file-prepend-yyyymmdd

#!/usr/bin/env perl
use v5.18;
use strict;
use warnings;

use File::Copy qw(move);
use File::Basename qw(dirname fileparse);
use File::Path qw(make_path);
use File::Spec::Functions qw(catfile catdir);
use File::Next;
use Getopt::Long;

sub main {
    my ($opts, $args) = @_;
    my @input = grep { -f || -d } @{ $opts->{i} };
    my $iter = File::Next::files(@input);
    my %plan;
    while (defined( my $file = $iter->() )) {
        my $filename = fileparse($file);
        my $dirname  = dirname($file);

        next if (($filename =~ /\A \d{8} \- /x) || $filename =~ /\A \.DS_Store \z/x);

        my $mtime = (stat($file))[9];
        my ($year, $month, $day) = ( localtime($mtime) )[5,4,3];
        $year += 1900; $month += 1;
        my $yyyy     = sprintf('%04d', $year);
        my $yyyymmdd = sprintf('%04d%02d%02d', $year, $month, $day);

        my $newfile = catfile($dirname, "$yyyymmdd-$filename");
        if ($opts->{n}) {
            say "mv $file $newfile";
        } else {
            move($file, $newfile);
        }
    }
}

my %opts;
GetOptions(
    \%opts,
    'i=s@',
    'd=s',
    'n',
    'ignore-existing'
);
main(\%opts, [@ARGV]);