#!/usr/bin/perl -w
# surl - sort URLs by their last modification date

use LWP::UserAgent;
use HTTP::Request;
use URI::URL qw(url);

my($url, %Date);
my $ua = LWP::UserAgent->new();

while ( $url = url(scalar <>) ) {
    my($req, $ans);
    next unless $url->scheme =~ /^(file|https?)$/;
    $ans = $ua->request(HTTP::Request->new("HEAD", $url));
    if ($ans->is_success) {
        $Date{$url} = $ans->last_modified || 0;  # unknown
    } else {
        print STDERR "$url: Error [", $ans->code, "] ", $ans->message, "!\n";
    }
}

foreach $url ( sort { $Date{$b} <=> $Date{$a} } keys %Date ) {
    printf "%-25s %s\n", $Date{$url} ? (scalar localtime $Date{$url})
                                     : "<NONE SPECIFIED>", $url;
}