umask in PHP

umask — Changes the current umask
Syntax:

int umask ([ int $mask ] )
umask() sets PHP's umask to mask & 0777 and returns the old umask. When PHP is being used as a server module, the umask is restored when each request is finished.

Parameters:

mask
The new umask.

Return values: umask() without arguments simply returns the current umask otherwise the old umask is returned.



Example #1 umask() example

<?php
$old = umask(0);
chmod("/path/some_dir/some_file.txt", 0755);
umask($old);

// Checking
if ($old != umask()) {
    die('An error occurred while changing back the umask');
}
?>


Note:
Avoid using this function in multithreaded webservers. It is better to change the file permissions with chmod() after creating the file. Using umask() can lead to unexpected behavior of concurrently running scripts and the webserver itself because they all use the same umask.