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:

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

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

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

       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.1‐2008, <stdlib.h>

COPYRIGHT

       Portions of this text are reprinted and  reproduced  in  electronic  form  from  IEEE  Std
       1003.1,  2013  Edition,  Standard  for Information Technology -- Portable Operating System
       Interface (POSIX), The Open Group Base Specifications Issue 7, Copyright (C) 2013  by  the
       Institute  of  Electrical  and  Electronics  Engineers,  Inc and The Open Group.  (This is
       POSIX.1-2008 with the  2013  Technical  Corrigendum  1  applied.)  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.unix.org/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 .