getpgid man page


This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

getpgid — get the process group ID for a process


#include <unistd.h>

pid_t getpgid(pid_t pid);


The getpgid() function shall return the process group ID of the process whose process ID is equal to pid. If pid is equal to 0, getpgid() shall return the process group ID of the calling process.

Return Value

Upon successful completion, getpgid() shall return a process group ID. Otherwise, it shall return (pid_t)-1 and set errno to indicate the error.


The getpgid() function shall fail if:

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.
There is no process with a process ID equal to pid.

The getpgid() function may fail if:

The value of the pid argument is invalid.

The following sections are informative.

See Also

exec, fork(), getpgrp(), getpid(), getsid(), setpgid(), setsid()

The Base Definitions volume of POSIX.1‐2008, <unistd.h>