The latest issue of Mac Addict has an article on how to get below Aqua (OS X
Gui) to a command line interface with the Unix core (shell? I am out of my
league here). If you are a Unix user you probably are familiar with the
interface. It is called "X Windows." My problem is buying a new computer
while the airplane project is breaking the bank. A G-4 with OS X is a
powerful tool and sooner or later I will have one. Jerry
Paul Lamar responded:
Not quite right Jerry. I run X-Windows on Linux. Perhaps one simple way of
describing X-Windows is; it is a graphics server for GUI programs.
The command line in UNIX & Linux is called a "shell". When I am working on
this newsletter I use both GUI programs (Netscape, XV and Paint) and shell
commands. Shell commands are better for some things than a GUI could ever
be. The same thing can be said for GUI's about shell commands.
X Windows gives me four 12xx by 10xx virtual screens to work with with.
There is a little icon on the bottom of the screen to allow you to select,
with a mouse, which screen you are working with.
Something half way between a GUI and a shell are programs like XTree Gold or
Norton Commander for DOS or Windows. It is a quicker way of running shell
commands with out memorizing them all. You kind of select the one you want
to run. The same thing can be had for Linux and it is called YTree. One of
my four virtual screens always has YTree running.
[Warning: Computer pedantry follows.]
This is like the newsgroups: beware of being a spelling/grammar nanny, for
your postings will be scrutinized for every niggling error.
Mac OS-X is based not on Unix (formerly an AT&T product, then purchased by
SCO, now owned by God knows who), but rather on a Unix-like OS called Mach.
X-Windows is a communications protocol between programs (X clients) and the
user interface device (the X server). Note that X-Windows (aka X11 or X11R5
or X11R6) *appears* to turn the client/server relationship on its head. It is
easy to get confused, so if you care, pay attention: the X server (which is
software) runs on whatever is in front of you (which may be a workstation,
diskless client, network client); the X client(s) (which are also software)
are running on whatever system has the data/CPU cycles/resources that the
program needs. In the case of Linux, the PC is the hardware which runs *both*
the X server (one) and the X clients (several; generally one per window). But
if you have 2 (or more) Linux boxes, the X server and the X client can be on
separate boxes. This separation of the presentation from the computation is
also done in Windoze land -- provided you have a rather pricey thing called a
Windows Terminal Server. In general, one cannot seperate the GUI from the OS
in Windows. (There's some 3rd party software that I use that comes close. It
is called "ControlIT".)
So if one gets "below Aqua" to the "X windows" layer (as Jerry wrote), one is
*still* in a GUI environment.
Note that X windows can provide command line interfaces within it (a shell
window). This is analogous to Win98/NT having an MS-DOS window. I do not
know if Mac OS-X provides a shell window.
As for Paul having "four virtual screens", that is less a feature of pure X11
than of Linux's X11 server *port* and window manager program. Pure X11 has
one screen per output device. (Yes, one computer can have one X11 server with
multiple video cards and monitors. That's the ".0" part of the window name,
as in "loopback.ti.com:0.0"). Each X11 window can have one window manager.
The window manager handles the window frame actions (resizing, moving,
collapse/expand). In Windows, the OS itself with one special copy of Windows
Explorer (*NOT* Internet Explorer) is the equivalent.
BTW, Windows has a shell: command.com
(Hey, I never claimed is a *good* shell...)
Russell Kent
Clear as mud Russell but thanks anyway :-)
Paul Lamar
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