Naming Files
Each file must have a unique filename so you can retrieve it
when you need to. The filename consists of two parts: the name
and the extension (which is optional).
You can choose a name up to eight characters long. Create a
name that identifies the information the file contains. The
name can contain any characters or numbers except for blank
spaces and the following symbols:
* \ / { } : I < > + = ; . ?
The extension is optional and can be up to three characters
long. You can use the extension to further identify a file or to
describe what type of file it is, such as a text file or program file.
When you use an extension, separate it from the filename with
a period. For example, an MS-DOS filename might look like this:
DATA.TXT
Some application programs automatically add extensions to the
files you create. These programs use the extension to determine
whether it is a compatible data file. Avoid using the same
extensions as your application programs. Also, do not use
uppercase and lowercase letters to distinguish between files.
MS-DOS does not recognize the difference and displays all
filenames in uppercase.
Certain extensions are reserved for program files and you must
not use them for your data files. The reserved extensions are
.COM, .EXE, and .BAT. Files with these extensions are also
sometimes called executable files.
The .BAT extension denotes a particular kind of executable
file called a batch file. Batch files can be used to automate
sequences of MS-DOS instructions. Even if you are not a
programmer, you may want to create some batch files to assist
you in your work. A particularly useful kind of batch file, called
an autoexecute batch file (or “AUTOEXEC” file) is discussed
later in this chapter.
Using MS-DOS With Your Computer
3-9
