could execute php code as a specific user at runtime

[Pocholo]

hello
i would like to create a specific user for sudo operations.

the default php user is the apache user... i don't know if php can to change the user at rumtime for execute some functions...

some like that:

<?php
$user_name="dummy";
$pass="dummy_pass";
change_the_user($user_name,$pass); // <-(exist some function like that?)
exec("sudo mkdir $this->home_dir");
close_change_the_user();
?>

so the /etc/sudoers could be...
dummy ALL=NOPASSWD:/bin/chown

and don't use the apache user.