The <sys/wait.h> header shall define the following symbolic
constants for use with waitpid():
Do not hang if no status is available; return
Report status of stopped child process.
The <sys/wait.h> header shall define the following macros for
analysis of process status values:
Return exit status.
True if child has been continued.
True if child exited normally.
True if child exited due to uncaught signal.
True if child is currently stopped.
Return signal number that caused process to stop.
Return signal number that caused process to terminate.
The following symbolic constants shall be defined as possible values for the
options argument to waitid():
Wait for processes that have exited.
Status is returned for any child that has stopped upon
receipt of a signal.
Status is returned for any child that was stopped and has
Return immediately if there are no children to wait
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
The siginfo_t type shall be defined as described in
The rusage structure shall be defined as described in
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.
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