by Kamran Husain

IN THIS CHAPTER

• Getting Motif for Linux

• General Installation Procedures

• Getting Started with X Window

• Using the Root Menu

• Working with Motif Clients

• Other Types of Widgets

• Customizing with Resources

• Customizing Motif

• Using the Command Line

• Using the .mwmrc File

• Customizing Your Desktop with Clients

• Colors

• Fonts

In this chapter, we will cover the following topics:

• Installing Motif on your Linux machine.

• Some of the basic concepts required for using X Window. Displays, windows, screens, and the Client Server Architecture in X are introduced.

• An introduction to Window Managers, specifically the Motif Window Manager (mwm) because this is a chapter on Motif!

• Navigating in mwm windows with the keyboard and mouse.

• Widgets and their characteristics.

• Customizing your desktop with resource files and client applications, and how to set your environment to your liking.

• Using some standard X tools available in Linux.

The following assumptions are made about you, the reader, as we go further into this chapter:

• You have completely read Chapter 21, "Installing XFree86," and successfully installed X Window on your system.

• You have played at least a little with Linux or UNIX, and know the syntax of using some basic UNIX commands such as find, cpio, tar, and ln.

• You have the X11R6 version of X Window, called XFree86, installed on your machine.

Take a look at the typical xterm window in Motif, shown in Figure 23.2.

You will now work with some of the Motif windows you have on the screen. Typically, you work with a mouse for the pointer, so the text refers to mice at times. You can always substitute your device name, however, for the word mouse or pointer, and not lose any of the meaning of the discussion.

Pointers in the mwm environment typically use three buttons, called Button1, Button2, and Button3. As an affront to left-handed individuals, Button1 is usually referred to as the left button because it is the most used button of the three. The left button on a mouse is the one that is pressed with your right index finger. When you take the pointer to an item and press a button, you are clicking the button.

If you are left handed, you can map your mouse or pointer buttons differently. See the section "Help for Left-Handed Users: xmodmap," later in this chapter.

The minimize button enables you to iconify an application. An icon is a small symbol that represents an inactive window. The contents of that window are not visible, although they can be updated internally by its process. Icons can be moved around on-screen, but they cannot be resized. Inactive windows that become active can hide icons. Icons save valuable screen space when you're using applications that do not require your constant attention.

Move the cursor to the minimize button, and press the left button on the mouse. The window is removed from the screen, and a smaller icon is seen somewhere on the left side of the screen. The minimize button is the button with the smaller square near the right side of the frame. The maximize button is the one next to it, with the bigger square.

To restore an icon to a screen, move the cursor to the icon and click Button1 twice in quick succession. This is known as double-clicking the mouse. Some Motif icons are shown in the lower portion of Figure 23.3.

Move the cursor to the maximize button, and press Button1. This action enlarges the window to the size of the root window. This way, you can have, say, a huge clock on your screen. Some applications, such as older versions of calc, do not adjust their internal graphics areas when their frames are resized. This leads to annoying blank space on a screen.

Use the maximize button as a toggle. Clicking this button on an already maximized window causes the window to revert to its size and position (also known as geometry) before it was maximized. Clicking it again remaximizes it.

The entire frame on a Motif window is a control that enables you to resize the window. Refer to Figure 23.2 for the size controls. Each of the four corners of the frame enables you to stretch the window. The four long bars of the frame let you move the edges of the window with the mouse.

To stretch the window using a corner, move the mouse to that corner. Press Button1 and, while keeping it pressed, move the mouse. The cursor changes its shape to a double-headed arrow, and a thin border appears, indicating the size and orientation of the current stretch operation. Size the window by moving the mouse with Button1 pressed. Release the button when you have achieved the desired size.

Note that some applications do not have these sizing controls enabled. An example is the cute, but not very useful, pointer tracking program called xeyes, or the clock program called oclock, shown in Figure 23.4.

You can select a window or an icon to get the focus by moving the pointer to that item and pressing the left button. This moves the window or icon to the top of the stack. This way, the window or icon isn't obscured by any other screen item.

When a window has the focus, it collects all the user input from the pointer and the keyboard. A window can have two types of focus: click-to-type and explicit. The click-to-type focus requires a user to click a pointer button in a window for it to get the focus. The explicit focus requires only that the cursor be in the window for the window to get the focus. Explicit focus is sometimes referred to as real-estate driven focus.

In some cases, you want to have the focus where the mouse is, without having to click the pointer button. Sometimes this is not useful for touch typists, because a single movement of the pointer can send the keystroke to the wrong window.

After you give the focus to a client, it collects all typed or graphics information until the user clicks elsewhere. It has the focus.

Getting the focus also raises the window to the top of the stack. The window frame color changes at this point. You can set the focus to an icon too by selecting it with a mouse. The name of the icon expands at that point, and you see the window menu for that icon. You can move the mouse away from the menu, but the icon retains the focus until you click elsewhere.

The color-change scheme depends on your site's default colors. You might not see any color change if the focused and out-of-focus colors are the same.

To move a window's location on the screen, complete the following steps:

1. Move the cursor on top of the title bar.

2. Press and hold down pointer Button1.

3. Move the pointer to the desired location. You should see an outline of the window border move with your pointer.

4. Place the outline at the part of the screen where you want your window to be. This is referred to as dragging the window.

5. Release Button1. The window now appears at the new location. It is also the window with the focus by default.

This procedure can be duplicated for an icon. In the case of an icon, you click and drag with the cursor in the icon itself.

While you are moving the window, you see a small box in the center of the screen with two numbers in it. These are positive X and Y offsets of the upper-left corner of the window from the upper-left corner of the screen. This information is very useful when you're trying to precisely place a window on the screen.

You can achieve some fine precision by pressing the arrow keys on the numeric keypad to move the window one step at a time. You must keep the pointer button pressed while you use the arrow keys.

Say you want to add a calculator to your screen. At the prompt in an xterm window, type this:

$ xcalc &

The calculator should appear on-screen. To get another xterm, type the following command:

$ xterm &

Depending on your site, the new window can appear anywhere on the screen. Typically, it is placed in the upper-left corner (x=0,y=0) or in the center of the root window.

Almost all clients accept the -geometry command-line option. This option tells the window manager where to locate the window on the screen. If you do not specify any geometry, the window manager uses its defaults.

The coordinate system for the root window is as listed here:

• The origin is top left (0,0).

• The number of display units is in pixels for graphics.

• The number of display units is in character sizes for xterms.

A pixel is the smallest unit available on a screen. Usually, screens are displayed in 1024x768 pixels, 2048x2048 pixels, or something similar. The size of a pixel on-screen is very much hardware-dependent. A 200x200 window appears as different sizes on monitors with different resolutions.

The geometry parameter is of the following form:

widthxheight[{+-}xoff{-+}yoff]

The height and width are usually given in pixels. In the case of xterms, height is given in lines, and width is given in characters per line. It is common to have a 24x80 xterm.

The xoff and yoff are offsets from the left and top edges of the screen, respectively. These represent the location of the window on the root window. The curly braces show that either the - or the + character can be included, but not both. These are the different parameters in the command:

+xoff	A positive offset from the left edge of the screen to the left edge of the window.
-xoff	A negative offset from the right edge of the screen to the right edge of the window.
+yoff	A positive offset from the top edge of the screen to the top edge of the window.
-yoff	A negative offset from the bottom edge of the screen to the bottom edge of the window.

A visual representation of the geometry is shown in Figure 23.5. For example, the line

xterm -geometry -50+50 &

places the xterm on the upper-right corner, 50 pixels from the right edge of the screen and 50 pixels from the top of the screen. The following parameters specify the edges of the screen:

-0-0	Lower-right corner
-0+0	Upper-right corner
+0-0	Lower-left corner
+0+0	Upper-left corner

Using the window menu requires you to have the focus on a window. Let's look at a typical window menu. This also might be different on your screen, but the basic functionality listed here should exist for all later versions of Motif. Take the cursor to the window menu button, and press the left button. The following menu (or something close to it) should appear:

Restore	alt-F5
Move	alt-F7
Size	alt-F8
Minimize	alt-F9
Maximize	alt-F10
Lower	alt-F3
Close	alt-F4

It's important to bring up this point about the keyboard and its special keys under X. Keyboards come in different types, and the most important key for using keystrokes in X can be radically different from one keyboard to another. On PC-based keyboards, it is usually the Alt key; on Macintoshes, it is the fan-shaped key; on Suns, it is Left, Alternate; and other keyboards use other keys.

In short, the Meta key is the special key for your special keyboard. For a PC-based keyboard, this is the Alt key, so don't look for a key called Meta on your keyboard. Where the text reads Meta, use Alt, the fan key, or whatever key your special keyboard is mapped to.

You can invoke any item on this window menu in one of two ways:

• You can use the pointer. This way, you click on the window menu and press Button1. Then move the cursor to the item you want, and release Button1; or press the Meta key and the character that is underlined in the menu. For moving a window, you press Meta-M. Note that this does not work on some Motif distributions.

• While the window has focus, you can press the Meta-function key combination. Then use the arrow keys on your keyboard to simulate the movement of the cursor, or just use the pointer.

Note that some of these functions might not be available for a menu shown for an icon. You might not be able to size or minimize an icon, but you can move, maximize, or close it.

Click Button3 while the cursor is in the root window. You see a menu pop up on top of all the windows. This is known as the root menu. Keep in mind that this menu is very customizable, so it might look radically different on your machine.

A typical root menu might list the following items (your system might have a different list depending on the type of Motif you purchased):

"Root Menu"

New Window

Shuffle Up

Shuffle Down

Refresh

Utils >

Restart

Exit

While holding down Button1, move the cursor down the list to the item you want to select. When you get to the menu item you want, release the button. If you do not want to select any items, move the cursor off the menu and release the button.

In the preceding list, the functionality can be set in this way:

• New Window starts a new xterm and sets focus to it.

• Shuffle Up and Shuffle Down shuffle the stacking order of the windows up or down. The current window with focus is moved down to the bottom when shuffling down, and the next highest window is given the focus. The last window in the stack is brought to the top and given the focus when shuffling up.

• Refresh redraws the entire screen and all windows.

• Utils brings up another submenu with more choices to select from. See the "Customizing Motif" section, later in this chapter, for details on how to set your menu items.

• Restart kills mwm and restarts it.

• Exit kills mwm and leaves you without a window manager. If this is the last command in your startup script, your windowing session terminates.

Now, let's work with Motif clients.

Most programmers find the X Window system libraries too basic to work with, so they use the next building block, called toolkits. The most common interface toolkit is the XtIntrinsics toolkit from MIT. This is called Xt. On top of Xt, you can have other toolkits such as Motif or the Open Look Interface Toolkit (OLIT). When you are working with Motif, you are working with a Motif toolkit. In Motif, you are working with Motif Widgets.

Widgets help developers program consistent user interfaces in Motif. By using Widgets, programmers can quickly put together interfaces that have the same look and feel of all Motif applications.

Some Widgets display information. Some Widgets collect user input (mouse or keyboard) information. Some Widgets react to user input by changing their appearance or performing some programmed function. Some Widgets are simply containers for other Widgets. All Widgets can be customized in one form or another, whether it is appearance, font size or style, colors, or whatever other parameter is required.

All Widgets of the same type have two data structures with information that describes their attributes: class and instance. The instance data structure contains information for a specific Widget on the screen. The class information contains information required for all Widgets of the class.

Widgets are grouped into several classes. Each class depends on the type of functionality offered by the Widget. Normally, the internal functions of a Widget are hidden from the applications programmer (encapsulation). A Widget class shares a set of functions and data structures for all Widgets in that class. A new Widget class can be derived from an existing Widget class. The newly derived class can inherit all the data structures and functions of the parent class. A Widget is created and destroyed during a Motif program execution.

A Widget is really a pointer to a data structure when viewed in a debugger. This data structure is allocated on the creation of a Widget, and it is destroyed when a Widget is destroyed.

Let's look at a typical application screen to see some Widgets in action. You will work with a demo application called xmdialogs, shown in Figure 23.6. The Widgets shown here are described later in this chapter. The xmdialogs application can be found in the /usr/bin/X11 directory. If you do not have this application, you can still learn about working with Widgets by applying these concepts to different applications.

Figure 23.6 shows a menu bar, a file selection list with scrollbars, an option button, some radio and toggle buttons, some push buttons, some labels, and a text display box.

The Actions and Help items are shown on the menu bar. By moving the pointer to either of these items and pressing Button1, you are presented with a menu of options very similar in operation to the window and root menu.

The Motif toolkit also supplies the following Widgets. Refer to the items in the periodic table shown in Figure 23.8 to see what most of these Widgets should look like on-screen. XmArrowButton This is a directional arrow with a border around it. A programmer can modify the arrow's direction, thickness, and border color by setting the Widget's parameters. Look at the ends of a scrollbar to see two examples of such a Widget.

XmDrawnButton A drawn button provides a rectangular area with a border for the programmer. The programmer can size, redraw, or reposition text or graphics within this window. This Widget provides hooks to set parameters for its border appearance, as well as to attach functions for accepting user input.

XmLabel This is a rectangular box consisting of either text or graphics. It is instantiated, but is also used as a base class for all button Widgets. A label's text can be multiline, multifont, or even multidirectional. In the xmdialogs example, this would be the labels Active Dialog and Motif Dialog Widgets.

Many features of the labels can be modified. This includes the fonts, foreground and background colors, and alignment (left, center, or right justification); in fact, this Widget can even store a pixmap graphics image.

XmPushButton This is a text label or pixmap with a border around it. This Widget accepts keystrokes or mouse button presses. In the smdialogs example, these are the create, destroy, manage, and unmanage buttons. When a button has focus, it draws a heavy border around itself.

When you press Enter or a pointer on a button, the button has focus. Move the cursor to a button. Press a key or button and hold it down. You have armed the button. The color on the button should change, and the border colors should reverse. This gives the impression that the button has been pressed down. When you release the button, the button reverts to its original state. When a mouse button is pressed in this Widget, the foreground and background colors of the Widget usually also invert.

XmSeparator This is used to create a line between functional sections of a screen. There is really not much that users can do with this Widget except position it on-screen.

XmText This is used to create a fully functional multiline text editor on a screen. The user can select text by dragging the mouse from one location to another while Button1 is pressed. Users can also click anywhere on the Widget to mark the insertion point. If the text Widget is enabled for user input, the user can type at the insertion point and insert the text into the text Widget.

Pull-down menus These are rectangular areas in the window that enable users to select from a number of items. The items are generally laid out in push buttons. Users can select a push button either by moving the mouse to that selection or by pressing Alt-K, in which K is the letter of the alphabet that is underlined in the menu button. In the xmdialogs function, the Meta-A key selected the Actions item, and Meta-H selected the Help item.

Pop-up menus The Motif root window menu is a good example of a pop-up menu. When you press the mouse button, a menu is displayed. You can select an item in the menu by moving the cursor onto the item and pressing Button1.

Scale Widgets The scale Widget is used to display the value of a data item between two extremes. It can also be used to accept user input. A scale Widget has a scroll region that is very similar to the scrollbar. It does not, however, have the arrow buttons at each end.

XmScrolledWindow This is a combination of a horizontal scrollbar, a vertical scrollbar, and a drawing area. If the size of the drawing area fits within the window, you can't see the scrollbars. If the size of the drawing area is greater than the visible area of the scrolled window, you see the horizontal or vertical scrollbars, or both. You can then use the scrollbars to move the visible portion on top of the drawing area. This is known as panning the window.

XmFrame This is a simple Widget used to put a consistent border around one single Widget. Frames can hold only one Widget at a time.

XmRowColumn This is a general-purpose Widget organizer. The Widget can lay out its Widget collection in various ways, including the following:

Row major: In this case, all Widgets on this Row Column Widget are stored until one row fills up, and a new row is created when another Widget is added that doesn't fit on this Widget. The creation of a new row is sometimes called wraparound.

Column major: This is the same as a row major, but it wraps around in a columnar fashion.

In conjunction with this, you can specify the width of each column to be that of the widest Widget, and you can specify the number of fixed columns, the packing (whether all Widgets should be packed as closely as possible), or that the individual Widgets specify their own positions.

Several other Widgets are available in the Motif Widget set. You can see the complete listing and their options in The Programmers Reference Manual from the Open Software Foundation.

Motif Widgets create a window in X Window. A complex Motif application can create several X windows very quickly. Each window uses X resources in the server, and many windows can slow your overall system performance.

Gadgets are windowless versions of a Widget. Most Gadgets have the same names as Widgets but have the string Gadget appended to their name. So, XmLabel has a counterpart called XmLabelGadget.

Gadgets do not have all the features of Widgets. For example, Gadgets share the foreground and background colors of their parent. Also, some Gadgets actually turn out to be slower than the Widgets they are trying to replace. Given the troubles you can get into by using Gadgets, you might be better off not using them.

Now that you are familiar with Widgets, let's talk about the parameters that affect them--resources.

As you saw in previous sections, you can customize some aspects of an application from the command-line prompt. X enables you to modify the aspects of an existing application every time a client runs that application. X does this by setting control variables for that client. These control variables, called resources, have a value associated with them.

For example, consider the case of an xterm. An xterm's resources are its font size, its pointer shape, the foreground color for all displayed text, its background color, and so on. These are only a few of the resources for an xterm. Most of these resources exist as predefined defaults for all the common clients in a system.

You can specify resources on an application-specific basis, or for all applications on your system. These resources are normally stored in an ASCII file called .Xresources in your home directory. This file affects only the applications you run. This file normally contains only the options you want to customize over those values that are set in system files.

You can always override the defaults specified in the system-wide file with defaults in your .Xresources file. In turn, your command-line options for a single client override those in the .Xresources file. Keep in mind, however, that the command-line default applies only to a specific client. The .Xresources default setting becomes the default for all your clients.

Also, remember that the command-line operations override any default resources set in a file. Normally, you set how you want your application to look under normal circumstances, and then override the changes via command-line options.

To make your resource specifications available to all clients, use the X resource database manager program, xrdb. This stores the resources directly on the server and makes the resources available to all clients on the system. This step takes some care because your change will affect all your clients, regardless of which platform they are running on.

A resource definition file is basically a line-by-line list of all the resources in the file. Each line consists of two entries: one for the resource type and the other for the value for the resource. The two entries are colon-separated.

The simplest syntax for a resource definition is as follows:

client*variable: value

client is the name of the client. The variable for that client is set to the value. Note that the colon follows the variable without any spaces.

Let's look at the resource declaration for an xterm client:

XTerm*foreground: white

XTerm*background: blue

XTerm*font: 10x20

...

If you don't already have an .Xdefaults file, you can create one with a text editor.

The values can be Boolean, numeric, or string. Values can be specified for Widgets in an application as well. For example, if you want to set the background color for all PushButtons in an application, myWorld, you set the following resource:

myWorld*PushButton.background: red

myWorld*background: blue

Note that the asterisk represents the Widgets between the actual myWorld application and all PushButtons in that application. If you specify

myWorld.mainForm.PushButton: blue

only the buttons on the Widget mainForm, which in turn must exist on myWorld, are affected. This is tight binding. Using the asterisk (*) is loose binding because it allows for multiple levels of Widget hierarchy between the objects on either side of the asterisk. If this has a hierarchy of

myWorld.mainForm.subForm.PushButton

the first two of the following declarations affect the PushButtons on the subForm, and the last does not:

myWorld*PushButton.background: red

myWorld*background: blue

myWorld.mainForm.PushButton: blue

Another example is the settings for an xterm. If you attempt to set the scrollbars using

xterm.scrollbar: true

it probably won't work. Most likely, there is a Widget hierarchy between the top-level application and the scrollbar Widgets. In this case, it works if you use this:

xterm*scrollbar: true

After you have modified the .Xresources file, you probably expect to see the changes occur immediately. Not so. You now have to inform the server of your defaults by using the xrdb command. Use the following command:

xrdb -load .Xresources

This reflects the changes for all subsequent executions of your client. These remain in effect until overridden, or until your session terminates. If you save your .Xresources file in your login directory, these changes are loaded whenever you start X with the following command:

xrdb -load .Xresources

This command is useful when you're creating .Xresources for the first time in a session. That is why, in most cases, this command is run when the windowing system is first created. If you want to keep the previous settings, use the -merge command option rather than -load, like so:

xrdb -merge .myOwnResources

Also, you can use the exclamation point as the comment character at any point in the input line before text begins. The following lines are comments:

! This is a comment

! another one

! commented*labelString: This resource is not used.

You can also use the cpp preprocessor's directives #if, #ifdef, #else, and #endif. This is running through xrdb only. The cpp preprocessor is not run when the .Xresources file is parsed. You can override the run through cpp by using the -nocpp parameter on the command line. No other parameters are required. If you want to remove a resource, use the -remove operation:

xrdb -remove .myOldResources

Resource files are of two types: user and class. User files apply to each instance of all applications. These are the resources you set in the .Xresources file. Class files pertain to all the instances of a particular class. These exist in files usually in your home directory or your path. The name of this file is the name of the class.

For example, all xterms belong to the class XTerm. Note that the class name is the name of a type of application with the first letter capitalized. XTerm is an exception to this rule because it has XT capitalized rather than only X.

Let's look at setting the resources for a particular class of an application:

*labelString:  Hello World

This command sets the labelString resource to Hello World for all Widgets in every application in your session. This might not be exactly what you want. Here's a revised command:

Xapp*labelString:  Hello World

This command sets the labelString resource to Hello World for all Widgets in every Xapp application in your session. This doesn't affect Widgets within other applications. This effect might be desirable if you are trying to set only one type of application resource.

You can also specify your own class for setting resources. You do so by setting the -name option on a client. For example, you can define all the resources for an xterm with 10x20 font to be of class hugeterm. Then, whenever you run

xterm -name hugeterm &

it uses the resources in the class hugeterm. Now you can set the foreground color to whatever you want for xterms with a name of hugeterm.

Note that the name resource cannot contain the * or . characters. These values cause your resource setting to be ignored. The mwm environment simply ignores bad syntax instead of informing the user about these errors.

Customizing Motif is very similar to customizing the X resources. Motif, however, offers a far greater set of features and enables the user to customize just about every item on the screen. Without changing a line of code, the resources here can be set to maintain a consistent set of interfaces for all applications. For example, it's easy to change the background color of all the forms in your applications by simply editing the resources file, instead of editing each source file individually. Here are some more methods for setting resources:

• Hard-code resource settings

• Use command-line parameters

• Use the environment variables to specify class files

You can set resources by hard-coding the values in your application source code. Refer to Chapter 34, "Motif Programming."

Hard-coding resource settings is justifiable in the following cases:

• When you do not want to give control to the end user for application-critical resources. A good example is the locations of all buttons on a data entry form. An end user is liable to shuffle them around to the point that the entry application might become unusable.

• When you do not have to worry about locations of resource files. The application is completely standalone.

• When you also do not have to worry about user intervention in your program code.

• When you want to shield users from modifying their UNIX environment variables and having to learn the customization syntax.

Using the command line was discussed earlier when we talked about customizing X applications and listed some of the resources that can be set from the command line. Motif applications usually list their options in man pages. See the section on appres, "Listing an Application's Resources," later in this chapter.

Use the -xrm command-line option to set or override a particular resource. The usage of this option is as follows:

xclient -xrm "resource*variable: value"

Note that you can concatenate several resource settings using the \ operator.

xclient -xrm "resource*variable: value" \

-xrm "resource*variable: value"     \

-xrm "resource*variable: value"

So how do you know which resources to set? Look in the OSF/Motif Programmers Reference Manual for the description of a Widget's resources.

Looking at the Label Widget, you see resources grouped by the class and all its inherited resources. Some of the resources are declared under the class Core, some under Manager, and so on. Let's look at some of the resources for a XmPushButton Widget. You see these listed with the letters XmN in front of them. These letters signify that it is a Motif resource.

XmNacctivateback XcCallback   XtCallBackList

_ NULL        C      XmNarmColor XmCarmColor Pixel       Dynamic

_           CSG      XmNarmPixmap      XmCArmPixmap      Pixmap

_      XmUNSPECIFIED_PIXMAP    CSG

XmNdefaultButtonThickness

XmCdefaultButtonShadowThickness Dimension 0 CSG

....

Note the letters CSG for the access description:

• The C signifies creation. This tells us that the resource can be set at creation.

• The S signifies that this value can be set at runtime.

• The G signifies that it can be read (get) at runtime.

So in the case of the previous PushButton Widget, the XmNactivateCallback class can be set only at the time it is created: once, at runtime. This is usually done in the code section, where an address to a pointer is set for this Widget.

The other values can be set at runtime. For example, XmNarmColor can be set from a resource file because it does have the S set for it. Likewise, when programming Widgets, this resource can be read from an application because the G value is specified for this resource.

Motif uses several environment variables to hold its pointers to locations for resource files.

The XENVIRONMENT environment variable can hold the complete path to a file that holds the resource file. This must be the complete path of the application. If this variable is not set, the Xt toolkit looks in .Xresources-HostName, in the application's home directory.

The XUSERFILESEARCHPATH is a pointer to the locations of application resource files. This is a colon-delimited string. Each field is expanded into meaningful names at runtime. Following are some of the most common fields:

%C	Customize color
%l	Language part
%L	Full language instruction
%N	Application class name
%S	Suffix

The RESOURCE_MANAGER variable is set by xrd. This xrd is executed at runtime. This usually happens at startup.

The XFILESEARCH environment variable holds a colon-delimited list of directories for the app-defaults file. Usually, these defaults are in the /usr/lib/X11/app-defaults directory.

Note that some of the classes in the directory have the first two letters of their names capitalized, rather than just one letter (XTerm, XDbx, XMdemos). So if your class resource settings do not work as expected, look in this directory for some hints on what the resource class name might look like. Again, the contents of this directory depend on your installation of Motif and X.

The search for the missing .Xresources occurs in the following order: Check in XUSERFILESEARCHPATH;

if not successful or XFILEUSERSEARCHPATH not set,

check in XFILESEARCHPATH;

if not successful or XFILESEARCHPATH not set,

check user HOME directory.

Now that you have all this information, keep this advice in mind: In all but the most unavoidable cases, you should not rely on environments to set your application resources.

The methods are too complicated to learn, especially for the end user. However, they can be a very powerful customization tool. Editing resource files is hard enough on the programmer; it's even worse on the user. To be a good Motif user, however, you should know about the environment variables that affect applications that come from other vendors.

Two Motif applications can assist you in determining an application's resources: appres and editres. Here is the appres program's syntax:

appres Class [instance]

This lists all the resources in a given class for the named instance of an application. Listing 23.2 shows the manual options of the command appres XTerm for advanced users.

$ appres XTerm

*VT100*font5:

*VT100*font5:     9x15

*VT100*font3:     6x10

*VT100*font4:     7x13

*VT100*font2:     5x7

*VT100*font1:     nil2

*VT100*font6:     10x20

*tekMenu*vtshow*Label:     Show VT Window

*tekMenu*tektextsmall*Label:     Small Characters

*tekMenu*vtmode*Label:     Switch to VT Mode

*tekMenu*tektextlarge*Label:     Large Characters

*tekMenu*tekpage*Label:     PAGE

*tekMenu*tekreset*Label:     RESET

*tekMenu*tektext2*Label:     #2 Size Characters

*tekMenu*tekhide*Label:     Hide Tek Window

*tekMenu*tekcopy*Label:     COPY

*tekMenu*tektext3*Label:     #3 Size Characters

*tekMenu.Label:     Tek Options

*fontMenu*font5*Label:     Large

*fontMenu*font6*Label:     Huge

*fontMenu*font2*Label:     Tiny

*fontMenu*fontescape*Label:     Escape Sequence

*fontMenu*fontdefault*Label:     Default

*fontMenu*font3*Label:     Small

*fontMenu*fontsel*Label:     Selection

*fontMenu*font1*Label:     Unreadable

*fontMenu*font4*Label:     Medium

*fontMenu.Label:     VT Fonts

*SimpleMenu*menuLabel.font:     -adobe-helvetica-bold-r-normal--*-120-*-*-*-*-

Âiso8859-*

*SimpleMenu*menuLabel.vertSpace:     100

*SimpleMenu*Sme.height:     16

*SimpleMenu*BackingStore:     NotUseful

*SimpleMenu*HorizontalMargins:     16

*SimpleMenu*Cursor:     left_ptr

*mainMenu*terminate*Label:     Send TERM Signal

*mainMenu*securekbd*Label:     Secure Keyboard

*mainMenu*suspend*Label:     Send STOP Signal

*mainMenu*continue*Label:     Send CONT Signal

*mainMenu*allowsends*Label:     Allow SendEvents

*mainMenu*kill*Label:     Send KILL Signal

*mainMenu*interrupt*Label:     Send INT Signal

*mainMenu*logging*Label:     Log to File

*mainMenu*quit*Label:     Quit

*mainMenu*hangup*Label:     Send HUP Signal

*mainMenu*redraw*Label:     Redraw Window

*mainMenu.Label:     Main Options

*vtMenu*hardreset*Label:     Do Full Reset

*vtMenu*scrollbar*Label:     Enable Scrollbar

*vtMenu*scrollkey*Label:     Scroll to Bottom on Key Press

*vtMenu*scrollttyoutput*Label:     Scroll to Bottom on Tty Output

*vtMenu*jumpscroll*Label:     Enable Jump Scroll

*vtMenu*clearsavedlines*Label:     Reset and Clear Saved Lines

*vtMenu*allow132*Label:     Allow 80/132 Column Switching

*vtMenu*reversevideo*Label:     Enable Reverse Video

*vtMenu*tekshow*Label:     Show Tek Window

*vtMenu*cursesemul*Label:     Enable Curses Emulation

*vtMenu*autowrap*Label:     Enable Auto Wraparound

*vtMenu*tekmode*Label:     Switch to Tek Mode

*vtMenu*visualbell*Label:     Enable Visual Bell

*vtMenu*reversewrap*Label:     Enable Reverse Wraparound

*vtMenu*vthide*Label:     Hide VT Window

*vtMenu*marginbell*Label:     Enable Margin Bell

*vtMenu*autolinefeed*Label:     Enable Auto Linefeed

*vtMenu*altscreen*Label:     Show Alternate Screen

*vtMenu*appcursor*Label:     Enable Application Cursor Keys

*vtMenu*softreset*Label:     Do Soft Reset

*vtMenu*appkeypad*Label:     Enable Application Keypad

*vtMenu.Label:     VT Options

*tek4014*fontLarge:     9x15

*tek4014*font2:     8x13

*tek4014*font3:     6x13

*tek4014*fontSmall:     6x10

XTerm.JoinSession:     False

The second command is a menu-driven GUI program, editres, which enables you to edit the given resources for an application. This is available for X11R5 and later. The program displays a treelike representation of all the Widget classes in a program and enables the user to move through the tree node by node. Search your release for this file. If you do not have this file, don't despair; use the find command. Figure 23.10 shows an editres session.

Create this file from the system.mwmrc file by copying it into your $HOME directory as .mwmrc, and then edit it. (Look in the /var/X11R6/lib directory, and search for the system.mwmrc file using the find command.)

Listing 23.3 shows a sample .mwmrc file. As I stated earlier, with .Xresources, comments are started with a ! character on a line. Note that, depending on your version of Motif, your listing might look very different from the one shown here. You will, however, be able to see the general information presented here.

!!

!!          $HOME/.mwmrc

!!    Modified system.mwmrc for personal changes. kh.

!!

!!

!! Root Menu Description

!!

Menu DefaultRootMenu

{

"Root Menu"             f.title

"New Window"            f.exec "xterm &"

"Shuffle Up"            f.circle_up

"Shuffle Down"          f.circle_down

"Refresh"               f.refresh

"Pack Icons"            f.pack_icons

!     "Toggle Behavior..."    f.set_behavior

no-label               f.separator

"Restart..."            f.restart

!     "Quit..."               f.quit_mwm

}

Menu RootMenu_1.1

{

"Root Menu"             f.title

"New Window"            f.exec "xterm &"

"Shuffle Up"            f.circle_up

"Shuffle Down"          f.circle_down

"Refresh"               f.refresh

!     "Pack Icons"            f.pack_icons

!     "Toggle Behavior"       f.set_behavior

no-label               f.separator

"Restart..."            f.restart

}

!!

!! Default Window Menu Description

!!

Menu DefaultWindowMenu

{

Restore           _R    Alt<Key>F5  f.restore

Move              _M    Alt<Key>F7  f.move

Size              _S    Alt<Key>F8  f.resize

Minimize          _n    Alt<Key>F9  f.minimize

Maximize          _x    Alt<Key>F10 f.maximize

Lower             _L    Alt<Key>F3  f.lower

no-label                           f.separator

Close             _C    Alt<Key>F4  f.kill

}

!!

!! Key Binding Description

!!8

Keys DefaultKeyBindings

{

Shift<Key>Escape  window|icon       f.post_wmenu

Alt<Key>space     window|icon       f.post_wmenu

Alt<Key>Tab       root|icon|window  f.next_key

Alt Shift<Key>Tab         root|icon|window     f.prev_key

Alt<Key>Escape            root|icon|window     f.circle_down

Alt Shift<Key>Escape      root|icon|window     f.circle_up

Alt Shift Ctrl<Key>exclam root|icon|window     f.set_behavior

Alt<Key>F6        window                  f.next_key transient

Alt Shift<Key>F6  window                  f.prev_key transient

Shift<Key>F10           icon              f.post_wmenu

!     Alt Shift<Key>Delete    root|icon|window  f.restart

}

!!

!! Button Binding Description(s)

!!

Buttons DefaultButtonBindings

{

<Btn1Down>  icon|frame  f.raise

<Btn3Down>  icon|frame  f.post_wmenu

<Btn3Down>  root        f.menu      DefaultRootMenu

}

Buttons ExplicitButtonBindings

{

<Btn1Down>  frame|icon  f.raise

<Btn3Down>  frame|icon  f.post_wmenu

<Btn3Down>  root        f.menu      DefaultRootMenu

!     <Btn1Up>    icon        f.restore

Alt<Btn1Down>     window|icon f.lower

!     Alt<Btn2Down>     window|icon f.resize

!     Alt<Btn3Down>     window|icon f.move

}

Buttons PointerButtonBindings

{

<Btn1Down>  frame|icon  f.raise

<Btn3Down>  frame|icon  f.post_wmenu

<Btn3Down>  root        f.menu      DefaultRootMenu

<Btn1Down>  window      f.raise

!     <Btn1Up>    icon        f.restore

Alt<Btn1Down>     window|icon f.lower

!     Alt<Btn2Down>     window|icon f.resize

!     Alt<Btn3Down>     window|icon f.move

}

!!

!!  END OF mwm RESOURCE DESCRIPTION FILE

!!

Note a few key features here:

• Key bindings

• Button bindings

• Menu items

A binding is a mapping between a user action and a function. The key bindings map keystrokes to actions, and the button bindings map button presses and releases to actions. Menus display the menu items for the user and let you organize action items into sections.

The format for all the items is as shown here:

Section_type Section_Title

{

.. definitions..

.. definitions..



}

In this format, Section_type can be Menu, Keys, or Buttons. The Section_Title is a string defining the variable name. It's a name that can be used to refer to this section in other portions of the file.

The functions shown in the sample file begin with an f. keyword. Some actions are fairly obvious: f.move, f.resize, f.maximize, f.minimize, f.title, f.lower, and so on. Some actions are not so obvious: f.separator (displays a line on the menu item), f.circle_up (shuffles window stacking order up), f.circle_down (shuffles window stacking order down).

You can get more information from the OSF/Motif reference book. In my humble opinion, it's dry but informative; the book will supply you with all the information you could possibly want about these commands.

Let's see about defining your own menu items. This could be a sample menu item:

Menu MyGames

{

"Kamran Games" f.title

no-label       f.separator

"Tetris"       f.exec "xtetris &"

"Mahhjong"     f.exec "xmahjongg &"

"Chess"        f.exec "xchess &"

}

The f.title action specifies a heading for the submenu. The f.separator draws a line under the title. The f.exec fires up the command shown in quotation marks.

Now, you can add this new menu to the root menu by adding the following line in your DefaultRootMenu definitions:

"Utils"           f.menu      MyGames

The key and button bindings work much in the same way as menus. The first obvious difference is the extra column with the words icon, frame, window, and root in it. These words force the bindings on the context. The root applies to any location of the pointer on the root window; the frame or window keywords apply binding only when the pointer is in a window or its frame. The icon bindings apply to icons.

In your .Xdefaults file, refer to these key bindings for the class Mwm:

Mwm*keyBindings: DefaultKeyBindings

Here are some of the descriptions in the key bindings:

Shift<Key>Escape  window|icon       f.post_wmenu

Alt<Key>space     window|icon       f.post_wmenu

Alt<Key>Tab       root      f.menu  DefaultRootMenu

The syntax for a keystroke binding is

modifier<Key>key

in which modifier is Alt, Control, or Shift. The key can be a keystroke, function key, or such. The first two declarations describe the same action--show the window menu--but with different keystrokes. The third key binding shows a method for displaying the root menu.

The button bindings are the bindings for your buttons. These are the three important bindings to remember:

Buttons DefaultButtonBindings

Buttons ExplicitButtonBindings

Buttons PointerButtonBindings

In your .Xresource or .Xresources file, refer to one of the preceding button bindings for the class Mwm as

Mwm*buttonBindings: DefaultButtonBindings

or

Mwm*buttonBindings: ExplicitButtonBindings

or

Mwm*buttonBindings: PointerButtonBindings

You can customize your desktop by using some of the client software that comes with your X11R6 distribution. We will cover the following applications:

• xsetroot

• xset

• xdpyinfo

• xmodmap

Several more utilities are in the /usr/bin/X11 directory for you to play with: bitmap, xmag, xcalc, and more. Check out each one to customize your desktop. The ones described here are not so intuitively obvious.

This client customizes the root window characteristics. Here are some of the options available: -cursor cursorfile maskfile This option changes the cursor to a displayed mask value.

-cursor_name name This is the name of the standard cursors in the X11 protocol.

-bitmap filename This option creates a tiled surface on the root window with a bitmap. Check the /usr/lib/X11/bitmaps directory for a list of the standard bitmaps.

-fg color foreground This option sets the foreground color for the bitmap on the root display.

-bg color background This option sets the background color for the bitmap on the root display.

-gray or -grey This option sets the background to a pleasant (for some) gray background.

-rv This option reverses the foreground and background colors.

-solid color This option sets the root window to a solid color; for example, -solid red sets a red background.

Look in the /usr/lib/X11 directory of the file called rgb.txt for a list of colors, and look at the section "Colors," later in this chapter, for more information.

See the man pages for additional features of xsetroot.

The xset command sets up some of the basic options on your environment. Some of these options might not work on your particular system. It's worth it to check these out.

Set your bell volume with this command:

xset b volume frequency durationInMilliseconds.

For example, the command

xset b 70 4000 60

sets the keyboard bell to about 70 percent of maximum, at a frequency of 4000Hz, and on for 60 milliseconds.

To turn on the speaker, use the following command:

xset b on

To turn it off, type this:

xset b off

Turning the speaker back on returns the volume to its default.

Use xset c volume to set the keyclick volume in percentages. A volume setting of 0 turns it off. Any other number (1 through 100) turns it on for that percentage. Of course, for this command to work, you must have your speaker turned on.

To set the mouse speed, use the following command at the prompt:

xset m acceleration threshold

The acceleration is the number of times faster than the threshold that each mouse movement travels. This way, you can zip across the screen with a twitch. Use care in setting this feature unless you are very dexterous. Invoking the Screen Saver Use xset s seconds to enable the screen saver. You can turn off the screen saver with the off option. The default option reverts to system default time for blanking the screen.

For more options, type xset. Using Fonts For example, to load your own fonts, use the following command:

$      xset fp /user/home/myfont,/usr/lib/X11/fontsdir



$      xset fp rehash

The rehash command forces the server to reread its systems files for your command to take effect.

To restore to normal, use the following command:

$      xset fp default



$      xset fp rehash

See the section "Fonts," later in this chapter.

The xdpyinfo utility gives you more information about your X server. It is used to list the capabilities of your server and all its predefined parameters, including the following:

• Name of display

• Version number

• Vendor name

• Extensions

The list is too exhaustive to be included here, and it will be different for your installation. Pipe its output to a file and review it for information about the server. Your output should look different from what's shown in Listing 23.4.

$ xdpyinfo

name of display:    :0.0

version number:    11.0

vendor string:    XFree86

vendor release number:    2110

maximum request size:  262140 bytes

motion buffer size:  0

bitmap unit, bit order, padding:    32, LSBFirst, 32

image byte order:    LSBFirst

number of supported pixmap formats:    2

supported pixmap formats:

depth 1, bits_per_pixel 1, scanline_pad 32

depth 8, bits_per_pixel 8, scanline_pad 32

keycode range:    minimum 8, maximum 134

focus:  window 0x200000d, revert to Parent

number of extensions:    6

XTestExtension1

SHAPE

MIT-SHM

Multi-Buffering

XTEST

MIT-SUNDRY-NONSTANDARD

default screen number:    0

number of screens:    1

screen #0:

dimensions:    800x600 pixels (270x203 millimeters)

8  resolution:    75x75 dots per inch

depths (2):    1, 8

root window id:    0x29

depth of root window:    8 planes

number of colormaps:    minimum 1, maximum 1

default colormap:    0x27

default number of colormap cells:    256

preallocated pixels:    black 1, white 0

options:    backing-store YES, save-unders YES

current input event mask:    0x30003c

ButtonPressMask          ButtonReleaseMask        EnterWindowMask

LeaveWindowMask          SubstructureRedirectMask FocusChangeMask

number of visuals:    6

default visual id:  0x20

visual:

visual id:    0x20

class:    PseudoColor

depth:    8 planes

size of colormap:    256 entries

red, green, blue masks:    0x0, 0x0, 0x0

significant bits in color specification:    6 bits

visual:

visual id:    0x21

class:    DirectColor

depth:    8 planes

size of colormap:    8 entries

red, green, blue masks:    0x7, 0x38, 0xc0

significant bits in color specification:    6 bits

 (... this is a very long listing ... )

***END LISTING

If you are a left-handed user, it might a bit uncomfortable to use the "left" button with your third or second finger. The X designers kept you in mind. If you want to swap the functionality of the pointers on your mouse or pointer, use the xmodmap command. First, display the current mappings like so:

xmodmap -pp

You see the following display:

Physical    Button

Button      Code

1           1

2           2

3           3

This shows you that button code 1 is mapped to physical button 1, button code 2 is mapped to physical button 2, and button code 3 is mapped to physical button 3.

Now issue this command:

xmodmap -e `pointer =  3 2 1'

This command reverses the mappings on the buttons. Now, physical button 1 is mapped to button code 3, and so on. To confirm this, retype the xmodmap -pp command, and you'll see this display:

Physical    Button

Button      Code

1           3

2           2

3           1

You can always revert to the default with this:

xmodmap -e `pointer = default'

Some other standard input parameters that can be used to change the behavior of a window from the command line are listed here:

-borderwidth or -bw	The border width of pixels in the frame. This might not be available for all clients.
-foreground or -fg	The foreground color. For example, this can be the text color for an xterm.
-background or -bg	The background color. For example, this can be the text color for an xterm.
-display	The display on which the client runs.
-font or -fn	The font to use for a particular text display.
-geometry	Specifies the geometry.
-iconic	Starts the application in an iconic form.
-rv or -reverse	Swaps foreground and background colors.
-title	The title for the title bar.
-name	The name for the application.

Of course, the man pages on an application can give you more detailed information than one chapter in a book. Explore a little. For example, you can call one terminal name editor, and set your resources in the .Xresources file for name editor.

The following command starts a remote session on another node:

-display nodename:displayname.ScreenName

The displayname and ScreenName are optional and default to zero if not entered.

You can log into remote machines by using the xterm -display option, provided that you have set up your Linux machine for networks. The remote system must allow you to open a display on its machine. This is done with the xhost + command on its machine. The xhost + command is dangerous because it allows anyone to access your machine, so use it cautiously.

When you want to open an xterm on the remote machine alma, run this command:

xterm -display alma:0.0 &

The format for the option into the display parameter is as follows:

[host]:[server][:screen]

If you are given permission to open a display, you are logged into the remote machine. You can verify this with the uname command. Check the DISPLAY with the echo $DISPLAY command.

When you log out with the exit command, the remote session and the xterm are terminated.

All the colors in the X Window system are located in the /usr/lib/X11/rgb.txt file. This file consists of four columns. The first three columns specify red, green, and blue values; the last entry specifies the name you can use in your parameters.

A partial listing of the rgb.txt file is shown in Listing 23.5.

255 250 250       snow

248 248 255       ghost white

248 248 255       GhostWhite

245 245 245       white smoke

245 245 245       WhiteSmoke

220 220 220       gainsboro

255 250 240       floral white

255 250 240       FloralWhite

253 245 230       old lace

253 245 230       OldLace

250 240 230       linen

250 235 215       antique white

255 239 213       PapayaWhip

255 235 205       blanched almond

255 235 205       BlanchedAlmond

255 218 185       peach puff

255 218 185       PeachPuff

255 222 173       navajo white

255 223 181       moccasin

255 248 220       cornsilk

255 255 240       ivory

255 250 205       lemon chiffon

255 250 205       LemonChiffon

255 245 238       seashell

240 255 240       honeydew

245 255 250       mint cream

255 240 245       LavenderBlush

255 223 225       misty rose

255 223 225       MistyRose

255 255 255       white

0   0   0       black

47  79  79       dark slate grey

47  79  79       DarkSlateGrey

105 105 105       dim gray

105 105 105       DimGray

105 105 105       dim grey

105 105 105       DimGrey

112 123 144       slate gray

112 123 144       SlateGray

112 123 144       slate grey

112 123 144       SlateGrey

119 136 153       light slate gray

119 136 153       LightSlateGray

119 136 153       light slate grey

119 136 153       LightSlateGrey

190 190 190       gray

190 190 190       grey

211 211 211       light grey

Because red, green, and blue have 256 values each, the number of possible colors is 16,777,216. Not many workstations can display that many colors at one time. Therefore, X uses a facility to map these colors onto the display, called a colormap. A color display uses several bits for displaying entries from this map. The xdpyinfo program gives you the number of bits for the display. This is a frame buffer. A 1-bit frame signifies a black-and-white display. An 8-bit frame buffer signifies 2 to the power of 8 entries, or 256 possible colors.

Unfortunately, due to different phosphors on different screens, your color specification on one monitor might be completely different on another monitor. Tektronix provides a tool called xtici, an API, and docs to counter such problems by using the international CIEXYZ standard for color specifications. This is called the Color Management System (CMS), which uses a model called HVC (Hue-Value-Chroma). In the X11R5 (or later) release, look for Xcms for more details, or contact Tektronix.

Fonts in the X Window system are designed for maximum flexibility. These are two good utilities to help you sift through some of the 400 or so font types on a basic system:

xlsfonts	Lists the fonts in your system.
xfontsel	Enables you to interactively see which fonts are available on your system and what they look like on the screen.

First, let's examine the font names themselves. Use the xlsfonts command to list the fonts on your system. Type the command on an xterm, and because the listing from xlsfonts is very long, be sure to pipe to a text file for review. You should see a listing in which each line is of this form:

-foundry-family-wt-sl-wd-p-pts-hr-vr-sp-ave-charset-style

The foundry is the company that first developed the font. The most common ones are misc, Adobe, Bitstream, and B&H. You might see more on your system from the results of your xlsfonts command. A foundry of misc implies a font with fixed width and height per character; the rest were donated by their respective manufacturers.

The family is the general type of font: Courier, Helvetica, New Century Schoolbook, Lucida, and so on. Some families are monospaced, meaning that all their characters have the same width. The other families are proportionally spaced, meaning that each character has a separate width. Courier and Lucida are monospaced fonts. New Century Schoolbook is proportionally spaced.

Use monospaced fonts for tabular information or running text. This makes your text line up cleanly in running displays. Proportionally spaced fonts are helpful for text in buttons or menu items.

The wt and sl parameters stand for weights and slants, respectively. The common weights are bold and medium. Bold text is drawn with a thicker pen than the normal pen. The common slants are (r) roman, (o) oblique, and (i) italic. Roman text is drawn upright, and oblique text has characters sheared to the right. Italic text is similar to oblique text, but the characters are touched up to show a smoother effect. You might also have reverse oblique (ro) and reverse italic (ri), which make the text lean to the left rather than the right.

The p stands for the point size, which traditionally is 1/72 of an inch. Most monitors support only 75 or 100 dots per inch (dpi) resolution. Because X fonts are bitmaps, it seems logical that the most common fonts within X are of two types: 75dpi and 100dpi.

This number is found in the two fields hr and vr, which stand for the horizontal and vertical resolution, respectively. In almost all cases, you specify either 75 or 100 in each of these fields.

The sp refers to the spacing between two characters on the screen. This can be m for monospaced, p for proportional, or c for fixed fonts in which each character occupies a fixed box.

The ave is 1/10 of the average width of all the characters in the set.

The charset and style are usually set to ISO8859-1. This refers to the ISO Latin-1 character set, which includes characters found in ASCII and other European character sets.

Now that you've seen the large number of options that can define a font, you can rely on using wildcards to specify most of the options for a font. The server matches the first font name that matches your specification with a wildcard. In other words, you only have to specify the parameters you want to change, and you can use the asterisk for the rest.

For example, *courier-roman gets the first specification for the roman-weighted Courier font. *Courier, however, gets the bold Courier font. This is because the bold specification exists before the roman specification in the fonts file.

The font search path is the path used by the server to search for the fonts in your system. This path is usually set to the following value:

/usr/lib/X11/fonts/misc,/usr/lib/X11/fonts/75dpi,/usr/lib/X11/fonts/100dpi

In each of these directories is a file called fonts.dir. This file is a list of all the fonts in the directory, and it has two entries per line. The first entry gives a font filename; the second gives the complete font description. The first line in the file gives the number of entries in the file.

You can create another file in the font path to alias your own font names by using the file called fonts.alias. The server uses only the first such file it finds in its path, so keep just one such file in the first directory in your font path. The fonts.alias format is very similar to that of the fonts.dir file, except that the first entry is not a filename; it is an alias for a font name. So if you want to specify a special font type for all your editor xterms, you need the following line:

editterm   *lucida-medium-r-*-100*

Then, you can invoke your xterm with this command:

xterm -fn editterm &

This gets an xterm window with the desired font, and it is a lot better than typing the full font specification. Also, by changing the alias once, you can change it for all scripts that use this alias, instead of modifying each script individually.

A good place to start is the /usr/lib/X11/fonts/misc directory, where a fonts.alias exists from your initial X installation. This file has the fixed and variable aliases defined for you to work with.

The xfontsel program, shown in Figure 23.11, helps you get a better feel for some of the parameters of a particular font.

In Chapter 34, "Motif Programming," you will learn how to program your application.

If you want more information about specific vendors, you can get a wealth of information from the Internet about the latest releases and sources to shareware utilities. Listed in Table 23.2 are some of the newsgroups that can provide you with more information about vendors.

A good starting point for progammers is the following site:

arachnid.cs.cf.ac.uk/Dave/X_lecture/X_lecture

In this chapter, you have learned

• How to install Motif on Linux.

• How to start an X Window session from the prompt.

• The basics of the Motif Window Manager, mwm.

• How to move about in mwm and control windows with the keyboard and mouse.

• How to customize your desktop with resource files and client applications.

• How to set your environment to your liking with resources.

• How to use some standard tools available in X to further set up your desktop.

• Where to look next for more information.

• How to use Widgets and the characteristics of these Widgets. This provides the basis for learning how to program your own applications in the Motif environment.