#!/usr/bin/perl
sub usage
{
	print STDERR "usage: $0 [-g] [file ...]\n";
	exit(1);
}

if ($ARGV[0] eq "-g") {
	$grep = 1;
	shift @ARGV;
}
&usage if $ARGV[0] =~ /^-/;

while (<>) {
	@c = unpack "C*";
	for (@c) {
		if ($_ == 10) {
			print "$s\n" if $found || !$grep;
			$found = 0;
			undef $s;
		} elsif ($_ < 0x80) {
			$s .= pack("c", $_);
		} else {
			$s .= sprintf("\e[7m%02x\e[0m", $_);
			$found = 1;
		}
	}
}