NAME

       unlockpt - unlock a pseudo-terminal master/slave pair

SYNOPSIS

       #include <stdlib.h>

       int unlockpt(int fildes);

DESCRIPTION

       The unlockpt() function shall unlock the slave pseudo-terminal device associated with the master to which
       fildes refers.

       Conforming applications shall ensure that they call unlockpt() before opening the slave side of a pseudo-
       terminal device.

RETURN VALUE

       Upon  successful  completion,  unlockpt()  shall return 0. Otherwise, it shall return -1 and set errno to
       indicate the error.

ERRORS

       The unlockpt() function may fail if:

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

       EINVAL The fildes argument is not associated with a master pseudo-terminal device.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       None.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       grantpt() , open() , ptsname() , the Base Definitions volume of IEEE Std 1003.1-2001, <stdlib.h>

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition,
       Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open  Group  Base
       Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers,
       Inc  and  The  Open Group. In the event of any discrepancy between this version and the original IEEE and
       The Open Group Standard, the original IEEE and The Open Group  Standard  is  the  referee  document.  The
       original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

IEEE/The Open Group                                   2003                                           UNLOCKPT(P)