All features, can add the option to accept the contents of the file without having to pass in one file at a time.

[17Reset]

Is it possible to add an option inside the program to accept code contents directly as input instead of having to accept a file?

[IEncinas10]

I'm not sure if I understood you correctly, but you should be able to do things like:

cat some-file | verible-verilog-lint - , verible-verilog-lint - < some-file

I'm not sure if it is documented, after a quick look I couldn't find it.