README.md
# Completely - Bash Completions Generator
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---
Completely is a command line utility and a Ruby library that lets you generate
bash completion scripts from simple YAML configuration.
This tool is for you if:
1. You develop your own command line tools.
2. Your life feels empty without bash completions.
3. Bash completion scripts seem overly complex to you.
Note that if you are building bash command line scripts with [bashly][bashly],
then this functionality is already integrated with it.
---
## Install
```bash
$ gem install completely
```
or with homebrew:
```bash
$ brew install brew-gem
$ brew gem install completely
```
or with Docker:
```bash
$ alias completely='docker run --rm -it --user $(id -u):$(id -g) --volume "$PWD:/app" dannyben/completely'
```
## Using the `completely` command line
The `completely` command line works with a simple YAML configuration file as
input, and generates a bash completions script as output.
The configuration file is built of blocks that look like this:
```yaml
pattern:
- --argument
- --param
- command
```
Each pattern contains an array of words (or functions) that will be suggested
for the auto complete process.
You can save a sample YAML file by running:
```
$ completely init
```
This will generate a file named `completely.yaml` with this content:
```yaml
mygit:
- --help
- --version
- status
- init
- commit
mygit status:
- --help
- --verbose
- --branch
- $(git branch 2>/dev/null)
mygit init:
- --bare
- <directory>
mygit commit:
- <file>
- --help
- --message
- --all
- -a
- --quiet
- -q
```
Each pattern in this configuration file will be checked against the user's
input, and if the input **starts with** a matching pattern, the list that
follows it will be suggested as completions.
Note that the suggested completions will not show flags (string that start with
a hyphen `-`) unless the input ends with a hyphen.
To generate the bash script, simply run:
```bash
$ completely generate
# or, to just preview it without saving:
$ completely preview
```
For more options (like setting input/output path), run:
```bash
$ completely --help
```
### Suggesting files, directories and other bash built-ins
In addition to specifying a simple array of completion words, you may use
the special syntax `<..>` to suggest more advanced functions.
```yaml
pattern:
- <file>
- <directory>
```
These suggestions will add the list of files and directories
(when `<file>` is used) or just directories (when `<directory>` is used) to
the list of suggestions.
You may use any of the below keywords to add additional suggestions:
| Keyword | Meaning
|---------------|---------------------
| `<alias>` | Alias names
| `<arrayvar>` | Array variable names
| `<binding>` | Readline key binding names
| `<builtin>` | Names of shell builtin commands
| `<command>` | Command names
| `<directory>` | Directory names
| `<disabled>` | Names of disabled shell builtins
| `<enabled>` | Names of enabled shell builtins
| `<export>` | Names of exported shell variables
| `<file>` | File names
| `<function>` | Names of shell functions
| `<group>` | Group names
| `<helptopic>` | Help topics as accepted by the help builtin
| `<hostname>` | Hostnames, as taken from the file specified by the HOSTFILE shell variable
| `<job>` | Job names
| `<keyword>` | Shell reserved words
| `<running>` | Names of running jobs
| `<service>` | Service names
| `<signal>` | Signal names
| `<stopped>` | Names of stopped jobs
| `<user>` | User names
| `<variable>` | Names of all shell variables
For those interested in the technical details, any word between `<...>` will
simply be added using the [`compgen -A action`][compgen] function, so you can
in fact use any of its supported arguments.
### Suggesting custom dynamic suggestions
You can also use any command that outputs a whitespace-delimited list as a
suggestions list, by wrapping it in `$(..)`. For example, in order to add git
branches to your suggestions, use the following:
```yaml
mygit:
- $(git branch 2>/dev/null)
```
The `2> /dev/null` is used so that if the command is executed in a directory
without a git repository, it will still behave as expected.
### Suggesting flag arguments
Adding a `*` wildcard in the middle of a pattern can be useful for suggesting
arguments for flags. For example:
```yaml
mygit checkout:
- --branch
- -b
mygit checkout*--branch:
- $(git branch 2>/dev/null)
mygit checkout*-b:
- $(git branch 2>/dev/null)
```
The above will suggest git branches for commands that end with `-b` or `--branch`.
To avoid code duplication, you may use YAML aliases, so the above can also be
written like this:
```yaml
mygit checkout:
- --branch
- -b
mygit checkout*--branch: &branches
- $(git branch 2>/dev/null)
mygit checkout*-b: *branches
```
## Using the generated completion scripts
In order to enable the completions, simply source the generated script:
```bash
$ source completely.bash
```
If you are satisfied with the result, and wish to copy the script to your bash
completions directory, simply run:
```bash
$ completely install
```
Alternatively, you can copy the script manually to one of these directories
(whichever exists):
- `/usr/share/bash-completion/completions`
- `/usr/local/etc/bash_completion.d`
- `~/.local/share/bash-completion/completions`
## Testing and debugging completion scripts
You can use the built in completions script tester by running `completely test`.
This command lets you test completions for your completions script.
In addition, you can set the `COMPLETELY_DEBUG` environment variable to any value
in order to generate scripts with some additional debugging functionality. Run
`completely generate --help` for additional information.
## Using from within Ruby code
```ruby
require 'completely'
# Load from file
completions = Completely::Completions.load "input.yaml"
# Or, from a hash
input = {
"mygit" => %w[--help --version status init commit],
"mygit status" => %w[--help --verbose --branch]
}
completions = Completely::Completions.new input
# Generate the script
puts completions.script
# Or, generate a function that echos the script
puts completions.wrapper_function
puts completions.wrapper_function "custom_function_name"
# Or, test the completions with the Tester object
p completions.tester.test "mygit status "
```
## Completions in ZSH
If you are using Oh-My-Zsh, bash completions should already be enabled,
otherwise, you should enable completion by adding this to your `~/.zshrc`
(if is it not already there):
```bash
# Load completion functions
autoload -Uz +X compinit && compinit
autoload -Uz +X bashcompinit && bashcompinit
```
## Contributing / Support
If you experience any issue, have a question or a suggestion, or if you wish
to contribute, feel free to [open an issue][issues].
---
[issues]: https://github.com/DannyBen/completely/issues
[compgen]: https://www.gnu.org/software/bash/manual/html_node/Programmable-Completion-Builtins.html
[bashly]: https://bashly.dannyb.co/