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
   corresponding to the master pseudoterminal referred to by 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 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 4.09 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)

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