VIM syntax highlighting of text files

Question

Vim used to syntax highlight plain text files(*.txt) as conf files if the first character of the file was a #. But after I updated to 8.0.3, this feature has disappeared. Is there a way to fix this other than the solution mentioned here? i.e without modifying the file.

Answer 1

function SetConfType()
  if !empty(matchstr(getline('1'), '^#\s.*'))
    set filetype=conf
  endif
endfunction

autocmd  BufEnter *.txt call SetConfType()

Update:

This oneliner does not require a function. It is a little bit more elegant.

au BufRead * if getline(1) =~ '^#\s.*' | setlocal ft=javascript.flow | endif