SHELL = /bin/bash

.PHONY: run
run: compare
	$(MAKE) glob    > /dev/null
	$(MAKE) readdir > /dev/null
	$(MAKE) path    > /dev/null


.PHONY: prepare
prepare:
	gen.sh

.PHONY: clean
clean:
	rm -rf {100..200}

.PHONY: glob
glob:
	time glob.pl

.PHONY: readdir
readdir:
	time readdir.pl

.PHONY: path
path:
	time path.pl

.PHONY: compare
compare:
	diff <(glob.pl | sort) <(readdir.pl | sort)
	diff <(glob.pl | sort) <(path.pl | sort)

##</code><code>##

#! /bin/bash
now=$(date +%s)
yday=$(date -d yesterday +%s)
tmrw=$(date -d tomorrow +%s)

mkdir {100..200}

for d in {100..200} ; do

    for r in {1..250} ; do
	mkdir $d/$(date +%Y%m%d -d @$((yday-10000*RANDOM)))
    done 2>/dev/null

    mkdir $d/$(date +%Y%m%d -d @$((tmrw+10*RANDOM)))

    for r in {1..250} ; do
	mkdir $d/$(date +%Y%m%d -d @$((yday-10000*RANDOM)))
    done 2>/dev/null
    echo $d >&2
done

##</code><code>##

#!/usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

use Time::Piece;

my $now = localtime->ymd("");

for my $dir (glob '???/') {
    say substr +(glob "$dir*/")[-1], 0, -1;
}

##</code><code>##

#!/usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

use Time::Piece;
use Path::Tiny qw{ path };

my $now = localtime->ymd("");

for my $dir (grep $_->is_dir, path('.')->children) {
    for my $date (grep $_->is_dir, $dir->children) {
        say $date if $date->basename > $now;
    }
}

##</code><code>##

#!/usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

use Time::Piece;

my $now = localtime->ymd("");

opendir my $dir, '.' or die $!;
while (my $pdir = readdir $dir) {
    next if $pdir =~ /^\.{1,2}$/ || ! -d $pdir;

    opendir my $ddir, $pdir or die $!;
    while (my $date = readdir $ddir) {
        next if $date =~ /^\.{1,2}$/ || ! -d $dir;

        say "$pdir/$date" if $date > $now;
    }
}

##</code><code>##

make glob    > /dev/null

real	0m0.109s
user	0m0.054s
sys	0m0.053s
make readdir > /dev/null

real	0m0.074s
user	0m0.045s
sys	0m0.029s
make path    > /dev/null

real	0m0.440s
user	0m0.380s
sys	0m0.060s