Colorizing your terminal and shell environment?

Question

I spend most of my time working in Unix environments and using terminal emulators. I try to use color on the command line, because color makes the output more useful and intuitive.

What options exist to add color to my terminal environment? What tricks do you use? What pitfalls have you encountered?

Unfortunately, support for color varies depending on terminal type, OS, TERM setting, utility, buggy implementations, etc.

Here are some tips from my setup, after a lot of experimentation:

1. I tend to set TERM=xterm-color, which is supported on most hosts (but not all).
2. I work on a number of different hosts, different OS versions, etc. I use everything from macOS X, Ubuntu Linux, RHEL/CentOS/Scientific Linux and FreeBSD. I'm trying to keep things simple and generic, if possible.
3. I do a bunch of work using GNU screen, which adds another layer of fun.
4. Many OSs set things like dircolors and by default, and I don't want to modify this on a hundred different hosts. So I try to stick with the defaults. Instead, I tweak my terminal's color configuration.

5. Use color for some Unix commands (ls, grep, less, vim) and the Bash prompt. These commands seem to use the standard "ANSI escape sequences". For example:

   alias less='less --RAW-CONTROL-CHARS'
   export LS_OPTS='--color=auto'
   alias ls='ls ${LS_OPTS}
   

I'll post my .bashrc and answer my own question Jeopardy Style.

Answer 1

Here are a couple of things you can do:

Editors + Code
A lot of editors have syntax highlighting support. vim and emacs have it on by default. You can also enable it under nano.

You can also syntax highlight code on the terminal by using Pygments as a command-line tool.

grep
grep --color=auto highlights all matches. You can also use export GREP_OPTIONS='--color=auto' to make it persistent without an alias. If you use --color=always, it'll use colour even when piping, which confuses things.

ls

ls --color=always

Colors specified by:

export LS_COLORS='rs=0:di=01;34:ln=01;36:mh=00:pi=40;33'

(hint: dircolors can be helpful)

PS1
You can set your PS1 (shell prompt) to use colours. For example:

PS1='\e[33;1m\u@\h: \e[31m\W\e[0m\$ '

Will produce a PS1 like:

[yellow]lucas@ubuntu: [red]~[normal]$

You can get really creative with this. As an idea:

PS1='\e[s\e[0;0H\e[1;33m\h    \t\n\e[1;32mThis is my computer\e[u[\u@\h:  \w]\$ '

Puts a bar at the top of your terminal with some random info. (For best results, also use alias clear="echo -e '\e[2J\n\n'".)

Getting Rid of Escape Sequences

If something is stuck outputting colour when you don't want it to, I use this sed line to strip the escape sequences:

sed "s/\[^[[0-9;]*[a-zA-Z]//gi"

If you want a more authentic experience, you can also get rid of lines starting with \e[8m, which instructs the terminal to hide the text. (Not widely supported.)

sed "s/^\[^[8m.*$//gi"

Also note that those ^[s should be actual, literal ^[s. You can type them by pressing ^V^[ in bash, that is Ctrl + V, Ctrl + [.

Answer 2

I also use:

export TERM=xterm-color
export GREP_OPTIONS='--color=auto' GREP_COLOR='1;32'
export CLICOLOR=1
export LSCOLORS=ExFxCxDxBxegedabagacad

And if you like colorizing your prompt, defined color vars can be useful:

export COLOR_NC='\e[0m' # No Color
export COLOR_WHITE='\e[1;37m'
export COLOR_BLACK='\e[0;30m'
export COLOR_BLUE='\e[0;34m'
export COLOR_LIGHT_BLUE='\e[1;34m'
export COLOR_GREEN='\e[0;32m'
export COLOR_LIGHT_GREEN='\e[1;32m'
export COLOR_CYAN='\e[0;36m'
export COLOR_LIGHT_CYAN='\e[1;36m'
export COLOR_RED='\e[0;31m'
export COLOR_LIGHT_RED='\e[1;31m'
export COLOR_PURPLE='\e[0;35m'
export COLOR_LIGHT_PURPLE='\e[1;35m'
export COLOR_BROWN='\e[0;33m'
export COLOR_YELLOW='\e[1;33m'
export COLOR_GRAY='\e[0;30m'
export COLOR_LIGHT_GRAY='\e[0;37m'

And then my prompt is something like this:

case $TERM in
     xterm*|rxvt*)
         local TITLEBAR='\[\033]0;\u ${NEW_PWD}\007\]'
          ;;
     *)
         local TITLEBAR=""
          ;;
    esac

local UC=$COLOR_WHITE               # user's color
[ $UID -eq "0" ] && UC=$COLOR_RED   # root's color

PS1="$TITLEBAR\n\[${UC}\]\u \[${COLOR_LIGHT_BLUE}\]\${PWD} \[${COLOR_BLACK}\]\$(vcprompt) \n\[${COLOR_LIGHT_GREEN}\]→\[${COLOR_NC}\] "  

$(vcprompt) is calling a python script in my ~/sbin which prints version control information about the current path. It includes support for Mercurial, Git, Svn, Cvs, etc. The author of the script has the source here.

Answer 3

grep and ls have already been mentioned, if you want a lot more colors check out Generic Coloriser, its initial purpose was to colorize logfiles, but right out of the box it also colorizes ping, traceroute, gcc, make, netstat, diff, last, ldap, and cvs.

It's easily extended if you know regexes. I've added ps and nmap to the list (if you get into grc I'll be more than glad to share the .conf files for those two tools)

(Btw, to install it via synaptic, pacman, and alike you might have better luck searching for "grc")

Answer 4

I've honed my .bashrc over the years to work on both OSX and Ubuntu.
I've also reduced it in size to 28 lines with compact condition statements.
With it, my PS1 prompt looks like:

with time in red, username in green, machine name in light blue, pwd in darker blue and git branch in yellow.

Feature of my PS1 prompt:

• shows git branch!
• long directory paths (more than 6 elements) are 'trimmed' to show top 3 and bottom 3 directories with _ between then (that's the pwd sed part of LOCATION).
• carriage return at the end so that prompt is always on the left!

The relevant lines from my .bashrc file are:

git_branch () { git branch 2> /dev/null | sed -e '/^[^*]/d' -e 's/* \(.*\)/\1/'; }
HOST='\033[02;36m\]\h'; HOST=' '$HOST
TIME='\033[01;31m\]\t \033[01;32m\]'
LOCATION=' \033[01;34m\]`pwd | sed "s#\(/[^/]\{1,\}/[^/]\{1,\}/[^/]\{1,\}/\).*\(/[^/]\{1,\}/[^/]\{1,\}\)/\{0,1\}#\1_\2#g"`'
BRANCH=' \033[00;33m\]$(git_branch)\[\033[00m\]\n\$ '
PS1=$TIME$USER$HOST$LOCATION$BRANCH
PS2='\[\033[01;36m\]>'

For ls with colors when available and no errors when not (i.e. OSX):

ls --color=al > /dev/null 2>&1 && alias ls='ls -F --color=al' || alias ls='ls -G'

Answer 5

Set a bold/colored prompt. From cyberciti.biz and the BashFAQ

# 'tput bold' will work regardless of the foreground and background colors.
# Place the tput output into variables, so they are only execd once.
bold=$(tput bold) # This could also be a color.
reset=$(tput sgr0)
export PS1="\u@\[$bold\]\h\[$reset\]:\w \$ "

I've also managed to find color settings which are widely supported, and which don't print gobbledygook characters in older environments (even FreeBSD4!), and seems to work fine if TERM=vt100, xterm, xterm-color. (For the most part). From my .bashrc:

# Set some options, based on the OS
OS=`uname -s` 

case "$OS" in
    "SunOS" ) 
        # Solaris ls doesn't allow color, so use special characters
        LS_OPTS='-F'
        alias  ls='ls ${LS_OPTS}'
        ;;
    "Linux" )
        # GNU ls supports colors!
        # See dircolors to customize colors
        export LS_OPTS='--color=auto' 
        alias  ls='ls ${LS_OPTS}'

        # Get color support for 'less'
        export LESS="--RAW-CONTROL-CHARS"

        # Use colors for less, man, etc.
        [[ -f ~/.LESS_TERMCAP ]] && . ~/.LESS_TERMCAP

        export GREP_OPTIONS="--color=auto"

        ;;
    "Darwin"|"FreeBSD")

        # Most FreeBSD & Apple Darwin supports colors
        export CLICOLOR=true
        # Get color support for 'less'
        export LESS="--RAW-CONTROL-CHARS"

        # Use colors for less, man, etc.
        [[ -f ~/.LESS_TERMCAP ]] && . ~/.LESS_TERMCAP

        export GREP_OPTIONS="--color=auto"
        ;;
    * ) 
        echo "Unknown OS [$OS]"
        ;;
esac

Answer 6

Colors for man pages (more detail):

function _colorman() {
  env \
    LESS_TERMCAP_mb=$(printf "\e[1;35m") \
    LESS_TERMCAP_md=$(printf "\e[1;34m") \
    LESS_TERMCAP_me=$(printf "\e[0m") \
    LESS_TERMCAP_se=$(printf "\e[0m") \
    LESS_TERMCAP_so=$(printf "\e[7;40m") \
    LESS_TERMCAP_ue=$(printf "\e[0m") \
    LESS_TERMCAP_us=$(printf "\e[1;33m") \
      "$@"
}
function man() { _colorman man "$@"; }
function perldoc() { command perldoc -n less "$@" |man -l -; }

Colors for grep (1;32 is bright green, see other posts here for other colors):

GREP_OPTS='--color=auto'      # for aliases since $GREP_OPTIONS is deprecated
GREP_COLOR='1;32'             # (legacy) bright green rather than default red
GREP_COLORS="ms=$GREP_COLOR"  # (new) Matching text in Selected line = green
alias   grep='grep $GREP_OPTS'
alias egrep='egrep $GREP_OPTS'
alias fgrep='fgrep $GREP_OPTS'

More colors for GNU ls:

# use the config at ~/.dircolors if it exists, otherwise generate anew
eval "$( dircolors --sh $(ls -d ~/.dircolors 2>/dev/null) )"

# Usage: _ls_colors_add BASE NEW [NEW...]
# Have LS color given NEW extensions the way BASE extension is colored
_ls_colors_add() {
  local BASE_COLOR="${LS_COLORS##*:?.$1=}" NEW
  if [ "$LS_COLORS" != "$BASE_COLOR" ]; then
    BASE_COLOR="${BASE_COLOR%%:*}"
    shift
    for NEW in "$@"; do
      if [ "$LS_COLORS" = "${LS_COLORS#*.$NEW=}" ]; then
        LS_COLORS="${LS_COLORS%%:}:*.$NEW=$BASE_COLOR:"
      fi
    done
  fi
  export LS_COLORS
}

_ls_colors_add zip jar xpi            # archives
_ls_colors_add jpg ico JPG PNG webp   # images
_ls_colors_add ogg opus               # audio (opus now included by default)

CLICOLOR=1   # BSD auto-color trigger (like  ls -G  but for everything)
if ls -ld --color=auto / >/dev/null 2>&1
  then alias ls="ls -ph --color=auto"
  else alias ls="ls -ph"
fi

Install grc (Generic Colouriser) and add it to your aliases:

# using this as a variable allows easier calling down lower
export GRC='grc -es --colour=auto'

# loop through known commands plus all those with named conf files
for cmd in g++ head ld ping6 tail traceroute6 `locate grc/conf.`; do
  cmd="${cmd##*grc/conf.}"  # we want just the command
  # if the command exists, alias it to pass through grc
  type "$cmd" >/dev/null 2>&1 && alias "$cmd"="$GRC $cmd"
done

# This needs run-time detection. We even fake the 'command not found' error.
configure() {
  if [[ -x ./configure ]]; then
    colourify ./configure "$@"
  else
    echo "configure: command not found" >&2
    return 127
  fi
}

# GRC plus LS awesomeness (assumes you have an alias for ls)
unalias ll 2>/dev/null
if ls -ld --color=always / >/dev/null 2>&1; then GNU_LS="--color=always"; fi

ll() {
  if [[ -t 1 ]] || [[ -n "$CLICOLOR_FORCE" ]]
    then colourify ls -l $GNU_LS "$@"
    else ls -l "$@"
  fi
}

Colors for diff: Too much content for a function, use a script and alias it in your rc file (unnecessary if you installed grc):

#!/usr/bin/perl
use strict;
use warnings;

open (DIFF, "-|", "diff", @ARGV) or die $!;

my $ydiff = 1;
while (<DIFF>) {
  if (not -t 1) {
    print;
    next;
  }
  chomp;
  $ydiff = 0 if /^[ <>\@+-]/ or ($. == 1 && /^\d+[a-z]{1,5}\d+$/);
  my $color = "";
  if (! $ydiff && /^[\@+-<>]/) {
    $color = (/^[<-](?!--$)/ ? 1 : /^[+>]/ ? 2 : 5);
  } elsif ($ydiff && /\t {6}([<|>])(?:\t|$)/) {
    $color = ($1 eq "<" ? 1 : $1 eq ">" ? 2 : 4);
  }
  $color ? printf ("\e[1;3%dm%s\e[0;0m\n",$color,$_) : print "$_\n";
}
close DIFF;

Colors for bash prompt:

# Shorten home dir, cygwin drives, paths that are too long
if [ -d /cygdrive ] && uname -a |grep -qi cygwin; then CYGWIN_OS=1; fi
function PSWD() {
  local p="$*" space A B cols="${COLUMNS:-`tput cols 2>/dev/null || echo 80`}"
  p="${p/$HOME/\~}"         # shrink home down to a tilde
  if [ -n "$CYGWIN_OS" ] && [ "${p#/cygdrive/?/}" != "$p" ]; then
    p="${p:10:1}:${p:11}"   # /cygdrive/c/hi -> c:/hi
  fi
  space="$((${#USER}+${#HOSTNAME}+6))"  # width w/out the path
  if [ "$cols" -lt 60 ]; then echo -n "$N "; space=-29; p="$p$N\b"; fi
  if [ "$cols" -lt "$((space+${#p}+20))" ]; then # < 20 chars for the command
    A=$(( (cols-20-space)/4 ))      # a quarter of the space (-20 for cmd)
    if [ $A -lt 4 ]; then A=4; fi   # 4+ chars from beginning
    B=$(( cols-20-space-A*2 ))      # half (plus rounding) of the space
    if [ $B -lt 8 ]; then B=8; fi   # 8+ chars from end
    p="${p:0:$A}..${p: -$B}"
  fi
  echo "$p"
}

PSC() { echo -ne "\[\033[${1:-0;38}m\]"; }
PR="0;32"       # default color used in prompt is green
if [ "$(id -u)" = 0 ]; then
    sudo=41     # root is red background
  elif [ "$USER" != "${SUDO_USER:-$USER}" ]; then
    sudo=31     # not root, not self: red text
  else sudo="$PR"   # standard user color
fi
PROMPT_COMMAND='[ $? = 0 ] && PS1=${PS1[1]} || PS1=${PS1[2]}'
PSbase="$(PSC $sudo)\u$(PSC $PR)@\h $(PSC 33)\$(PSWD \w)"
PS1[1]="$PSbase$(PSC $PR)\$ $(PSC)"
PS1[2]="$PSbase$(PSC  31)\$ $(PSC)"
PS1="${PS1[1]}"
unset sudo PR PSbase

Answer 7

Things that have not been said already here:

To colorize the output of your compilations with gcc, there is colorgcc by Johannes Schlüter

To colorize logs, there is multitail

To colorize any stdout, I put together xcol

I personally use these from the xcol tool.

#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}"

I also like this little function coloredEcho ( found on Stack Overflow )

function coloredEcho(){
    local exp=$1;
    local color=$2;
    if ! [[ $color =~ '^[0-9]$' ]] ; then
       case $(echo $color | tr '[:upper:]' '[:lower:]') in
        black) color=0 ;;
        red) color=1 ;;
        green) color=2 ;;
        yellow) color=3 ;;
        blue) color=4 ;;
        magenta) color=5 ;;
        cyan) color=6 ;;
        white|*) color=7 ;; # white or invalid color
       esac
    fi
    tput setaf $color;
    echo $exp;
    tput sgr0;
}

coloredEcho "This text is green" green

Sorry, not allowed to post more links

Answer 8

There's a good tool for setting up your colours for the ls command - http://geoff.greer.fm/lscolors/

Answer 9

Some text decoration (bold) to easily differentiate between root and non-root shell. For Zsh:

if test $UID = 0
    then PS1="%B${PS1}%b "
fi

For Bash:

if test $UID = 0
    then PS1="\033[1m${PS1}\033[0m"
fi

Answer 10

I just wondered the same thing. I have my own approach, but I'm looking for alternatives.

I write bash wrappers around program calls and pipe their output though sed. What I like about sed is that it will modify and echo each line right away => not much buffering. However, I dislike that for every call to a wrapped program the sed code is parsed and compiled.

For example this is what I do to color the output of ip:

#
# Colorcodes
#
NORMAL=`echo -e '\033[0m'`
RED=`echo -e '\033[31m'`
GREEN=`echo -e '\033[0;32m'`
LGREEN=`echo -e '\033[1;32m'`
BLUE=`echo -e '\033[0;34m'`
LBLUE=`echo -e '\033[1;34m'`
YELLOW=`echo -e '\033[0;33m'`


#
# command: ip
# highlight ip addresses, default route and interface names
#

IP4=$GREEN
IP6=$LBLUE
IFACE=${YELLOW}
DEFAULT_ROUTE=$LBLUE

IP_CMD=$(which ip)

function colored_ip()
{
${IP_CMD} $@ | sed \
    -e "s/inet [^ ]\+ /${IP4}&${NORMAL}/g"\
    -e "s/inet6 [^ ]\+ /${IP6}&${NORMAL}/g"\
    -e "s/^default via .*$/${DEFAULT_ROUTE}&${NORMAL}/"\
    -e "s/^\([0-9]\+: \+\)\([^ \t]\+\)/\1${IFACE}\2${NORMAL}/"
}

alias ip='colored_ip'

Answer 11

I suggest you check out ZSH and its plugin oh-my-zsh which has one of the most powerfull console features that I saw. One of them is picking theme for your terminal. This is example of my theme... In tty the colors are not so warm but they are the same like in this picture... Any way you will love it!

Answer 12

You can try a project that helps on colorizing scripts output also, its named ScriptEchoColor at source forge: http://scriptechocolor.sourceforge.net/

ex.:

echoc "@{lr}text output in light red"
echoc "@{bLGu}text outpus in blue, light green background and underlined"
echoc "you @{lr} can @{bLGu} mix @{-a} it all too"
echoc -x "ls" #executes ls command and colorizes it automatically to be easy to be seen

The automatic colors are configurable.

This is an example done with it:

Answer 13

For setting the prompt, I have this in my .bashrc file.

#Set variables for foreground colors
fgRed=$(tput setaf 1)     ; fgGreen=$(tput setaf 2)  ; fgBlue=$(tput setaf 4)
fgMagenta=$(tput setaf 5) ; fgYellow=$(tput setaf 3) ; fgCyan=$(tput setaf 6)
fgWhite=$(tput setaf 7)   ; fgBlack=$(tput setaf 0)
#Set variables for background colors
bgRed=$(tput setab 1)     ; bgGreen=$(tput setab 2)  ; bgBlue=$(tput setab 4)
bgMagenta=$(tput setab 5) ; bgYellow=$(tput setab 3) ; bgCyan=$(tput setab 6)
bgWhite=$(tput setab 7)   ; bgBlack=$(tput setab 0)
#Set variables for font weight and text decoration
B=$(tput bold) ; U=$(tput smul) ; C=$(tput sgr0)
#NOTE: ${C} clears the current formatting

if [[ $USER = "root" ]]; then
  PS1="${B}${fgRed}\u${C}@\h(\s): ${fgGreen}\w${C} > "
else
  PS1="${B}${fgCyan}\u${C}@\h(\s): ${fgGreen}\w${C} > "
fi

This gives me a prompt that looks something like this:

user@host(bash): ~/bin >

The working directory is in green. And the user name is bold and cyan unless I ran the shell with sudo, in which case the user name ("root") displays bold and red.

I personally really like having the formatting control characters stored in variables because it makes reading the code for setting the prompt easier. It also makes editing the prompt much easier.

The reason I use tput is that it's supposed to be more universally supported than the weird 033[01;31m\] sequences. Also, as an added bonus, if you do echo $PS1 at the prompt, you will see the raw prompt with colors instead of those unintelligible control sequences.

Answer 14

A great general-purpose Python tool for coloring the output of commands is 'colout'

You give it a regex with N groups, followed by a comma separated list of N colors. Any text that matches a group will be displayed in the corresponding color.

So for example, if you're looking at some test output:

python -m unittest discover -v

then you can spruce it up with:

python -m unittest discover -v 2>&1 | colout '(.*ERROR$)|(.*FAIL$)|(\(.*\))' red,yellow,black bold

See how my regex has three groups (the parenthesis) followed by three colors (and optionally three styles, but I've used a shorthand to set all the colors to 'bold', so the 'black' group, which matches text in brackets, comes out as dark grey.)

Note also how I had to add 2>&1 to the end of the Python invocation, because the output of unittest is on stderr, so I transferred it to stdout so that I could pipe it into colout.

This is generally so easy to use that I often find myself creating new colout invocations on-the-fly, and reusing or modifying them from my command-line history.

The only downside of it is that it comes as a Python package, not a standalone executable, so you need to install it using pip, or sudo python setup.py install.

Answer 15

For viewing diff output in color, use colordiff.

sudo apt-get install colordiff

Pipe any diff-format output into colordiff:

This includes some of diff's alternate formats, like -y (side-by-side.)

Alternatively, if invoked standalone (without anything piped into it) then it acts as a wrapper around 'diff', and colors the output. Hence I have this in my .bashrc, to alias 'diff' to colordiff.

# if colordiff is installed, use it
if type colordiff &>/dev/null ; then
    alias diff=colordiff

Answer 16

I find Solarized useful. Its a neat project with uniform colors for lots of applications.

http://ethanschoonover.com/solarized https://github.com/altercation/solarized

Answer 17

I use color wrapper.

cw is a non-intrusive real-time ANSI color wrapper for common unix-based commands on GNU/linux. cw is designed to simulate the environment of the commands being executed, so that if a person types 'du', 'df', 'ping', etc. in their shell it will automatically color the output in real-time according to a definition file containing the color format desired. cw has support for wildcard match coloring, tokenized coloring, headers/footers, case scenario coloring, command line dependent definition coloring, and includes over 50 pre-made definition files.

It is almost seamless, but once i found that ps in interactive shell returns different output comparing ps in a pipe.

Answer 18

For Mac you can use following as specified here

if [ "$TERM" = xterm ]; then TERM=xterm-256color; fi