Question

Vim has a built-in way for executing programs, namely :!start foo for Windows and :!bar & for Unix. However, the problem I have with those is that they steal focus from Vim. I’d like to launch my build & test script, and while its working and showing output in its command window never have to manually switch back to GVim.

I have thought of 3 possible solutions:

• Use Auto-It/AutoHotkey to set focus back to Gvim. Unfortunately that only works in Windows and it’s brittle.
• Have another process watching my sourcecode, and let that process automatically launch the script when the sourecode changes. (Another process creating a new window does not steal focus). This is a bit gimmicky, as you need to hold off on writing files until you want to start the script, and sometimes write a useless change if you want to re-test even though nothing in the source changed.
• Use a client-server architecture, where Vim sends the command over a socket or something similar. This is actually my preferred solution, if there is any existing cross-platform way to do it. (I would prefer not having an extra GVim instance running for this though.)

So what would be a good way to do this? I have tried AsyncCommander but unfortunately it also steals focus.

Answer 1

When I’m not using a nice build system like sbt that watches source code and re-builds/re-tests for me, I tend to come up with hacks like this:

 :map <F9> :!touch and-go<CR><CR>

Here hitting F9 updates a file. Pick any key binding you like.
(and of course you could do the same with imap for vim’s insert mode as well.)

Then all one needs is a shell script that watches this file and executes the
command that builds/tests your project. On unix, I’d just do:

 while stat -c "%Y" and-go; do sleep 1; done | 
 stdbuf -i0 -o0 uniq -c | 
 while read l; do 
    echo build...;  # Your build/test execution commands here.
 done

Running that in a separate window will be neat, because your vim/gvim window will retain it’s focus throughout, while you just keep hitting F9 (or whatever) and glancing at this other window to see how your build went.

If you’re up to writing a windows batch script (or powershell, I don’t know) version of that as well, you should be good to go.