Writing to Config File

[josephnexus]

I'm trying to learn how to write my own custom php scripts to modify the config.  I've got some code that works wonderfully (it is used for adding users to a specific group).  I'm wanting to now start using this in a production environment, but I have some concerns first.

Mostly, how can I ensure that if two people hit this script at the same time that the last one to hit the script will not destroy the first one's settings?  I see that there is some locking/unlocking that happens.  Can I just check if -1 was returned when calling write_config() and if so, reload the config, reapply my settings, and try again?  Would something like that work?

Thanks a ton!