regfiletype file ...
Between Regina versions 2.4 and 3.0, the data files changed from using an impenetrable and undocumented binary format to using (optionally compressed) XML.
This utility determines which of these formats a given Regina data file is in.
You may pass multiple files on the command line; the format of each file will be written to standard output.
If you downloaded a drag-and-drop app bundle, this utility is shipped inside it. If you dragged Regina to the main Applications folder, you can run it as /Applications/Regina.app/Contents/MacOS/regfiletype.
The command-line utilities are installed beneath the Program~Files directory; on some machines this directory is called Program~Files~(x86). You can start this utility by running c:\Program~Files\Regina\Regina~4.96\bin\regfiletype.exe.
This utility was written by Benjamin Burton <[email protected]>. Many people have been involved in the development of Regina; see the users' handbook for a full list of credits.