GRANTPT(3) Library Functions Manual GRANTPT(3)

NAME

grantpt — grant access to the subsidiary pseudo-terminal device

SYNOPSIS

[XSI]
#include <stdlib.h>

int grantpt(int fildes);

DESCRIPTION

The grantpt () function shall change the mode and ownership of the subsidiary pseudo-terminal device associated with its manager pseudo-terminal counterpart. The fildes argument is a file descriptor that refers to a manager pseudo-terminal device. The user ID of the subsidiary shall be set to the real UID of the calling process and the group ID shall be set to an unspecified group ID. The permission mode of the subsidiary pseudo-terminal shall be set to readable and writable by the owner, and writable by the group.

The behavior of the grantpt () function is unspecified if the application has installed a signal handler to catch SIGCHLD signals.

RETURN VALUE

Upon successful completion, grantpt () shall return 0; otherwise, it shall return -1 and set errno to indicate the error.

ERRORS

The grantpt () function may fail if:

[EACCES]: The corresponding subsidiary pseudo-terminal device could not be accessed.
[EBADF]: The fildes argument is not a valid open file descriptor.
[EINVAL]: The fildes argument is not associated with a manager pseudo-terminal device.

The following sections are informative.