#!/bin/sh

#################################################
## hl v1.1                                     ##
## display a matched pattern in reverse text   ##
## hl is an acronym for HighLight              ##
##                                             ##
## documentation at:                           ##
## http://Business-PHP.com/opensource/hl/      ##
##                                             ##
## Copyright (c) 15 May 2003 Atom Emet         ##
## Atom*Business-PHP.com                       ##
##                                             ##
## This program 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 program 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  ##
## program; if not, write to                   ##
##    the Free Software Foundation, Inc.       ##
##    59 Temple Place - Suite 330              ##
##    Boston, MA  02111-1307, USA              ##
#################################################

#######################################
## allow either one or two arguments ##
#######################################
if [ "${#}" -gt '2' ] || [ "${#}" -eq '0' ] || [ ! "${1}" ]
then
	#################################################
	## if the wrong number of arguments are given, ##
	## echo an error message into STANDARD ERROR   ##
	## and exit leaving an exit status "1"         ##
	#################################################
	echo "hl: usage:" >&2
	echo "   hl '[pattern]' [file]" >&2
	echo "     -- or --" >&2
	echo "   command | hl '[pattern]'" >&2
	exit 1
fi

###########################################################
## check if a file argument is given on the command line ##
###########################################################
if [ "${#}" = '2' ]
then
	########################################################
	## if there's an argument, check that the file exists ##
	########################################################
	if [ -e "${2}" ]
	then
	    ###########################################################
	    ## if the file specified on the command line does exist, ##
	    ## input comes from that file                            ##
	    ###########################################################
	    pattern1=`echo "${1}" | sed 's,/,\\\/,g'`
	    pattern2=`printf '\033[7m&\033[0m'`
	    sed "s/${pattern1}/${pattern2}/g" "${2}"
	    exit 0
	else
	    ###############################################################
	    ## if the file specified on the command line does not exist, ##
	    ## echo an error message into STANDARD ERROR                 ##
	    ## and exit leaving an exit status "2"                       ##
	    ###############################################################
	    echo "hl: No such file or directory \"${2}\"" >&2
	    exit 2
	fi
else
	##################################################
	## if no file is specified on the command line, ##
	## then input comes from STANDARD INPUT         ##
	##################################################
	    pattern1=`echo "${1}" | sed 's,/,\\\/,g'`
	    pattern2=`printf '\033[7m&\033[0m'`
	    sed "s/${pattern1}/${pattern2}/g"
	    exit 0
fi