xref: /csrg-svn/lib/libc/sys/getpgrp.2 (revision 47208)
1*47208Scael.\" Copyright (c) 1983, 1991 Regents of the University of California.
2*47208Scael.\" All rights reserved.
320235Smckusick.\"
4*47208Scael.\" %sccs.include.redist.man%
520235Smckusick.\"
6*47208Scael.\"     @(#)getpgrp.2	6.4 (Berkeley) 03/10/91
7*47208Scael.\"
8*47208Scael.Dd
9*47208Scael.Dt GETPGRP 2
10*47208Scael.Os BSD 4.2
11*47208Scael.Sh NAME
12*47208Scael.Nm getpgrp
13*47208Scael.Nd get process group
14*47208Scael.Sh SYNOPSIS
15*47208Scael.Ft pid_t
16*47208Scael.Fn getpgrp "int pid"
17*47208Scael.Sh DESCRIPTION
1820235SmckusickThe process group of the specified process is returned by
19*47208Scael.Fn getpgrp .
2020235SmckusickIf
21*47208Scael.Fa pid
22*47208Scaelis zero, the call applies to the current process.
23*47208Scael.Pp
2420235SmckusickProcess groups are used for distribution of signals, and
2520235Smckusickby terminals to arbitrate requests for their input: processes
2623805Ssechrestthat have the same process group as the terminal are foreground
2720235Smckusickand may read, while others will block with a signal if they attempt
2820235Smckusickto read.
29*47208Scael.Pp
3020235SmckusickThis call is thus used by programs such as
31*47208Scael.Xr csh 1
3220235Smckusickto create
3320235Smckusickprocess groups
3420235Smckusickin implementing job control.
35*47208ScaelThe
36*47208Scael.Dv TIOCGPGRP
37*47208Scaeland
38*47208Scael.Dv TIOCSPGRP
39*47208Scaelcalls
4020235Smckusickdescribed in
41*47208Scael.Xr termios 4
4220235Smckusickare used to get/set the process group of the control terminal.
43*47208Scael.Sh SEE ALSO
44*47208Scael.Xr setpgrp 2 ,
45*47208Scael.Xr getuid 2 ,
46*47208Scael.Xr termios 4
47*47208Scael.Sh HISTORY
48*47208ScaelThe
49*47208Scael.Nm
50*47208Scaelfunction call appeared in
51*47208Scael.Bx 4.0 .
52