PROLOG

       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.

NAME

       grantpt — grant access to the slave pseudo-terminal device

SYNOPSIS

       #include <stdlib.h>

       int grantpt(int fildes);

DESCRIPTION

       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.

RETURN VALUE

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

ERRORS

       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.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       None.

RATIONALE

       See the RATIONALE section for posix_openpt().

FUTURE DIRECTIONS

       None.

SEE ALSO

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

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

COPYRIGHT

       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 .