use strict;
use warnings;

my @array = qw(a1 a10 a100 a11 b2 b10 b200 b25);

print 'bobf sort: ', join ' ', sort @array;
print "\n  GF sort: ", join ' ', sort alfNum @array;

sub alfNum {
    my ($aAlf, $aNum) = $a =~ /([a-z]+)(\d+)/i;
    my ($bAlf, $bNum) = $b =~ /([a-z]+)(\d+)/i;
   
    return $aAlf cmp $bAlf if $aAlf ne $bAlf;
    return $aNum <=> $bNum;
}