remove whitespace and special character from string
<p>i am using this code to save the uploaded file but the problem is it is allowing the file with name with special character and space.
for example it is allowing </p>

<pre><code>hi how are you
</code></pre>

<p>but i dont want to allow any space ,special charater etc. here is my code .i tried with preg_replace in uri but after that i tried to upload file but nothing got uploaded.</p>

<pre><code>function save_file($file) {
    $allowed_ext = array('jpg','png','gif','jpeg');
    $ext = $file['name'];
    $ext = strtolower($ext);

    if (in_array($ext, $allowed_ext)) {
        die('Sorry, the file type is incorrect:'.$file['name']);
    }

    $fname = date("H_i",time()).'_'.get_rand(5);
    $dir = date("Ym",time());
    $folder = 'uploads/userfiles/'.$dir;
    $uri = $folder.'/'.$fname.'.'.$ext;

    if (!is_dir($folder))
        mkdir($folder, 0777);

    if (copy($file['tmp_name'],$uri))
        return $uri;
    else {
        return false;
    }
}
</code></pre>
