Option to read starting format file for an existing style file?

[dwmckee]

I'd like to start the comparison against an existing style file.

OK, so I can write a miniscript and fashion a command-line that will massage the file to the format of --startstyle, but reading a file would be convenient.

[mikr]

Could you please describe your use case and what result you would expect
with respect to the source files you are giving to whatstyle?