The getppid() function shall return the parent process ID of
the calling process.
The getppid() function shall always be successful and no return
value is reserved to indicate an error.
No errors are defined.
The following sections are informative.
exec() , fork() , getpgid() , getpgrp() ,
getpid() , kill() , setpgid() , setsid() ,
Base Definitions volume of IEEE Std 1003.1-2001, <sys/types.h>,
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