Filenames and Extensions

Needless to say, each file on a disk must be uniquely identifiable. To achieve this, MS-DOS requires that you name every file you create, as you create it.

In order to be able to manipulate files easily, MS-DOS has certain rules that you must follow when naming files. As you will see, these rules leave you a great deal of freedom in your selection of filenames.

Each filename can be up to eight characters long. To this eight character name can be added an “extension.” Extensions always begin with a period ( . ) which is followed by up to three characters.

The format for a valid MS-DOS filename is:

ABCDEFGHJKL

Most of the characters and symbols on your keyboard are available for use in filenames. These are:

The letters A through Z

The numbers 0 through 9

The following symbols:

!(exclamation point)

@(“at” sign)

#(number sign)

$

(dollar sign)

% (percent sign)

Using MS-DOS With Your Computer 4-21