1.\" Copyright (c) 1990, 1991 The Regents of the University of California. 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.\" 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 5.2 (Berkeley) 4/19/91 33.\" 34.Dd April 19, 1991 35.Dt CTERMID 3 36.Os 37.Sh NAME 38.Nm ctermid 39.Nd generate terminal pathname 40.Sh SYNOPSIS 41.Fd #include <stdio.h> 42.Ft char * 43.Fn ctermid "char *buf" 44.Sh DESCRIPTION 45The 46.Fn ctermid 47function generates a string, that, when used as a pathname, refers to 48the current controlling terminal of the calling process. 49.Pp 50If 51.Ar buf 52is the 53.Dv NULL 54pointer, a pointer to a static area is returned. 55Otherwise, the pathname is copied into the memory referenced by 56.Ar buf . 57The argument 58.Ar buf 59is assumed to be at least 60.Dv L_ctermid 61(as defined in the include 62file 63.Aq Pa stdio.h ) 64bytes long. 65.Pp 66The current implementation simply returns 67.Ql /dev/tty . 68.Sh RETURN VALUES 69Upon successful completion, a 70.Pf non- Dv NULL 71pointer is returned. 72Otherwise, a 73.Dv NULL 74pointer is returned and the global variable 75.Va errno 76is set to indicate the error. 77.Sh ERRORS 78The current implementation detects no error conditions. 79.Sh SEE ALSO 80.Xr ttyname 3 81.Sh STANDARDS 82The 83.Xr ctermid 84function conforms to 85.St -p1003.1-88 . 86.Sh BUGS 87By default the 88.Fn ctermid 89function 90writes all information to an internal static object. 91Subsequent calls to 92.Fn ctermid 93will modify the same object. 94