Lock variable initialisation

[kne]

Hi Everyone,

              I am relatively new to PHP. I have a code(upload.php) which asks files from user, uploads them to a user directory and calls shell script passing the user variable in the process. Since the shell script will be shared by multiple users, i need to implement a lock to restrict users into the script.

 

I want to initialize a lock variable that needs to be in the scope of upload.php but should be initialized somewhere else (so that each time an user uploads file, the lock variable wont keep initializing). Kindly help me out in this.

 

Thanks in advance,

kne