Colored shell script output library

Question

I am looking for a definitive way to build shell scripts that generates colored output.

Unfortunately I am having a hard time finding an appropriate lib or good technique for doing this. I found a lot of helpful but simple examples like this. Also the most comprehensive guide that I found until now is this one.

Before I start writing my own library, I want to check if anyone already wrote it

If your solution does not fit into the observations below thats not a problem. I would like also to read it so it can help me out if decide to write my own solution

My main concerns/observations:

Needs to be safe. Want to avoid garbage output as not all terminals or pagers/editors (like less, more, vim, and so on) support colored output or more styled output (bold, blinked, italic, etc)
Needs to be easy and readable. Using ANSI escape codes directly is horrible: echo -e '\033[32mthis is ugly and \033[1;32mvery green\033[0m'
Needs to give me access to the whole color palette and styles for foreground and background text. Most of the examples I found uses only the basic colors for foreground text only.
Its preferable to use only simple commands like bash or simpler shells built in commands and/or common commands that can be found on most operating systems. For instance I can use colorize but I would need ruby (that's somewhat ok) and the colorize gem installed (not ok)
Tput seems to be a good option as it can manipulate the shell cursor quite well, but it is somewhat simpler/less flexible

Edit

After some research on terminal control and output formatting, I am writing this gist that tries to accomplish this. So far it is doing quite well

`echo -e '\033[32mthis is ugly and \033[1;32mvery green\033[0m'` is not so horrible, when you use variables like `RED=\033[32m` or even a color array. — Micha Wiedenmann, May 30 '13 at 18:28
Indeed. I wanted to write a more advanced lib but will probably stick to formatting variables inside strings — Bruno Penteado, May 31 '13 at 01:00

demure · Accepted Answer · 2016-02-14T03:17:55.953

102

Here is an modified snippet from my dotfiles that should do what you want

RCol='\e[0m'    # Text Reset

# Regular           Bold                Underline           High Intensity      BoldHigh Intens     Background          High Intensity Backgrounds
Bla='\e[0;30m';     BBla='\e[1;30m';    UBla='\e[4;30m';    IBla='\e[0;90m';    BIBla='\e[1;90m';   On_Bla='\e[40m';    On_IBla='\e[0;100m';
Red='\e[0;31m';     BRed='\e[1;31m';    URed='\e[4;31m';    IRed='\e[0;91m';    BIRed='\e[1;91m';   On_Red='\e[41m';    On_IRed='\e[0;101m';
Gre='\e[0;32m';     BGre='\e[1;32m';    UGre='\e[4;32m';    IGre='\e[0;92m';    BIGre='\e[1;92m';   On_Gre='\e[42m';    On_IGre='\e[0;102m';
Yel='\e[0;33m';     BYel='\e[1;33m';    UYel='\e[4;33m';    IYel='\e[0;93m';    BIYel='\e[1;93m';   On_Yel='\e[43m';    On_IYel='\e[0;103m';
Blu='\e[0;34m';     BBlu='\e[1;34m';    UBlu='\e[4;34m';    IBlu='\e[0;94m';    BIBlu='\e[1;94m';   On_Blu='\e[44m';    On_IBlu='\e[0;104m';
Pur='\e[0;35m';     BPur='\e[1;35m';    UPur='\e[4;35m';    IPur='\e[0;95m';    BIPur='\e[1;95m';   On_Pur='\e[45m';    On_IPur='\e[0;105m';
Cya='\e[0;36m';     BCya='\e[1;36m';    UCya='\e[4;36m';    ICya='\e[0;96m';    BICya='\e[1;96m';   On_Cya='\e[46m';    On_ICya='\e[0;106m';
Whi='\e[0;37m';     BWhi='\e[1;37m';    UWhi='\e[4;37m';    IWhi='\e[0;97m';    BIWhi='\e[1;97m';   On_Whi='\e[47m';    On_IWhi='\e[0;107m';

Then you can just echo -e "${Blu}blue ${Red}red ${RCol}etc...."

edited Feb 14 '16 at 03:17

answered May 30 '13 at 19:25

demure

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Thanks demure. I am writing a gist thats based on your answer (added the link to my post) – Bruno Penteado May 31 '13 at 01:01
I may end up borrowing your style vars and $TC sub var – demure May 31 '13 at 01:19
5

On a Mac, use `\x1B` instead of `\e`. – Joseph Christopher Apr 19 '14 at 12:49
@JosephChristopher When I posted this, I was still using OS X, and `/e` worked fine; it also happens to be the standard escape sequence. – demure Apr 19 '14 at 23:10
@demure I agree. It didn't work for me and I am not sure why. (OS X 10.9.2) – Joseph Christopher Apr 22 '14 at 07:59
Thank you for the snippet. Goes to my dotfiles, as well. :D – markusschwed Aug 13 '14 at 11:19
Does anyone know how to reset the colour of the shell to the original color? mine got all red after executing the script :-D – MeV Dec 17 '15 at 13:59
1

@MaRco85 echoing `'\e[0m'` will reset the colors. You could also start a new terminal. – demure Dec 18 '15 at 20:23
5

If you use `\033` instead of `\e` you don't have to worry about system support. – Wallace Sidhrée May 18 '16 at 19:28
Made a little script with examples which supports even busybox/ash: https://gist.github.com/tavinus/925c7c9e67b5ba20ae38637fd0e06b07 – Gus Neves Dec 27 '18 at 04:17

score 16 · Answer 2 · edited Mar 13 '22 at 10:30

16

echo -e "\033[33;31m Color Text" - red
echo -e "\033[33;32m Color Text" - green
echo -e "\033[33;33m Color Text" - yellow
echo -e "\033[33;34m Color Text" - blue
echo -e "\033[33;35m Color Text" - Magenta
echo -e "\033[33;30m Color Text" - Gray
echo -e "\033[33;36m Color Text" - Cyan

http://techietent.blogspot.in/2013/03/how-to-echo-colored-text-in-linux-shell.html

edited Mar 13 '22 at 10:30

alper

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answered Oct 17 '13 at 06:39

Ranjithkumar T

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please stop using raw control codes, this is not portable, and instead start using tools to generate them like `tput` – Eric Aug 26 '22 at 08:38

score 14 · Answer 3 · 2014-07-28T08:55:26.163

I took demure's list as inspiration and did a little DRYing out of it. (And changed \e to the hexadecimal \x1B, since the former isn't supported in OS X's Terminal.app since Snow Leopard.) Here's what I came up with:

## Colours and font styles
## Syntax: echo -e "${FOREGROUND_COLOUR}${BACKGROUND_COLOUR}${STYLE}Hello world!${RESET_ALL}"

# Escape sequence and resets
ESC_SEQ="\x1b["
RESET_ALL="${ESC_SEQ}0m"
RESET_BOLD="${ESC_SEQ}21m"
RESET_UL="${ESC_SEQ}24m"

# Foreground colours
FG_BLACK="${ESC_SEQ}30;"
FG_RED="${ESC_SEQ}31;"
FG_GREEN="${ESC_SEQ}32;"
FG_YELLOW="${ESC_SEQ}33;"
FG_BLUE="${ESC_SEQ}34;"
FG_MAGENTA="${ESC_SEQ}35;"
FG_CYAN="${ESC_SEQ}36;"
FG_WHITE="${ESC_SEQ}37;"
FG_BR_BLACK="${ESC_SEQ}90;"
FG_BR_RED="${ESC_SEQ}91;"
FG_BR_GREEN="${ESC_SEQ}92;"
FG_BR_YELLOW="${ESC_SEQ}93;"
FG_BR_BLUE="${ESC_SEQ}94;"
FG_BR_MAGENTA="${ESC_SEQ}95;"
FG_BR_CYAN="${ESC_SEQ}96;"
FG_BR_WHITE="${ESC_SEQ}97;"

# Background colours (optional)
BG_BLACK="40;"
BG_RED="41;"
BG_GREEN="42;"
BG_YELLOW="43;"
BG_BLUE="44;"
BG_MAGENTA="45;"
BG_CYAN="46;"
BG_WHITE="47;"

# Font styles
FS_REG="0m"
FS_BOLD="1m"
FS_UL="4m"

The BR_ colours are the "bright" or "high-intensity" colours. Done this way, you can even mix them with other font styles. (e.g. underlined bright white)

If you want to bookmark this, I made a gist for it: https://gist.github.com/ian128K/39a490e5aa8d3bb77a8b

MGP · Answer 4 · 2021-11-09T07:52:00.490

6

Shameless plug... check Rainbow.sh

Usage

Just import rainbow.sh and start using the available functions in your scripts.

source rainbow.sh 

vargreen=$(echogreen "Grass is green")
varred=$(echored "Roses are red")

echo "$vargreen ..Crickets are noisy.. $varred"

enter image description here

edited Nov 09 '21 at 07:52

answered Dec 19 '13 at 20:53

MGP

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@Hugh Perkins License would be MIT, I'll update the repo later today. – MGP Oct 06 '16 at 12:44

score 5 · Answer 5 · answered Mar 26 '14 at 20:44

tput can handle more than is indicated on the page you link to. All tput does is output the characters you would include in your echo statement, based on what appears in the current terminal's termcap/terminfo database. Some examples:

$ tput setaf 5 | hexdump -C
00000000  1b 5b 33 35 6d                                    |.[35m|
$ tput setaf 17 | hexdump -C
00000000  1b 5b 33 38 3b 35 3b 31  37 6d                    |.[38;5;17m|
$ tput reset | hexdump -C
00000000  1b 63 1b 5b 3f 31 30 30  30 6c 1b 5b 3f 32 35 68  |.c.[?1000l.[?25h|

You would use it the same way you use the variable defined in your gist; in fact, you could use it to create your gist, in a portable fashion:

black=$(tput setaf 0)

nachoparker · Answer 6 · 2017-01-24T08:29:19.973

I personally use these in my xcol tool that I developed using Andreas Schamanek code as a reference.

#normal=$(tput sgr0)                      # normal text
normal=$'\e[0m'                           # (works better sometimes)
bold=$(tput bold)                         # make colors bold/bright
red="$bold$(tput setaf 1)"                # bright red text
green=$(tput setaf 2)                     # dim green text
fawn=$(tput setaf 3); beige="$fawn"       # dark yellow text
yellow="$bold$fawn"                       # bright yellow text
darkblue=$(tput setaf 4)                  # dim blue text
blue="$bold$darkblue"                     # bright blue text
purple=$(tput setaf 5); magenta="$purple" # magenta text
pink="$bold$purple"                       # bright magenta text
darkcyan=$(tput setaf 6)                  # dim cyan text
cyan="$bold$darkcyan"                     # bright cyan text
gray=$(tput setaf 7)                      # dim white text
darkgray="$bold"$(tput setaf 0)           # bold black = dark gray text
white="$bold$gray"                        # bright white text

I use these variables in my scripts like so

echo "${red}hello ${yellow}this is ${green}coloured${normal}"

Checkout my xcol tool for ideas and examples

https://ownyourbits.com/2017/01/23/colorize-your-stdout-with-xcol/

background image distracts to detect colors – alper Mar 13 '22 at 10:35 — alper, Mar 13 '22 at 10:35

score 2 · Answer 7 · answered Jul 13 '20 at 08:28

Just in case someone comes here looking for a shell filter colorizing the output, there's a POSIX shell implementation by Alexey Gladkov lurking as utils/cgrep within libshell (it's designed in a pretty defensive manner) as well as his more involved cfilter written in golang.

Jonathan Parton · Answer 8 · 2021-07-25T23:54:45.547

Just a quick add to this using all the awesome answers on this thread but also adding support for the --no-color flag and the NO_COLOR environmental variable.

## Enable our easy to read Colour Flags as long as --no-colors hasn't been passed or the NO_COLOR Env Variable is set. 
## NOTE: the NO_COLOR env variable is from: https://no-color.org/
if [[ ! $* == *--no-color* && -z "${NO_COLOR}" ]]
then 

    ESeq="\x1b["

    # Set up our Colour Holders. 
    ResetColor="$ESeq"'0m'    # Text Reset

    Bold="$ESeq"'1m';    Underline="$ESeq"'4m'

    # Regular              Bold                        Underline                       High Intensity           
    Black="$ESeq"'0;30m';  BoldBlack="$ESeq"'1;30m';   UnderlineBlack="$ESeq"'4;30m';  IntenseBlack="$ESeq"'0;90m'; 
    Red="$ESeq"'0;31m';    BoldRed="$ESeq"'1;31m';     UnderlineRed="$ESeq"'4;31m';    IntenseRed="$ESeq"'0;91m';   
    Green="$ESeq"'0;32m';  BoldGreen="$ESeq"'1;32m';   UnderlineGreen="$ESeq"'4;32m';  IntenseGreen="$ESeq"'0;92m'; 
    Yellow="$ESeq"'0;33m'; BoldYelllow="$ESeq"'1;33m'; UnderlineYellow="$ESeq"'4;33m'; IntenseYellow="$ESeq"'0;93m';
    Blue="$ESeq"'0;34m';   BoldBlue="$ESeq"'1;34m';    UnderlineBlue="$ESeq"'4;34m';   IntenseBlue="$ESeq"'0;94m';  
    Purple="$ESeq"'0;35m'; BoldPurple="$ESeq"'1;35m';  UnderlinePurple="$ESeq"'4;35m'; IntensePurple="$ESeq"'0;95m';
    Cyan="$ESeq"'0;36m';   BoldCyan="$ESeq"'1;36m';    UnderlineCyan="$ESeq"'4;36m';   IntenseCyan="$ESeq"'0;96m';  
    White="$ESeq"'0;37m';  BoldWhite="$ESeq"'1;37m';   UnderlineWhite="$ESeq"'4;37m';  IntenseWhite="$ESeq"'0;97m'; 

    #Bold High Intensity                Background              High Intensity Backgrounds
    BoldIntenseBlack="$ESeq"'1;90m';    OnBlack="$ESeq"'40m';   OnIntenseBlack="$ESeq"'0;100m';
    BoldIntenseRed="$ESeq"'1;91m';      OnRed="$ESeq"'41m';     OnIntenseRed="$ESeq"'0;101m';
    BoldIntenseGreen="$ESeq"'1;92m';    OnGreen="$ESeq"'42m';  OnIntenseGreen="$ESeq"'0;102m';
    BoldIntenseYellow="$ESeq"'1;93m';   OnYellow="$ESeq"'43m';  OnIntenseYellow="$ESeq"'0;103m';
    BoldIntenseBlue="$ESeq"'1;94m';     OnBlue="$ESeq"'44m';    OnIntenseBlue="$ESeq"'0;104m';
    BoldIntensePurple="$ESeq"'1;95m';   OnPurple="$ESeq"'45m';  OnIntensePurple="$ESeq"'0;105m';
    BoldIntenseCyan="$ESeq"'1;96m';     OnCyan="$ESeq"'46m';    OnIntenseCyan="$ESeq"'0;106m';
    BoldIntenseWhite="$ESeq"'1;97m';    OnWhite="$ESeq"'47m';   OnIntenseWhite="$ESeq"'0;107m';
fi

You can then use these in an echo as below:

echo -e "${BoldGreen}Grabbing our variables${ResetColor}"
echo -e "${BoldGreen}Done${ResetColor} ${Red}Moving on ...${ResetColor}"

To disable output you can either export NO_COLOR=true to disable colours for the whole session or add the flag to individual script calls ./myscript.sh --no-color

This addition was prompted from https://no-color.org/ and some experience of seeing the colour codes appear in things like logs and file outputs making them hard to read. With these flags wrapped around the colour definitions it is easy to turn off colour output from your scripts when you expect a non-console medium is going to be involved.

I also expanded out the colour names for readability, as hopefully you have a bit of an IDE to help when writing scripts; so length isn't as important as readability. I even kept the American color's

I'm not a Bash/shell expert so please let me know any issues you spot; but I hope this helps some people!

please stop using raw control codes, this is not portable, and instead start using tools to generate them like `tput` — Eric, Aug 26 '22 at 08:40

score 0 · Answer 9 · answered Apr 05 '23 at 16:02

You can use colors.sh. First you have to source colors.sh to your script then you can use echo like follow:

source colors.sh

# with colors.sh sourced, you can use the constants
echo "${RED}This is red text${NC}"

# or you can use the functions
echo $(gray "[INFO] " && green "This is green test")

There are two approaches. The first is to use functions and the second is to use constants. You can choose what is best for you.

Colored shell script output library

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