|GETPGRP(2)||System Calls Manual||GETPGRP(2)|
— get process group
The process group of the current process is returned by
The process group of the pid process is returned by
If pid is zero,
returns the process group of the current process.
Process groups are used for distribution of signals, and by terminals to arbitrate requests for their input: processes that have the same process group as the terminal are foreground and may read, while others will block with a signal if they attempt to read.
These calls are thus used by programs such as
csh(1) to create process groups
in implementing job control. The
calls are used to get/set the process group of the control terminal.
getpgrp() always succeeds, however
getpgid() will succeed unless:
This version of
getpgrp() differs from
past Berkeley versions by not taking a pid_t pid
argument. This incompatibility is required by IEEE Std
From the IEEE Std 1003.1-1988 (“POSIX.1”) Rationale:
4.3BSD provides a
getpgrp() function that returns the process group ID
for a specified process. Although this function is used to support job
control, all known job-control shells always specify the calling process
with this function. Thus, the simpler System V
getpgrp() suffices, and the added complexity of the
getpgrp() has been
omitted from POSIX.1.
getpgrp() function conforms to
IEEE Std 1003.1-1988 (“POSIX.1”). The
getpgid() function call is derived from its usage in
System V Release 4, and first appeared in NetBSD
getpgrp() function call appeared in
|July 21, 2007||OpenBSD-5.1|