Color regex matches - without dropping misses

Question

When using grep --color=always I can get pretty color highlighting for regex matches.

However, grep only returns lines with at least one match.

Answer 1

Here is a script I use to colorize output.

I think I found the idea/snippet on some kind of blog or bash/sed tutorial - can't find it anymore, it was very long time ago.

#!/bin/bash

red=$(tput bold;tput setaf 1)            
green=$(tput setaf 2)                    
yellow=$(tput bold;tput setaf 3)         
fawn=$(tput setaf 3)
blue=$(tput bold;tput setaf 4)           
purple=$(tput setaf 5)
pink=$(tput bold;tput setaf 5)           
cyan=$(tput bold;tput setaf 6)           
gray=$(tput setaf 7)                     
white=$(tput bold;tput setaf 7)          
normal=$(tput sgr0)                      

sep=`echo -e '\001'` # use \001 as a separator instead of '/'

while [ -n "$1" ] ; do
  color=${!1}
  pattern="$2"
  shift 2

  rules="$rules;s$sep\($pattern\)$sep$color\1$normal${sep}g"
done

#stdbuf -o0 -i0 sed -u -e "$rules"
sed -u -e "$rules"

Usage:

./colorize.sh color1 pattern1 color2 pattern2 ...

e.g.

dmesg | colorize.sh red '.*Hardware Error.*' red 'CPU[0-9]*: Core temperature above threshold' \
green 'wlan.: authenticated.*' yellow 'wlan.: deauthenticated.*'

Doesn't work well with overlapping patterns, but I've found it very useful anyway.

HTH