PHP is a very popular programming language that can be used to implement a variety of operations. Among them, traversing folders and obtaining file information therein is a frequently needed operation. In this article, I will explain how to implement folder traversal in PHP.
opendir() function is a function used by PHP to open a folder. When calling this function, you need to pass in the folder path as a parameter. After the folder is opened successfully, the contents of the folder can be read through the readdir() function.
Sample code:
$dir = './test'; //文件夹路径 $handle = opendir($dir); //打开文件夹 while ($file = readdir($handle)) { //循环读取所有文件 if ($file != "." && $file != "..") { //排除"."和".."两个特殊的文件夹 echo $file."<br>"; //输出文件名 } } closedir($handle); //关闭文件夹
In the above sample code, I opened a folder named "test" and read all the file names in the folder in a loop, And ignore the two special folders "." and "..".
If we want to traverse all subdirectories and files in a directory, we can use the recursive method. During the traversal process, we also need to determine whether the current traversal is a folder or a file. We can use the is_dir() function to determine.
Sample code:
function scanDir($dir){ if(!is_dir($dir)){ echo '不是一个有效的文件夹路径'; return; } $handle = opendir($dir); //打开文件夹 while($file = readdir($handle)){ //循环读取所有文件 if($file == '.' || $file == '..'){ //忽略掉 ".",".." 特殊文件夹 continue; } $path = $dir.'/'.$file; //当前文件或文件夹的完整路径 if(is_dir($path)){ //如果是一个文件夹 echo '<b>'.$file.'</b><br>'; //输出文件夹名称 scanDir($path); //递归遍历子文件夹 }else{ //如果是一个文件 echo $file.'<br>'; //输出文件名称 } } closedir($handle); //关闭文件夹 }
In the above sample code, I defined a function scanDir()
, which accepts a folder path as a parameter. Inside the function, I first determine whether the incoming path is a folder. If it is not a folder, return directly.
Next, I open the folder and read the files and folders in it in a loop. When traversing to a folder, I output the folder name and recursively call the scanDir()
function to traverse the subfolders. When iterating to a file, I just output the file name.
PHP also provides a very simple function scandir()
, which can be used to obtain a folder at one time All file and folder names under . Different from the opendir()
function, this function returns an array that contains the names of all subfolders and files.
Sample code:
$dir = './test'; //文件夹路径 $files = scandir($dir); //获取文件夹下所有文件和文件夹名称 foreach($files as $file){ //循环遍历 if($file == '.' || $file == '..'){ //忽略掉 ".",".." 特殊文件夹 continue; } echo $file.'<br>'; //输出文件或文件夹名称 }
In the above sample code, I called the scandir()
function to get all the file and folder names under the folder, and looped This array is traversed. Likewise, I ignored the two special folders "." and ".." and only output the names of the folders and files.
Summary
In this article, I introduced how to implement folder traversal with PHP and demonstrated three different ways. Through the opendir() and readdir() functions, we can loop through all files and folders in a folder and perform corresponding operations by judging the file type. Through recursive traversal, we can traverse all subdirectories and files in a directory. Through the scandir() function, we obtain all subfolders and file names under a folder at once. If you need to iterate through folders in PHP, I hope this article can provide you with some reference.
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