colorize your stdout with xcol for bash

xcol_bash.sh

#!/bin/bash
# Simple colorize for bash by means of sed
#
# Copyright 2008-2015 by Andreas Schamanek <andreas@schamanek.net>
#
# 2017 - Modified from mycolorize into a shell function 
#     by Ignacio Nunez Hernanz <nacho _a_t_ ownyourbits _d_o_t_ com>
#
# GPL licensed (see end of file) * Use at your own risk!
#
# Usage examples:
#   tail -f somemaillog | xcolorize white '^From: .*' bell
#   tail -f somemaillog | xcolorize white '^From: \/.*' green 'Folder: .*'
#   tail -f somemaillog | xcolorize --unbuffered white '^From: .*'
#
# Notes:
#   Regular expressions need to be suitable for _sed --regexp-extended_
#   Slashes / need no escaping (we use ^A as delimiter).
#   \/ splits the coloring (similar to procmailrc. Matches behind get color.
#   Even "white '(for|to) \/(her|him).*$'" works :) Surprisingly ;)
#   To color the string '\/' use the regular expression '\\()/'.
#   If the 1st argument is -u or --unbuffered, _sed_ will be run so.

# For the colors see tput(1) and terminfo(5), or e.g.
# https://wiki.archlinux.org/index.php/Color_Bash_Prompt
# and http://stackoverflow.com/a/20983251/196133

function xcolorize()
{
  local bold=$(tput bold)                         # make colors bold/bright
  local normal=$'\e[0m'                           # (works better sometimes)

  local red="$bold$(tput setaf 1)"                # bright red text
  local green=$(tput setaf 2)                     # dim green text
  local fawn=$(tput setaf 3); beige="$fawn"       # dark yellow text
  local yellow="$bold$fawn"                       # bright yellow text
  local darkblue=$(tput setaf 4)                  # dim blue text
  local blue="$bold$darkblue"                     # bright blue text
  local purple=$(tput setaf 5); magenta="$purple" # magenta text
  local pink="$bold$purple"                       # bright magenta text
  local darkcyan=$(tput setaf 6)                  # dim cyan text
  local cyan="$bold$darkcyan"                     # bright cyan text
  local gray=$(tput setaf 7)                      # dim white text
  local darkgray="$bold"$(tput setaf 0)           # bold black = dark gray text
  local white="$bold$gray"                        # bright white text

  local bell=$(tput bel)                          # bell/beep
  local y=0

  # Make output unbuffered? (Pass argument -u|--unbuffered to _sed_.)
  if [ "/$1/" = '/-u/' -o "/$1/" = '/--unbuffered/' ] ; then
    local UNBUFFERED='-u'; shift
  else
    local UNBUFFERED=""
  fi

  # produce separator character ^A (for _sed_)
  local A=$(echo | tr '\012' '\001')

  # compile all rules given at command line to 1 set of rules for SED
  while [ "/$1/" != '//' ] ; do
    local c1=''; local re='';  local beep=''
    c1=$1 ; re="$2" ; shift 2 || break
    # if a beep is requested in the optional 3rd parameter set $beep
    [ "/$1/" != '//' ] && [[ ( "$1" = 'bell' || "$1" = 'beep' ) ]] \
      && beep=$bell && shift
    # if the regular expression includes \/ we split the substitution
    if [ "/${re/*\\\/*/}/" = '//' ] ; then
      # we need to count "("s before the \/ (=$left)
      local left="${re%\\/*}"; local leftlength=${#left}
      # first we count "\("
      local dummy=${left//\\(}; escdgroups=$(( (leftlength-${#dummy})/2 ))
      # now "(" (and we add 2 for the groups used for ($re) in $sedrules)
      local dummy=${left//(}; groupcnt=$((leftlength-${#dummy}-escdgroups+2))
      # replace \/ with )( so below we get (left-re)(right-re)
      re="${re/\\\//)(}"
      local sedrules="$sedrules;s$A($re)$A\1${!c1}\\$groupcnt$beep$normal${A}g"
      sedrules="${sedrules}I"   # add case insensitive
    else
      local sedrules="$sedrules;s$A($re)$A${!c1}\1$beep$normal${A}g"
      sedrules="${sedrules}I"   # add case insensitive
    fi
    # limit parsing of arguments
    (( y++ && y>888 )) && { echo "$0: too many arguments" >&2; return 1; }
  done

  # call sed to do the main job
  sed $UNBUFFERED --regexp-extended -e "$sedrules"

  return
}

# Colorize your standard output using xcolorize with a grep-like usage
#
# Copyleft 2017 by Ignacio Nunez Hernanz <nacho _a_t_ ownyourbits _d_o_t_ com>
# GPL licensed (see end of file) * Use at your own risk!
#
# Usage piping from stdin:
#   mount | xcol mnt "sda." "sdb." cgroup tmpfs proc
#
# Usage reading from a file:
#   xcol pae fpu vme mhz sse2 cache cores /proc/cpuinfo
#
# Notes:
#   It supports sed compatible regular expressions
function xcol()
{
  local bold=$(tput bold)                         # make colors bold/bright
  local red="$bold$(tput setaf 1)"                # bright red text
  local green=$(tput setaf 2)                     # dim green text
  local fawn=$(tput setaf 3); beige="$fawn"       # dark yellow text
  local yellow="$bold$fawn"                       # bright yellow text
  local darkblue=$(tput setaf 4)                  # dim blue text
  local blue="$bold$darkblue"                     # bright blue text
  local purple=$(tput setaf 5); magenta="$purple" # magenta text
  local pink="$bold$purple"                       # bright magenta text
  local darkcyan=$(tput setaf 6)                  # dim cyan text
  local cyan="$bold$darkcyan"                     # bright cyan text
  local gray=$(tput setaf 7)                      # dim white text
  local darkgray="$bold"$(tput setaf 0)           # bold black = dark gray text
  local white="$bold$gray"                        # bright white text

  local COLS=( white yellow red cyan gray purple pink fawn )

  [ -t 0 ] && local STDIN=0 || local STDIN=1

  if [[ $STDIN == 0 ]]; then 
    local ARGVS=${@: 1 : $#-1 }                   # all arguments except last one
    local FILE=${@: -1}                           # last argument is the file name
  else
    local ARGVS=$@;
  fi

  local IDX=1                                     # rotate colors in a cycle
  for arg in ${ARGVS[@]}; do
    local ARGS=( ${ARGS[@]} ${COLS[$IDX]} $arg )
    IDX=$(( IDX + 1 )) 
    [[ $IDX == ${#COLS[@]} ]] && IDX=1
  done
  [[ $STDIN == 1 ]] && {
    xcolorize --unbuffered ${ARGS[@]}
    } || {
    cat $FILE | xcolorize --unbuffered ${ARGS[@]}
  }
}
# License
#
# This script is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This script is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this script; if not, write to the
# Free Software Foundation, Inc., 59 Temple Place, Suite 330,
# Boston, MA  02111-1307  USA