netselct-apt is used to select the fastest mirrors (one non-us, one of any origin) for debian package retrieval. It has two main shortcomings - it clobbers sources.list in the current directory and it only picks one mirror of each type. Both of these are fixed with the below script. Hope you find it useful!

usage: script.pl [distro] [#mirrors] >> /etc/apt/sources.list

#! /usr/bin/perl -w
use strict;

if (scalar(@ARGV)==0){
        print "#Usage: [stable|unstable|testing] [number of mirrors]\n
+#Assuming \"stable\" and \"3\"\n";
}


my ($distro,$howMany)=@ARGV;

$distro="stable"        if (!defined($distro));
$howMany = 3            if (!defined($howMany));

&displayList ("$distro", &selectSome($howMany,&getMirrors("^Packages")
+));
&displayList ("$distro/non-US", &selectSome($howMany,&getMirrors("Non-
+US packages")));




sub displayList {
        my $distro=shift;
        my @mirrors=@_;
        foreach (@mirrors){
                print "deb $_ $distro main contrib non-free\n";
                print "# deb-src deb $_ $distro main contrib non-free\
+n";
        }
}



sub getMirrors {
        my $search=shift;
        my $invert=shift;
        $search="." if (!defined($search));
        my @mirrorPage = `lynx -source "http://www.debian.org/mirror/m
+irrors_full"`;
        my @mirrors;
        foreach (@mirrorPage){
                if ($_=~/(.*)<a href="(http:\/\/.*?)">/) {
                    my $description=$1;
                    my $url=$2;
                    push @mirrors,$url if ($invert && $description!~/$
+search/i);
                    push @mirrors,$url if (!$invert && $description=~/
+$search/i);
                }
        }
        return @mirrors;

}

sub selectSome {
        my $howMany=shift;
        my @list = @_;
        my $command = "netselect -v -s $howMany ".join (' ',@list);
        my @arr = split(/\n/,`$command`);
        foreach (@arr){
                $_=~s/\s*-?\d+\s*([a-z]+:\/\/.*)/$1/i; #snag url
        }
        return @arr;
}
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