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.\" $DragonFly: src/lib/libc/gen/tcgetpgrp.3,v 1.2 2003/06/17 04:26:42 dillon Exp $ 35.\" 36.Dd June 4, 1993 37.Dt TCGETPGRP 3 38.Os 39.Sh NAME 40.Nm tcgetpgrp 41.Nd get foreground process group ID 42.Sh LIBRARY 43.Lb libc 44.Sh SYNOPSIS 45.In sys/types.h 46.In unistd.h 47.Ft pid_t 48.Fn tcgetpgrp "int fd" 49.Sh DESCRIPTION 50The 51.Fn tcgetpgrp 52function returns the value of the process group ID of the foreground 53process group associated with the terminal device. 54If there is no foreground process group, 55.Fn tcgetpgrp 56returns an invalid process ID. 57.Sh ERRORS 58If an error occurs, 59.Fn tcgetpgrp 60returns -1 and the global variable 61.Va errno 62is set to indicate the error, as follows: 63.Bl -tag -width Er 64.It Bq Er EBADF 65The 66.Fa fd 67argument is not a valid file descriptor. 68.It Bq Er ENOTTY 69The calling process does not have a controlling terminal or the 70underlying terminal device represented by 71.Fa fd 72is not the controlling terminal. 73.El 74.Sh SEE ALSO 75.Xr setpgid 2 , 76.Xr setsid 2 , 77.Xr tcsetpgrp 3 78.Sh STANDARDS 79The 80.Fn tcgetpgrp 81function is expected to be compliant with the 82.St -p1003.1-88 83specification. 84