getppid() of a process (not necessarily the one who calls getppid)

ksames · 10-25-2009, 01:34 PM

Hello people!

I have a program in C that fork()'s a child, which in turn fork()'s another one. Is there some function to use in the last child to find the parent's ppid?

I am looking for a way to implement getppid(getppid()) which is not available through the C library since getppid() doesn't accept arguments..

I know can find the parents ppid in other ways, like store it in some variable etc, but I was wondering whether there exists such a function!

Thanks in advance!

nadroj · 10-25-2009, 01:50 PM

I dont think there is a function to get a parent's parent's PID, like a "getpppid()". I dont think it exists because there isnt really anything "special" about a parent's parent's PID. In other words, if there were a "getpppid()", why wouldnt there be a "getppppid", or a "getpppppid", etc. (of course theres other ways this could have been implemented). I think you would have to go with your other method, such as passing the parent's PID to its first child, which passes that same value to its new child.

Hko · 10-25-2009, 01:57 PM

See this thread: http://www.linuxquestions.org/questi...rocess-276839/

And this seems to be for OSX, but might work as well for linux:
http://www.objectpark.net/parentpid.html

ksames · 10-25-2009, 02:04 PM

Nadroj, you missed the point.. I was not looking for a getpppppppppppid() etc, I was looking for a getppid(foo) where foo is ANY current process' PID.. and I would simply use the PID of getppid(). Anyways!

Thank you both, 'specially Hko, this is what I was looking for.
Best regards!

ta0kira · 10-25-2009, 02:52 PM

How exactly do programs like ksysguard give you a process tree? That might be worth looking into.
Kevin Barry