GRANTPT(3) Linux Programmer's Manual GRANTPT(3)
NAME
grantpt - grant access to the slave pseudotty
SYNOPSIS
#include<stdlib.h>
intgrantpt(int fd);
DESCRIPTION
The grantpt() function changes the mode and owner of the slave pseudo-
terminal device (pty) corresponding to the master pty 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.
RETURNVALUE
When successful, grantpt() returns 0. Otherwise, it returns -1 and sets
errno appropriately.
ERRORS
EBADF The fd argument is not a valid open file descriptor.
EINVAL The fd argument is valid but not associated with a master pty.
EACCES The corresponding slave pty could not be accessed.
CONFORMINGTO
POSIX 1003.1-2001
NOTES
This is part of the Unix98 pty support, see pts(4). Many systems
implement this function via a setuid helper binary called "pt_chown".
With Linux devpts no such helper binary is required.
SEEALSO
open(2), getpt(3), ptsname(3), unlockpt(3), pts(4)
PTY Control 2003-01-30 GRANTPT(3)
Take our 
