Files Names

Here are some facts about them and short file names:

Every long file name has an alias that complies with the 8.3 file names for backward compatibility.

8.3 aliases to long file names consist of the first 6 characters of the long file name followed by a ~ and an incrementing number/character. For example, if there are two or more long file names starting with the same six characters, then the number/character followed by ~ will be incremented until an unique file name is generated.

Length of the long file names are limited to 255 characters (260 for full paths) and short file names are limited to 8+3 or 11 characters (80 for full path names).

About long file names

In the beginning, Microsoft operating systems such as MS-DOS or Windows 3.x did not support long file names that were supported in other operating systems such as Unix, OS/2, and the Apple Macintosh MAC OS. The earlier versions of Microsoft's operating systems had a limitation of an eight character file name or directory, and a three character extension. This standard was more commonly known as 8.3 file naming convention; an example of this would look similar to the below example.

filename.ext

With the release of Windows 95 and the new FAT called VFAT, Microsoft has enabled users to use long file names up to 255 characters in length as well as a three character extension without losing backwards compatibility with existing DOS volumes. Because of the backwards compatibility, long file names, if present, are converted by VFAT to the original 8.3 character file naming convention by each file going through the below changes.

The extended characters + , ; = [ and ] are converted to underscores ( _ ).

The first three characters after a period become the extension.

Spaces are ignored.

The first six characters now remaining are converted to uppercase.

Long file names allow users to input a complete description of their files using any characters they need, except for the below characters.

/ \ : * ? " < > |

With these new features, to access a long filename or directory such as "my long filename or directory", a user would need to use its MS-DOS short name as shown below.

mylong~1

file extension

File extension is usually three or more letter code at the end of computer file names. File extensions are useful to computer operating systems like Microsoft Windows or Apple MAC OS X and tells to OS what kind of data file they are dealing with and what associated program can open or edit the file.

For file extension list, please click here.