The
getpid ();
system call
returns
the process ID of
the calling process.
Though the ID is guaranteed to be unique, it should
NOT
be used for constructing temporary file names, for
security reasons; see
mkstemp(3)
instead.
The
getppid ();
system call
returns the process ID of the parent
of the calling process.
ERRORS
The
getpid ();
and
getppid ();
system calls are always successful, and no return value is reserved to
indicate an error.