How to set permission for a folder without cpanel access

Hello iam using wordpress and i need to set permission for a plugin folder to be 755, Iam the admin of the blog bu开发者_JAVA百科t i don't have permission in the cpanel is their a way to do it using php or any other stuff? badly need some help....

PHP you say?

chmod("/foo/bar", 0755);

http://php.net/manual/en/function.chmod.php