[unix-history] / lib / libc / sys / getpgrp.2

.\" Copyright (c) 1983, 1991 Regents of the University of California.
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"     @(#)getpgrp.2	6.4 (Berkeley) 3/10/91
.\"
.Dd March 10, 1991
.Dt GETPGRP 2
.Os BSD 4.2
.Sh NAME
.Nm getpgrp
.Nd get process group
.Sh SYNOPSIS
.Fd #include <unistd.h>
.Ft pid_t
.Fn getpgrp "void"
.Sh DESCRIPTION
The process group of the current process is returned by
.Fn getpgrp .
.Pp
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.
.Pp
This call is thus used by programs such as
.Xr csh 1
to create
process groups
in implementing job control.
The
.Dv TIOCGPGRP
and
.Dv TIOCSPGRP
calls
described in
.Xr termios 4
are used to get/set the process group of the control terminal.
.Sh SEE ALSO
.Xr setpgrp 2 ,
.Xr getuid 2 ,
.Xr termios 4
.Sh HISTORY
The
.Nm
function call appeared in
.Bx 4.0 .
.Sh STANDARDS
The
.Fn getpgrp
function conforms to IEEE Std 1003.1-1988
.Pq Dq Tn POSIX .
.Sh COMPATABILITY
This version of
.Fn getpgrp
differs from past Berkeley versions by not taking a
.Fa "pid_t pid"
argument.
This incompatibility is required by
.St -p1003.1-88 .
Commit	Line	Data
15637ed4 RG	1	.\" Copyright (c) 1983, 1991 Regents of the University of California.
	2	.\" All rights reserved.
	3	.\"
	4	.\" Redistribution and use in source and binary forms, with or without
	5	.\" modification, are permitted provided that the following conditions
	6	.\" are met:
	7	.\" 1. Redistributions of source code must retain the above copyright
	8	.\" notice, this list of conditions and the following disclaimer.
	9	.\" 2. Redistributions in binary form must reproduce the above copyright
	10	.\" notice, this list of conditions and the following disclaimer in the
	11	.\" documentation and/or other materials provided with the distribution.
	12	.\" 3. All advertising materials mentioning features or use of this software
	13	.\" must display the following acknowledgement:
	14	.\" This product includes software developed by the University of
	15	.\" California, Berkeley and its contributors.
	16	.\" 4. Neither the name of the University nor the names of its contributors
	17	.\" may be used to endorse or promote products derived from this software
	18	.\" without specific prior written permission.
	19	.\"
	20	.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	21	.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	22	.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	23	.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	24	.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	25	.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	26	.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	27	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	28	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	29	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	30	.\" SUCH DAMAGE.
	31	.\"
	32	.\" @(#)getpgrp.2 6.4 (Berkeley) 3/10/91
	33	.\"
	34	.Dd March 10, 1991
	35	.Dt GETPGRP 2
	36	.Os BSD 4.2
	37	.Sh NAME
	38	.Nm getpgrp
	39	.Nd get process group
	40	.Sh SYNOPSIS
78ed81a3	41	.Fd #include <unistd.h>
15637ed4	42	.Ft pid_t
78ed81a3	43	.Fn getpgrp "void"
15637ed4	44	.Sh DESCRIPTION
78ed81a3	45	The process group of the current process is returned by
15637ed4	46	.Fn getpgrp .
15637ed4 RG	47	.Pp
	48	Process groups are used for distribution of signals, and
	49	by terminals to arbitrate requests for their input: processes
	50	that have the same process group as the terminal are foreground
	51	and may read, while others will block with a signal if they attempt
	52	to read.
	53	.Pp
	54	This call is thus used by programs such as
	55	.Xr csh 1
	56	to create
	57	process groups
	58	in implementing job control.
	59	The
	60	.Dv TIOCGPGRP
	61	and
	62	.Dv TIOCSPGRP
	63	calls
	64	described in
	65	.Xr termios 4
	66	are used to get/set the process group of the control terminal.
	67	.Sh SEE ALSO
	68	.Xr setpgrp 2 ,
	69	.Xr getuid 2 ,
	70	.Xr termios 4
	71	.Sh HISTORY
	72	The
	73	.Nm
	74	function call appeared in
	75	.Bx 4.0 .
78ed81a3	76	.Sh STANDARDS
	77	The
	78	.Fn getpgrp
	79	function conforms to IEEE Std 1003.1-1988
	80	.Pq Dq Tn POSIX .
	81	.Sh COMPATABILITY
	82	This version of
	83	.Fn getpgrp
	84	differs from past Berkeley versions by not taking a
	85	.Fa "pid_t pid"
	86	argument.
	87	This incompatibility is required by
	88	.St -p1003.1-88 .