You should forward this to the AZPHP user group.
http://azphp.org


> A customer of ours is using a program named microcom called from his own
> php scripts to interface with it. He wants to know how he can put an
> exlusive lock on the program from php and then release it. He's doing
> this so more than one person can use microcom (which is hooked up to a
> device sitting on the serial port). He said that flock() in php only
> works with file pointers, not processes.