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.

Cynical

oh no. I don't want to display a binary. I just want to display the output of a binary in a colorized manner. – Cynical

I edited to avoid the confusion regarding the term "binary" – Brandie

I think that the answer by @buergi matches the question, and this is also supported by the number of upvotes it has. Consider changing the accepted answer. – Cash

The best solution is: sudo apt-get install lolcat && echo {a..z}{a..z}{a..z} | lolcat – Hostess

TL;DR(Correct me if I am wrong): highlight (I use), pygmentize, bat, vimcat, supercat, ccat, source-highlight?. For less use: yourColorCatCommand yourFile | less -R. – Bascomb

As @myfirstAnswer said, "bat" (batcat) is an alternative solution for "code highlighting" instead of cat. – Lianna

Answer 1

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.

Shakitashako

I was thinking of something like this. But I need something that would do it universally. Not just cat/grep/any particular program – Cynical

Then you can simply pass the command to be executed as an argument to the script and replace the hard-coded cat invocation with some $cmd which is initialized as $1 if there are two arguments or a default if there's only one. Then you simply write: colorful.sh grep file. – Shakitashako

"cat is not meant for that." Cat isn't meant for writing individual files to stdout either - it's for concatenation. But that still doesn't mean that writing individual files to stdout isn't useful. Not does that mean highlighting them isn't useful. – Lofton

I tried, under cygwin pygmentize is not able to color. Any tips? – Adaptive

Answer 2

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'

Add one of these above commands to ~/.bash_aliases for permanent effect

Condon

Another solution is to use the linux highlight command. alias ccat='highlight -O ansi' – Estelaestele

step (1) easy_install --install-dir=/your/pygmentize/path Pygments, step (2) alias ccat /your/pygmentize/path/pygmentize -g – Stockpile

This should be the accepted answer IMHO. Adding to that, I aliased it as alias dog='pygmentize -g', because dogs are cooler than cats! – Selfsufficient

You can add less -R to make the code scrollable: #!/bin/bash \n pygmentize -g $1 | less -R – Bronwen

I called my alias nyancat. – Morality

pygmentize works as expected, but unfortunately seems to be rather slow. :-/ – Insect

How is it possible to connect it to nano? – Slot

BTW, pygmentize also supports monokai style, which makes it exactly what I wanted (i.e. Sublime Text-like highlighting). – Subdue

@FrerichRaabe try highlight as suggested above - it's noticeably faster in my case. – Crissy

Also, when using the highlight command in alias or a function, add the --force option to output even when it cannot guess what the filetype is. – Rodriques

Why -g ? I couldn't find any information in pygmentize's command line usage document about the option -g – Rank

According to pygments -h: If -g is passed, attempt to guess the lexer from the file contents, or pass through as plain text if this fails (this can work for stdin). – Condon

Don't forget to add the alias command to ~/.bashrc if you don't want to repeat it every time you login – Nall

@EvanPurkhiser I just don't like the red javascript strings of highlight. I have never seen such JS syntax highlight, putting strings on vivid red. – Nall

I went for it... until I realized there is not a single style in default Pygments that works well on a dark background. All that I tried on Ubuntu output some elements in unreadable dark blue. – Ferricyanide

Answer 3

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:

Coligny

Thanks! It seems a bit slow, any way to make it faster? – Mingmingche

highlight worked great for my needs and installed easily, thanks. If you want to look at files without extensions (e.g. .bash_aliases) then add --syntax=bash in addition to -O ansi to force it. – Ciborium

# pip install Pygments # echo "alias catc='pygmentize -g'" >> "~/.bashrc" # close terminal # open terminal # catc test.js --- and perfect works :-) 😊 – Jareb

Is there a way to make "highlight" guess the input language, much like the -g switch does for "pygmentize"? – Insect

highlight is 34x faster than that python program. The power of the classical languages holds strong. – Deadwood

I also feel that pygmentize is very slow now a days. I guess most of the time must go in regex matching. – Coligny

For highlight, you want to add --force to the alias, otherwise it will throw an error for file formats that it does not understand, while as cat replacement you want it to still show the output without highlighting, which is what --force does. All together: alias cat="highlight -O ansi --force" – Abnormality

Thank you so much for replying, I was looking for this kind of tool, awesome! – Epidiascope

tried highlight but it give me some html output not the syntax highlighted content, Imgur what is the problem? how could I fix it? – Rayfordrayle

@Rayfordrayle that's why you should add the -O ansi the default is to output html :-) – Hardy

-O xterm256 provides more colours than -O ansi, if your terminal supports it – Eurythermal

I just don't like the red javascript strings of highlight. I have never seen such JS syntax highlight, putting strings on vivid red. – Nall

@Alexander Klimetschek I wouldn't alias cat itself here. This might mess up its usage in pipe commands and scripts. – Pedersen

Answer 4

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.

Stockpile

What people forget to mention is that bat stays in interactive mode by default. For it to behave more like cat, use it with -pp argument. An alias like alias cat="bat -pp" is propably what people are looking for. – Fauve

I've been using pygmentize for colorizing cat before, but the solution with bat is much better suited for large files (logs of several MB), where pygmentize performance is subpar. – Bichloride

Great answer! Together with the -p option, and less paging, this is exactly what I wanted – Dissimilitude

bat is the coolest thing I've seen this week. This is awesome, thanks! – Fuqua

Yes, this is so much better than pygmentize, thank you ! – Indisputable

Just what I needed. On ubuntu while installing using apt install bat, the command to use is batcat. For removing paging while preserving bat's excellent line formatting, the command is batcat --paging "never" $file. – Asafetida

Answer 5

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#installation

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

# NOTE: as of Go 1.18 instead of 'go get xyz' use 'go install xyz', e.g.
go install github.com/jingweno/ccat@latest

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 ottb cat you can still invoke the unaliased version by prefixing with a backslash, e.g.

\cat /etc/hosts

or using the absolute path:

/bin/cat /etc/hosts

Pick

What's the proper repo name? apt-get ccat in Ubuntu 16 gives me some sort of encryption program and somewhat hilariously bricked my terminal as it's currently trying to encrypt or decrypt my entire proc directory... – Virgilio

@KatasticVoyage: my bad: for some reason I assumed it was in the repos, and I forgot how I got it in my ubuntu box. See the updated answer. – Pick

Currently, it seems like brew install ccat is enough, no need to brew tap anymore. – Oppressive

Yeah, ccat isn't the best name choice as ccat is already part of ccrypt. – Jacklynjackman

I really enjoy how bat --help colorizes its own usage information. – Keane

I also think that bat was the easiest to install from its project release. One must only establish an alias which instructs bat to not use paging, if one intends to use it as a drop-in replacement for cat: alias cat='bat --paging=never' – Keane

I really enjoyed the bat application, thanks! – Carcinogen

Answer 6

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>".

Hypochondriac

One thing that is really nice about vimcat (or vimpager) is that it will respect the colorscheme you have defined in your ~/.vimrc so syntax highlighting will be the same both when wanting to edit (vim) or print out (vimcat). Note that an updated version of vimcat can be found in the vimpager repositiory. – Siddons

Amaynut's answer is older and similar – Ensemble

vimpager doesn't use my vim colorscheme. – Crunch

In my quick unscientific test, vimcat (1~2 second execution time) is much slower than pymentize (~200ms), which is much slower than highlight (~20ms), which is much slower than cat (~2ms). On the other hand, vimcat handles more file types and is more accurate than hightlight and pygmentize, and it is still faster than first vim then :q. So it earns my pick for this specific task. – Greeting

@olibre This answer seems older than the one from Amaynut. – Tristatristam

Answer 7

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).

Caudillo

This doesn't seem to work so easily, I installed it and used the example config, but that had no colour effect – Expeditious

Nice, everything else is too slow. This is good. For help with configuration, see manpages.debian.org/testing/supercat/spc.1.en.html – Clearsighted

Additionally for some configs for various languages: github.com/tanderson92/supercat/tree/master/spcrc – Clearsighted

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

Allcot

I love the idea, but vimcat is among the slower ones here. It's about as slow as pygmentize. 15x slower than highlight and 3x slower than bat for a 30-line bash script on my machine. – Calvary

vimcat is a very nice solution. However, when I use an example (vimcat afile.md) I have to press any key to see the result. How can I fix this? – Altruism

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

Trillion

If you want to also colorize less with source-highlight, someone on GitHub gives the answer : export LESSOPEN="| source-highlight -f esc -i %s -o STDOUT" and export LESS=" -R ". Very useful when pygmentize is not available and cannot be installed. – Autocratic

@hastur pcat is not working for me. source-highlight: missing feature: language inference requires input file – Tiffanytiffi

@KhurshidAlam Maybe it is not one of the supported language. Try --lang-list list all the supported language and associated language definition file. Check if the language is supported, or force one enough similar... (BTW without your command line it is diffucult to guess what happened). It can even be a bad guess from the )"extension"_. Good Luck. – Trillion

Answer 10

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

Trulatrull

bat is realllly nice, written in Rust so very performant and safe. Love the colors and cleanness. I recommend the flag -p as in bat -p yourFileName – Flake

Answer 11

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.

Grillage

“cat isn't for printing files with line numbers, it isn't for compressing multiple blank lines, it's not for looking at non-printing ASCII characters, it's for concatenating files.” – from UNIX Style, or cat -v Considered Harmful. – Miniature

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.

Congeneric

Nice. Has some language limitations but it does feel a lot faster than pygments. – Protactinium

ccat can also be found in the AUR repository of Arch Linux. Use yaourt or pacaur to install the package. – Leboff

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.

Concoct

A more robust way to highlight a pattern while including all lines is egrep 'snozzberries|$' – Kos

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

Beachhead

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.

Ice

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.

Span

Hi, this seems like the less command. What we need is cat. BTW: when you have colored cat command, you can use less -R as in someColorCatCommand someFile | less -R – Bascomb

Answer 17

I wrote a small Rust-based software to do exactly that. It is named highlighter and can be found in the following repo:

https://codeberg.org/mehrad/highlighter

Basically you just pipe the output of the previous command into it and tell it to color it based on your preference. For example:

locale | highlighter  --blue="=" --red="_U.*" --yellow "NAME" --green="_ME.*"

I suggest creating an alias to it if you think the name is too long. I'd rather go with a longer but descriptive name than a short ambiguous one.

Lennielenno

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.

Gablet

Answer 19

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:

Clearsighted

Hi, I don't think this was the OP question. I think the question was not to color all text in one color, but to color in different colors according to specific program language. – Bascomb

@myfirstAnswer I don't think so, OP is asking for a way to color like grep, and grep uses one color. The other answers are instead focused on syntax highlighting, which is not what OP asked for. – Clearsighted

@myfirstAnswer In fact if you read the accepted answer you will see a discussion where OP is looking for a way to set one color for the whole output. But thank you for reading my answer and giving me feedback. – Clearsighted

@myfirstAnswer It's not really worth your time. It's an old question and the answer has been selected. Good bye. – Clearsighted

Answer 20

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.

Abrams