1.\" Copyright (c) 1983, 1991 Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" %sccs.include.redist.man% 5.\" 6.\" @(#)getpgrp.2 6.6 (Berkeley) 08/01/92 7.\" 8.Dd 9.Dt GETPGRP 2 10.Os BSD 4.2 11.Sh NAME 12.Nm getpgrp 13.Nd get process group 14.Sh SYNOPSIS 15.Ft pid_t 16.Fn getpgrp "void" 17.Sh DESCRIPTION 18The process group of the current process is returned by 19.Fn getpgrp . 20.Pp 21Process groups are used for distribution of signals, and 22by terminals to arbitrate requests for their input: processes 23that have the same process group as the terminal are foreground 24and may read, while others will block with a signal if they attempt 25to read. 26.Pp 27This call is thus used by programs such as 28.Xr csh 1 29to create 30process groups 31in implementing job control. 32The 33.Fn tcgetpgrp 34and 35.Fn tcsetpgrp 36calls 37are used to get/set the process group of the control terminal. 38.Sh SEE ALSO 39.Xr setpgid 2 , 40.Xr termios 4 41.Sh HISTORY 42The 43.Nm 44function call appeared in 45.Bx 4.0 . 46.Sh STANDARDS 47The 48.Fn getpgrp 49function conforms to IEEE Std 1003.1-1988 50.Pq Dq Tn POSIX . 51.Sh COMPATABILITY 52This version of 53.Fn getpgrp 54differs from past Berkeley versions by not taking a 55.Fa "pid_t pid" 56argument. 57This incompatibility is required by 58.St -p1003.1-88 . 59.Pp 60From the 61.St -p1003.1-88 62Rationale: 63.sp 644.3BSD provides a 65.Fn getpgrp 66function that returns the process group ID for a specified process. 67Although this function is used to support job control, all known 68job-control shells always specify the calling process with this 69function. 70Thus, the simpler System V 71.Fn getpgrp 72suffices, and the added complexity of the 4.3BSD 73.Fn getpgrp 74has been omitted from POSIX.1. 75