General-purpose system call for waiting for status of a child process.
Linux 2.6.9 (glibc had a broken implementation)
System V derived; now in SUSv3; available on many implementations (not on BSDs!).
More flexible than wait(2) and waitpid(2).
Main functional difference from waitpid(2) is in options argument:
WEXITED (terminated child)
WSTOPPED (stopped child)
WCONTINUED (child resumed by SIGCONT)
waitpid(2) always returns tor "terminated" transition.
Manual page: waitid(2)
(C) 2006, Michael Kerrisk