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 .