1.\" $NetBSD: posix_openpt.3,v 1.4 2008/04/30 13:10:51 martin Exp $ 2.\" 3.\" Copyright (c) 2004 The NetBSD Foundation, Inc. 4.\" All rights reserved. 5.\" 6.\" This code is derived from software contributed to The NetBSD Foundation 7.\" by Christos Zoulas. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 19.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 20.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 21.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 22.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28.\" POSSIBILITY OF SUCH DAMAGE. 29.\" 30.Dd May 25, 2004 31.Dt POSIX_OPENPT 3 32.Os 33.Sh NAME 34.Nm posix_openpt 35.Nd open a pseudo-terminal device 36.Sh LIBRARY 37.Lb libc 38.Sh SYNOPSIS 39.In stdlib.h 40.In fcntl.h 41.Ft int 42.Fn posix_openpt "int oflag" 43.Sh DESCRIPTION 44.Fn posix_openpt 45Searches for an unused master pseudo-terminal device, opens it, and returns 46a file descriptor associated the now used pseudo-terminal device. 47The 48.Fa oflag 49argument has the same meaning as in the 50.Xr open 2 51call. 52.Sh RETURN VALUES 53If successful, 54.Fn posix_openpt 55returns a non-negative integer, which corresponds to a file descriptor 56pointing to the master pseudo-terminal device. 57Otherwise, a value of \-1 is returned and 58.Va errno 59is set to indicate the error. 60.Sh SEE ALSO 61.Xr ioctl 2 , 62.Xr open 2 , 63.Xr grantpt 3 , 64.Xr ptsname 3 , 65.Xr unlockpt 3 66.Sh RATIONALE 67The standards committee did not want to directly expose the cloning device, 68thus decided to wrap the functionality in this function. 69The equivalent code would be: 70.Bd -literal 71 int 72 posix_openpt(int oflag) { 73 return open("/dev/ptmx", oflag); 74 } 75.Ed 76.Sh STANDARDS 77The 78.Fn posix_openpt 79function conforms to 80.St -p1003.1-2001 . 81