Question

I want to create vim syntax highlighting file for custom programming language. Namely C/AL which is internal for Dynamics NAV system.

The issue is that it’s impossible to detect via file extension. Historically C/AL uses *.TXT files. It also not good to highlight all *.TXT files, since some of them might contain C/AL code.

I know that VIM is able to detect language not only by extension, but also by file content. And I have found some examples in official manual. However it states I can use either first approach, or second.

Is it possible to combine them in one go? Where I can find an examples of such behavior?

Thank you in advance!

Answer 1

You can use getline to refine your detection based on file contents. For example, this detects XML in .tmp files:

autocmd! BufNewFile,BufRead *.tmp
    \ if getline(1) =~ '<?\s*xml.*?>' |
    \     setfiletype xml |
    \ endif

Another approach is to add a modeline to each C/AL file.