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
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.
Upon successful completion, getpgid() shall return a process group ID.
Otherwise, it shall return (pid_t)-1 and set errno to indicate
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
- 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.
exec, fork(), getpgrp(),
getpid(), getsid(), setpgid(),
The Base Definitions volume of POSIX.1‐2017,
Portions of this text are reprinted and reproduced in electronic form from IEEE
Std 1003.1-2017, Standard for Information Technology -- Portable Operating
System Interface (POSIX), The Open Group Base Specifications Issue 7, 2018
Edition, Copyright (C) 2018 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 .
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