xref: /netbsd-src/lib/libc/stdlib/grantpt.3 (revision d48f14661dda8638fee055ba15d35bdfb29b9fa8)
1.\" $NetBSD: grantpt.3,v 1.3 2004/05/28 00:10:57 wiz Exp $
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3.\" Copyright (c) 2004 The NetBSD Foundation, Inc.
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6.\" This code is derived from software contributed to The NetBSD Foundation
7.\" by Christos Zoulas.
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37.Dd May 25, 2004
38.Dt GRANTPT 3
39.Os
40.Sh NAME
41.Nm grantpt
42.Nd grant access to a slave pseudo-terminal device
43.Sh LIBRARY
44.Lb libc
45.Sh SYNOPSIS
46.In stdlib.h
47.Ft int
48.Fn grantpt "int fildes"
49.Sh DESCRIPTION
50The
51.Fn grantpt
52function changes the mode and ownership of the slave pseudo-terminal device
53that corresponds to the master pseudo-terminal device associated with
54.Fa fildes
55to be owned by the real user id of the calling process, group id of
56.Dv tty .
57The permissions are set to readable and writable by owner, and writable by
58group.
59If the slave pseudo-terminal device was being accessed by other file
60descriptors at the time, all such access will be revoked.
61.Sh RETURN VALUES
62If successful,
63.Fn grantpt
64returns 0; otherwise a value of \-1 is returned and
65.Va errno
66is set to indicate the error.
67.Sh ERRORS
68The
69.Fn grantpt
70function will fail if:
71.Bl -tag -width Er
72.It Bq Er EACCESS
73the corresponding pseudo-terminal device could not be accessed.
74.It Bq Er EBADF
75.Fa fildes
76is not a valid descriptor.
77.It Bq Er EINVAL
78.Fa fildes
79is not associated with a master pseudo-terminal device.
80.El
81.Sh NOTES
82Setting the group to
83.Dv tty
84and revoking accesses by other file descriptors are
85.Nx
86extensions.
87Calling
88.Fn grantpt
89is equivalent to:
90.Bd -literal
91	ioctl(fildes, TIOCGRANTPT, 0);
92.Ed
93.Sh SEE ALSO
94.Xr ioctl 2 ,
95.Xr posix_openpt 3 ,
96.Xr ptsname 3 ,
97.Xr unlockpt 3
98.Sh STANDARDS
99The
100.Fn grantpt
101function conforms to
102.St -p1003.1-2001 .
103Its first release was in
104.St -xpg4.2 .
105