The GNU C Library also provides the
wait3 function for compatibility
with BSD. This function is declared in sys/wait.h. It is the
wait4, which is more flexible.
Preliminary: | MT-Safe | AS-Safe | AC-Safe | See POSIX Safety Concepts.
If usage is a null pointer,
wait3 is equivalent to
waitpid (-1, status-ptr, options).
If usage is not null,
wait3 stores usage figures for the
child process in
*rusage (but only if the child has
terminated, not if it has stopped). See Resource Usage.