title: PHP,Linux,Apache: naming file based on user input
body: <p>whats up guys?
  so my question is simple: my application receives the name of the file as a $_POST['fieldname'] from user and then create the file in a folder on server, or in another case using the $_POST['fieldname'] return the path of the file if file exists. so, is it safe?!
  thank you guys!</p>