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Getting Help
These days, the manuals supplied with DOS don't provide all the information they did in previous versions. They no longer contain a complete printed reference for all the DOS commands. To get the official Microsoft syntax for every DOS command, you have to pony up extra dollars to buy the MS-DOS Technical Reference. Because you already have this book, you probably don't want or need the Technical Reference. Appendix F, "Command Reference," contains a wealth of information about undocumented switches and parameters.
In place of the printed manual that used to come with DOS, Microsoft has opted instead to supply an online command reference. It falls short of the reference in the back of this book, of course, because it doesn't include the undocumented information; but most of the time, you will find the online reference to be adequate and handy.
To access online help for the use of a particular command, use one of the following procedures from the DOS prompt:
Type the DOS command, followed by the switch /?.
Type HELP, followed by the DOS command.
The following sections describe each method in detail.
Using the Command-Line Help Switch
One DOS command-line switch is never documented in the syntax examples, but you can use this switch with any DOS command. The /? switch is universal to all DOS commands.
After you enter a DOS command followed by the /? switch, DOS prints to the screen a summary of the command syntax. In some cases, the sample syntax is simplified by omitting options not available to you at the command line. A good example is the EMM386 command. Usually, EMM386 is loaded via CONFIG.SYS. After DOS is running, only those parts of the command that are accessible during a DOS session are displayed, omitting the parameters that can be given only at boot time.
The handy thing about using the /? switch is that it gives you a short summary of the command, leaving enough room onscreen for a DOS prompt. This way, you can refer to the syntax and type the command without taking your attention away from the screen.
To get a command summary of the DIR command, for example, type the following command and then press Enter:
DIR /?
DOS displays the command summary help screen shown in Figure 3.1.
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Figure 3.1 Using the DOS command summary help.
Using the Online Help System
The second method for obtaining help is to use HELP, followed by the keyword you want information about. If you don't know the keyword you are looking for, just type HELP and you are presented with a list of command keywords from which to choose.
The online help system displays a detailed description of the command's function, correct syntax, available switches, and a detailed explanation of the effect of each switch.
The online help system also contains special notes and examples related to each command, which enables you to view information on related commands or topics by using only a few keystrokes. If you have a mouse, using the online help system is a snap. You even can print information on selected commands.
To get the complete online help for the DIR command, for example, type the following and then press Enter:
HELP DIR
DOS displays the online help screen shown in Figure 3.2.
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Navigating the Help System
The online help system contains a great deal of information and provides several ways for you to locate, view, and print topics of interest to you. You can use either a mouse or the keyboard to issue commands in the online help system; this section describes both methods. Most of the keystrokes and mouse movements are the same for the help system as they are for the DOS Shell program.
→ For more detailed information about moving around a window, see Chapter 4, "Using the DOS Shell," p. 57.
Figure 3.2 The DOS online help facility shows syntax, notes, and examples about each DOS command.
Because the HELP command provides such complete information, information about a topic or command usually requires more than one screen. To view all the information about a topic, you must scroll the display forward and backward.
To scroll through the text one line at a time, use one of the following methods:
Click the downward-pointing scroll arrow in the scrollbar at the right edge of the screen to move forward one line. To move backward, click the upward-pointing scroll arrow.
Press the Ctrl+down arrow key combination to move forward; press the Ctrl+up arrow key combination to move backward.
To scroll through the text one screen at a time, use one of these methods:
Click the scrollbar below the scroll box to move forward one screen; click above the scroll box to move backward.
Press the PgDn key to move forward one whole screen; press the PgUp key to move backward.
In Figure 3.2, notice the words Notes and Examples near the top-left corner of the screen. Each word is enclosed within solid, triangular characters. Each of these specially marked words is a jump. A jump provides a link to additional information on the currently selected topic or to related topics.
Jumps in the body of the help system's text are marked with angle brackets (<>). The brackets are colored to help you more easily see them if your video card and monitor support color. Although not shown in Figure 3.2, the word <TREE> at the end of the DIR help text is another example of a jump.
When you select a jump, the online help system displays the text related to the topic named by the jump word. To select a jump, use one of the following methods:
Click the jump with the mouse.
Move the cursor over the jump and then press Enter.
If you select the <Examples> jump shown in Figure 3.2, the help system displays a screen containing examples of the DIR command and explanations of each example. Selecting a jump such as <TREE> causes the help system to display the help for the TREE command.
In Figure 3.2, the solid bar across the top of the screen with the words File and Search is the help system's menu bar. You use the help system's pull-down menus in the same way you use the pull-down menus in the DOS Shell.
→ If you are unfamiliar with using pull-down menus, see Chapter 4, "Using the DOS Shell," p. 57.
The choices on the File menu enable you to print a topic or exit the online help system. The choices on the Search menu enable you to search for a topic, word, or phrase and repeat the last search.
Another solid bar appears at the bottom of the screen (refer again to Figure 3.2). The bottom-right corner of this area of the help screen displays numbers indicating the current line and column number of the cursor. In Figure 3.2, the cursor is at line 1, column 2 of the help text for the DIR command.
At the left edge of this area, three keystroke combinations and their functions are displayed:
<Alt+C=Contents> <Alt+N=Next> <Alt+B=Back>
Each label enclosed in brackets also doubles as a command button if you have a mouse. You can click the command button or press the key command, Alt+C, causes the online help system to display its table of contents. Each item in the table of contents is a jump. The Next command, Alt+N, causes the online help system to display the next topic. The Back command, Alt+B, causes the online help system to display the last topic you looked at.
Table 3.1 summarizes the command keys, and their actions, available in the online help system.
Table 3.1 Online Help Command Keys
|
Key |
Action |
|
Alt |
Activates the help system menu |
|
Alt+B |
Returns to the last topic you viewed |
|
Alt+C |
Displays the list of topics covered in the help system |
|
Alt+F |
Opens the File menu |
|
Alt+S |
Opens the Search menu |
|
Alt+N |
Moves to the next topic |
|
Ctrl+down arrow |
Scrolls the screen down one line |
|
Ctrl+up arrow |
Scrolls the screen up one line |
|
Ctrl+Home |
Moves to the beginning of the current topic |
|
Ctrl+End |
Moves to the end of the current topic |
|
Enter |
Selects a menu command or selects the jump under the cursor (the DOS help system displays the text for the jump topic) |
|
Esc |
Cancels a command; closes a menu or dialog box without making a selection or carrying out the action |
|
F1 |
Displays context-sensitive help on using the online help system |
|
F3 |
Repeats the last search |
|
A–Z |
Moves to the next jump beginning with the letter pressed |
|
Shift+letter |
Moves to the previous jump beginning with the letter pressed |
|
PgUp |
Scrolls the text up one screen |
|
PgDn |
Scrolls the text down one screen |
|
Shift+Ctrl+F1 |
Moves to the preceding topic |
|
Tab |
Moves clockwise to the next jump |
|
Shift+Tab |
Moves counterclockwise to the next jump |
Printing a Topic
The online help system enables you to print the text for the currently displayed topic. You may optionally send the output to a file on your disk instead of to the printer. The Print command is located on the File menu.
When the help system displays the File menu, click the Print command. The help system opens the Print dialog box shown in Figure 3.3.
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→ For information on using dialog boxes, option buttons, text boxes, and command buttons, see Chapter 4, "Using the DOS Shell," p. 57.
Figure 3.3 The online help system's Print dialog box.
To print the current topic on your printer, simply press Enter or click the OK command button. To send the text for the current topic to a disk file, select the File option button; then, in the text box, enter the name of the file to which you want to send the output. Finally, press Enter or click the OK command button.
Searching for a Topic
You use the Find command to search for a specific topic, word, or phrase. The Find command is located on the Search menu.
When the help system opens the Find dialog box, you see a screen similar to the one shown in Figure 3.4.
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Figure 3.4 The online help system's Find dialog box.
When the Find dialog box first opens, the Find What text box contains the word that the cursor was on when you selected the Find command. In Figure 3.4, the cursor was on the word Notes when the Find command was selected, so the Find What text box con-tains the word Notes.
Enter the topic, word, or phrase that you want to search for in the Find What text box, or use the word already in the text box. Then, select which of the two Find options you want to use. You can use one, both, or neither of these options.
If you check the Match Upper/Lowercase option check box, the search is case sensitive. If you check the Whole Word option check box, it is assumed that you are searching for a whole word; partial word matches will be ignored.
You can repeat any search by selecting the Repeat Last Find command on the Search menu or by pressing F3.
Exiting the Help System
To exit the online help system using the mouse, pull down the File menu and click Exit. To exit the help system using the keyboard, press Alt+F, followed by X.