RE: [PHP] Re: Ensure only one instance of a script is running

[snip]
> Unluckily, this will not prevent a race condition. The only
> file operations that are guaranteed to be atomic are mkdir()
> and symlink(). Try to create the directory and see if it
> fails. Also remember to rmdir() the lock directory before exiting

How about grabbing the output from `ps -ax` and looping thourhgthe results
to see if your script is being run?

HTH,

Mikey