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

NAME

     unlockpt - unlock a pseudoterminal master/slave pair

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

DESCRIPTION

     The  unlockpt() function unlocks the slave pseudoterminal device corre-
     sponding to the master pseudoterminal referred to by fd.

     unlockpt() should be called before opening the slave side  of  a  pseu-
     doterminal.

RETURN VALUE

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

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 in glibc since version 2.1.

ATTRIBUTES

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

     +-----------+---------------+---------+
     |Interface  | Attribute     | Value   |
     +-----------+---------------+---------+
     |unlockpt() | Thread safety | MT-Safe |
     +-----------+---------------+---------+

CONFORMING TO

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

SEE ALSO

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

COLOPHON

     This page is part of release 4.16 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)