php如何对文件进行hash运算

这篇文章将为大家详细讲解有关php如何对文件进行hash运算，小编觉得挺实用的，因此分享给大家做个参考，希望大家阅读完这篇文章后可以有所收获。

具体如下：

这段代码非常有用，如果你下载了一个文件，网站提供了hash结果，你可以对你下载下来的文件进行hash运算，以验证下载的文件是否正确。

      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      
      Filename:      
   Expected hash(optional):    

Choose an algorithm (This is the list of all the available algorithms in your php installation)
   $algo
";    } else {    echo "$algo
";    }   }   ?>  
 

关于"php如何对文件进行hash运算"这篇文章就分享到这里了，希望以上内容可以对大家有一定的帮助，使各位可以学到更多知识，如果觉得文章不错，请把它分享出去让更多的人看到。