unlockpt(3C)

NAME

unlockpt − unlock a pseudo-terminal master/slave pair

#include <stdlib.h>

int unlockpt(int fildes);

The unlockpt() function unlocks the slave pseudo-terminal device associated with the master to which fildes refers.

Portable applications must call unlockpt() before opening the slave side of a pseudo-terminal device.

Upon successful completion, unlockpt() returns 0. Otherwise, it returns −1 and sets errno to indicate the error.

The unlockpt() function may fail if:

EBADF The fildes argument is not a file descriptor open for writing.

EINVAL The fildes argument is not associated with a master pseudo-terminal device.

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE	ATTRIBUTE VALUE
MT-Level	Safe