Random file

This function returns a random file from a given folder. It also allows extension filtering.

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[] = $file;                
        // close directory
    else {
        die('Could not open the folder "'.$folder.'"');
    if (count($files) == 0){
        die('No files where found :-(');
    // seed random function:
    // 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];
Snippet Details

// "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

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Older comments:

sharmili February 19, 2011 at 07:34
Though i tried to generate a file with this code, i couldn't find any inside the folder. What could be the issue?
Raphaƫl November 04, 2010 at 13:39
Great ! Good work.
Daniel May 21, 2009 at 10:01
Hy, and first sorry for my poor english.
I have been looking for long time for such a script. I am beginer in php.
I started to develop a such script but it is" stronger " by me...and i have a lot of errors.

I try to make a script to send to an random email an random html file ( with link insertion inside) from a folder or from a random folder.
I was able to make the post to email script ( without random loaded from a xls file) But the rest it is too hard for me.

I do not understand from your script:

where I indicate the folder path? I want to put near the script.php a folder "folder" containing all trhe html file...but where I will indicate its path?