dglopen - opens a Graphics Library connection to a graphics server
long dglopen(svname, type)
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:
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
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:
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.
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
dglclose, finish, gflush, winopen, winset, scrnselect
rlogin(1C), gethostbyname(3N) in the IRIS-4D User's Reference Manual
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.
PPPPaaaaggggeeee 2222 [ Back ]