#include <sys/types.h> #include <sys/time.h> #include <sys/resource.h> #include <sys/wait.h> pid_t wait3(int *status, int options, struct rusage *rusage); pid_t wait4(pid_t pid, int *status, int options, struct rusage *rusage);
Other than the use of the rusage argument, the following wait3() call:
wait3(status, options, rusage);is equivalent to:
waitpid(-1, status, options);Similarly, the following wait4() call:
wait4(pid, status, options, rusage);is equivalent to:
waitpid(pid, status, options);In other words, wait3() waits of any child, while wait4() can be used to select a specific child, or children, on which to wait. See wait(2) for further details.
If rusage is not NULL, the struct rusage to which it points will be filled with accounting information about the child. See getrusage(2) for details.
The prototype for these functions is only available if _BSD_SOURCE is defined.