getpid(2) getpid(2)
NAME
getpid, getpgrp, getppid, getpgid - get process, process
group, and parent process IDs
SYNOPSIS
#include <sys/types.h>
#include <unistd.h>
pid_t getpid(void);
pid_t getpgrp(void);
pid_t getppid(void);
pid_t getpgid(pid_t pid);
DESCRIPTION
getpid returns the process ID of the calling process.
getpgrp returns the process group ID of the calling process.
getppid returns the parent process ID of the calling process.
getpgid returns the process group ID of the process whose
process ID is equal to pid, or the process group ID of the
calling process, if pid is equal to zero.
Return Values
On success, getpgid returns a process group ID. On failure,
getpgid returns (pid_t) -1 and sets errno to identify the
error.
Errors
In the following conditions, getpgid fails and sets errno to:
EPERM The process whose process ID is equal to pid is
not in the same session as the calling process,
and the implementation does not allow access to
the process group ID of that process from the
calling process.
ESRCH There is no process with a process ID equal to
pid.
REFERENCES
exec(2), fork(2), getsid(2), intro(2), setpgid(2), setpgrp(2),
setsid(2), signal(2)
Copyright 1994 Novell, Inc. Page 1
getpid(2) getpid(2)
NOTICES
Considerations for Threads Programming
These ID numbers are attributes of the containing process and
are shared by sibling threads.
Copyright 1994 Novell, Inc. Page 2