file_duration.pl

#!/usr/bin/env perl
use strict;
use warnings;
use File::Find;
use Cwd;

my $filetype = '.m4a$';

find(\&wanted, getcwd);

sub wanted {
	return if -d;
	return unless (/$filetype/);
	my @info = `ffprobe -i $_ 2>&1`;
	my @filter = grep /Duration:/, @info;

	$_ = pop @filter;
	chomp;
	s/,.*//;
	print "$_ $File::Find::name\n";
}

file_duration_sort.pl

#!/usr/bin/env perl
use strict;
use warnings;
use File::Find;
use Cwd;

my $filetype = '.m4a$';

my @len_name;

find(\&wanted, getcwd);

print sort @len_name;

sub wanted {
	return if -d;
	return unless (/$filetype/);
	my @info = `ffmpeg -i $_ 2>&1`;
	my @filter = grep /Duration:/, @info;

	$_ = pop @filter;
	chomp;
	s/,.*//;
	# print "$_ $File::Find::name\n";
	# push @len_name, [$_, $File::Find::name];
	push @len_name, "$_ $File::Find::name\n";
}