GRANTPT(3C) Standard C Library Functions GRANTPT(3C)
grantpt - grant access to the subsidiary device of a pseudo-terminal
#include <stdlib.h>
int
grantpt(int fildes);
The grantpt() function changes the mode and ownership of the pseudo-
terminal subsidiary device associated with its pseudo-terminal manager
counterpart.
The fildes argument is the file descriptor returned from a successful
open(2) of the pseudo-terminal manager device; e.g., by calling
posix_openpt(3C) or by performing an open(2) of the ptm(4D) device.
The user ID owner of the subsidiary device is set to the real user ID
of the calling process. The group ID owner is set to a reserved group.
The permission mode of the subsidiary device is set to be readable and
writable by the owner, and writable by the group.
The grantpt() function returns the value 0 if successful; otherwise the
value -1 is returned and the global variable errno is set to indicate
the error.
See posix_openpt(3C) for an example that includes a call to grantpt().
The grantpt() function may fail if:
EBADF The fildes argument is not a valid open file
descriptor.
EINVAL The fildes argument is not associated with a pseudo-
terminal manager device.
EACCES The corresponding pseudo-terminal subsidiary device
could not be accessed.
Committed
Safe
open(2), posix_openpt(3C), ptsname(3C), unlockpt(3C), ptm(4D),
attributes(7), standards(7)
illumos February 5, 2022 illumos
NAME
grantpt - grant access to the subsidiary device of a pseudo-terminal
SYNOPSIS
#include <stdlib.h>
int
grantpt(int fildes);
DESCRIPTION
The grantpt() function changes the mode and ownership of the pseudo-
terminal subsidiary device associated with its pseudo-terminal manager
counterpart.
The fildes argument is the file descriptor returned from a successful
open(2) of the pseudo-terminal manager device; e.g., by calling
posix_openpt(3C) or by performing an open(2) of the ptm(4D) device.
The user ID owner of the subsidiary device is set to the real user ID
of the calling process. The group ID owner is set to a reserved group.
The permission mode of the subsidiary device is set to be readable and
writable by the owner, and writable by the group.
RETURN VALUES
The grantpt() function returns the value 0 if successful; otherwise the
value -1 is returned and the global variable errno is set to indicate
the error.
EXAMPLES
See posix_openpt(3C) for an example that includes a call to grantpt().
ERRORS
The grantpt() function may fail if:
EBADF The fildes argument is not a valid open file
descriptor.
EINVAL The fildes argument is not associated with a pseudo-
terminal manager device.
EACCES The corresponding pseudo-terminal subsidiary device
could not be accessed.
INTERFACE STABILITY
Committed
MT LEVEL
Safe
SEE ALSO
open(2), posix_openpt(3C), ptsname(3C), unlockpt(3C), ptm(4D),
attributes(7), standards(7)
illumos February 5, 2022 illumos