#!/usr/bin/perl
use strict;
use warnings;
use URI;

my $no_base_url_err = 1;

my $base_url = shift
	|| (warn "Must provide a base URL to make URLs absolute" and exit($no_base_url_err));

# converts relative URLs to absolute URLs, assuming
# it's getting one URL per line.
while(<>) {
	my $url = URI->new($_);
	print $url->abs($base_url), "\n";
}