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   grantpt    ( 3 )

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Имя (Name)

grantpt - grant access to the slave pseudoterminal

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Синопсис (Synopsis)

#include <stdlib.h>

       int grantpt(int fd);

   Feature Test Macro Requirements for glibc (see
   feature_test_macros(7)):

       grantpt():
           Since glibc 2.24:
               _XOPEN_SOURCE >= 500
           Glibc 2.23 and earlier:
               _XOPEN_SOURCE

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Описание (Description)

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

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Возвращаемое значение (Return value)

When successful, grantpt() returns 0.  Otherwise, it returns -1
       and sets errno to indicate the error.

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Ошибки (Error)

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.

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Версии (Versions)

grantpt() is provided in glibc since version 2.1.

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Атрибуты (Attributes)

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

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

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Стандарты (Conforming to)

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

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Примечание (Note)

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".  On Linux systems with a devpts
       filesystem (present since Linux 2.2), the kernel normally sets
       the correct ownership and permissions for the pseudoterminal
       slave when the master is opened (posix_openpt(3)), so that
       nothing must be done by grantpt().  Thus, no such helper binary
       is required (and indeed it is configured to be absent during the
       glibc build that is typical on many systems).

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Смотри также (See also)

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

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