1.\" Copyright (c) 2008 David Xu <davidxu@FreeBSD.org> 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.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.\" $FreeBSD$ 26.\" 27.Dd November 28, 2022 28.Dt TCGETSID 3 29.Os 30.Sh NAME 31.Nm tcgetsid 32.Nd get session ID associated with a controlling terminal 33.Sh LIBRARY 34.Lb libc 35.Sh SYNOPSIS 36.In termios.h 37.Ft pid_t 38.Fn tcgetsid "int fd" 39.Sh DESCRIPTION 40The 41.Fn tcgetsid 42function returns the process group ID of the session leader for a 43controlling terminal specified by 44.Fa fd . 45.Sh ERRORS 46If an error occurs, 47.Fn tcgetsid 48returns -1 and the global variable 49.Va errno 50is set to indicate the error, as follows: 51.Bl -tag -width Er 52.It Bq Er EBADF 53The 54.Fa fd 55argument is not a valid file descriptor. 56.It Bq Er ENOTTY 57The calling process does not have a controlling terminal or the 58underlying terminal device represented by 59.Fa fd 60is not the controlling terminal. 61.El 62.Sh SEE ALSO 63.Xr getsid 2 , 64.Xr setsid 2 , 65.Xr tcgetpgrp 3 , 66.Xr tcsetsid 3 67.Sh STANDARDS 68The 69.Fn tcgetsid 70function conforms to 71.St -xpg4.2 . 72