Apart from the fact that the OP
isn't looking for a subset.
#!/usr/bin/perl
use strict;
use warnings;
use Benchmark qw /cmpthese/;
chdir shift or die;
cmpthese -5 => {
glob => sub {
1 while glob '*';
},
readdir => sub {
opendir my $dh, '.' or die;
1 while readdir $dh;
},
};
__END__
$ mkdir x ; cd x ; touch `seq 1 20000` ; cd ..
$ perl glob_vs_readdir.pl x
Benchmark: running glob, readdir for at least 5 CPU seconds...
glob: 6 wallclock secs ( 4.02 usr + 1.07 sys = 5.09 CPU) @ 5.30
+/s (n=27)
readdir: 6 wallclock secs ( 3.93 usr + 1.37 sys = 5.30 CPU) @ 65.28
+/s (n=346)
Rate glob readdir
glob 5.30/s -- -92%
readdir 65.3/s 1131% --
Makeshifts last the longest.