sys_wait.h(7POSIX) POSIX Programmer's Manual sys_wait.h(7POSIX)
This manual page is part of the POSIX Programmer's Manual. The Linux implementation of
this interface may differ (consult the corresponding Linux manual page for details of
Linux behavior), or the interface may not be implemented on Linux.
sys/wait.h — declarations for waiting
The <sys/wait.h> header shall define the following symbolic constants for use with wait‐
WCONTINUED Report status of continued child process.
WNOHANG Do not hang if no status is available; return immediately.
WUNTRACED Report status of stopped child process.
The <sys/wait.h> header shall define the following macros for analysis of process status
WEXITSTATUS Return exit status.
WIFCONTINUED True if child has been continued.
WIFEXITED True if child exited normally.
WIFSIGNALED True if child exited due to uncaught signal.
WIFSTOPPED True if child is currently stopped.
WSTOPSIG Return signal number that caused process to stop.
WTERMSIG Return signal number that caused process to terminate.
The <sys/wait.h> header shall define the following symbolic constants as possible values
for the options argument to waitid():
WEXITED Wait for processes that have exited.
WNOWAIT Keep the process whose status is returned in infop in a waitable state.
WSTOPPED Status is returned for any child that has stopped upon receipt of a signal.
The WCONTINUED and WNOHANG constants, described above for waitpid(), can also be used with
The type idtype_t shall be defined as an enumeration type whose possible values shall
include at least the following: P_ALL P_PGID P_PID
The <sys/wait.h> header shall define the id_t and pid_t types as described in
The <sys/wait.h> header shall define the siginfo_t type as described in <signal.h>.
Inclusion of the <sys/wait.h> header may also make visible all symbols from <signal.h>.
The following shall be declared as functions and may also be defined as macros. Function
prototypes shall be provided.
pid_t wait(int *);
int waitid(idtype_t, id_t, siginfo_t *, int);
pid_t waitpid(pid_t, int *, int);
The following sections are informative.
The System Interfaces volume of POSIX.1‐2008, wait(), waitid()
Portions of this text are reprinted and reproduced in electronic form from IEEE Std
1003.1, 2013 Edition, Standard for Information Technology -- Portable Operating System
Interface (POSIX), The Open Group Base Specifications Issue 7, Copyright (C) 2013 by the
Institute of Electrical and Electronics Engineers, Inc and The Open Group. (This is
POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the event of any discrep‐
ancy between this version and the original IEEE and The Open Group Standard, the original
IEEE and The Open Group Standard is the referee document. The original Standard can be
obtained online at http://www.unix.org/online.html .
Any typographical or formatting errors that appear in this page are most likely to have
been introduced during the conversion of the source files to man page format. To report
such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2013 sys_wait.h(7POSIX)