grantpt

       #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 pseu-
       doterminal device corresponding to the master  pseudoterminal  referred
       to by fd.  The user ID of the slave is set to the real UID of the call-
       ing 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 pseu-
              doterminal.

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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