home   contributing   bugs   download   online pages  

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | VERSIONS | CONFORMING TO | NOTES | SEE ALSO | COLOPHON


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

NAME         top

       grantpt - grant access to the slave pseudo-terminal

SYNOPSIS         top

       #define _XOPEN_SOURCE
       #include <stdlib.h>

       int grantpt(int fd);

DESCRIPTION         top

       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         top

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

ERRORS         top

       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         top

       grantpt() is provided in glibc since version 2.1.

CONFORMING TO         top

       POSIX.1-2001.

NOTES         top

       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         top

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

COLOPHON         top

       This page is part of release 3.23 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)