php从文件夹随机读取文件的方法
这篇文章主要介绍了php从文件夹随机读取文件的方法,可实现php从指定的目录随机读取文件及设置参数进行文件过滤的功能,需要的朋友可以参考下。
本文实例讲述了php从文件夹随机读取文件的方法，分享给大家供大家参考，具体实现方法如下：
- function RandomFile($folder='', $extensions='.*'){
- // fix path:
- $folder = trim($folder);
- $folder = ($folder == '') ? './' : $folder;
- // check folder:
- if (!is_dir($folder)){ die('invalid folder given!'); }
- // create files array
- $files = array();
- // open directory
- if ($dir = @opendir($folder)){
- // go trough all files:
- while($file = readdir($dir)){
- if (!preg_match('/^\.+$/', $file) and
- preg_match('/\.('.$extensions.')$/', $file)){
- // feed the array:
- $files[] = $file;
- }
- }
- // close directory
- closedir($dir);
- }
- else {
- die('Could not open the folder "'.$folder.'"');
- }
- if (count($files) == 0){
- die('No files where found :-(');
- }
- // seed random function:
- mt_srand((double)microtime()*1000000);
- // get an random index:
- $rand = mt_rand(0, count($files)-1);
- // check again:
- if (!isset($files[$rand])){
- die('Array index was not found! very strange!');
- }
- // return the random file:
- return $folder . $files[$rand];
- }
- //用法演示：
- // "jpg|png|gif" matches all files with these extensions
- print RandomFile('test_images/','jpg|png|gif');
- // returns test_07.gif
- // ".*" matches all extensions (all files)
- print RandomFile('test_files/','.*');
- // returns foobar_1.zip
- // "[0-9]+" matches all extensions that just
- // contain numbers (like backup.1, backup.2)
- print RandomFile('test_files/','[0-9]+');
- // returns backup.7