---
name: "sys_wait.h"
section: "0p"
platform: "linux"
package: "man-pages"
version: "6.19-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/sys_wait.h"
---

# sys\_wait.h(0p)

declarations for waiting

## 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 .