NAME

unlockpt − Unlock a pseudoterminal master and slave pair

SYNOPSIS

#include <stdlib.h>
int unlockpt(
        int mastfd );

LIBRARY

Standard C Library (libc)

STANDARDS

Interfaces documented on this reference page conform to industry standards as follows:

unlockpt(): XSH5.0

Refer to the standards(5) reference page for more information about industry standards and associated tags. 

PARAMETERS

mastfd
Specifies a file descriptor that is returned from a successful open of the master pseudoterminal device.

DESCRIPTION

The unlockpt() function unlocks a slave pseudoterminal from its associated master counterpart. It does this by clearing a lock option so that the slave device can be opened. 

ERRORS

The unlockpt() function sets errno to the specified values for the following conditions:

[EBADF]
The file descriptor specified by the mastfd parameter is not an open file descriptor. 

[EINVAL]
The file descriptor specified by the mastfd parameter is not associated with a master pseudoterminal device. 

RETURN VALUE

Upon successful completion, the unlockpt() function returns a value of 0. Otherwise, it returns a value of -1 and sets errno to indicate the error. 

SEE ALSO

Functions: openpty(3)

Standards: standards(5)