タイムスタンプをファイル名にリネームするスクリプト（同じタイムスタンプで元のファイル名が異なる場合を想定し、連番をつける）

rename.pl

#!/usr/bin/env perl

use warnings;
use strict;

use feature 'say';
use Cwd;

my $dir = shift || Cwd::getcwd();
say $dir;
my $count = 0;

rename_emls($dir);

sub rename_emls {
    my $dir = shift;
    opendir my $dh, $dir or die "$!";
    for my $subf (grep !/^\.\.?/, readdir($dh)) {
        my $f = "$dir/$subf";
        if (-d $f) {
            rename_emls($f);
            next;
        }
        if ($f =~ /\.eml$/) {
            my $org_name = $f;
            my @stat = stat($org_name);
            my ($sec, $min, $hour, $day, $mon, $year) = localtime($stat[9]);
            my $renamed_name = sprintf("$dir/%04d%02d%02d-%02d%02d%02d-%08d.eml", $year + 1900, $mon + 1, $day, $hour, $min, $sec, ++$count);
#            say "$org_name => $renamed_name";
            rename $org_name, $renamed_name if ($org_name ne $renamed_name);
        }
    }
    closedir $dh;
}