NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | VERSIONS | ATTRIBUTES | CONFORMING TO | SEE ALSO | COLOPHON 

UNLOCKPT(3)               Linux Programmer's Manual              UNLOCKPT(3)

NAME         top

       unlockpt - unlock a pseudoterminal master/slave pair

SYNOPSIS         top

       #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 ||
                   (_XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED)
           Glibc 2.23 and earlier:
               _XOPEN_SOURCE

DESCRIPTION         top

       The unlockpt() function unlocks the slave pseudoterminal device
       corresponding to the master pseudoterminal referred to by fd.
       unlockpt() should be called before opening the slave side of a
       pseudoterminal.

RETURN VALUE         top

       When successful, unlockpt() returns 0.  Otherwise, it returns -1 and
       sets errno appropriately.

ERRORS         top

       EBADF  The fd argument is not a file descriptor open for writing.
       EINVAL The fd argument is not associated with a master
              pseudoterminal.

VERSIONS         top

       unlockpt() is provided in glibc since version 2.1.

ATTRIBUTES         top

       For an explanation of the terms used in this section, see
       attributes(7).
       ┌───────────┬───────────────┬─────────┐
       │Interface  │ Attribute     │ Value   │
       ├───────────┼───────────────┼─────────┤
       │unlockpt() │ Thread safety │ MT-Safe │
       └───────────┴───────────────┴─────────┘

CONFORMING TO         top

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

SEE ALSO         top

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

COLOPHON         top

       This page is part of release 4.12 of the Linux man-pages project.  A
       description of the project, information about reporting bugs, and the
       latest version of this page, can be found at
       https://www.kernel.org/doc/man-pages/.
                                 2017-07-13                      UNLOCKPT(3)

Pages that refer to this page: ioctl_tty(2),  getpt(3),  grantpt(3),  posix_openpt(3),  ptsname(3),  pts(4),  pty(7)