NAME

       grantpt - grant access to the slave pseudoterminal

SYNOPSIS

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

       int grantpt(int fd);

DESCRIPTION

       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

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

ERRORS

       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

       grantpt() is provided in glibc since version 2.1.

ATTRIBUTES

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

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

CONFORMING TO

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

NOTES

       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

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

COLOPHON

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