How do I create file on server?

Question

Let say I want create file call style.css in /css/ folder.

Example : When I click Save button script will create style.css with content

Answer 1

$data = "body {background:#fff;}
a {color:#333; text-decoration:none; }";

if (false === file_put_contents('/css/style.css', $data))
   echo 'Please chmod 777 to /css/ folder';