1.\" Copyright (c) 1991, 1993 2.\" The Regents of the University of California. 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.\" @(#)tcgetpgrp.3 8.1 (Berkeley) 6/4/93 33.\" $FreeBSD: src/lib/libc/gen/tcgetpgrp.3,v 1.6.2.2 2001/12/14 18:33:51 ru Exp $ 34.\" 35.Dd June 4, 1993 36.Dt TCGETPGRP 3 37.Os 38.Sh NAME 39.Nm tcgetpgrp 40.Nd get foreground process group ID 41.Sh LIBRARY 42.Lb libc 43.Sh SYNOPSIS 44.In sys/types.h 45.In unistd.h 46.Ft pid_t 47.Fn tcgetpgrp "int fd" 48.Sh DESCRIPTION 49The 50.Fn tcgetpgrp 51function returns the value of the process group ID of the foreground 52process group associated with the terminal device. 53If there is no foreground process group, 54.Fn tcgetpgrp 55returns an invalid process ID. 56.Sh ERRORS 57If an error occurs, 58.Fn tcgetpgrp 59returns -1 and the global variable 60.Va errno 61is set to indicate the error, as follows: 62.Bl -tag -width Er 63.It Bq Er EBADF 64The 65.Fa fd 66argument is not a valid file descriptor. 67.It Bq Er ENOTTY 68The calling process does not have a controlling terminal or the 69underlying terminal device represented by 70.Fa fd 71is not the controlling terminal. 72.El 73.Sh SEE ALSO 74.Xr setpgid 2 , 75.Xr setsid 2 , 76.Xr tcsetpgrp 3 77.Sh STANDARDS 78The 79.Fn tcgetpgrp 80function is expected to be compliant with the 81.St -p1003.1-88 82specification. 83