unlockpt(3)

NAME
unlockpt - unlock a pseudoterminal master/slave pair

LIBRARY
Standard C library (libc, -lc)

SYNOPSIS
#define _XOPEN_SOURCE
#include <stdlib.h>

int unlockpt(int fd);

    Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

unlockpt():
    Since glibc 2.24:
        _XOPEN_SOURCE >= 500
    glibc 2.23 and earlier:
        _XOPEN_SOURCE

DESCRIPTION
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.

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

ERRORS

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

EINVAL
    The fd argument is not associated with a master pseudoterminal.

VERSIONS
unlockpt() is provided since glibc 2.1.

ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7).
Interface | Attribute | Value
 | Thread safety | MT-Safe

STANDARDS
POSIX.1-2001, POSIX.1-2008.

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