Count files in a (LARGE) directory

countdir.pl

#!/usr/bin/perl
if (!defined($ARGV[0]) or ! -d $ARGV[0]) {
        print "Supply a valid path\n";
}
opendir(THEDIR,$ARGV[0]);
my $counter = 0;
while (my $file = readdir(THEDIR)) {
        $counter++;
}
closedir(THEDIR);
print "$counter $ARGV[0]\n";