WAIT4(2)                            Linux Programmer's Manual                            WAIT4(2)



NAME
       wait3, wait4 - wait for process to change state, BSD style

SYNOPSIS
       #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);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       wait3():
           _BSD_SOURCE || _XOPEN_SOURCE >= 500 || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED
       wait4():
           _BSD_SOURCE

DESCRIPTION
       These functions are obsolete; use waitpid(2) or waitid(2) in new programs.

       The  wait3()  and  wait4() system calls are similar to waitpid(2), but additionally return
       resource usage information about the child in the structure pointed to by 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.

RETURN VALUE
       As for waitpid(2).

ERRORS
       As for waitpid(2).

CONFORMING TO
       4.3BSD.

       SUSv1 included a specification of wait3(); SUSv2 included wait3(), but marked  it  LEGACY;
       SUSv3 removed it.

NOTES
       Including  <sys/time.h>  is  not required these days, but increases portability.  (Indeed,
       <sys/resource.h> defines the rusage structure with fields of type struct  timeval  defined
       in <sys/time.h>.)

       On Linux, wait3() is a library function implemented on top of the wait4() system call.

SEE ALSO
       fork(2), getrusage(2), sigaction(2), signal(2), wait(2), signal(7)

COLOPHON
       This  page  is  part of release 3.74 of the Linux man-pages project.  A description of the
       project, information about reporting bugs, and the latest version of  this  page,  can  be
       found at http://www.kernel.org/doc/man-pages/.



Linux                                       2012-09-23                                   WAIT4(2)