X:\database> perl -le "@foo = `dir /b ABC*`; print scalar @foo"
540

##</code><code>##

X:\database> perl -le "@foo = glob('ABC*'); print scalar @foo"
540

##</code><code>##


use strict;
use warnings;
use Benchmark;

use Cwd;

my $path = '\\\\big\unc\path\name';
my $wild = 'ABC*';

chdir($path);
my $cwd = cwd;
print $cwd, $/;

my $results =
timethese( 10,
	   {
	     'plglob' => sub { my @files = plglob($wild); die if not @files },
	     'rdglob' => sub { my @files = rdglob($wild); die if not @files },
	     'qxglob' => sub { my @files = qxglob($wild); die if not @files },
	     'fdglob' => sub { my @files = fdglob($wild); die if not @files }
	   } );

Benchmark::cmpthese( $results );

sub plglob
{
    my $wild = shift;
    return glob($wild);
}

sub rdglob
{
    my $wild = shift;
    opendir(DIR, '.') or return ();
    my @files;
    $wild = wildcard($wild);
    while (defined($_ = readdir(DIR)))
    {
	push(@files, $_) if m{$wild};
    }
    closedir(DIR);
    return @files;
}

sub qxglob
{
    my $wild = shift;
    my @files = `dir /b`;
    chomp @files;
    $wild = wildcard($wild);
    @files = grep { m{$wild} } @files;
    return @files;
}

sub fdglob
{
    my $wild = shift;
    use File::DosGlob;
    my @files = DosGlob($wild);
    return @files;
}

# turn a file mask like "ABC*.txt" into a regex like qr{ABC[^/\\]*\.txt}
# (yes, this is a really fragile bug-prone way to go!)
sub wildcard
{
    my $wild = shift || '*';
    $wild =~ s!\?![^\/\\]!g;
    $wild =~ s!\*![^\/\\]*!g;
    $wild =~ s!\\!\\\\!g;
    $wild =~ s!\.!\\.!g;
    $wild = qr{\A$wild\z};
    return $wild;
}

##</code><code>##

Benchmark: timing 10 iterations of fdglob, plglob, qxglob, rdglob...
              Rate qxglob fdglob rdglob plglob
qxglob 1.27e-002/s     --  -100%  -100%  -100%
fdglob      3.44/s 26995%     --   -35%   -40%
rdglob      5.33/s 41871%    55%     --    -7%
plglob      5.71/s 44893%    66%     7%     --