DOS ain't dead - translating LFNs into short 8.3 form

translating LFNs into short 8.3 form (Miscellaneous)

posted by ecm , Düsseldorf, Germany, 13.11.2010, 21:46

The difficulty lies in insuring the result is unique within the directory. This is done by that algorithm by storing the created name in the directory. (Storing the number behind the tilde would theoretically be sufficient.) This is not usable on file systems that do not provide storage for the short names.

One workaround is to define and maintain a file yourself (usually in the root directory, or one in each subdirectory as necessary) that holds short name aliases and their long (real) names. This was used in the other direction (to provide long names on FAT) even before W95 came around with long file names.

Another workaround is to use some value that makes the name unique in the directory as "tilde number". For example, the directory index of the file's name. IIRC that is used by DOSLFN's CD-ROM access. This method is best employed on read-only file systems as otherwise you need low-level hooks to avoid directory entry re-ordering (because it would change the assigned short name). Users want name assignments to persist, both generally (ease of use) and for shorter periods (while the file is opened by a program, it is critical that it persists).

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l

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Complete thread:

exFAT - Drewfus, 10.11.2010, 13:49 (Miscellaneous)
- exFAT == less than ideal - Rugxulo, 10.11.2010, 14:12
  - exFAT - Laaca, 10.11.2010, 14:44
    - translating LFNs into short 8.3 form - Arjay, 13.11.2010, 21:32
      - translating LFNs into short 8.3 form - ecm, 13.11.2010, 21:46
        translating LFNs into short 8.3 form - Drewfus, 14.11.2010, 22:30
        translating LFNs into short 8.3 form - RayeR, 15.11.2010, 02:37
        translating LFNs into short 8.3 form - Laaca, 11.01.2011, 00:20
        translating LFNs into short 8.3 form - ecm, 11.01.2011, 16:09
        translating LFNs into short 8.3 form - bretjohn, 11.01.2011, 19:40
        translating LFNs into short 8.3 form - Laaca, 11.01.2011, 21:58
        translating LFNs into short 8.3 form - ecm, 11.01.2011, 23:06
        translating LFNs into short 8.3 form - RayeR, 12.01.2011, 02:29
        translating LFNs into short 8.3 form - roytam, 12.01.2011, 09:11