dglopen(3G)							   dglopen(3G)

NAME    [Toc]    [Back]

     dglopen - opens a Graphics	Library	connection to a	graphics server

C SPECIFICATION    [Toc]    [Back]

     long dglopen(svname, type)
     String svname;
     long type;

PARAMETERS    [Toc]    [Back]

     svname   expects a	pointer	to the name of the graphics server to which
	      you want to open a connection.

	      For a successful connection, the client host must	have
	      permission to connect to the graphics server.  Authentication is
	      accomplished via the same	mechanisms as for X clients.  See
	      xhost(1) for further details.

	      The svname parameter has the following syntax:

	      [[username ]password@]hostname[:server[.screen]]

	      where hostname is	an internet host name recognized by
	      gethostname(3N).	server and screen are ignored, and both	are
	      set to 0.

	      For DECnet connections, if the server account has	a password,
	      this password must be specified by including username and
	      password.	 This password is used only for	opening	the DECnet
	      connection; the local and	remote accounts	must still be
	      equivalent in the	rlogin sense.

     type     expects a	symbolic constant that specifies the kind of
	      connection.  There are three defined constants for this
	      parameter:

	      DGLLOCAL indicates a direct connection to	the local graphics
	      hardware.	 This type of connection is not	supported on client
	      machines without IRIS graphics hardware.

	      DGLTSOCKET indicates a remote connection via TCP/IP.

	      DGL4DDN indicates	a remote connection via	DECnet.

FUNCTION RETURN	VALUE
     If	the connection succeeds, the returned value of the function is a nonnegative
 integer, serverid, that identifies the graphics server.  If the
     connection	failed,	the returned value for the function is a negative
     integer.  The absolute value of a negative	returned value is either a
     standard error value (defined in <errno.h>) or one	of several error
     returns associated	specifically with dglopen:





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dglopen(3G)							   dglopen(3G)



     ENODEV	 type is not a valid connection	type.

     EACCES	 login incorrect or permission denied.

     EMFILE	 too many graphics connections are currently open.

     ENOPROTOOPT DGL service not found in /etc/services.

     ERANGE	 invalid or unrecognizable number representation.

     EPROTONOSUPPORT    [Toc]    [Back]
		 DGL version mismatch.

     ESRCH	 the window manager is not running on the server.

DESCRIPTION    [Toc]    [Back]

     dglopen opens a Graphics Library connection to a graphics server
     (svname).	After a	connection is open, all	graphics preferences, input,
     and output	are directed to	that connection.  This direction is continued
     until either the connection is closed, another connection is opened, or a
     different connection is selected.	A different connection can be selected
     by	calling	a subroutine that takes	a graphics window identifier as	an
     input parameter, e.g. winset.  The	server connection associated with that
     graphics window identifier	becomes	the current connection.	 To close a
     connection, call dglclose with the	server identifier returned by dglopen.

     If	a remote server	error occurs, the graphics application may exit	with a
     status value EIO and produce the following	error message:

	  dgl error (comm): read returned 0

SEE ALSO    [Toc]    [Back]

     dglclose, finish, gflush, winopen,	winset,	scrnselect

     rlogin(1C), gethostbyname(3N) in the IRIS-4D User's Reference Manual

NOTES    [Toc]    [Back]

     This routine is available only in immediate mode.

     This routine is available in both the GL and DGL libraries.  However, the
     DGLLOCAL connection type is not supported by the DGL library.


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