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



NAME
       unlockpt - unlock a pseudoterminal master/slave pair

SYNOPSIS
       #define _XOPEN_SOURCE	   /* See feature_test_macros(7) */
       #include <stdlib.h>

       int unlockpt(int fd);

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 4.10 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/.



				  2015-08-08			   UNLOCKPT(3)