vim Autocommands
Remarks
Surround autocmd commands
autocmd is an additive command, and you probably don't want this behaviour by default.
For example, if you re-source your .vimrc a few times while editing it, vim can slow down.
Here's proof:
:autocmd BufWritePost * if &diff | diffupdate | endif " update diff after save
:autocmd BufWritePost * if &diff | diffupdate | endif " update diff after save
If you now type :autocmd BufWritePost *, you'll see both lines in the output, not just one. Both get executed.
To avoid this behaviour, surround all your autocmds as follows:
if has ('autocmd') " Remain compatible with vi which doesn't have autocmd
augroup MyDiffUpdate " A unique name for the group. DO NOT use the same name twice!
autocmd! " Clears the old autocommands for this group name
autocmd BufWritePost * if &diff | diffupdate | endif " Update diff after save
" ... etc ...
augroup END
endif
