How do you pass user input to a system command?

Question

I'm trying to write an autocmd to make a commit to a git repository. Here is some non-functional code that should illustrate what I'm trying to do:

let g: CommMsg = ''

augroup misc
  autocmd!
  autocmd nmap <buffer> gc :call GetCommMsg()<CR>!git commit -m '=CommMsg'<CR>
augroup END

function! GetCommMsg()
  let curline = getline('.')
  call inputsave()
  let name = input('Enter message: ')
  call inputrestore()
  let CommMsg = call setline(',', curline . ' ' . name)
endfunction

The intention here is to use the GetCommMsg() function to get the message from the user, set a global variable to this value and then pass it to the git commit command as the message argument.

Is this possible?

Answer 1

Maybe this is what you're aiming for?

nnoremap gc :execute '!git commit -m "'.input('Enter message: ').'"'<cr>

The only parts of your script that would do anything useful is the first line and the nmap line. The rest of it would either do nothing or not run at all.

Since you're starting to learn VimL, here's a tip: Test simple ideas in the command line. Every line in a VimL script is something that you can type verbatim in the command line. You would've seen that the '=CommMsg' part of your script would end up being your commit message.

Answer 2

So this seems to work pretty well:

augroup misc
  autocmd!
  autocmd BufEnter * nmap <buffer> gc :call GetCommMsg()<CR>
augroup END

function! GetCommMsg()
  let curline = getline('.')
  call inputsave()
  let msg = input('Enter commit message: ')
  call inputrestore()
  call system("git commit -m '" . msg . "'")
endfunction

Not sure if there are any downsides to doing it this way or not.