unlockpt - Man Page

Standard C library (libc, -lc)

#define _XOPEN_SOURCE
#include <stdlib.h>

int unlockpt(int fd);

unlockpt():

    Since glibc 2.24:
        _XOPEN_SOURCE >= 500
    glibc 2.23 and earlier:
        _XOPEN_SOURCE

The unlockpt() function unlocks the slave pseudoterminal device corresponding to the master pseudoterminal referred to by the file descriptor fd.

unlockpt() should be called before opening the slave side of a pseudoterminal.

When successful, unlockpt() returns 0. Otherwise, it returns -1 and sets errno to indicate the error.

EBADF

The fd argument is not a file descriptor open for writing.

EINVAL

The fd argument is not associated with a master pseudoterminal.

For an explanation of the terms used in this section, see attributes(7).

POSIX.1-2008.

glibc 2.1. POSIX.1-2001.

grantpt(3), posix_openpt(3), ptsname(3), pts(4), pty(7)

getpt(3), grantpt(3), posix_openpt(3), pts(4), ptsname(3), pty(7).