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 .