Seeking co-maintainers: I don't have much time to maintain this project these days. If someone would like to jump in and become a co-maintainer, it would be appreciated!

McFly - fly through your shell history

McFly replaces your default ctrl-r shell 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 where 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 shell 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.
• You can type % to match any number of characters when searching.

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 macOS or Linux)

1. Install mcfly:

   brew install mcfly

2. Add the following to the end of your ~/.bashrc, ~/.zshrc, or ~/.config/fish/config.fish file:

   Bash:

   eval "$(mcfly init bash)"

   Zsh:

   eval "$(mcfly init zsh)"

   Fish:

   mcfly init fish | source

3. Run . ~/.bashrc / . ~/.zshrc / source ~/.config/fish/config.fish or restart your terminal emulator.

Uninstalling with Homebrew

1. Remove mcfly:

   brew uninstall mcfly

2. Remove the lines you added to ~/.bashrc / ~/.zshrc / ~/.config/fish/config.fish.

Install with MacPorts (on macOS)

1. Update the ports tree

   sudo port selfupdate

2. Install mcfly:

   sudo port install mcfly

3. Add the following to the end of your ~/.bashrc, ~/.zshrc, or ~/.config/fish/config.fish file, as appropriate:

   Bash:

   eval "$(mcfly init bash)"

   Zsh:

   eval "$(mcfly init zsh)"

   Fish:

   mcfly init fish | source

4. Run . ~/.bashrc / . ~/.zshrc / source ~/.config/fish/config.fish or restart your terminal emulator.

Uninstalling with MacPorts

1. Remove mcfly:

   sudo port uninstall mcfly

2. Remove the lines you added to ~/.bashrc / ~/.zshrc / ~/.config/fish/config.fish.

Installing using our install script (macOS or Linux)

1. curl -LSfs https://raw.githubusercontent.com/cantino/mcfly/master/ci/install.sh | sh -s -- --git cantino/mcfly (or, if the current user doesn't have permissions to edit /usr/local/bin, then use sudo sh -s.)

2. Add the following to the end of your ~/.bashrc, ~/.zshrc, or ~/.config/fish/config.fish file, respectively:

   Bash:

   eval "$(mcfly init bash)"

   Zsh:

   eval "$(mcfly init zsh)"

   Fish:

   mcfly init fish | source

3. Run . ~/.bashrc / . ~/.zshrc / source ~/.config/fish/config.fish or restart your terminal emulator.

Installing manually from GitHub (macOS or Linux)

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:$HOME/bin" to your .bashrc / .zshrc, or run set -Ua fish_user_paths "$HOME/bin" for fish.)

3. Add the following to the end of your ~/.bashrc, ~/.zshrc, or ~/.config/fish/config.fish, respectively:

   Bash:

   eval "$(mcfly init bash)"

   Zsh:

   eval "$(mcfly init zsh)"

   Fish:

   mcfly init fish | source

4. Run . ~/.bashrc / . ~/.zshrc / source ~/.config/fish/config.fish or restart your terminal emulator.

Install manually from source (macOS, Linux, or Windows)

1. Install Rust 1.40 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, ~/.zshrc, ~/.config/fish/config.fish, or powershell $PROFILE, respectively:

   Bash:

   eval "$(mcfly init bash)"

   Zsh:

   eval "$(mcfly init zsh)"

   Fish:

   mcfly init fish | source

   Powershell Core (pwsh)

   Invoke-Expression -Command $(mcfly init powershell | out-string)

6. Run . ~/.bashrc / . ~/.zshrc / source ~/.config/fish/config.fish / . $PROFILE or restart your terminal emulator.

Install by Zinit

• Add below code to your zshrc.

  zinit ice lucid wait"0a" from"gh-r" as"program" atload'eval "$(mcfly init zsh)"'
  zinit light cantino/mcfly

• It will download mcfly and install for you.

• $(mcfly init zsh) will be executed after prompt

iTerm2

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

Dump history

McFly can dump the command history into stdout.

For example:

mcfly dump --since '2023-01-01' --before '2023-09-12 09:15:30'

will dump the command run between 2023-01-01 00:00:00.0 to 2023-09-12 09:15:30(exclusive) as json. You can specify csv as dump format via --format csv as well.

Each item in dumped commands has the following fields:

• cmd: The run command.
• when_run: The time when the command ran in your local timezone.

You can dump all the commands history without any arguments:

mcfly dump

Timestamp format

McFly parses timestamps via chrono-systemd-time, a non-strict implementation of systemd.time, with the following exceptions:

• time units must accompany all time span values.
• time zone suffixes are not supported.
• weekday prefixes are not supported.

McFly users simply need to understand specifying timezone in timestamp isn't allowed. McFly will always use your local timezone.

For more details, please refer to the chrono-systemd-time documentation.

Regex

Dump supports filtering commands with regex. The regex syntax follows crate regex.

For example:

mcfly dump -r '^cargo run'

will dump all command prefixes with cargo run.

You can use -r/--regex and time options at the same time.

For example:

mcfly dump -r '^cargo run' --since '2023-09-12 09:15:30'

will dump all command prefixes with cargo run ran since 2023-09-12 09:15:30.

Settings

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

Light Mode

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

bash / zsh:

export MCFLY_LIGHT=TRUE

fish:

set -gx MCFLY_LIGHT TRUE

powershell:

$env:MCFLY_LIGHT = "TRUE"

Tip: on macOS you can use the following snippet for color scheme to be configured based on system-wide settings:

bash / zsh:

if [[ "$(defaults read -g AppleInterfaceStyle 2&>/dev/null)" != "Dark" ]]; then
    export MCFLY_LIGHT=TRUE
fi

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.

bash / zsh:

export MCFLY_KEY_SCHEME=vim

fish:

set -gx MCFLY_KEY_SCHEME vim

powershell:

$env:MCFLY_KEY_SCHEME="vim"

Fuzzy Searching

To enable fuzzy searching, set MCFLY_FUZZY to an integer. 0 is off; higher numbers weight toward shorter matches. Values in the 2-5 range get good results so far; try a few and report what works best for you!

bash / zsh:

export MCFLY_FUZZY=2

fish:

set -gx MCFLY_FUZZY 2

powershell:

$env:MCFLY_FUZZY=2

Results Count

To change the maximum number of results shown, set MCFLY_RESULTS (default: 10).

bash / zsh:

export MCFLY_RESULTS=50

fish:

set -gx MCFLY_RESULTS 50

powershell:

$env:MCFLY_RESULTS=50

Delete without confirmation

To delete without confirmation, set MCFLY_DELETE_WITHOUT_CONFIRM to true.

bash / zsh:

export MCFLY_DELETE_WITHOUT_CONFIRM=true

fish:

set -gx MCFLY_DELETE_WITHOUT_CONFIRM true

powershell:

$env:MCFLY_DELETE_WITHOUT_CONFIRM="true"

Interface view

To change interface view, set MCFLY_INTERFACE_VIEW (default: TOP). Available options: TOP and BOTTOM

bash / zsh:

export MCFLY_INTERFACE_VIEW=BOTTOM

fish:

set -gx MCFLY_INTERFACE_VIEW BOTTOM

powershell:

$env:MCFLY_INTERFACE_VIEW="BOTTOM"

Disable menu interface

To disable the menu interface, set the environment variable MCFLY_DISABLE_MENU.

bash / zsh:

export MCFLY_DISABLE_MENU=TRUE

fish:

set -gx MCFLY_DISABLE_MENU TRUE

powershell:

$env:MCFLY_DISABLE_MENU=true

Results sorting

To change the sorting of results shown, set MCFLY_RESULTS_SORT (default: RANK). Possible values RANK and LAST_RUN

bash / zsh:

export MCFLY_RESULTS_SORT=LAST_RUN

fish:

set -gx MCFLY_RESULTS_SORT LAST_RUN

powershell:

$env:MCFLY_RESULTS_SORT="LAST_RUN"

Custom Prompt

To change the prompt, set MCFLY_PROMPT (default: $).

bash / zsh:

export MCFLY_PROMPT="❯"

fish:

set -gx MCFLY_PROMPT "❯"

powershell:

$env:MCFLY_PROMPT=">"

Note that only single-character-prompts are allowed. setting MCFLY_PROMPT to "<str>" will reset it to the default prompt.

Database Location

McFly stores its SQLite database in the standard location for the OS. On OS X, this is in ~/Library/Application Support/McFly, on Linux it is in $XDG_DATA_DIR/mcfly/history.db (default would be ~/.local/share/mcfly/history.db), and on Windows, it is %LOCALAPPDATA%\McFly\data\history.db. For legacy support, if ~/.mcfly/ exists, it is used instead.

Slow startup

If you have a very large history database and you notice that McFly launches slowly, you can set MCFLY_HISTORY_LIMIT to something like 10000 to limit how many records are considered when searching. In this example, McFly would search only the latest 10,000 entries.

Bash TIOCSTI

Starting with Linux kernel version 6.2, some systems have disabled TIOCSTI (which McFly previously used to write the selected command). McFly works around this issue by using two "dummy" keybindings, which default to ctrl-x 1 and ctrl-x 2. If you are using either of these for another purpose, you can set the MCFLY_BASH_SEARCH_KEYBINDING and MCFLY_BASH_ACCEPT_LINE_KEYBINDING, respectively, to something you are not using. If you would prefer to use the legacy TIOCSTI behavior, you can enable it by setting the sysctl variable dev.tty.legacy_tiocsti to 1 on your system and set the MCFLY_BASH_USE_TIOCSTI bash variable to 1.

HISTTIMEFORMAT

McFly currently doesn't parse or use HISTTIMEFORMAT.

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

Contributing

Contributions and bug fixes are encouraged! However, we may not merge PRs that increase complexity significantly beyond what is already required to maintain the project. If you're in doubt, feel free to open an issue and ask.

Running tests

cargo test

Releasing (notes for @cantino)

1. Edit Cargo.toml and bump the version.
2. Edit CHANGELOG.txt
3. Run cargo clippy and cargo fmt.
4. Recompile (cargo build) and test (cargo test)
5. git add -p
6. git ci -m 'Bumping to vx.x.x'
7. git tag vx.x.x
8. git push origin head --tags
9. Let the build finish.
10. Edit the new Release on Github.
11. cargo publish
12. TBD: update homebrew-core Formula at https://github.com/Homebrew/homebrew-core/blob/master/Formula/m/mcfly.rb

Old:

1. Edit pkg/brew/mcfly.rb and update the version and SHAs. (shasum -a 256 ...)
2. Edit ../homebrew-mcfly/pkg/brew/mcfly.rb too.
3. cp pkg/brew/mcfly.rb ../homebrew-mcfly/pkg/brew/mcfly.rb
4. Compare with diff ../homebrew-mcfly/pkg/brew/mcfly.rb ../mcfly/pkg/brew/mcfly.rb ; diff ../homebrew-mcfly/HomebrewFormula/mcfly.rb ../mcfly/HomebrewFormula/mcfly.rb
5. git add -p && git ci -m 'Update homebrew' && git push
6. cd ../homebrew-mcfly && git add -p && git ci -m 'Update homebrew' && git push && cd ../mcfly