具體如下：
這段代碼非常有用，如果你下載了一個文件，網站提供了hash結果，你可以對你下載下來的文件進行hash運算，以驗證下載的文件是否正確。
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 <html> <head> <title>Hash (Check) Files</title> <style type='text/css'> #ok{color:green;} #nono{color:red;} </style> </head> <body> <?php if(!empty($_FILES)){ if ($_FILES["file"]["error"] > 0){ switch($_FILES["file"]["error"]){ case 1: echo "<b id='nono'>Error: The uploaded file exceeds the upload_max_filesize directive in php.ini</b><br>"; break; case 2: echo "<b id='nono'>Error: The uploaded file exceeds the MAX_FILE_SIZE directive that was specified in the HTML form.</b><br>"; break; case 3: echo "<b id='nono'>Error: The uploaded file was only partially uploaded.</b><br>"; break; case 4: echo "<b id='nono'>Error: No file was uploaded.</b><br>"; break; case 6: echo "<b id='nono'>Error: Missing a temporary folder.</b><br>"; break; case 7: echo "<b id='nono'>Error: Failed to write file to disk.</b><br>"; break; case 8: echo "<b id='nono'>Error: A PHP extension stopped the file upload.</b><br>"; break; default: echo "<b id='nono'>Unknown error occured.</b><br>"; } } else { echo 'Upload: ' . $_FILES['file']['name'] . '<br>'; echo 'Type: ' . $_FILES['file']['type'] . '<br>'; echo 'Size: ' . (round($_FILES['file']['size'] / 1024, 2)) . ' Kb<br><br>'; if(array_search($_POST['algo'], hash_algos())===false){ echo 'Unknown hashing algorithm requested.<br>'; } else { echo 'Hashing Algorithm: '. $_POST['algo'] . '<br>'; $hash = hash_file($_POST['algo'], $_FILES['file']['tmp_name']); echo 'Calculated hash: ' . $hash . '<br>'; if($_POST['exphash']!=='none' && !empty($_POST['exphash'])){ echo 'Expected hash: ' . $_POST['exphash'] . '<br><br>'; echo ($hash==$_POST['exphash'])? '<b id="ok">Hash matched expected value.</b>' : '<b id="nono">Hash did not match expected value.</b>'; echo '<br>'; } } } ?> <br> <button onClick="document.location.reload(true)">Again</button> <?php } else { ?> <form action="" method="post" enctype="multipart/form-data"> <input type="hidden" name="exphash" value="none"> <label for="file">Filename:</label> <input type="file" name="file" id="file"> <input type="submit" name="submit" value="Submit" /><br> <label>Expected hash(optional): <input type="text" name="exphash" size="100"></label> <br><br>Choose an algorithm (This is the list of all the available algorithms in your php installation)<br> <?php foreach(hash_algos() as $algo){ if($algo=='md5'){ echo "<label><input type='radio' name='algo' value='$algo' checked='checked'>$algo</label><br>"; } else { echo "<label><input type='radio' name='algo' value='$algo'>$algo</label><br>"; } } ?> </form> <?php } ?> </body> </html>
