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”).