On Apr 19, 2019, at 16:25, Helmut K. C. Tessarek wrote:
> I want macOS to let me choose the app every time I double click on an
> .md file.
I don't think macOS has this capability built-in.
I just created a new file with an unusual extension. I opened it in the Finder
and it said there's no application that can open it. When I clicked Choose
Application in that dialog and chose an application, it opened the file into
that application. When I went back to the Finder and opened the file again, it
didn't ask again; it opened it with the app I previously selected.
There is an app called Choosy that lets you configure what happens when you
click a URL outside of a web browser. It can be configured to ask every time
which browser should open the URL. This only works for URLs, but it illustrates
that it would be possible to write a program that does the same thing for file
MIME types or extensions. You would tell the OS that you want .md files to open
into this new hypothetical application, and the app would then ask you what
program you really want to open it with. It would probably not be too difficult
to write such a program. There may even be one out there already.
