linux man page for grantpt

GRANTPT(3)						     Linux Programmer's Manual							GRANTPT(3)

NAME
       grantpt - grant access to the slave pseudo-terminal

SYNOPSIS
       #define _XOPEN_SOURCE
       #include <stdlib.h>

       int grantpt(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.

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

ERRORS
       EACCES The corresponding slave pty 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 pty.

VERSIONS
       grantpt() is provided in glibc since version 2.1.

CONFORMING TO
       POSIX.1-2001.

NOTES
       This  is  part  of  the	Unix98	pty  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), feature_test_macros(7), pty(7)

COLOPHON
       This page is part of release 3.27 of the Linux man-pages project.  A description of the project, and information about reporting bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.

GNU
								    2008-06-14								GRANTPT(3)