8.3 filename

(Also known as 8-point 3- names ) 8.3 is a commonly used notation for the restrictions which file names are in FAT file systems such as CP / M, DOS, and the versions of Microsoft Windows prior to Windows 95, subject. Similar restrictions exist for certain file systems from Data General and DEC.

8.3 file and directory names are a maximum of eight letters or digits followed by a dot ( ".") And the extension, which may consist of up to three characters. In file and directory names are not case- sensitive, is usually to uppercase letters displayed (ie, lower-case letters are not allowed). Furthermore, some special characters are not allowed, as these are control characters (eg, colon, question mark, star) or are used differently in different code pages, for example, is the path delimiters in Germany (code page 850), the backslash ("\" ) and in Japan (code page 932 ) the yen symbol ( "¥ " ), although its file system - internal encoding is identical.

With Windows 95 and Windows NT 3.5 VFAT was introduced as a variant of the FAT file system with extended directory entries. So long, large and kleinbuchstabig written file name (LFN ) were in addition to the 8.3 schema in the MS- DOS or Windows " world " is possible.

To maintain backward compatibility with older applications, a 8.3 version is entered in the directory for each long file name in addition, to deal with such files under the older programs.

Under MS- Windows, the procedure is this, follow:

The 8.3 names are usually regenerated in each directory. Copy or move files, it may lead to a change in the numbering of the short file name depending on the order of execution in several similar file name. Example: There is first created a " My file.txt ", which " ~ 1.TXT MEINED " receives the nickname. Then create a " My data.txt " which " MEINED ~ 2.txt " receives. If the second file first copied or moved to a new directory, receives " My data.txt " the nickname " MEINED ~ 1.TXT " and copied as a second " My file.txt " the nickname " MEINED ~ 2.txt ".

Problems can arise when files have lost their long file name ( for example, editing with old programs, disclosure of non- compatible systems ) and a LFN file with the same name as your nickname already exists. Then asked if the file should be overwritten. This can also happen if both files peacefully existed previously in a common directory. Example: There is a " MEINED ~ 1.TXT ". In addition a file " My file.txt ", which receives the nickname " MEINED ~ 2.txt ", since " ~ 1" is already taken. If now in the processing sequence first " My file.txt " moves (because is processed, for example by file date ) it is given the name " MEINED ~ 1.TXT ". In the later moving " MEINED ~ 1.TXT ", which only has this and no long file names, it is then determined that the file name is already taken.

The NTFS file system of Windows NT variants based on the LFN system, but also supports the 8.3 schema. The latter support can be disabled in order to increase the processing speed.

Although the used CDs ISO 9660 file system allows file names up to 31 characters, but the 8.3 naming scheme is used by many burning programs also supported for compatibility reasons.

• File system