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. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.Dd October 1, 2011 29.Dt CTERMID 3 30.Os 31.Sh NAME 32.Nm ctermid 33.Nd generate terminal pathname 34.Sh LIBRARY 35.Lb libc 36.Sh SYNOPSIS 37.In stdio.h 38.Ft char * 39.Fn ctermid "char *buf" 40.Ft char * 41.Fn ctermid_r "char *buf" 42.Sh DESCRIPTION 43The 44.Fn ctermid 45function generates a string, that, when used as a pathname, refers to 46the current controlling terminal of the calling process. 47.Pp 48If 49.Fa buf 50is the 51.Dv NULL 52pointer, a pointer to a static area is returned. 53Otherwise, the pathname is copied into the memory referenced by 54.Fa buf . 55The argument 56.Fa buf 57is assumed to be at least 58.Dv L_ctermid 59(as defined in the include 60file 61.In stdio.h ) 62bytes long. 63.Pp 64The 65.Fn ctermid_r 66function 67provides the same functionality as 68.Fn ctermid 69except that if 70.Fa buf 71is a 72.Dv NULL 73pointer, 74.Dv NULL 75is returned. 76.Pp 77If no suitable lookup of the controlling terminal name can be performed, 78this implementation returns 79.Ql /dev/tty . 80.Sh RETURN VALUES 81Upon successful completion, a 82.Pf non- Dv NULL 83pointer is returned. 84Otherwise, a 85.Dv NULL 86pointer is returned and the global variable 87.Va errno 88is set to indicate the error. 89.Sh ERRORS 90The current implementation detects no error conditions. 91.Sh SEE ALSO 92.Xr ttyname 3 93.Sh STANDARDS 94The 95.Fn ctermid 96function conforms to 97.St -p1003.1-88 . 98.Sh BUGS 99By default the 100.Fn ctermid 101function 102writes all information to an internal static object. 103Subsequent calls to 104.Fn ctermid 105will modify the same object. 106