use File::Find::Rule;

my $template = 'aaaa-nnnnnnnn';
(my $regex = $template)
  =~ s/([an])/$1 eq 'a' ? '[a-z]' : '[0-9]'/eig;

my $matcher = rule(
  file     =>
  maxdepth => 1,
  name     => qr/^$regex/i,
  start    => $ARGV[0]
);

while(my $file = $matcher->match) {
  ...
}
[download]

_________
broquaint

#!/usr/bin/perl -w
use strict;
use File::Find::Rule;

my @files = File::Find::Rule->file()
                            ->name( qr/^[a-zA-Z]{4}-\d{8}/ )
                            ->in( / );
[download]

Cheers - L~R

Update: Bah, broquaint beat me to it, so yes it will work. What's worse - his solution provides the ability to modify the template without modifying the regex. I guess the only thing I would have done differently is changed the character class to [a-zA-Z] instead of using /i for speed reasons - but if it runs a tad bit slower it just means you can go get more caffeine.

even a simple readdir should do the trick

#!/usr/bin/perl -w

use strict;

my $dir     = '/some/dir';
my $file_re = qr/^(?:\.+|[a-zA-Z]{4}-[0-9]{8})$/;

opendir(DIR, $dir) or die "opening $dir: $!\n";

for ( grep(!/$file_re/, readdir(DIR)) ) {
# deal with non conforming file names here
}
closedir(DIR);
[download]

use perl;