grantpt(3) [netbsd man page]

GRANTPT(3)						   BSD Library Functions Manual 						GRANTPT(3)

NAME

     grantpt -- grant access to a slave pseudo-terminal device

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <stdlib.h>

     int
     grantpt(int fildes);

DESCRIPTION

     The grantpt() function changes the mode and ownership of the slave pseudo-terminal device that corresponds to the master pseudo-terminal
     device associated with fildes to be owned by the real user id of the calling process, group id of tty.  The permissions are set to readable
     and writable by owner, and writable by group.  If the slave pseudo-terminal device was being accessed by other file descriptors at the time,
     all such access will be revoked.

RETURN VALUES

     If successful, grantpt() returns 0; otherwise a value of -1 is returned and errno is set to indicate the error.

ERRORS

     The grantpt() function will fail if:

     [EACCESS]		the corresponding pseudo-terminal device could not be accessed.

     [EBADF]		fildes is not a valid descriptor.

     [EINVAL]		fildes is not associated with a master pseudo-terminal device.

NOTES

     Setting the group to tty and revoking accesses by other file descriptors are NetBSD extensions.  Calling grantpt() is equivalent to:

	     ioctl(fildes, TIOCGRANTPT, 0);

SEE ALSO

     ioctl(2), posix_openpt(3), ptsname(3), unlockpt(3)

STANDARDS

     The grantpt() function conforms to IEEE Std 1003.1-2001 (``POSIX.1'').  Its first release was in X/Open Portability Guide Issue 4, Version 2
     (``XPG4.2'').

BSD
								   May 25, 2004 							       BSD

PTSNAME(3)						   BSD Library Functions Manual 						PTSNAME(3)

NAME

     grantpt, ptsname, unlockpt -- pseudo-terminal access functions

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <stdlib.h>

     int
     grantpt(int fildes);

     char *
     ptsname(int fildes);

     int
     unlockpt(int fildes);

DESCRIPTION

     The grantpt(), ptsname(), and unlockpt() functions allow access to pseudo-terminal devices.  These three functions accept a file descriptor
     that references the master half of a pseudo-terminal pair.  This file descriptor is created with posix_openpt(2).

     The grantpt() function is used to establish ownership and permissions of the slave device counterpart to the master device specified with
     fildes.  The slave device's ownership is set to the real user ID of the calling process, and the permissions are set to user readable-
     writable and group writable.  The group owner of the slave device is also set to the group ``tty''.

     The ptsname() function returns the full pathname of the slave device counterpart to the master device specified with fildes.  This value can
     be used to subsequently open the appropriate slave after posix_openpt(2) and grantpt() have been called.

     The unlockpt() function clears the lock held on the pseudo-terminal pair for the master device specified with fildes.

RETURN VALUES

     The grantpt() and unlockpt() functions return the value 0 if successful; otherwise the value -1 is returned and the global variable errno is
     set to indicate the error.

     The ptsname() function returns a pointer to the name of the slave device on success; otherwise a NULL pointer is returned.

ERRORS

     The grantpt(), ptsname() and unlockpt() functions may fail and set errno to:

     [EBADF]		fildes is not a valid open file descriptor.

     [EINVAL]		fildes is not a master pseudo-terminal device.

     In addition, the grantpt() function may set errno to:

     [EACCES]		The slave pseudo-terminal device could not be accessed.

SEE ALSO

     posix_openpt(2), pts(4), tty(4)

STANDARDS

     The ptsname() function conforms to IEEE Std 1003.1-2008 (``POSIX.1'').

     This implementation of grantpt() and unlockpt() does not conform to IEEE Std 1003.1-2008 (``POSIX.1''), because it depends on posix_openpt(2)
     to create the pseudo-terminal device with proper permissions in place.  It only validates whether fildes is a valid pseudo-terminal master
     device.  Future revisions of the specification will likely allow this behaviour, as stated by the Austin Group.

HISTORY

     The grantpt(), ptsname() and unlockpt() functions appeared in FreeBSD 5.0.

BSD
								  August 20, 2008							       BSD