You could use split or regular expressions.

perl -e '$s="Location: http://www.google.com Status Code: 200 OK"; @pc
+s = split(/ /, $s); for ( @pcs ) { print $_ . "\n" if /http/; }'
[download]

which produces

http://www.google.com
[download]

or

#! /usr/bin/perl

use strict;
use warnings;

my @hits;

while( <DATA> ) {
    chomp;
    push @hits, $1 if  $_ =~ /\w*(http:\S+)/;    
}

print join("\n", @hits) . "\n";

1;

__DATA__
Location: http://www.google.com Status Code: 200 OK
<br />
File : http://www.aby.cos Status code: 500 Server Error
[download]

which produces

http://www.google.com
http://www.aby.cos
[download]