in reply to Perl Golf Proposal

Keeping in mind that this golf challenge asks for a program rather than a subroutine... :)

48 characters:

#!perl $m=pop;for$"(pop..$m){$_="@ARGV";-e||warn"$_\n"}
example usage: perl bar .jpg 0000 0050

Hurrah for the range operator and magical auto-increment!

As best I can figure it, the only way to accurately accomplish the bonus (checking for a comparison string that's too big) is to check all the files in the directory. Otherwise there could be one file in there with a unique part of the right length.