Programmatically get parent pid of another process?

Question

I tried google, but found getppid() which gets the parent pid of the current process.

I need something like getppid(some_other_pid), is there such a thing? Basically takes the pid of some process and returns the parent process' pid.

Answer 1

I think the simplest thing would be to open "/proc" and parse the contents.

You'll find the ppid as the 4th parameter of /proc/pid/stat

In C, libproc has a get_proc_stats function for parsing that file: see Given a child PID how can you get the parent PID for an example.