1.\" $NetBSD: ioctl.2,v 1.5 1995/02/27 12:33:47 cgd Exp $ 2.\" 3.\" Copyright (c) 1980, 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. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" @(#)ioctl.2 8.2 (Berkeley) 12/11/93 35.\" 36.Dd December 11, 1993 37.Dt IOCTL 2 38.Os BSD 4 39.Sh NAME 40.Nm ioctl 41.Nd control device 42.Sh SYNOPSIS 43.Fd #include <sys/ioctl.h> 44.Ft int 45.Fn ioctl "int d" "unsigned long request" "char *argp" 46.Sh DESCRIPTION 47The 48.Fn ioctl 49function manipulates the underlying device parameters of special files. 50In particular, many operating 51characteristics of character special files (e.g. terminals) 52may be controlled with 53.Fn ioctl 54requests. 55The argument 56.Fa d 57must be an open file descriptor. 58.Pp 59An ioctl 60.Fa request 61has encoded in it whether the argument is an 62.Dq in 63parameter 64or 65.Dq out 66parameter, and the size of the argument 67.Fa argp 68in bytes. 69Macros and defines used in specifying an ioctl 70.Fa request 71are located in the file 72.Ao Pa sys/ioctl.h Ac . 73.Sh RETURN VALUES 74If an error has occurred, a value of -1 is returned and 75.Va errno 76is set to indicate the error. 77.Sh ERRORS 78.Fn Ioctl 79will fail if: 80.Bl -tag -width Er 81.It Bq Er EBADF 82.Fa d 83is not a valid descriptor. 84.It Bq Er ENOTTY 85.Fa d 86is not associated with a character 87special device. 88.It Bq Er ENOTTY 89The specified request does not apply to the kind 90of object that the descriptor 91.Fa d 92references. 93.It Bq Er EINVAL 94.Fa Request 95or 96.Fa argp 97is not valid. 98.El 99.Sh SEE ALSO 100.Xr mt 1 , 101.Xr cdio 1 , 102.Xr chio 1 , 103.Xr execve 2 , 104.Xr fcntl 2 , 105.Xr tty 4 , 106.Xr intro 4 107.Sh HISTORY 108An 109.Fn ioctl 110function call appeared in 111.At v7 . 112