Hydra

a C implementation of Emacs Hydra package to be used in terminal.

What is Hydra

Just list Emacs Hydra. It's a program that groups your terminal commands and bind them to common key on your keyboard. Commands can also be grouped in a tree like structure each node in the tree has a name and key bound to it.

Spacemacs for example is an emacs configuration centered around hydra commands, with all user commands grouped as trees bound in a mnemonic way. for example:

• openenig a file is bound to space f f
• deleting current file is bound to space f D
• Git status space g s

This repo implements a program that can be invoked in your terminal, it reads CSV files of key,name,command lines then shows Terminal UI similar to Emacs Hydra.

Binding Hydra to space key in your terminal means pressing space will make your terminal behave similar to spacemacs. this repo has a bash script hydra-completion.bash which achieve this binding.

Build

To build from source:

make

Install

build and install

make
sudo make install

in your .bashrc export environment variable HYDRA to has a list of hydras files. Hydra example files are installed under /usr/share/hydra/hydras. The following setup Hydra to load git commands

export HYDRA="/usr/share/hydra/hydras/git"
source /usr/share/hydra/hydra-completion.bash

loading /usr/share/hydra-completion.bash will bind hydra to Space key in your keyboard and will invoke hydra when the line is empty.

Hydra file

• Hydra files are simple CSV files that define the commands hydra can load.
• The file has 3 columns without header. an example is under hydras directory in this repo.

a simple example can be as follow

g,Git,
gs,Status,git status

• it defines Git command that doesn't execute a command under the key g
• and defines a command named Status under key s inside g that will execute the command git status

Running

You can run hydra binary with a list of hydra files passed to it for example:

hydra hydras/git hydras/systemd hydras/github

Hydra will load the files in the order passed.

Here is an example running hydras/git

Project status

The project is still in the prototype phase. I haven't written C in a while (10+ years) so I'm a bit rusty. probably there could be a lot of improvements. However I would encourage you to try it out.