NAME
getpgrp - get process group

SYNOPSIS
pgrp = getpgrp(pid)
int pgrp;
int pid;

DESCRIPTION
The process group of the specified process is returned by getpgrp.
If pid is zero, then the call applies to 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.

This call is thus used by programs such as csh(1) to create process
groups in implementing job control. The TIOCGPGRP and TIOCSPGRP
calls described in tty(4) are used to get/set the process group of
the control terminal.

SEE ALSO
setpgrp(2), getuid(2), tty(4)