homebrew-command-not-found

This project tries to reproduce Ubuntu’s command-not-found for Homebrew users on OSX.

On Ubuntu, when you try to use a command that doesn’t exist locally but is available through a package, Bash will suggest you a command to install it.

Using this script, you can replicate this feature on OSX:

# on Ubuntu
$ when
The program 'when' is currently not installed.  You can install it by typing:
sudo apt-get install when

# on OSX with Homebrew
$ when
The program 'when' is currently not installed. You can install it by typing:
  brew install when

Install

First, tap this repository:

brew tap homebrew/command-not-found

• Bash and Zsh: Add the following line to your .bashrc (bash) or .zshrc (zsh):

  if brew command command-not-found-init > /dev/null; then eval "$(brew command-not-found-init)"; fi

• Fish: Run the following command:

brew command-not-found-init-fish --fish

* _Note_: If your functions directory isn't  `~/.config/fish/functions/` 
then pass custom path as the second argument. You can find that out with 
`echo $fish_function_path`. Eg.

```
brew command-not-found-init-fish --fish /usr/local/fish/functions/
```

Upgrade from 0.1.1

Before the 0.2.0 version this was a simple handler.sh script which grep-ed in formulae to find the binaries. It worked well for most formulae but wasn’t exhaustive.

The 0.2.0 version changed how it works. If you’d like to keep your existing handler script, it’s fine, it’ll continue to work. If instead you’d like to upgrade to 0.2.0 just remove it and follow the install instructions above.

Support

This tool supports Bash (version 4 and higher), Zsh, and Fish (2.2.0).

How does it work?

When you tap the repo you’ll get two more brew commands: brew which-formula and brew which-update. The first one uses a file database to gives you which formula you have to install in order to get a specific command. The file is generated by the second command by crawling all installed formulae and collect their binaries. If we regularly run this update script on multiple Homebrew installations I hope we’ll cover most of the formulae. Having this as a tap means you get an up-to-date binaries database each time you run brew update.

For Bash and Zsh, the handler.sh script defines a function command_not_found_handle and command_not_found_handler, respectively. Which is used when you try a command that doesn’t exist. The function calls brew which-formula on your command, and if it finds a match it’ll print it to you. If not, you’ll get an error as expected.

For Fish, the handler.fish defines a function command-not-found-handler with is used by Fish when a command doesn't exist. The function is symlinked in your functions directory. Fish recognises the function, and uses this instead of its default handler. The function utilises brew which-formula to find and prints the relevant information about the command; on the case where it finds nothing, the function runs the default handler (__fish_default_command_not_found_handler).

Over 4300 formulae have been imported in the database, representing more than 19900 different commands (99% of the main Homebrew repo + 69% of all official taps).