So, if I'm reading this right, you've got a bunch of numbers like so:

64/2829
1/349834
37823/8338
5/989328
[download]

And you want them sorted like this:

1/349834
5/989328
64/2829
37823/8338
[download]

Here:

sub sortbyfirst {
   my ($f_a, undef) = split(/\//, $a);
   my ($f_b, undef) = split(/\//, $b);
   return $f_a <=> $f_b;
}

@sorted = sort sortbyfirst @numbers;
[download]

Note: Untested.

This won't be superfast... If you've got a huge list, or this runs constantly, look into the tye transductor, illustrated here.

stephen