sys_wait.h(7POSIX)

PROLOG
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.

NAME
sys/wait.h — declarations for waiting

SYNOPSIS

#include <sys/wait.h>

DESCRIPTION
The <sys/wait.h> header shall define the following symbolic constants for use with waitpid():

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 values:

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 waitid().

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 <sys/types.h>.

The <sys/wait.h> header shall define the siginfo_t type and the sigval union 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.

APPLICATION USAGE
None.

RATIONALE
None.

FUTURE DIRECTIONS
None.

SEE ALSO
<signal.h>, <sys_resource.h>, <sys_types.h>

The System Interfaces volume of POSIX.1-2017, wait(), waitid()

COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy 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.opengroup.org/unix/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 .