Manual Reference Pages  - <sys/wait.h> (P)

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.

CONTENTS

Name
Synopsis
Description
Application Usage
Rationale
Future Directions
See Also
Copyright

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():
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 following symbolic constants shall be defined as possible values for the options argument to waitid():
WEXITED Wait for processes that have exited.
WSTOPPED
  Status is returned for any child that has stopped upon receipt of a signal.
WCONTINUED
  Status is returned for any child that was stopped and has been continued.
WNOHANG Return immediately if there are no children to wait for.
WNOWAIT Keep the process whose status is returned in infop in a waitable state.

The type idtype_t shall be defined as an enumeration type whose possible values shall include at least the following: P_ALL P_PID P_PGID

The id_t and pid_t types shall be defined as described in <sys/types.h> .

The siginfo_t type shall be defined as described in <signal.h> .

The rusage structure shall be defined as described in <sys/resource.h> .

Inclusion of the <sys/wait.h> header may also make visible all symbols from <signal.h> and <sys/resource.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 IEEE Std 1003.1-2001, wait(), waitid()

COPYRIGHT

Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 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 .


IEEE/The Open Group <sys/wait.h> (P) 2003
blog comments powered by Disqus