNAME")
        lexer=`pygmentize -N \"$filename\"`
        if [ "Z$lexer" != "Ztext" ]; then
            pygmentize -l $lexer "$FNAME"
        else
            pygmentize -g "$FNAME"
        fi
    done
}

And then make an alias to script. alias cat=colorize_via_pygmentize. Also dont forget to save this in ~/.bashrc.

Answer 16

just use vim and this vimrc file.

oneliner:

vim -c '1' -c 'set cmdheight=1' -c 'set readonly' -c 'set nomodifiable' -c 'syntax enable' -c 'set guioptions=aiMr' -c 'nmap q :q!<CR>' -c 'nmap <Up> <C-Y>' -c 'nmap <Down> <C-E>' -c 'nmap ^V <C-F><C-G>' "$@" 

nano -v may also be an alternative.

Answer 17

If you just want a one liner to set cat output to a given color, you can append

alias cat="echo -en 'code' | cat - "

to your ~/.$(basename $SHELL)rc

Here is a gist with color codes: https://gist.github.com/chrisopedia/8754917

I like '\e[1;93m', which is high intensity yellow. It looks like this:

Answer 18

Place in your ~/.bashrc

function ccat() { docker run -it -v "$(pwd)":/workdir -w /workdir whalebrew/pygmentize $1; }

then

ccat filename

Whalebrew creates aliases for Docker images so you can run them as if they were native commands. It's like Homebrew, but with Docker images.

Answer 19

This question is exceedingly old, but I stumbled on it anyway. For completeness' sake, the question asked "is there a way to get cat to colorize its output?". Yes, for ansi-encoded outputs, you can add these exports to your .bashrc:

# colorful less output
export LESS_TERMCAP_mb=$'\e[1;32m'
export LESS_TERMCAP_md=$'\e[1;32m'
export LESS_TERMCAP_me=$'\e[0m'
export LESS_TERMCAP_se=$'\e[0m'
export LESS_TERMCAP_so=$'\e[01;33m'
export LESS_TERMCAP_ue=$'\e[0m'
export LESS_TERMCAP_us=$'\e[1;4;31m'

This will colorize the output of ansi-encoded text, like terraform plan:

This is not, however, the same thing as bat, which can do better parsing of json, shows line numbers, and is generally a better user experience.