GRANTPT(3)                                          Linux Programmer's Manual                                         GRANTPT(3)



NAME
       grantpt - grant access to the slave pseudo-terminal

SYNOPSIS
       #define _XOPEN_SOURCE
       #include <stdlib.h>

       int grantpt(int fd);

DESCRIPTION
       The  grantpt()  function changes the mode and owner of the slave pseudo-terminal device (pty) corresponding to the master
       pty referred to by fd.  The user ID of the slave is set to the real UID of the calling process.  The group ID is  set  to
       an unspecified value (e.g., tty).  The mode of the slave is set to 0620 (crw--w----).

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

RETURN VALUE
       When successful, grantpt() returns 0.  Otherwise, it returns -1 and sets errno appropriately.

ERRORS
       EACCES The corresponding slave pty could not be accessed.

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

       EINVAL The fd argument is valid but not associated with a master pty.

VERSIONS
       grantpt() is provided in glibc since version 2.1.

CONFORMING TO
       POSIX.1-2001.

NOTES
       This is part of the Unix98 pty support, see pts(4).  Many systems implement this function via a set-user-ID helper binary
       called "pt_chown".  With Linux devpts no such helper binary is required.

SEE ALSO
       open(2), posix_openpt(3), ptsname(3), unlockpt(3), pts(4), feature_test_macros(7), pty(7)

COLOPHON
       This page is part of release 3.25 of the Linux man-pages project.  A description of the project,  and  information  about
       reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.



GNU                                                        2008-06-14                                                 GRANTPT(3)