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. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.Dd November 28, 2022 29.Dt TCGETPGRP 3 30.Os 31.Sh NAME 32.Nm tcgetpgrp 33.Nd get foreground process group ID 34.Sh LIBRARY 35.Lb libc 36.Sh SYNOPSIS 37.In unistd.h 38.Ft pid_t 39.Fn tcgetpgrp "int fd" 40.Sh DESCRIPTION 41The 42.Fn tcgetpgrp 43function returns the value of the process group ID of the foreground 44process group associated with the terminal device. 45If there is no foreground process group, 46.Fn tcgetpgrp 47returns an invalid process ID. 48.Sh ERRORS 49If an error occurs, 50.Fn tcgetpgrp 51returns -1 and the global variable 52.Va errno 53is set to indicate the error, as follows: 54.Bl -tag -width Er 55.It Bq Er EBADF 56The 57.Fa fd 58argument is not a valid file descriptor. 59.It Bq Er ENOTTY 60The calling process does not have a controlling terminal or the 61underlying terminal device represented by 62.Fa fd 63is not the controlling terminal. 64.El 65.Sh SEE ALSO 66.Xr setpgid 2 , 67.Xr setsid 2 , 68.Xr tcsetpgrp 3 69.Sh STANDARDS 70The 71.Fn tcgetpgrp 72function is expected to be compliant with the 73.St -p1003.1-88 74specification. 75