jaredmichaelwilliams

1. Open slack in a browser
2. Go to the channel you want to invite everyone to
3. Using Command/Control and the '-' key, make the page small
4. Open the Javascript console
5. Copy into the console the contents of inviteusers.js
6. Hit enter and watch it invite the users.
7. You might have to run it a few times if you have a lot of users and it doesnt add everyone at first
8. Took 4 times to invite 3,000 people to a channel on my slack 

jaredmichaelwilliams

Preparation

Purchase YubiKey NEO
Install X Code and Command Line Tools, if installing anything from source.
X Code can be installed from the App Store.
Command Line Tools are installed from X Code: X Code -> Preferences -> Downloads -> Components -> Command Line Tools.
Install YubiKey reader library libyubikey (aka yubico-c)
Using homebrew: 
brew install libyubikey
brew install ykpers