bonzai

README

Bonzai! Simple CLI Command Trees in Go

Bonzai command trees are unlike anything you've probably encountered so far, no getopt dashes (we kind of hate them), no ugly commander interface to learn, no 12637 lines of shell tab completion bloat to source before your command will complete, just well manicured nested-tab-complete-with-magical-aliases-enabled commands organized into rooted node trees for your command-line enjoyment. Your right-pinky will be particularly grateful.

Installation

🎉 Bonzai shamelessly requires Go 1.18+ 💋

1. Install Go 1.18 and the tooling your require for it
2. go install github.com/rwxrob/bonzai@latest
3. import "github.com/rwxrob/bonzai"
4. Consider using the template to get started

😎 Yes, we use the wonderful new generics within the filter subpackage.

Embedded Text or Web Docs FTW!

And, all the documentation for your command tree goes inside the binary (if you want). That's right. Portable, text or web-enabled "man" pages without the man page. You can use one of the composable interactive-color-terminal-sensing help documentation commands like cmd.Help that will easily marshal into JSON, or text, or well-styled HTML locally while enabling you to write your embedded docs in simplified CommonMark. Think "readthedocs" but without the Internet dependency. And if you don't want cmd.Help you don't need it. You can even write your own composable Bonzai command or pick from a rich ecosystem of embeddable Bonzai command trees available from anywhere on the Internet or maintained by the Bonzai project. No registries to worry about. Just use good 'ol Go module imports are all that are need to share your creations.

Contributors/PRs Welcome

... especially for "Completers" and Runtime Detection.

Speaking of sharing, why not send a PR for your addition to the ever growing collection of comp subpackage Completers for everything from days of the week, to tab-driven inline math calculations, to a list of all the listening ports running on your current system.

CONTRIBUTING

"It's spelled bonsai/banzai."

We know. The domains were taken. Plus, this makes it more unique and easier to find once you know the strange spelling we chose to use. Sorry if that triggers your OCD.

On a lighter note, it just so happens that "banzai" means 'a traditional Japanese idiom meaning "ten thousand years" of long life,' a cheer used in celebrations. So combining the notion of a happy, little, well-manicured, beautiful tree and "ten thousand years of long life" works out just fine for us.

Then, of course, there's the image of Buckaroo invoked every time we say the name. In fact, I think we have our new theme song.

What People Are Saying

"It's like a modular, multicall BusyBox builder for Go with built in completion and embedded documentation support."

"The utility here is that Bonzai lets you maintain your own personal 'toolbox' with built in auto-complete that you can assemble from various Go modules. Individual commands are isolated and unaware of each other and possibly maintained by other people." (tadasv123)

Example GitHub Template

https://github.com/rwxrob/bonzai-template

Design Considerations

• Promote high-level package library API calls over Cmd bloat. Code belongs in package libraries, not Cmds. While Bonzai allows for rapid applications development by putting everything initially in Cmd Methods, Cmds are most designed for documentation and completion, not heavy Method implementations. Eventually, most Method implementations should be moved into their own package libraries, perhaps even in the same Go module. Cmds should never be communicating with each other directly. While the idea of adding a Channel attribute was intriguing, it quickly became clear that doing so would promote too much code and tight coupling --- even with channels --- between specific commands. Cmds should be very light. In fact, most Cmds should assign their Method directly from one matching the Method function signature in a callable, high-level library.

• Only bash completion planned. Zsh, Powershell, and Fish have no equivalent to complete -C (which allows any executable to provide its own completion) This forces inferior dependencies on overly verbose external "completer" scripts written in only those languages for those specific shells. This dependency completely negates any possibility of providing modular completers and composable commands that carry their own completion logic. This one objective fact alone should give every pause before opting to use one of these inferior shells for their command line interactions. Bonzai commands leverage this best-of-breed completion functionality of bash to provide an unlimited number of completion methods and combinations. The equivalent implementations, perhaps as an export collected from all composed commands providing their shell equivalent of completion scripts, would be preposterously large (even though kubectl requires 12637 lines of bash just for its basic completion). Bonzai uses Go itself to manage that completion --- drawing on a rich collection of completers included in the standard Bonzai module --- and provides documented shortcut aliases when completion is not available (h|help, for example).

• Bonzai commands may default to cmd.Shell or cmd.Help These provide help information and optional interactive assistance including tab completion in runtime environments that do not have complete -C foo foo enabled.

Acknowledgements

The https://twitch.tv/rwxrob community has been constantly involved with the development of this project, making suggestions about everything from my use of init, to the name "bonzai". While all their contributions are too numerous to name specifically, they more than deserve a huge thank you here.

Legal

Copyright 2022 Robert S. Muhlestein (mailto:rob@rwx.gg)
SPDX-License-Identifier: Apache-2.0

"Bonzai" and "bonzai" are legal trademarks of Robert S. Muhlestein but can be used freely to refer to the Bonzai project https://github.com/rwxrob/bonzai without limitation. To avoid potential developer confusion, intentionally using these trademarks to refer to other projects --- free or proprietary --- is prohibited.

Documentation

Overview

Package bonzai provides a rooted node tree of commands and singular parameters making tab completion a breeze and complicated applications much easier to intuit without reading all the docs. Documentation is embedded with each command removing the need for separate man pages and such and can be viewed as text or a locally served web page.

Rooted Node Tree

Commands and parameters are linked to create a rooted node tree of the following types of nodes:

• Leaves with a method and optional parameters
• Branches with leaves, other branches, and a optional method
• Parameters, single words that are passed to a leaf command

Index

• Variables
• func ArgsFrom(line string) []string
• func Exit()
• func ExitError(err ...interface{})
• func ExitOff()
• func ExitOn()
• type Cmd
  • func (x *Cmd) Add(name string, aliases ...string) *Cmd
  • func (x *Cmd) Cmd(name string) *Cmd
  • func (x *Cmd) CmdNames() []string
  • func (x *Cmd) GetCaller() comp.Command
  • func (x *Cmd) GetCommands() []string
  • func (x *Cmd) GetCompleter() comp.Completer
  • func (x *Cmd) GetHidden() []string
  • func (x *Cmd) GetName() string
  • func (x *Cmd) GetOther() map[string]string
  • func (x *Cmd) GetParams() []string
  • func (x *Cmd) IsHidden(name string) bool
  • func (x *Cmd) Param(p string) string
  • func (x *Cmd) Run()
  • func (x *Cmd) Seek(args []string) (*Cmd, []string)
  • func (x *Cmd) UsageError() error
• type Method

Examples

• ArgsFrom
• Cmd.CmdNames
• Cmd.GetCommands
• Cmd.GetParams
• Cmd.Seek

Variables

var DoNotExit bool

DoNotExit effectively disables Exit and ExitError allowing the program to continue running, usually for test evaluation.

Functions

func ArgsFrom

func ArgsFrom(line string) []string

ArgsFrom returns a list of field strings split on space with an extra trailing special space item appended if the line has any trailing spaces at all signifying a definite word boundary and not a potential prefix.

Example

package main

import (
	"fmt"

	"github.com/rwxrob/bonzai"
)

func main() {
	fmt.Printf("%q\n", bonzai.ArgsFrom(`greet  hi french`))
	fmt.Printf("%q\n", bonzai.ArgsFrom(`greet hi   french `))
}

Output:
["greet" "hi" "french"]
["greet" "hi" "french" ""]

func Exit

func Exit()

Exit calls os.Exit(0) unless DoNotExit has been set to true. Cmds should never call Exit themselves returning a nil error from their Methods instead.

func ExitError

func ExitError(err ...interface{})

ExitError prints err and exits with 1 return value unless DoNotExit has been set to true. Commands should usually never call ExitError themselves returning an error from their Method instead.

func ExitOff

func ExitOff()

ExitOff sets DoNotExit to false.

func ExitOn

func ExitOn()

ExitOn sets DoNotExit to true.

Types

type Cmd

type Cmd struct {
	Name        string            `json:"name,omitempty"`
	Aliases     []string          `json:"aliases,omitempty"`
	Summary     string            `json:"summary,omitempty"`
	Usage       string            `json:"usage,omitempty"`
	Version     string            `json:"version,omitempty"`
	Copyright   string            `json:"copyright,omitempty"`
	License     string            `json:"license,omitempty"`
	Description string            `json:"description,omitempty"`
	Site        string            `json:"site,omitempty"`
	Source      string            `json:"source,omitempty"`
	Issues      string            `json:"issues,omitempty"`
	Other       map[string]string `json:"issues,omitempty"`
	Commands    []*Cmd            `json:"commands,omitempty"`
	Params      []string          `json:"params,omitempty"`
	Hidden      []string          `json:"hide,omitempty"`
	Completer   comp.Completer    `json:"-"`
	Call        Method            `json:"-"`
	Caller      *Cmd              `json:"-"`
	// contains filtered or unexported fields
}

Cmd is a struct the easier to use and read when creating implementations of the Command interface.

Params

Params require a Method. While Methods may receive any number of arguments, Params are a way of helping completion for regular parameters. Standard completion will not recursively complete multiple params, one param per completion.

func (*Cmd) Add

func (x *Cmd) Add(name string, aliases ...string) *Cmd

Add creates a new Cmd and sets the name and aliases and adds to Commands returning a reference to the new Cmd. The name must be first.

func (*Cmd) Cmd

func (x *Cmd) Cmd(name string) *Cmd

Cmd looks up a given Command by name or name from Aliases.

func (*Cmd) CmdNames

func (x *Cmd) CmdNames() []string

Example

package main

import (
	"fmt"

	"github.com/rwxrob/bonzai"
)

func main() {
	foo := new(bonzai.Cmd)
	foo.Add("bar")
	foo.Add("blah")
	foo.Add("other")
	fmt.Println(foo.CmdNames())
}

Output:
[bar blah other]

func (*Cmd) GetCaller

func (x *Cmd) GetCaller() comp.Command

GetCaller fulfills the comp.Command interface.

func (*Cmd) GetCommands

func (x *Cmd) GetCommands() []string

GetCommands fulfills the comp.Command interface.

Example

package main

import (
	"fmt"

	"github.com/rwxrob/bonzai"
)

func main() {
	foo := new(bonzai.Cmd)
	foo.Add("bar")
	foo.Add("blah")
	foo.Add("other")
	fmt.Println(foo.GetCommands())
}

Output:
[bar blah other]

func (*Cmd) GetCompleter

func (x *Cmd) GetCompleter() comp.Completer

GetCompleter fulfills the Command interface.

func (*Cmd) GetHidden

func (x *Cmd) GetHidden() []string

GetHidden fulfills the comp.Command interface.

func (*Cmd) GetName

func (x *Cmd) GetName() string

GetName fulfills the comp.Command interface.

func (*Cmd) GetOther

func (x *Cmd) GetOther() map[string]string

GetOther fulfills the comp.Command interface.

func (*Cmd) GetParams

func (x *Cmd) GetParams() []string

GetParams fulfills the comp.Command interface.

Example

package main

import (
	"fmt"

	"github.com/rwxrob/bonzai"
)

func main() {
	foo := new(bonzai.Cmd)
	foo.Params = []string{"box", "bing", "and"}
	fmt.Println(foo.GetParams())
}

Output:
[box bing and]

func (*Cmd) IsHidden

func (x *Cmd) IsHidden(name string) bool

IsHidden returns true if the specified name is in the list of Hidden commands.

func (*Cmd) Param

func (x *Cmd) Param(p string) string

Param returns Param matching name if found, empty string if not.

func (*Cmd) Run

func (x *Cmd) Run()

Run is for running a command within a specific runtime (shell) and performs completion if completion context is detected. Otherwise, it executes the leaf Cmd returned from Seek calling its Method, and then Exits. Normally, Run is called from within main() to convert the Cmd into an actual executable program and normally it exits the program. Exiting can be controlled, however, with ExitOn/ExitOff when testing or for other purposes requiring multiple Run calls. Using Call instead will also just call the Cmd's Call Method without exiting. Note: Only bash runtime ("COMP_LINE") is currently supported, but others such a zsh and shell-less REPLs are planned.

func (*Cmd) Seek

func (x *Cmd) Seek(args []string) (*Cmd, []string)

Example

package main

import (
	"fmt"

	"github.com/rwxrob/bonzai"
	"github.com/rwxrob/bonzai/cmd"
)

func main() {

	hello := &bonzai.Cmd{
		Name:   `hello`,
		Params: []string{"there"},
		Call: func(_ *bonzai.Cmd, args ...string) error {
			if len(args) > 0 {
				fmt.Printf("hello %v\n", args[0])
				return nil
			}
			fmt.Println("hello")
			return nil
		},
	}

	hi := &bonzai.Cmd{
		Name:   `hi`,
		Params: []string{"there", "ya"},
		Call: func(_ *bonzai.Cmd, args ...string) error {
			if len(args) > 0 {
				fmt.Printf("hi %v\n", args[0])
				return nil
			}
			fmt.Println("hi")
			return nil
		},
	}

	yo := &bonzai.Cmd{
		Name: `yo`,
		Call: func(_ *bonzai.Cmd, args ...string) error {
			fmt.Println("yo")
			return nil
		},
	}

	salut := &bonzai.Cmd{
		Name:   `salut`,
		Params: []string{"la"},
		Call: func(_ *bonzai.Cmd, args ...string) error {
			if len(args) > 0 {
				fmt.Printf("salut %v\n", args[0])
				return nil
			}
			fmt.Println("salut")
			return nil
		},
	}

	french := &bonzai.Cmd{
		Name:     `french`,
		Aliases:  []string{"fr"},
		Commands: []*bonzai.Cmd{cmd.Help, salut},
	}

	greet := &bonzai.Cmd{
		Name:     `greet`,
		Commands: []*bonzai.Cmd{cmd.Help, yo, hi, hello, french},
	}

	cmd, args := greet.Seek(bonzai.ArgsFrom(`hi there`))
	fmt.Printf("%v %q\n", cmd.Name, args)

	cmd, args = greet.Seek(bonzai.ArgsFrom(`french salut`))
	fmt.Printf("%v %q\n", cmd.Name, args)

	cmd, args = greet.Seek(bonzai.ArgsFrom(`french salut `))
	fmt.Printf("%v %q\n", cmd.Name, args)

	cmd, args = greet.Seek(bonzai.ArgsFrom(`french h`))
	fmt.Printf("%v %q\n", cmd.Name, args)

	cmd, args = greet.Seek(bonzai.ArgsFrom(`french help`))
	fmt.Printf("%v %q\n", cmd.Name, args)

}

Output:
hi ["there"]
salut []
salut [""]
french ["h"]
help []

func (*Cmd) UsageError

func (x *Cmd) UsageError() error

UsageError returns an error with a single-line usage string.

type Method

type Method func(caller *Cmd, args ...string) error

Method defines the main code to execute for a command (Cmd). By convention the parameter list should be named "args" if there are args expected and underscore (_) if not. Methods must never write error output to anything but standard error and should almost always use the log package to do so.