1.\" $OpenBSD: tcgetsid.3,v 1.2 2017/10/17 22:47:58 schwarze Exp $ 2.\" 3.\" Copyright (c) 1991 The Regents of the University of California. 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.Dd $Mdocdate: October 17 2017 $ 31.Dt TCGETSID 3 32.Os 33.Sh NAME 34.Nm tcgetsid 35.Nd get session ID associated with a controlling terminal 36.Sh SYNOPSIS 37.In termios.h 38.Ft pid_t 39.Fn tcgetsid "int fd" 40.Sh DESCRIPTION 41The 42.Fn tcgetsid 43function returns the value of the session ID associated with the specified 44controlling terminal device. 45The session ID is defined as the process group ID of the session leader. 46.Sh ERRORS 47If an error occurs, 48.Fn tcgetsid 49returns \-1 and the global variable 50.Va errno 51is set to indicate the error, as follows: 52.Bl -tag -width Er 53.It Bq Er EBADF 54The 55.Fa fd 56argument is not a valid file descriptor. 57.It Bq Er ENOTTY 58The calling process does not have a controlling terminal or the 59underlying terminal device represented by 60.Fa fd 61is not the controlling terminal. 62.El 63.Sh SEE ALSO 64.Xr getsid 2 , 65.Xr setsid 2 , 66.Xr tcgetpgrp 3 67.Sh STANDARDS 68The 69.Fn tcgetsid 70function is expected to be compliant with the 71.St -p1003.1-2008 72specification. 73.Sh HISTORY 74The 75.Fn tcgetsid 76function has been available since 77.Ox 5.5 . 78