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.Dd November 28, 2022 26.Dt TCGETSID 3 27.Os 28.Sh NAME 29.Nm tcgetsid 30.Nd get session ID associated with a controlling terminal 31.Sh LIBRARY 32.Lb libc 33.Sh SYNOPSIS 34.In termios.h 35.Ft pid_t 36.Fn tcgetsid "int fd" 37.Sh DESCRIPTION 38The 39.Fn tcgetsid 40function returns the process group ID of the session leader for a 41controlling terminal specified by 42.Fa fd . 43.Sh ERRORS 44If an error occurs, 45.Fn tcgetsid 46returns -1 and the global variable 47.Va errno 48is set to indicate the error, as follows: 49.Bl -tag -width Er 50.It Bq Er EBADF 51The 52.Fa fd 53argument is not a valid file descriptor. 54.It Bq Er ENOTTY 55The calling process does not have a controlling terminal or the 56underlying terminal device represented by 57.Fa fd 58is not the controlling terminal. 59.El 60.Sh SEE ALSO 61.Xr getsid 2 , 62.Xr setsid 2 , 63.Xr tcgetpgrp 3 , 64.Xr tcsetsid 3 65.Sh STANDARDS 66The 67.Fn tcgetsid 68function conforms to 69.St -xpg4.2 . 70