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Packages
Creating
To learn package creation let's create a new package that will provide a hello_world
command for your shell. Package names may only contain lowercase letters and hyphens to separate words.
Oh My Fish can scaffold a package structure for you. Use the command omf new
:
$ omf new plugin hello_world
Use
omf new theme my_theme_name
for themes.
The utility changes the current directory to the newly created package:
$ ls -l
README.md
init.fish
functions/hello_world.fish
completions/hello_world.fish
Always describe how your package works in the
README.md
.
Also read more about auto completion and take care to provide it for your utilities when applicable.
functions/hello_world.fish
defines a single function:
function hello_world -d "Prints hello world"
echo "Hello World!"
end
Each function in your package must be declared in its own file under functions
directory. This is required by fish autoloading mechanism, which loads functions on demand, avoiding loading unused functions at startup time.
Bear in mind that fish lacks a private scope, so if you need to split your package into functions, avoid name clashes prefixing your functions with something unique -- like your package name (e.g. hello_world_print_help
). To avoid polluting command namespace, consider prefixing private functions with two underscores (e.g. __function_name_print_help
).
Hooks
Oh My Fish provides a "hooks" system that allows you to write scripts for your package that run when other interesting events occur. Packages can use these hooks to provide advanced installation, custom resource management, etc. Hooks are ordinary Fish scripts named after the event they are triggered by. Most hooks reside in a hooks
directory inside a package's project directory.
Hooks that are called at startup time (
init.fish
andkey_bindings.fish
) can slow down shell startup. Be sure to avoid slow code at startup time! Also, if your package doesn't need a hook file, be sure to remove it.
The working directory inside a hook is always set to the root directory of the package. The hooks Oh My Fish currently supports are listed below:
init
The init
hook is run once when the shell first loads. Scripts to handle this hook should be located at init.fish
at package's root directory.
Inside this hook, you can access three package-related variables:
$package
: Package name$path
: Package installation path$dependencies
: Package dependencies
For example, with an init.fish
script containing the following code:
echo "hello_world initialized"
you will see the line hello_world initialized
at the top of the terminal when it is first opened.
Use this hook to modify the environment, load resources, autoload functions, etc. If your package does not export any function, you can still use this event to add functionality to your package, or dynamically create functions.
key_bindings
If your package or theme need to use key bindings, be sure to set them up in the key_bindings
hook. Key binding scripts must be located at key_bindings.fish
at package's root directory. In this hook you can freely use the bind
command to define custom key bindings.
Themes can define key bindings too! Oh My Fish will reload key bindings when you switch themes.
install
The install
hook is triggered when a package is first installed. Scripts for this hook must be located at hooks/install.fish
.
Inside this hook, you can access two package-related variables:
$package
: Package name$path
: Package installation path
This hook is useful for downloading additional resources, setting up Git submodules, or installing third-party dependencies like Bash scripts.
update
As you might have guessed, the update
hook is triggered for a package after it is updated. Scripts for this hook must be located at hooks/update.fish
.
Inside this hook, you can access two package-related variables:
$package
: Package name$path
: Package installation path
This hook is useful for updating Git submodules or checking for new versions of third-party dependencies.
uninstall
The uninstall
hook will be triggered before a package is removed via omf remove <pkg>
. Scripts for this hook must be located at hooks/uninstall.fish
.
Inside this hook, you can access two package-related variables:
$package
: Package name$path
: Package installation path
Packages can use this hook to clean up custom resources, etc.
Note: for backwards-compatibility, uninstall hooks will also be run if they are located at
uninstall.fish
in the package root.
Make it public
The official registry of public packages is managed in the oh-my-fish/packages-main repository. See the README of that repository for instructions on how to add your package to the official package database.