This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface

       None.

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard
       for Information  Technology  --  Portable  Operating  System  Interface  (POSIX),  The  Open  Group  Base
       Specifications  Issue  7, 2018 Edition, Copyright (C) 2018 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 .

       Any  typographical  or formatting errors that appear in this page are most likely to have been introduced
       during  the  conversion  of  the  source  files  to  man  page  format.  To  report  such   errors,   see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                                   2017                                       GRANTPT(3POSIX)

       The grantpt() function shall change the mode and ownership of the slave pseudo-terminal device associated
       with  its  master  pseudo-terminal counterpart. The fildes argument is a file descriptor that refers to a
       master pseudo-terminal device. The user ID of the slave shall be set to  the  real  UID  of  the  calling
       process  and  the  group  ID  shall  be  set to an unspecified group ID. The permission mode of the slave
       pseudo-terminal shall be set to readable and writable by the owner, and writable by the group.

       The behavior of the grantpt() function is unspecified if the application has installed a  signal  handler
       to catch SIGCHLD signals.

       The grantpt() function may fail if:

       EACCES The corresponding slave pseudo-terminal device could not be accessed.

       EBADF  The fildes argument is not a valid open file descriptor.

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

       Thefollowingsectionsareinformative.

       None.

       None.

       grantpt — grant access to the slave pseudo-terminal device

       This  manual  page  is part of the POSIX Programmer's Manual.  The Linux implementation of this interface
       may differ (consult the corresponding Linux manual page for details of Linux behavior), or the  interface
       may not be implemented on Linux.

       See the RATIONALE section for posix_openpt().

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

open(), posix_openpt(), ptsname(), unlockpt()

       The Base Definitions volume of POSIX.1‐2017, <stdlib.h>

       #include <stdlib.h>

       int grantpt(int fildes);