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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | CONFORMING TO | NOTES | SEE ALSO | COLOPHON |
WAIT4(2) Linux Programmer's Manual WAIT4(2)
wait3, wait4 - wait for process to change state, BSD style
#include <sys/types.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/wait.h>
pid_t wait3(int *wstatus, int options,
struct rusage *rusage);
pid_t wait4(pid_t pid, int *wstatus, int options,
struct rusage *rusage);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
wait3():
Since glibc 2.19:
_DEFAULT_SOURCE || _XOPEN_SOURCE >= 500
Glibc 2.19 and earlier:
_BSD_SOURCE || _XOPEN_SOURCE >= 500
wait4():
Since glibc 2.19:
_DEFAULT_SOURCE
Glibc 2.19 and earlier:
_BSD_SOURCE
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(wstatus, options, rusage);
is equivalent to:
waitpid(-1, wstatus, options);
Similarly, the following wait4() call:
wait4(pid, wstatus, options, rusage);
is equivalent to:
waitpid(pid, wstatus, 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.
As for waitpid(2).
As for waitpid(2).
4.3BSD.
SUSv1 included a specification of wait3(); SUSv2 included wait3(),
but marked it LEGACY; SUSv3 removed it.
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>.)
C library/kernel differences
On Linux, wait3() is a library function implemented on top of the
wait4() system call.
fork(2), getrusage(2), sigaction(2), signal(2), wait(2), signal(7)
This page is part of release 4.12 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
https://www.kernel.org/doc/man-pages/.
Linux 2016-03-15 WAIT4(2)
Pages that refer to this page: time(1), _exit(2), getrusage(2), syscalls(2), wait(2), popen(3), signal(7)