hl

#!/usr/bin/env bash

# ./hl
#
# color highlight by regexp pattern from stdin
#
# see --help for usage
#
# example:
#   echo -e "line1: SUCCESS cmd\nline2: FAIL test" | hl -bg red -fg white FAIL | hl -fg green -b SUCCESS
#   ./PROGRAM | hl -bg red -fg white FAIL | hl -fg green -b SUCCESS
#   cat /path/to/log | hl -bg r -l ERROR
#   tail -f /path/to.log | hl -bg r -m Error
#
# author: @qbbr

fg=""
bg=""
bold=""
line=""
i="i"
reset=$(tput sgr0)

usage() {
	echo "Usage: ${0##*/} [option] [argument] pattern"
	echo
	echo "Options:"
	echo "	-bg                - set background color"
	echo "	-fg                - set foreground color"
	echo "	-b, --bold         - set bold text"
	echo "	-l, --line         - highlight all line"
	echo "	-m, --match-case   - match case distinctions (default: ignore case)"
	echo "	-h, --help         - display this help and exit"
	exit 0
}

color_name_to_number () {
	case $1 in
		bla*)  echo 0;; # black
		r*)    echo 1;; # red
		g*)    echo 2;; # green
		y*)    echo 3;; # yellow
		b*)    echo 4;; # blue
		m*)    echo 5;; # magenta
		c*)    echo 6;; # cyan
		w*)    echo 7;; # white
		*)     echo 0;;
	esac
}

POSITIONAL=()

while [[ $# -gt 0 ]]; do
	key="$1"

	case ${key} in
		-fg)
			fg="$2"
			shift # past argument
			shift # past value
		;;
		-bg)
			bg="$2"
			shift
			shift
			;;
		-b|--bold)
			bold="$(tput bold)"
			shift # past argument
			;;
		-l|--line)
			line=".*"
			shift
			;;
		-m|--match-case)
			i=""
			shift
			;;
		-h|--help)
			usage
			;;
		*) # unknown option
			POSITIONAL+=("$1") # save it in an array for later
			shift
			;;
	esac
done

set -- "${POSITIONAL[@]}" # restore positional parameter

pattern="$*"

if [[ -n "${fg}" ]]; then
	fg=$(tput setaf $(color_name_to_number ${fg}))
fi

if [[ -n "${bg}" ]]; then
	bg=$(tput setab $(color_name_to_number ${bg}))
fi

if [[ -z "${fg}${bg}" ]]; then
	bg=$(tput smso)
fi

sed "s/${line}${pattern}${line}/${bold}${fg}${bg}&${reset}/g${i}"