1.\" Copyright (c) 1990, 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.\" @(#)ctermid.3 8.1 (Berkeley) 6/4/93 33.\" $FreeBSD$ 34.\" 35.Dd June 4, 1993 36.Dt CTERMID 3 37.Os 38.Sh NAME 39.Nm ctermid 40.Nd generate terminal pathname 41.Sh SYNOPSIS 42.Fd #include <stdio.h> 43.Ft char * 44.Fn ctermid "char *buf" 45.Sh DESCRIPTION 46The 47.Fn ctermid 48function generates a string, that, when used as a pathname, refers to 49the current controlling terminal of the calling process. 50.Pp 51If 52.Ar buf 53is the 54.Dv NULL 55pointer, a pointer to a static area is returned. 56Otherwise, the pathname is copied into the memory referenced by 57.Ar buf . 58The argument 59.Ar buf 60is assumed to be at least 61.Dv L_ctermid 62(as defined in the include 63file 64.Aq Pa stdio.h ) 65bytes long. 66.Pp 67The current implementation simply returns 68.Ql /dev/tty . 69.Sh RETURN VALUES 70Upon successful completion, a 71.Pf non- Dv NULL 72pointer is returned. 73Otherwise, a 74.Dv NULL 75pointer is returned and the global variable 76.Va errno 77is set to indicate the error. 78.Sh ERRORS 79The current implementation detects no error conditions. 80.Sh SEE ALSO 81.Xr ttyname 3 82.Sh STANDARDS 83The 84.Fn ctermid 85function conforms to 86.St -p1003.1-88 . 87.Sh BUGS 88By default the 89.Fn ctermid 90function 91writes all information to an internal static object. 92Subsequent calls to 93.Fn ctermid 94will modify the same object. 95