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

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.

ATTRIBUTES         top

       For an explanation of the terms used in this section, see
       attributes(7).

       ┌──────────┬───────────────┬────────────────┐
       │Interface Attribute     Value          │
       ├──────────┼───────────────┼────────────────┤
       │grantpt() │ Thread safety │ MT-Safe locale │
       └──────────┴───────────────┴────────────────┘

CONFORMING TO         top

       POSIX.1-2001, POSIX.1-2008.

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 4.10 of the Linux man-pages project.  A
       description of the project, information about reporting bugs, and the
       latest version of this page, can be found at
       https://www.kernel.org/doc/man-pages/.

GNU                              2015-08-08                       GRANTPT(3)