[FEATURE] Add command-line option to specify a custom configuration file

[rootnotez]

Please confirm the following points:

• This feature request is NOT for the Android apps in the Play Store
• I have searched the project page to check if a similar request was already made

Application or Project

projectM Standalone SDL2 Frontend (includes the Steam app)

Is Your Enhancement Related to a Problem?

projectMSDL.properties is created in a specific directory, but there is no command line option to override it.

https://github.com/projectM-visualizer/frontend-sdl-cpp/blob/master/README.md?plain=1#L94-L101

Your Suggested Enhancement

Add a command line option to specify a projectMSDL.properties file. Since there is a save option inside the projectMSDL app, may need to check if a config file was passed in, and make a decision whether changes should be saved to the currently loaded file. Perhaps the user could be provided the context of what save file is currently loaded.

I think also maybe copying the default file with the helpful commented out setting descriptions to the user file might be helpful.

Alternative Solutions

No response

Additional Context

No response

[kblaschke]

Had this idea on the back of my mind for some time now, but didn't create a ticket for that. Will add a --config/-c option to specify a custom configuration file that overrides the platform-specific default path. It's super easy to do, so won't take ages to implement 😉

[yetanothergeek]

One possible workaround on Linux is to use the XDG_CONFIG_HOME environment variable.

For example:

mkdir -p  /tmp/test/projectM
cp -i ~/.config/projectM/projectMSDL.properties /tmp/test/projectM/

Now make some noticeable changes to

/tmp/test/projectM/projectMSDL.properties

and then run:

XDG_CONFIG_HOME=/tmp/test/  projectMSDL

I think Windows has a similar concept like %PROFILEDIR% or something but I haven't tried it.

But yes, a --config option would be still be nice to have.