vim：进入插入模式时检测底层文件更改

Question

Here's a sequence of events:

1. Open a file in vim , make some edits, save it, and stay in normal mode;
2. The file gets changed by an external process, say git ;
3. Go back to vim , enter insert mode (at this point file has been changed, but vim sees a stale version);
4. Make some edits to the stale version, go back to normal mode;
5. Save the file in vim .

When I do things like above, what typically happens is that vim warns me at step 5:

WARNING: The file has been changed since reading it!!!
Do you really want to write to it (y/n)?

This is rather inconvenient, because I already made some "valuable" edits. How can I ask vim to do the check at step 3, that is, before entering insert mode, check if the buffer is outdated and offer to reload?

Answer 1

Add to your ~/.vimrc:

autocmd InsertEnter * checktime

Ie, on entering Insert mode for any file ( * ) execute checktime .