navi

An interactive cheatsheet tool for the command-line and application launchers.

navi allows you to browse through cheatsheets (that you may write yourself or download from maintainers) and execute commands. Argument suggestions are prompted to you.

Pros

• it will make you type less;
• it will spare you from knowing CLIs by heart;
• it will teach you new one-liners.

It uses fzf, skim, or Alfred under the hood and it can be either used as a command or as a shell widget (à la Ctrl-R).

Table of contents

• Installation
  • Using Homebrew or Linuxbrew
  • Using nix
  • Using cargo
  • Using install script
  • Downloading pre-compiled binaries
  • Building from source
  • Other package managers
• Usage
  • Shell widget
  • Alfred
  • More options
• Trying out online
• Cheatsheets
  • Importing cheatsheets
  • Adding your own cheatsheets
  • Submitting cheatsheets
• Cheatsheet syntax
  • Syntax overview
  • Variables
  • Advanced variable options
  • Variable dependency
  • Multiline snippets
  • Variable as multiple arguments
• List customization
• Related projects
• Etymology

Installation

Using Homebrew or Linuxbrew

brew install navi

Using nix

nix-env -iA nixpkgs.navi

Using cargo

cargo install navi

Using install script

bash <(curl -sL https://raw.githubusercontent.com/denisidoro/navi/master/scripts/install)

# alternatively, to set directories:
# SOURCE_DIR=/opt/navi BIN_DIR=/usr/local/bin bash <(curl -sL https://raw.githubusercontent.com/denisidoro/navi/master/scripts/install)

Downloading pre-compiled binaries

You can download binaries here.

Building from source

git clone https://github.com/denisidoro/navi ~/.navi
cd ~/.navi
make install 

# alternatively, to set install directory:
# make BIN_DIR=/usr/local/bin install

Other package managers

You can find navi for more package managers by clicking on the image below:

Feel free to be the maintainer of navi for any package manager you'd like!

Usage

By running navi for the first time, you'll be suggested to download some cheatsheets. By running navi again, these cheatsheets will appear.

Shell widget

You can use navi as a widget to your shell. This way, your history is correctly populated and you can edit the command as you wish before executing it. To set it up, add this line to your .bashrc-like file:

# bash
source <(echo "$(navi widget bash)")

# zsh
source <(echo "$(navi widget zsh)")

# fish
navi widget fish | source

By default, Ctrl+G is assigned to launching navi.

Alfred

This is experimental. If you face any issues, please report the issue here.

• make sure you have Alfred Powerpack;
• make sure navi is up to date;
• make sure that the navi binary is in the $PATH determined by ~/.bashrc;
• download and install the .alfredworkflow for the latest release.

More options

Please refer to navi --help for more details.

Trying out online

If you don't have access to a Unix shell at the moment and you want to live preview navi, head to this playground. It'll start a docker container with instructions for you to install and use the tool. Note: login required.

Cheatsheets

Importing cheatsheets

You can find cheatsheet repositories with:

navi repo browse

In addition, you can import cheatsheets from any git repository:

navi repo add https://github.com/denisidoro/cheats

Adding your own cheatsheets

You can either start a git repo with cheatsheets and import it as described above or you can add them directly to data_dir/navi.

Submitting cheatsheets

The main repository for cheatsheets is denisidoro/cheats. Feel free to open a PR there for me to include your contributions.

In order to add your own repository as a featured cheatsheet repo, please edit this file. This list will be displayed when navi repo browse is run.

Cheatsheet syntax

Cheatsheets are described in .cheat files that look like this:

% git, code

# Change branch
git checkout <branch>

$ branch: git branch | awk '{print $NF}'

Syntax overview

• lines starting with % determine the start of a new cheatsheet and should contain tags, useful for searching;
• lines starting with # should be descriptions of commands;
• lines starting with ; are ignored. You can use them for metacomments;
• lines starting with $ should contain commands that generate a list of possible values for a given argument;
• lines starting with @ should contain tags whose associated cheatsheet you want to base on;
• all the other non-empty lines are considered as executable commands.

It's irrelevant how many files are used to store cheatsheets. They can be all in a single file if you wish, as long as you split them accordingly with lines starting with %.

Variables

The interface prompts for variable names inside brackets (eg <branch>).

Variable names should only include alphanumeric characters and _.

If there's a corresponding line starting with $ for a variable, suggestions will be displayed. Otherwise, the user will be able to type any value for it.

If you hit <tab> the query typed will be prefered. If you hit <enter> the selection will be prefered.

Advanced variable options

For lines starting with $ you can use --- to customize the behavior of fzf or how the value is going to be used:

# This will pick the 3rd column and use the first line as header
docker rmi <image_id>

# Even though "false/true" is displayed, this will print "0/1"
echo <mapped>

$ image_id: docker images --- --column 3 --header-lines 1 --delimiter '\s\s+'
$ mapped: echo 'false true' | tr ' ' '\n' --- --map "[[ $0 == t* ]] && echo 1 || echo 0"

The supported parameters are:

• --prevent-extra (experimental): limits the user to select one of the suggestions;
• --column <number>: extracts a single column from the selected result;
• --map <bash_code> (experimental): applies a map function to the selected variable value;

In addition, it's possible to forward the following parameters to fzf:

• --multi;
• --header-lines <number>;
• --delimiter <regex>;
• --query <text>;
• --filter <text>;
• --header <text>;
• --preview <bash_code>;
• --preview-window <text>.

Variable dependency

The command for generating possible inputs can implicitly refer other variables by using the <varname> syntax:

# Should print /my/pictures/wallpapers
echo "<wallpaper_folder>"

$ pictures_folder: echo "/my/pictures"
$ wallpaper_folder: echo "<pictures_folder>/wallpapers"

If you want to make dependencies explicit, you can use the $varname syntax:

# If you select "hello" for <x>, the possible values of <y> will be "hello foo" and "hello bar"
echo <x> <y>

# If you want to ignore the contents of <x> and only print <y>
: <x>; echo <y>

$ x: echo "hello hi" | tr ' ' '\n'
$ y: echo "$x foo;$x bar" | tr ';' '\n'

Extending cheatsheets

With the @ same tags from other cheatsheet syntax you can reuse the same variable in multiple cheatsheets.

% dirs, common

$ pictures_folder: echo "/my/pictures"

% wallpapers
@ dirs, common

# Should print /my/pictures/wallpapers
echo "<pictures_folder>/wallpapers"

% screenshots
@ dirs, common

# Should print /my/pictures/screenshots
echo "<pictures_folder>/screenshots"

Multiline snippets

Commands may be multiline:

# This will output "foo\nyes"
echo foo
true \
   && echo yes \
   || echo no

Variable as multiple arguments

# This will result into: cat "file1.json" "file2.json"
jsons=($(echo "<jsons>"))
cat "${jsons[@]}"

$ jsons: find . -iname '*.json' -type f -print --- --multi

List customization

Lists can be stylized with the $FZF_DEFAULT_OPTS environment variable or similar variables/parameters (please refer to navi --help). This way, you can change the color scheme, for example.

Related projects

There are many similar projects out there (bro, eg, cheat.sh, tldr, cmdmenu, cheat, beavr, how2 and howdoi, to name a few).

Most of them provide excellent cheatsheet repositories, but lack a nice UI and argument suggestions.

Etymology

In The Legend of Zelda Ocarina of Time, navi is a character that provides Link with a variety of clues to help him solve puzzles and progress in his quest.