|GETPGRP(2)||System Calls Manual||GETPGRP(2)|
getpgrp(). The process group of the pid process is returned by
getpgid(). If pid is zero,
getpgid() 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
tcsetpgrp() calls are used to get/set the process
group of the control terminal.
getpgrp() always succeeds, however
getpgid() will succeed unless:
getpgid() functions conform to IEEE Std 1003.1-2008 (“POSIX.1”).
getpgrp() function call that took a pid_t pid argument appeared in 4.0BSD. This version, without an argument, is derived from its usage in System V Release 4, and first appeared in NetBSD 0.9.
getpgid() function call is derived
from its usage in System V Release 4, and first appeared in
|September 10, 2015||OpenBSD-current|