Fly through your shell history. Great Scott!

McFly - fly through your shell history

McFly replaces your default ctrl-r Bash history search with an intelligent search engine that takes into account your working directory and the context of recently executed commands. McFly’s suggestions are prioritized in real time with a small neural network.

TL;DR: an upgraded ctrl-r for Bash whose history results make sense for what you’re working on right now.

Features

• Rebinds ctrl-r to bring up a full-screen reverse history search prioritized with a small neural network.
• Augments your shell history to track command exit status, timestamp, and execution directory in a SQLite database.
• Maintains your normal Bash history file as well so that you can stop using McFly whenever you want.
• Unicode support throughout.
• Includes a simple action to scrub any history item from the McFly database and your shell history files.
• Designed to be extensible for other shells in the future.
• Written in Rust, so it’s fast and safe.

Prioritization

The key feature of McFly is smart command prioritization powered by a small neural network that runs in real time. The goal is for the command you want to run to always be one of the top suggestions.

When suggesting a command, McFly takes into consideration:

• The directory where you ran the command. You’re likely to run that command in the same directory in the future.
• What commands you typed before the command (e.g., the command’s execution context).
• How often you run the command.
• When you last ran the command.
• If you’ve selected the command in McFly before.
• The command’s historical exit status. You probably don’t want to run old failed commands.

Installation

Install with Homebrew (on OS X or Linux)

1. Install the tap:

   brew tap cantino/mcfly https://github.com/cantino/mcfly
   

2. Install mcfly:

   brew install mcfly
   

3. Add the following to the end of your ~/.bashrc file:

   if [[ -r "$(brew --prefix)/opt/mcfly/mcfly.bash" ]]; then
     source "$(brew --prefix)/opt/mcfly/mcfly.bash"
   fi
   

4. Run . ~/.bashrc or restart your terminal emulator.

Uninstalling with Homebrew

1. Remove mcfly:

   brew uninstall mcfly
   

2. Remove the tap:

   brew untap cantino/mcfly
   

3. Remove the lines you added to ~/.bashrc.

Installing manually from GitHub

1. Download the latest release from GitHub.
2. Install to a location in your $PATH. (For example, you could create a directory at ~/bin, copy mcfly to this location, and add export PATH="$PATH:$HOME/bin" to your .bashrc.)
3. Copy mcfly.bash to a known location.
4. Add the following to the end of your ~/.bashrc file:

   if [[ -r /path/to/mcfly.bash ]]; then
     source /path/to/mcfly.bash
   fi
   

5. Run . ~/.bashrc or restart your terminal emulator.

Install manually from source

1. Install Rust 1.29 or later
2. Run git clone https://github.com/cantino/mcfly and cd mcfly
3. Run cargo install --path .
4. Ensure ~/.cargo/bin is in your $PATH.
5. Add the following to the end of your ~/.bashrc file:

   if [[ -r /path/to/mcfly.bash ]]; then
     source /path/to/mcfly.bash
   fi
   

6. Run . ~/.bashrc or restart your terminal emulator.

iTerm2

To avoid McFly’s UI messing up your scrollback history in iTerm2, make sure this option is unchecked:

Settings

A number of settings can be set via environment variables. To set a setting you should add the following snippets to your ~/.bash_profile.

Light Mode

To swap the color scheme for use in a light terminal, set the environment variable MCFLY_LIGHT.

export MCFLY_LIGHT=TRUE

VIM Key Scheme

By default Mcfly uses an emacs inspired key scheme. If you would like to switch to the vim inspired key scheme, set the environment variable MCFLY_KEY_SCHEME.

export MCFLY_KEY_SCHEME=vim

Possible Future Features

• Add a screencast to README.
• Learn common command options and autocomplete them in the suggestion UI?
• Sort command line args when coming up with the template matching string.
• Possible prioritization improvements:
  • Cross validation & explicit training set selection.
  • Learn command embeddings

Development

Running tests

cargo test

Releasing

1. Edit Cargo.toml and bump the version.
2. Recompile.
3. git add Cargo.toml
4. Edit CHANGELOG.txt
5. git ci -m 'Bumping to vx.x.x'
6. git tag vx.x.x
7. git push origin head --tags
8. Let the build finish.
9. Edit the new Release on Github.
10. Edit pkg/brew/mcfly.rb and update the version and SHAs. (shasum -a 256 ...)
11. cargo publish