$NetBSD: grantpt.3,v 1.4 2008/04/30 13:10:51 martin Exp $ Copyright (c) 2004 The NetBSD Foundation, Inc. All rights reserved. This code is derived from software contributed to The NetBSD Foundation by Christos Zoulas. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE..Dd May 25, 2004
.Dt GRANTPT 3
.Os
.Sh NAME
.Nm grantpt
.Nd grant access to a slave pseudo-terminal device
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
n stdlib.h .Ft int
.Fn grantpt "int fildes"
.Sh DESCRIPTION
The
.Fn grantpt
function changes the mode and ownership of the slave pseudo-terminal device
that corresponds to the master pseudo-terminal device associated with
.Fa fildes
to be owned by the real user id of the calling process, group id of
.Dv tty .
The permissions are set to readable and writable by owner, and writable by
group.
If the slave pseudo-terminal device was being accessed by other file
descriptors at the time, all such access will be revoked.
.Sh RETURN VALUES
If successful,
.Fn grantpt
returns 0; otherwise a value of -1 is returned and
.Va errno
is set to indicate the error.
.Sh ERRORS
The
.Fn grantpt
function will fail if:
l -tag -width Er t Bq Er EACCESS the corresponding pseudo-terminal device could not be accessed.
t Bq Er EBADF .Fa fildes
is not a valid descriptor.
t Bq Er EINVAL .Fa fildes
is not associated with a master pseudo-terminal device.
.El
.Sh NOTES
Setting the group to
.Dv tty
and revoking accesses by other file descriptors are
.Nx
extensions.
Calling
.Fn grantpt
is equivalent to:
d -literal ioctl(fildes, TIOCGRANTPT, 0);
.Ed
.Sh SEE ALSO
.Xr ioctl 2 ,
.Xr posix_openpt 3 ,
.Xr ptsname 3 ,
.Xr unlockpt 3
.Sh STANDARDS
The
.Fn grantpt
function conforms to
.St -p1003.1-2001 .
Its first release was in
.St -xpg4.2 .