Ctrl-p is “Intellisense for Vim”, allowing you to quickly jump to a file by searching for a few letters or even fancy camel-case type searches. (e.g. find article_editor.rb by searching for “ae”).
However, doing all this requires it to maintain a search index, aka cache, to be maintained. That can be very frustrating with a big project as it takes 5-10 seconds to update, which is not a good thing when you’re desperately trying to jump around files. This delay would be fine if Ctrl-P worked in the background, but due to Vim limitations, it can’t, so you have to frequently run it on the command-line and wait for the update.
Or do you?
No you don’t. Here is a trick that lets you never wait for ctrl-p again! Just add this to your vimrc:
let g:ctrlp_user_command = 'ag %s -i --nocolor --nogroup --hidden \ --ignore .git \ --ignore .svn \ --ignore .hg \ --ignore .DS_Store \ --ignore "**/*.pyc" \ -g ""'
It’s taken straight from here. The cool thing about this trick is it doesn’t just speed up indexing, it completely removes the need for it. This is achieved by relying on the command-line tool Ag, aka Silver Searcher. It’s a brilliant grep replacement I would recommend to anyone, being exponentially faster than grep (as in, you can happily search a whole hard drive in real time).
I’ve used Ag for years but never realised it could be piped into Ctrl-P!
That page also includes some matching optimisation, but seriously the Ag trick was all I needed. Searching is now completely instantaneous and I never need to worry about the index going stale again.
The update has been pushed to my dotfiles.