1.\" $NetBSD: ctermid.3,v 1.11 2010/03/22 19:30:53 joerg Exp $ 2.\" 3.\" Copyright (c) 1990, 1991, 1993 4.\" The Regents of the University of California. 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.\" @(#)ctermid.3 8.1 (Berkeley) 6/4/93 31.\" 32.Dd June 4, 1993 33.Dt CTERMID 3 34.Os 35.Sh NAME 36.Nm ctermid 37.Nd generate terminal pathname 38.Sh LIBRARY 39.Lb libc 40.Sh SYNOPSIS 41.In 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 point to an array at least 60.Dv L_ctermid 61bytes long (as defined in the include file 62.In stdio.h ) . 63.Pp 64The current implementation simply returns 65.Ql /dev/tty . 66.Sh RETURN VALUES 67Upon successful completion, a 68.Pf non- Dv NULL 69pointer is returned. 70Otherwise, a 71.Dv NULL 72pointer is returned and the global variable 73.Va errno 74is set to indicate the error. 75.Sh ERRORS 76The current implementation detects no error conditions. 77.Sh SEE ALSO 78.Xr ttyname 3 79.Sh STANDARDS 80The 81.Fn ctermid 82function conforms to 83.St -p1003.1-90 . 84.Sh BUGS 85By default the 86.Fn ctermid 87function writes all information to an internal static object. 88Subsequent calls to 89.Fn ctermid 90will modify the same object. 91