illumos: manual page: grantpt.3c

GRANTPT(3C) Standard C Library Functions GRANTPT(3C)

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