Using Completion Characters in the Command Prompt

This article describes a special feature of the Windows Command Prompt called the File and Path Completion Characters, which allow you to enter file and folder names by typing in just a few characters instead of the entire file or folder name. This article will be useful to you if you use the Command Prompt already and want to save some keystrokes. If you don’t already use the Command Prompt, this article will not likely provide much benefit to you, and, since it entails editing the Registry, may even be hazardous to the health of your computer if you mess something up, so please proceed with caution!

Prerequisites

We’ll assume for this article that you already understand the basics of the Command Prompt:

• Starting the Command Prompt, using Start / All Programs / Accessories / Command Prompt.
• Running commands at the Command Prompt, by typing the command and any parameters followed by the Enter key, such as dir c:\ ENTER.
• Exiting the Command Prompt, by typing exit (followed by ENTER).
• Listing the available commands, by typing help (followed by ENTER).
• Getting help on a particular command, by typing help followed by the command name, such as help dir.
• Getting help on a particular command using an alternative method, that being typing the name of the command followed by /?, such as dir /?.
• Using basic commands such as dir, chdir/cd, mkdir/md, rmdir/rd, del, move, copy, tree, etc.

We will need to make two small changes to the Registry to accomplish our goal, so we also assume you can do the following in a safe and responsible manner:

• Start the Registry Editor (regedit.exe) by typing REGEDIT into the Start / Run box.
• Add or change DWORD Values in the Registry Editor.
• Exit the Registry Editor.
• Not mess up your entire Windows Operating System by using the Registry Editor.

If any of these assumptions are not true for you, you may want to check on the Internet or in the Windows XP Help and Support Center for information about the Windows Command Prompt and the Registry Editor. You may also want to skip to the next article. The Command Prompt and the Registry Editor are not for beginners. You CAN get into trouble if you’re not comfortable using either of them; therefore, please be sure you are comfortable with this material before trying the techniques detailed in this article. If you’ve never used the Command Prompt before, this is probably not a good time to start, and the information in this article probably does not provide a significant enough benefit to warrant bothering. If, on the other hand, you are comfortable using the Command Prompt and the Registry Editor and are looking to save some keystrokes, read on. If you stick to the path, you should be fine. Just please don’t come to me, or my editor/publisher, with a lawyer if you mess up your computer!

Using File and Path Names in the Command Prompt WITHOUT the Completion Characters

Without using Completion Characters, if you want to list the contents of a folder that has a long name, you are required to type the entire name. For example, if you’d like to see the contents of the C:\Documents and Settings\David folder and your current directory is C:\, you must type DIR "C:\Documents and Settings\David". (Yes, you could make use of the * and ? wildcard characters to some extent, but that‘s a subject for another article….)

Figure 1 – Typing Folder Names Without Completion Characters

You’ve got to spell it exactly correctly, or else you’ll see a File Not Found message.

Figure 2 – DIR Command with a Misspelled Folder Name

Well, perhaps your spelling isn’t that good, or maybe you don’t type that quickly. Completion Characters to the rescue!

Completion Characters

The Windows Command Prompt has a new feature called File and Path Completion Characters that lets you type in just a few of the characters of the folder or file name, hit a special key (of your choosing), and the Command Prompt will complete the rest for you. For example, on my machine, I can type DIR C:\Doc<Ctrl-D>\D<Ctrl-D> ENTER to get the same result as typing the entire line DIR "C:\Documents and Settings\David". This is because I’ve configured the Ctrl-D key sequence to be my Path Completion Character, or what I like to think of as my Directory Completion Character, hence the Ctrl-D. You do this by creating or changing a Registry value.

Choosing the Keystrokes for Your Completion Characters

There are two completion character settings available for your use – one which completes File names and another which completes Folder names (also known as Path or Directory names). You can configure which keys you want to use for these completion operations, or you can turn the features off completely (by setting them to 0). I like to use Ctrl-F for Filename Completion and Ctrl-D for Path (Directory) Completion. To make the keystroke selection, you must program the ASCII code of the desired keystroke into the Registry. Ctrl-A is ASCII 1, Ctrl-B is ASCII 2, and so on. Ctrl-D therefore is ASCII 4, while Ctrl-F is ASCII 6.

We’re almost ready to program the selections into the Registry. One last decision to be made is if you want these selections to apply to the currently logged-in user only or to all users on the machine. The answer to that question determines whether to use the HKEY_CURRENT_USER or the HKEY_LOCAL_MACHINE Registry hive.

An Example

WARNING!!! REGISTRY CHANGES AHEAD!!! PROCEED WITH CAUTION AND AT YOUR OWN RISK!!!

So let’s suppose for the sake of this example that you want to use Ctrl-F for Filename Completion and Ctrl-D for Directory (Path) Completion, and that you want this to take effect only for yourself, the currently logged-in user. Of course, in order to do this, you must have sufficient rights on your machine to edit your registry. If you’re in a tightly restricted office environment, you may not be able to do this.

These are the steps to perform for our example:

1. Select Start / Run.
2. Type REGEDIT and press ENTER.
3. Navigate to the HKEY_CURRENT_USER hive.
4. Open the Software\Microsoft\Command Processor key.
5. Let’s do the Filename Completion character first. Check to see if there is a DWORD Value named CompletionChar. This is the name of the Registry value for Filename Completion. If it already exists, skip to Step 8.
6. To create the new value, select Edit / New / DWORD Value.
7. Change the name of the new value from New Value #1 to CompletionChar by typing CompletionChar and pressing ENTER. Be sure to spell this correctly or else the technique will not work.
8. OK, now that the CompletionChar Value exists, select Edit / Modify.
9. Select Decimal entry as the Base so you don’t have to worry about Hexadecimal conversion.
10. Enter the ASCII code you selected for the Filename Completion Character in the Value Data textbox. In our example, we’ve selected 6 for Ctrl-F.
11. Click OK. One down, one to go!
12. Now let’s do the Folder (Path) Completion character. Check to see if there is a DWORD Value named PathCompletionChar. This is the name of the Registry value for Folder (Path) Completion. If it already exists, skip to Step 15.
13. To create the new value, select Edit / New / DWORD Value.
14. Change the name of the new value from New Value #1 to PathCompletionChar by typing PathCompletionChar and pressing ENTER. Be sure to spell this correctly or else the technique will not work.
15. OK, now that the PathCompletionChar Value exists, select Edit / Modify.
16. Select Decimal entry as the Base so you don’t have to worry about Hexadecimal conversion.
17. Enter the ASCII code you selected for the Folder (Path) Completion Character in the Value Data textbox. In our example, we’ve selected 4 for Ctrl-D.
18. Click OK.
19. You’re all done, so exit the Registry Editor using File / Exit.
20. The changes take effect in any new Command Prompt windows you open, so select Start / All Programs / Accessories / Command Prompt.

Figure 3 – Registry Editor Showing HKEY_CURRENT_USER\Software\Microsoft\Command Processor

A Demonstration of How to Use the Completion Characters

To see these completion characters in action, you type just the first few letters of the file or folder you’re looking for, and then press the appropriate completion character. The Command Prompt will fill in the rest of the file or folder name. If there is more than one match, you can press the same key repeatedly until you find the one you’re looking for.

Let’s look at an example. On my machine, the root folder of my hard drive looks like this:

Figure 4 – A Directory Listing of the Root Folder of My Hard Drive

So, at a Command Prompt, I can type DIR D and then hit Ctrl-D and it will be as if I had typed DIR Data. If I then hit Ctrl-D again, it will change to DIR Debug, and once more will give me DIR DELL. When I find the one I want, I can hit ENTER, just as if I had typed the folder name myself.

If I want specifically the Windows folder and not the Web folder, I can type DIR wi and hit ENTER to skip the Web folder and go straight to Windows.

If I want to see a file that is called Letter to Bob Smith.doc in my current folder, I can type DIR L and press Ctrl-F for Filename Completion. Notice the Ctrl-F key will list Folders in addition to Files when used with most commands, except for the commands that specifically work on Folders, such as CHDIR, MKDIR, and RMDIR, in which case it will only list Folders, which may be a little confusing, but makes sense!

Last Words

Note that any completion character selections you make in HKEY_CURRENT_USER will override corresponding selections in HKEY_LOCAL_MACHINE.

To disable the use of either Completion Character, set the corresponding Registry value to 0.

Don’t forget to use the EXIT command to close your Command Prompt windows when you’re finished with them.

And again, please be careful when editing the Registry and using the Command Prompt. Hope this article saves you some keystrokes and some time in your busy day!