Why do my Filenames Change Case?

The Problem

To avoid problems with links on web pages, you need to ensure that the case of the filename given in the Anchor tag <A> matches that of the actual file name. There is however a snag. Under Windows 9x (my shorthand for Windows Version 95 and later), long filenames are permitted, with any combination of upper and lower case letters. Depending upon which software you use to prepare the text and pictures making up your web pages, you may find that portions of file names appear to "mysteriously" change case.

The Cause

To ensure compatibility between the long filenames of Windows 95 and onwards and the 8 + 3 all capitals filenames of DOS and earlier versions of Windows, files under Windows 9x have two separate filenames. One in the old style and one in the new. For a full explanation of how this works, see http://www.zdnet.com/pcmag/issues/1512/pcmg0025.htm from PC Magazine Online. Programs written before long file names were introduced can only interact with the short version of the filename. (This includes "File Manager" which is still shipped as part of Windows 9x) If files are re-written with such programs the effect on the long filename is "unpredictable".

The Cure

You could simply throw away all your old software and use only programs that are aware of long filenames. However it is generally easiest to stick with the programs you are familiar with, then clean up the mess before uploading your pages.

You can do this by hand, using the rename command in Windows Explorer. However if you have many files to change, it is best to do it automatically. Hai Li has created a program Change Case which does exactly this job. It works well and he has generously made it available as CARDWARE. It is downloadable from his web site at http://www.zealsoftstudio.com/changecase/ Give it a try.

Copyright © Alan Simpson 2000 Back to index. Last Updated 2001-01-15