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.Ft char * 46.Fn ctermid_r "char *buf" 47.Sh DESCRIPTION 48The 49.Fn ctermid 50function generates a string, that, when used as a pathname, refers to 51the current controlling terminal of the calling process. 52.Pp 53If 54.Ar buf 55is the 56.Dv NULL 57pointer, a pointer to a static area is returned. 58Otherwise, the pathname is copied into the memory referenced by 59.Ar buf . 60The argument 61.Ar buf 62is assumed to be at least 63.Dv L_ctermid 64(as defined in the include 65file 66.Aq Pa stdio.h ) 67bytes long. 68.Pp 69.Fn ctermid_r 70provides the same functionality as 71.Fn ctermid 72except that if 73.Ar buf 74is a 75.Dv NULL 76pointer, 77.Dv NULL 78is returned. 79.Pp 80The current implementation simply returns 81.Ql /dev/tty . 82.Sh RETURN VALUES 83Upon successful completion, a 84.Pf non- Dv NULL 85pointer is returned. 86Otherwise, a 87.Dv NULL 88pointer is returned and the global variable 89.Va errno 90is set to indicate the error. 91.Sh ERRORS 92The current implementation detects no error conditions. 93.Sh SEE ALSO 94.Xr ttyname 3 95.Sh STANDARDS 96The 97.Fn ctermid 98function conforms to 99.St -p1003.1-88 . 100.Sh BUGS 101By default the 102.Fn ctermid 103function 104writes all information to an internal static object. 105Subsequent calls to 106.Fn ctermid 107will modify the same object. 108