- Logging in
- The pointer
- Logging out
- The window manager
- Opening another window
- Xterm operations
X is a windowing system which allows a number of applications to have their output displayed on the same screen in different windows, each of which can be manipulated independently. For example you might be running a data analysis or graphics program in one window, looking at its online manual page in a second window and perhaps using the editor in a third window to prepare data for the package. Most users will be familiar with the windowing concept in Microsoft Windows running on the machines in the PC labs. In addition, X works across the Ethernet network allowing programs running on several different computers on the network to have their output directed to the same physical screen.
Note that X terminals cannot be used to display output of PC programs. Computers which do currently support X include the Central Unix Service and SUN and HP workstations.
ISS manages 2 labs of X terminals and in addition the PCs in public labs may be used as X terminals by running the eXceed X terminal emulator. (Its logo is a large red X).
Both the X terminals and PCs running eXceed will, on starting up, display a list of computers to which you can make a connection. If you are using an X terminal you will see a menu looking rather like the following:
To make a connection you move the pointer to the computer of your choice and click any mouse button once. Both unixa and unixb are part of the new Unix service. In general it should not matter which of these you choose.
In the case of eXceed on one of the lab PCs you will see a slightly different looking menu, like the one below:
To make a connection you move the pointer to the computer of your choice and either double click or click once and then click on the OK button.
Once you have made a connection you should then see the login window for the computer of your choice. This should look the same whether you are using an X terminal or eXceed on a PC. In the case of the new Unix service you should see a login window looking like the following:
Log in by typing your username and password and the screen should change to the following form:
You have one window displayed in the top left hand corner of the screen and inside this window should appear the familiar system messages followed eventually by the system prompt. This window is known as an xterm; more precisely it has been created by a program called xterm which simulates an ordinary text terminal. The xterm program has been automatically started up for you on logging in. Xterm allows you to do the usual text based operations like issuing Unix system commands, editing files with ue and sending and receiving mail with elm. If you want to have more than one window you can invoke the xterm command at any time to create a new one; more about this in section 6 below.
Note that users in some departmental labs will find that their default screen looks rather different from the one above.
The pointer is a symbol which is moved about the screen by the mouse. Its appearance varies according to where it is on the screen. If it is against the background it takes the appearance of an X while inside an xterm window it changes to an I. It takes yet different forms if placed over the title bar above an xterm window; more about this in section 5 below. The pointer is used to perform many functions, one of which is to determine which window is the active one, in other words which window receives data which you type on the keyboard. Placing the pointer inside a window will normally make it active. Even if you have only one window you must still place the pointer inside it; if the pointer is against the background any data which you type will be ignored. Note that when a window becomes the active one its border will change colour.
To log out simply move the pointer into the xterm window and type the logout command just as on an ordinary text terminal. Remember that if you have opened more than one window you must log out of all of them. By default, if you type logout in the "Session Control" window it will log you out of all other windows as well. Typing logout in a window which you have opened later will cause that window to close but leave other windows still open on the screen. You will know that you have safely logged out when the login window reappears.
This imposing title is given to the program which controls the layout and appearance of windows on the screen. A window manager called mwm is started up automatically for you when you log in to unix and normally runs until you log out. Its job is to organise the screen and to respond to requests made by programs (like xterm) which open new windows and to requests made by the user to manipulate windows already on the screen. Such a request might be to make a window bigger or smaller, to move it to another part of the screen or to move it "in front of" another window which is obscuring it. Mwm is responsible for the title bar above each window and it is via this title bar that you can make requests to modify the appearance of a window.
(Note that other X window managers exist and they will cause different title bars to be drawn above windows on the screen.)
5.1 Moving a window
To move a window place the pointer in the title bar (the pointer changes to an arrow shape), press the left hand mouse button down and "drag" the mouse (move it while holding the button down). The outline of the window will move on the screen. Release the mouse button when the window is in the desired location.
5.2 Making a window bigger or smaller.
To make a window bigger or smaller place the pointer on the window border and drag in the direction in which you want the window to expand or contract. Release the mouse button when the window is the desired size. Dragging a corner of the window will cause both its width and height to change at the same time.
5.3 Minimising a window
If a window is not being used it may be convenient to "minimise" it, in other words reduce it to an icon. To do this move the pointer to the minimise button, a small square near the right hand end of the title bar, and click the left hand mouse button . To restore a window from its icon just move the pointer inside the icon and click the left hand mouse button again. A menu with various options will appear. Choosing Restore will return the window to its original appearence.
5.4 Moving a window "to the front"
To move a partially obscured window to the front, position the pointer inside the title bar and click the left hand mouse button. It may be that the title bar is totally obscured in which case the obscuring window can either be minimised or moved out of the way first.
5.5 Closing a window
Normally the application which opened the window will provide a way of closing it; perhaps a FILE menu with an EXIT option. In the event that the application does not do this a window may be closed by clicking on the control button in the top left-hand corner and selecting the CLOSE option.
Further window manager functions are available by clicking the mouse when the pointer is against the screen background. If the left hand mouse button is held down a menu will appear:
Clicking on the option Xterms this will display a list of computers on which an xterm can be started. These will include Unix and other computers:
Clicking on Unix will start up another xterm on the Unix service.
Note: Each new window places additional load on the system so please do not open any more windows than you actually need.
6.2 Other programs
There are many programs running on the Unix Service which have interfaces for X-Windows. To list them would go beyond the scope of this guide. In most cases the way in which they open windows is the same as the way in which a new xterm window is opened.
7. Xterm Operations
Xterm is able to "remember" more lines of text than it is capable of displaying within its window. At the left hand edge of an xterm window is a strip called the "scroll bar". Within the scroll bar is a grey coloured region which represents that fraction of the "remembered" text which is displayed within the window. Text previously displayed but which has since "scrolled" off the top of the window can be brought back by placing the pointer inside the grey region, holding the middle mouse button down and moving the pointer up the screen. To return to the latest line of text move the pointer down the screen until the grey region is at the bottom of the scroll bar. Note that as currently implemented xterm will remember a maximum of 200 lines.
7.2 Copy and Paste
It is possible to copy text displayed within an xterm window and paste or insert it at the location of the text cursor in the same window or any other xterm window which is open on the same screen. To copy the text move the pointer to the first character to be copied then with the left hand button held down drag the pointer to the last character. The copied text is then highlighted. To paste the text, move the pointer into the window which is to receive it and click the middle mouse button. If you are using eXceed then you will need to hold down both the left and right mouse buttons to simulate the middle button on an X terminal. Remember that the text will be inserted at the position of the text cursor in the receiving window.