Benchmark of listing files in directory in perl: ls vs glob vs readdir

gistfile1.pl

#!/usr/bin/perl

use strict;
use warnings;

use Benchmark qw(cmpthese);

qx(ls -1U); # Populate dir cache

cmpthese(1000, {
    'ls-1 (readline)'  => sub { open my $fh, "-|", "ls -1"; my @result = <$fh>; },
    'ls-1U (readline)' => sub { open my $fh, "-|", "ls -1U"; my @result = <$fh>; },
    'ls-1 (split)'     => sub { my $result = qx(ls -1); my @result = split /\n/, $result; },
    'ls-1U (split)'    => sub { my $result = qx(ls -1U); my @result = split /\n/, $result; },
    'glob'             => sub { my @result = glob("*"); },
    'readdir'          => sub { opendir(my $dh, "."); my @result = readdir($dh); },
});

Example output:

                   Rate glob ls-1 (readline) ls-1 (split) ls-1U (readline) ls-1U (split) readdir
glob             97.4/s   --            -32%         -38%             -46%          -59%    -84%
ls-1 (readline)   143/s  47%              --          -9%             -21%          -40%    -76%
ls-1 (split)      156/s  60%              9%           --             -13%          -34%    -74%
ls-1U (readline)  180/s  85%             26%          15%               --          -24%    -70%
ls-1U (split)     238/s 145%             67%          53%              32%            --    -60%
readdir           592/s 508%            315%         279%             228%          149%      --