Filename derived configuration

Allows a default configuration to be downloaded, with the URL found in the filename of the program itself. With this strategy, a mainstream version of Dull can be used.

The ConfigURL filename standard

Dull uses the following filename format in order to embed the configurl into the filename of the program.


The text before _configurl_ is ignored. The text match for _configurl_ is case-insensitive. The filename .exe extension is ignored. The base64-modified encoded segment contains the URL text when decoded.

The standard 3 non-alphanumeric characters { + / = } are not valid in most file system filenames, so a modified base64 is used that substitutes these characters for valid alternatives. Consideration was made for POSIX compliant filenames and also Windows. The following exchanges are made:

Standard base64 character

Substitute character for valid filename







The fullstop character might make the URL appear to have a multi-segment extension. Only the last dotted segment is removed as per‚Äč

An example

The filename:


The base64-modified:


The base64-standard:


The decoded url: