#!/usr/bin/env perl

use strict;
use warnings;
use POSIX qw (strftime);
use Path::Iterator::Rule;
use Image::ExifTool;

my $dir = q(./pdf);
my $rule = Path::Iterator::Rule->new;

# $rule->file('*.pdf'); # :-(
$rule->file->name(qr/.+\.pdf/);
$rule->max_depth(1);

my $next = $rule->iter($dir);

while ( defined( my $file = $next->() ) ) {
    my $mtime       = ( stat($file) )[9];
    my $atime       = ( stat($file) )[8];
    my $m_timestamp = strftime( "%Y:%m:%d %H:%M:%S%z", localtime($mtime) );
    my $exifTool = Image::ExifTool->new();                                               
    $exifTool->SetNewValue( "ModifyDate", $m_timestamp );
    $exifTool->SetNewValue( "CreateDate", $m_timestamp );
    $exifTool->WriteInfo($file);
    utime $atime, $mtime, $file;
}

__END__