How can I detect whether an /etc/rc.d/init.d script is being run at boot time versus by hand?

[Bill Freeman]

I'm trying to figure out whether to force the removal of an almost
certainly stale pid file or not in the service start case.

While I presume that the start up sequence normally handles this by
clearing /var/run before lighting off the init scripts for the level, I
have a need to have my pid file in an unusual place (needs to be written
and deleted by a non-root process).

I'd like start at boot to be automatic, and if shutdown was clean, it will
be.  But if the system crashes (or someone hits the reset button, etc.)
there will be a stale pid file come boot time.

I'd like to automatically delete any stale pid file at boot time, but start
later should fail claiming that there's an existing process.

So, can I count on parent pid, or maybe process group id, to identify the
at boot time case?  Or would that be unwise?

Bill
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mail.gnhlug.org/mailman/private/gnhlug-discuss/attachments/20130521/3545f72a/attachment.html