highlight.sh

#!/bin/bash
# 2015 (C) [email protected]
# loosly based on
#    https://github.com/kepkin/dev-shell-essentials
set -e

self=$(basename $0)

fg_colors=( red green yellow blue magenta cyan )
autocolor=
context=
use_pager=

declare -A fg_color_map
fg_color_map[black]=30
fg_color_map[red]=31
fg_color_map[green]=32
fg_color_map[yellow]=33
fg_color_map[blue]=34
fg_color_map[magenta]=35
fg_color_map[cyan]=36

function highlight() {
  local col="$1"
  local pat="$2"
   
  local fg_c="$(echo -e "\e[1;${fg_color_map[$col]}m")"
  local c_rs=$'\e[0m'
  #while read -r line; do echo $line | sed s"/$pat/$fg_c\0$c_rs/"; done
  sed -ure s"/$2/$fg_c\0$c_rs/g"
}

function show_help() {
  exit_with=$1
  cat <<END
$self -h
$self [ <col> <pattern> ] ...
$self -a [ <pattern> ] ...

    -h                 - this help
    -a                 - auto color assignment
    -C<num>            - pass input through grep -C first to limit the context
    -p                 - paginate through \$PAGER

END
  exit $exit_with
}

while [[ ${1:0:1} = '-' ]] ; do
  case "$1" in
    -h) show_help ;;
    -a) autocolor=0 ;;
    -p) use_pager="$PAGER" ;;
    -C[0-9]*) context="${1:2}" ;;
    -C) shift ; context="$1" ;;
  esac
  shift
done

if [[ -z "$1" ]] ; then
  show_help 1
fi

grep_cmd=()
cmd=()
sep=

while [[ -n "$1" ]] ; do
  if [[ -z "$autocolor" ]] ; then
    col="$1" ; shift
  else
    col=${fg_colors[$autocolor]}
    autocolor=$(($autocolor+1))
    [[ $autocolor > ${#fg_colors[*]} ]] && autocolor=0
  fi
  pat="$1" ; shift

  cmd=( "${cmd[*]}" $sep highlight "$col" "$pat" )
  sep='|'

  if [[ -n "$context" ]] ; then
    grep_cmd=( "${grep_cmd[*]}" -e "$pat" )
  fi
done


if [[ -n "$context" ]] ; then
  use_C=
  [[ $context -gt 0 ]] && use_C=-C"$context"
  cmd=( grep --line-buffered -E $use_C "${grep_cmd[*]}" '|' "${cmd[*]}" )
fi

if [[ -n "$use_pager" ]] ; then
  cmd=( "${cmd[*]}" '|' "$use_pager" )
fi

#echo "${cmd[*]}"
#exit 0

eval "${cmd[*]}"