grantpt(3) [osf1 man page]

grantpt(3)						     Library Functions Manual							grantpt(3)

NAME

       grantpt - Permits access to the slave pseudoterminal device

LIBRARY

       Standard C Library (libc.so, libc.a)

SYNOPSIS

       #include <stdlib.h>

       int grantpt(	 int fildes);

STANDARDS

       Interfaces documented on this reference page conform to industry standards as follows:

       grantpt():  XPG4-UNIX

       Refer to the standards(5) reference page for more information about industry standards and associated tags.

PARAMETERS

       Specifies a file descriptor that is returned from a successful open of a master pseudoterminal device.

DESCRIPTION

       The  grantpt()  function modifies the ownership and mode of the slave pseudoterminal device associated with its master pseudoterminal coun-
       terpart.

       The modifications of mode and ownership are performed as follows: The group ID is set to a reserved group.  The slave user ID is set to the
       real  UID  of  the calling process.  The permissions of the slave device are set so that the owner is allowed read and write access and the
       group is allowed write access.

RETURN VALUES

       Upon successful completion, the grantpt() function returns a value of 0 (zero). Otherwise, it returns a value of -1 and sets errno to indi-
       cate the error.

ERRORS

       The grantpt() function sets errno to the specified values for the following conditions:

       The corresponding slave device cannot be accessed.  The file descriptor specified by the fildes parameter is not a valid open file descrip-
       tor.  The file descriptor specified by the fildes parameter is not associated with a master device.

       The grantpt() function may also fail if the application has installed a signal handler to catch SIGCHLD (death of a child) signals.

       Applications calling grantpt() may get a SIGCHLD signal from processes that they did not explicitly create.

RELATED INFORMATION

       Functions: open(2), ptsname(3), setuid(2), unlockpt(3)

       Standards: standards(5) delim off

																	grantpt(3)

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