grantpt Subroutine
Purpose
Changes the mode and ownership of a pseudo-terminal device.
Library
Standard C Library (libc.a)
Syntax
#include <stdlib.h>int grantpt ( FileDescriptor)
int FileDescriptor;
int FileDescriptor;
Description
The grantpt subroutine changes the mode and the ownership of the worker pseudo-terminal associated with the controller pseudo-terminal device defined by the FileDescriptor parameter. The user ID of the worker pseudo-terminal is set to the real UID of the calling process. The group ID of the worker pseudo-terminal is set to an unspecified group ID. The permission mode of the worker pseudo-terminal is set to readable and writeable by the owner, and writeable by the group.
Parameters
| Item | Description |
|---|---|
| FileDescriptor | Specifies the file descriptor of the controller pseudo-terminal device. |
Return Value
Upon successful completion, a value of 0 is returned. Otherwise, a value of -1 is returned and the errno global variable is set to indicate the error.
Error Codes
The grantpt function may fail if:
| Item | Description |
|---|---|
| EBADF | The fildes argument is not a valid open file descriptor. |
| EINVAL | The fildes argument is not associated with a controller pseudo-terminal device. |
| EACCES | The corresponding worker pseudo-terminal device could not be accessed. |