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

NAME         top

       grantpt - grant access to the slave pseudoterminal

SYNOPSIS         top

       #define _XOPEN_SOURCE       /* See feature_test_macros(7) */
       #include <stdlib.h>

       int grantpt(int fd);

DESCRIPTION         top

       The grantpt() function changes the mode and owner of the slave pseudoterminal
       device corresponding to the master pseudoterminal 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 pseudoterminal 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
              pseudoterminal.

VERSIONS         top

       grantpt() is provided in glibc since version 2.1.

CONFORMING TO         top

       POSIX.1-2001.

NOTES         top

       This is part of the UNIX 98 pseudoterminal 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), pty(7)

COLOPHON         top

       This page is part of release 3.32 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)

HTML rendering created 2010-12-03 by Michael Kerrisk, author of The Linux Programming Interface

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