php 文件进行hash运算的简单示例

人气：713 时间：2018-09-21

这篇文章主要为大家详细介绍了php 文件进行hash运算的简单示例，具有一定的参考价值，可以用来参考一下。

对php对文件进行hash运算感兴趣的小伙伴，下面一起跟随四海网的小编两巴掌来看看吧！
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。


/**
 * php对文件进行hash运算
 *
 * @param 
 * @author 四海网 www.q1010.com
 **/
<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: &nbsp;&nbsp;' . $_POST['exphash'] . '<br><br>'; 
						echo ($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>
/***   来自四海网（www.q1010.com）   ***/

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关键词：hash

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