reading and writing to remote files (not log entries)

Hello, I'm trying to edit and qualify files placed in a respository before publishing. Knowing that this is a simplistic question, Is there a method that can be used to dynamically edit remote files? I've been trying to pass the contents of a <TEXTAREA name="text" formfield with >readfile($filename)</textarea> and then passing $text to $PHP_SELF using an <input type=hidden input field. is it possible to open a file with fsockopen() and read and write to a file? Obviously, I'm doing something wrong, does anyone have any suggestions? thanks, Dan