I want to scan my whatsapp images folder and move all the repeated images to folder named recycle bin to delete them later:


$dir    = 'C:\wamp\www\whatsapp';
$files = scandir($dir);

$x = 0;

foreach($files as $f1)

    $crc1 = strtoupper(dechex(crc32(file_get_contents("whatsapp/".$f1))));


    $j = 0;

    foreach($files as $f2)

        $crc2 = strtoupper(dechex(crc32(file_get_contents("whatsapp/".$f2))));

        if($crc1 == $crc2){

            rename("whatsapp/".$f2, "recycle bin/".$f2);





Does this code seems to be trusted to move only the repeated images without any mistakes?


1 Answer 1


Maybe you try with this pseudocode:

  • get files list from directory
  • declare array for crc
  • for each file in directory
  • check if the mime content type is correct
  • get crc for file
  • check if this crc is in array for crc
  • if is in array move it
  • else push crc into array

Thanks Pimgd. You are right. I should write it on the beginning. First of all there is only one loop, so if you have a lot of files, it will be faster. Second, it checks content file, so you will not touch not image files. Third, the code will be more clear.

  • 2
    \$\begingroup\$ Why would this pseudo code be a better algorithm than what the asker currently has? (Please add some explanation) \$\endgroup\$
    – Pimgd
    Feb 6, 2015 at 11:32

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