Php file hash calculation method

This article mainly introduces php's file hash calculation method, which involves file hash calculation techniques and is of great practical value, for more information about how php performs file hash operations, see the example in this article. Share it with you for your reference. The details are as follows:

This code is very useful. if you download a file and the website provides the hash result, you can perform a hash operation on the downloaded file to verify that the downloaded file is correct.

  Hash (Check) Files   <?php   if(!empty($_FILES)){   if ($_FILES["file"]["error"] > 0){    switch($_FILES["file"]["error"]){     case 1:     echo "Error: The uploaded file exceeds the upload_max_filesize directive in php.ini
";     break;     case 2:     echo "Error: The uploaded file exceeds the MAX_FILE_SIZE directive that was specified in the HTML form.
";     break;     case 3:     echo "Error: The uploaded file was only partially uploaded.
";     break;     case 4:     echo "Error: No file was uploaded.
";     break;     case 6:     echo "Error: Missing a temporary folder.
";     break;     case 7:     echo "Error: Failed to write file to disk.
";     break;     case 8:     echo "Error: A PHP extension stopped the file upload.
";     break;     default:     echo "Unknown error occured.
";    }   } else {    echo 'Upload: ' . $_FILES['file']['name'] . '
';    echo 'Type: ' . $_FILES['file']['type'] . '
';    echo 'Size: ' . (round($_FILES['file']['size'] / 1024, 2)) . ' Kb

';    if(array_search($_POST['algo'], hash_algos())===false){    echo 'Unknown hashing algorithm requested.
';    } else {    echo 'Hashing Algorithm: '. $_POST['algo'] . '
';    $hash = hash_file($_POST['algo'], $_FILES['file']['tmp_name']);    echo 'Calculated hash: ' . $hash . '
';    if($_POST['exphash']!=='none' && !empty($_POST['exphash'])){      echo 'Expected hash:   ' . $_POST['exphash'] . '

';      echo ($hash==$_POST['exphash'])? 'Hash matched expected value.' : 'Hash did not match expected value.';      echo '
';    }    }   }   ?>   
   Again    <?php   } else {  ?>   <?php   }  ?>

I hope this article will help you with php programming.