#!/usr/bin/perl

$USAGE = q(
SYNOPSIS: xdiff -- windiff for color xterm
USAGE:    diff x y | cmd [OPTIONS]	.. usual diff in color.
		 diff -wbc | cmd 		.. color context diff.
AUTHOR:   GPL(C) Mohsin Ahmed, http://www.cs.albany.edu/~mosh
OPTIONS: 
 -/pat   Show only lines matching =~ /pat/i.
 -v      verbose.
);

while( $_ = $ARGV[0],  m/^-/ ){
    shift; last if /^--$/;
    $verbose++, next if m/^-v/;
    ($pat = $1), next if m,^-/(.+),;
    die $USAGE if m/^-[h?]/;
}

if( ($ENV{ "TERM" } =~ m/xterm/i ) ){
	$NoCol  =  "\033[0m \033[39m \033[49m";
	$fGreen = "\033[32m";
	$fRed   = "\033[31m";
	$fBlue  = "\033[34m";
	$fWhite = "\033[97m";
	$bWhite = "\033[107m";
	$bRed   = "\033[41m";
	$fCyan  = "\033[36m";
}else{
	die "Only for xterms, maybe ANSI someday.\n"
}

while( <> ){
    chomp;
	next if defined($pat) && ! s/$pat/${fRed}$&${NoCol}/ig;
	print $fBlue  if m/^[<!]/;
	print $fGreen if m/^[>+]/;
	print $_;
	print $NoCol,"\n";
}