1.\" Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org> 2.\" All rights reserved. 3.\" 4.\" Portions of this software were developed under sponsorship from Snow 5.\" B.V., the Netherlands. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.\" Portions of this text are reprinted and reproduced in electronic form 29.\" from IEEE Std 1003.1, 2004 Edition, Standard for Information Technology -- 30.\" Portable Operating System Interface (POSIX), The Open Group Base 31.\" Specifications Issue 6, Copyright (C) 2001-2004 by the Institute of 32.\" Electrical and Electronics Engineers, Inc and The Open Group. In the 33.\" event of any discrepancy between this version and the original IEEE and 34.\" The Open Group Standard, the original IEEE and The Open Group Standard is 35.\" the referee document. The original Standard can be obtained online at 36.\" http://www.opengroup.org/unix/online.html. 37.\" 38.Dd September 21, 2016 39.Dt POSIX_OPENPT 2 40.Os 41.Sh NAME 42.Nm posix_openpt 43.Nd "open a pseudo-terminal device" 44.Sh LIBRARY 45.Lb libc 46.Sh SYNOPSIS 47.In fcntl.h 48.In stdlib.h 49.Ft int 50.Fn posix_openpt "int oflag" 51.Sh DESCRIPTION 52The 53.Fn posix_openpt 54function allocates a new pseudo-terminal and establishes a connection 55with its master device. 56A slave device shall be created in 57.Pa /dev/pts . 58After the pseudo-terminal has been allocated, the slave device should 59have the proper permissions before it can be used (see 60.Xr grantpt 3 ) . 61The name of the slave device can be determined by calling 62.Xr ptsname 3 . 63.Pp 64The file status flags and file access modes of the open file description 65shall be set according to the value of 66.Fa oflag . 67Values for 68.Fa oflag 69are constructed by a bitwise-inclusive OR of flags from the following 70list, defined in 71.In fcntl.h : 72.Bl -tag -width ".Dv O_CLOEXEC" 73.It Dv O_RDWR 74Open for reading and writing. 75.It Dv O_NOCTTY 76If set 77.Fn posix_openpt 78shall not cause the terminal device to become the controlling terminal 79for the process. 80.It Dv O_CLOEXEC 81Set the close-on-exec flag for the new file descriptor. 82.El 83.Pp 84The 85.Fn posix_openpt 86function shall fail when 87.Fa oflag 88contains other values. 89.Sh RETURN VALUES 90Upon successful completion, the 91.Fn posix_openpt 92function shall allocate a new pseudo-terminal device and return a 93non-negative integer representing a file descriptor, which is connected 94to its master device. 95Otherwise, -1 shall be returned and errno set to indicate the error. 96.Sh ERRORS 97The 98.Fn posix_openpt 99function shall fail if: 100.Bl -tag -width Er 101.It Bq Er ENFILE 102The system file table is full. 103.It Bq Er EINVAL 104The value of 105.Fa oflag 106is not valid. 107.It Bq Er EAGAIN 108Out of pseudo-terminal resources. 109.El 110.Sh SEE ALSO 111.Xr ptsname 3 , 112.Xr pts 4 , 113.Xr tty 4 114.Sh STANDARDS 115The 116.Fn posix_openpt 117function conforms to 118.St -p1003.1-2001 . 119The ability to use 120.Dv O_CLOEXEC 121is an extension to the standard. 122.Sh HISTORY 123The 124.Fn posix_openpt 125function appeared in 126.Fx 5.0 . 127In 128.Fx 8.0 , 129this function was changed to a system call. 130.Sh NOTES 131The flag 132.Dv O_NOCTTY 133is included for compatibility; in 134.Fx , 135opening a terminal does not cause it to become a process's controlling 136terminal. 137.Sh AUTHORS 138.An \&Ed Schouten Aq Mt ed@FreeBSD.org 139