@begin(header)
author: ackerman=ag@ics.uci.edu
show_author: ShowNone
author_organization: MIT
node_expert: ackerman=ag@ics.uci.edu 
expiration_date: 10/10/93
last_modifier: ackerman=ag@ics.uci.edu
last_mod_date: 10/10/91
mod_num: 2
@end(header)
The Display struct is created when the connection to the server is opened.

The format is:

Display *the_display;

the_display = XOpenDisplay(hostname);


If hostname is the null string (ie, ""), then the value of the
environment variable DISPLAY is used.  Most people use the null string
so that users can display on different workstations.

Note, the Display struct is defined in Xlib.h, which can be usually
found in /usr/include/X11 (although occasionally, it is in
/usr/local/include/X11).  You should not set the values for the 
structure directly.

There are a series of macros defined to access members of the struct.
These are also defined in Xlib.h.  At the Xlib level, for example,
DefaultRootWindow pulls out the default root window, and DisplayWidth
pulls out the size of the screen in pixels.  In these macros, scr is
an integer from 0 to the (number of screens - 1) on your display, and
is the screen number.  Usually it is 0 on a one-screen workstation.

If you need more information, click the "I'm Unhappy" button below, and 
ask a question.
