NAME
grantpt —
grant access to a slave
pseudo-terminal device
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <stdlib.h>
int
grantpt(
int
fildes);
DESCRIPTION
The
grantpt() function changes the mode and ownership of the
slave pseudo-terminal device that corresponds to the master pseudo-terminal
device associated with
fildes to be owned by the real
user id of the calling process, group id of
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.
RETURN VALUES
If successful,
grantpt() returns 0; otherwise a value of -1 is
returned and
errno is set to indicate the error.
ERRORS
The
grantpt() function will fail if:
-
-
- [
EACCESS
]
- the corresponding pseudo-terminal device could not be
accessed.
-
-
- [
EBADF
]
- fildes is not a valid
descriptor.
-
-
- [
EINVAL
]
- fildes is not associated with a
master pseudo-terminal device.
NOTES
Setting the group to
tty
and revoking accesses by other
file descriptors are
NetBSD extensions. Calling
grantpt() is equivalent to:
ioctl(fildes, TIOCGRANTPT, 0);
SEE ALSO
ioctl(2),
posix_openpt(3),
ptsname(3),
unlockpt(3)
STANDARDS
The
grantpt() function conforms to
IEEE Std
1003.1-2001 (“POSIX.1”). Its first release was in
X/Open Portability Guide Issue 4, Version 2
(“XPG4.2”).