cmder

This example demonstrates the simplest usage of cmder.BaseCommand. By using BaseCommand directly, you don't need to define your own command types. This can be a nice convenience for simple commands.

package main

import (
	"archive/tar"
	"bytes"
	"context"
	"encoding/hex"
	"flag"
	"fmt"
	"io"
	"os"

	"github.com/brandon1024/cmder"
)

// This example demonstrates the simplest usage of [cmder.BaseCommand]. By using BaseCommand directly, you don't need to
// define your own command types. This can be a nice convenience for simple commands.
func main() {
	exampleSetup()

	args := []string{"-Co-", "-"}

	if err := cmder.Execute(context.Background(), untar, cmder.WithArgs(args)); err != nil {
		fmt.Printf("unexpected error occurred: %v", err)
	}
}

const UntarDesc = `
'untar' demonstrates the simplest usage of [cmder.BaseCommand], using the type to implement a simple command that reads
a tar archive and dumps inflated content.
`

const UntarExamples = `
untar example.tar
untar -Co=example.out example.tar
untar -Co- - <example.tar
`

var (
	untar = &cmder.BaseCommand{
		CommandName: "untar",
		CommandDocumentation: cmder.CommandDocumentation{
			Usage:     "untar [-o <file>] [-C] <file>",
			ShortHelp: "A simple demonstration of direct usage of BaseCommand.",
			Help:      UntarDesc,
			Examples:  UntarExamples,
		},
		RunFunc:       run,
		InitFlagsFunc: flags,
	}
)

var (
	output  string = "-"
	hexdump bool
)

var (
	in io.ReadWriter = os.Stdin
)

// Configure flags. We register two flags, '-o' and '-C'.
func flags(fs *flag.FlagSet) {
	fs.StringVar(&output, "o", output, "dump archive content to `file`")
	fs.BoolVar(&hexdump, "C", hexdump, "dump archive content in a canonical hex+ascii format")
}

// The command's run function.
func run(ctx context.Context, args []string) error {
	if len(args) != 1 {
		return cmder.ErrShowUsage
	}

	var out io.Writer = os.Stdout

	if args[0] != "-" {
		inputf, err := os.Open(args[0])
		if err != nil {
			return err
		}

		defer inputf.Close()
		in = inputf
	}

	if output != "-" {
		outputf, err := os.Create(output)
		if err != nil {
			return err
		}

		defer outputf.Close()
		out = outputf
	}

	if hexdump {
		dumper := hex.Dumper(out)
		defer dumper.Close()
		out = dumper
	}

	reader := tar.NewReader(in)
	for {
		_, err := reader.Next()
		if err == io.EOF {
			break
		}
		if err != nil {
			return err
		}

		if _, err := io.Copy(out, reader); err != nil {
			return err
		}
	}

	return nil
}

// Setup for the example.
func exampleSetup() {
	in = &bytes.Buffer{}

	tw := tar.NewWriter(in)
	defer tw.Close()

	tw.WriteHeader(&tar.Header{
		Name: "usage-example",
		Mode: 0644,
		Size: int64(len(UntarDesc)),
	})
	tw.Write([]byte(UntarDesc))
}

Output:

00000000  0a 27 75 6e 74 61 72 27  20 64 65 6d 6f 6e 73 74  |.'untar' demonst|
00000010  72 61 74 65 73 20 74 68  65 20 73 69 6d 70 6c 65  |rates the simple|
00000020  73 74 20 75 73 61 67 65  20 6f 66 20 5b 63 6d 64  |st usage of [cmd|
00000030  65 72 2e 42 61 73 65 43  6f 6d 6d 61 6e 64 5d 2c  |er.BaseCommand],|
00000040  20 75 73 69 6e 67 20 74  68 65 20 74 79 70 65 20  | using the type |
00000050  74 6f 20 69 6d 70 6c 65  6d 65 6e 74 20 61 20 73  |to implement a s|
00000060  69 6d 70 6c 65 20 63 6f  6d 6d 61 6e 64 20 74 68  |imple command th|
00000070  61 74 20 72 65 61 64 73  0a 61 20 74 61 72 20 61  |at reads.a tar a|
00000080  72 63 68 69 76 65 20 61  6e 64 20 64 75 6d 70 73  |rchive and dumps|
00000090  20 69 6e 66 6c 61 74 65  64 20 63 6f 6e 74 65 6e  | inflated conten|
000000a0  74 2e 0a                                          |t..|

This example demonstrates an alternative usage of cmder.BaseCommand. By embedding BaseCommand into your own types, your type implements all required interfaces needed to fulfill cmder.Command. You can override the standard methods with your own implementation.

package main

import (
	"context"
	"flag"
	"fmt"
	"strconv"
	"strings"

	"github.com/brandon1024/cmder"
	"github.com/brandon1024/cmder/getopt"
)

// This example demonstrates an alternative usage of [cmder.BaseCommand]. By embedding BaseCommand into your own types,
// your type implements all required interfaces needed to fulfill [cmder.Command]. You can override the standard methods
// with your own implementation.
func main() {
	args := []string{"-m", "1.6.17-beta.0+20130313144700"}

	if err := cmder.Execute(context.Background(), semver, cmder.WithArgs(args)); err != nil {
		fmt.Printf("unexpected error occurred: %v", err)
	}
}

const SemverDesc = `
'semver' demonstrates an alternative usage of [cmder.BaseCommand]. By embedding BaseCommand into your own types, your
type implements all required interfaces needed to fulfill [cmder.Command]. You can override the standard methods with
your own implementation.

Example 'semver' manipulates a version string, bumping it up a major/minor/patch version or attaches build/pre-release
information. By default, input versoins are bumped up a patch version.
`

const SemverExamples = `
semver 0.5.3
semver --minor 1.6.17-alpha
semver --pre-release alpha --build ${BUILD_ID} 1.3.4
`

var (
	semver = &Semver{
		BaseCommand: cmder.BaseCommand{
			CommandName: "semver",
			CommandDocumentation: cmder.CommandDocumentation{
				Usage:     "semver [--major | --minor | --patch] [--pre-release <pre>] [--build <build>] <version>",
				ShortHelp: "A simple demonstration of embedding BaseCommand in custom types.",
				Help:      SemverDesc,
				Examples:  SemverExamples,
			},
		},
	}
)

type Semver struct {
	cmder.BaseCommand

	major, minor, patch bool
	pre, build          string
}

// Configure command flags. Register short aliases for all long flag options.
//
// InitializeFlags overrides the default [cmder.BaseCommand.InitializeFlags] implementation.
func (s *Semver) InitializeFlags(fs *flag.FlagSet) {
	fs.BoolVar(&s.major, "major", s.major, "bump version to the next major version")
	fs.BoolVar(&s.minor, "minor", s.minor, "bump version to the next minor version")
	fs.BoolVar(&s.patch, "patch", s.patch, "bump version to the next patch version")
	fs.StringVar(&s.pre, "pre-release", s.pre, "include pre-release information in output (e.g. alpha, x.7.z.92)")
	fs.StringVar(&s.build, "build", s.build, "include build information in output (e.g. 20130313144700, exp.sha.5114f85)")

	getopt.Alias(fs, "major", "M")
	getopt.Alias(fs, "minor", "m")
	getopt.Alias(fs, "patch", "p")
	getopt.Alias(fs, "pre-release", "x")
	getopt.Alias(fs, "build", "b")
}

// The command's run function.
//
// Run overrides the default [cmder.BaseCommand.Run] implementation.
func (s *Semver) Run(ctx context.Context, args []string) error {
	if len(args) != 1 {
		return cmder.ErrShowUsage
	}

	version, _, _ := strings.Cut(args[0], "+")
	version, pre, _ := strings.Cut(version, "-")

	var (
		parts []string
		level = 2
	)

	if s.minor {
		level = 1
	}
	if s.major {
		level = 0
	}

	for i, v := range strings.Split(version, ".") {
		num, err := strconv.Atoi(v)
		if err != nil {
			return fmt.Errorf("semver: invalid input: %s", args[0])
		}
		if i == level {
			num++
		}
		if i > level {
			num = 0
		}

		parts = append(parts, strconv.Itoa(num))
	}

	version = strings.Join(parts, ".")

	if s.pre != "" {
		version += "-" + s.pre
	} else if pre != "" {
		version += "-" + pre
	}

	if s.build != "" {
		version += "+" + s.build
	}

	fmt.Println(version)

	return nil
}

Output:

1.7.0-beta.0

package main

import (
	"context"
	"fmt"

	"github.com/brandon1024/cmder"
)

func main() {
	cmd := &HelloWorldCommand{}

	args := []string{"from", "cmder"}

	if err := cmder.Execute(context.Background(), cmd, cmder.WithArgs(args)); err != nil {
		fmt.Printf("unexpected error occurred: %v", err)
	}
}

const HelloWorldCommandUsageLine = `hello-world [<args>...]`

const HelloWorldCommandShortHelpText = `Simple demonstration of cmder`

const HelloWorldCommandHelpText = `
'hello-world' demonstrates the simplest usage of cmder. This example defines a single command 'hello-world' that
implements the Runnable and Documented interfaces.
`

const HelloWorldCommandExamples = `
# broadcast hello to the world
hello-world from cmder
`

type HelloWorldCommand struct{}

func (c *HelloWorldCommand) Name() string {
	return "hello-world"
}

func (c *HelloWorldCommand) Run(ctx context.Context, args []string) error {
	fmt.Printf("%s: %v\n", c.Name(), args)
	return nil
}

func (c *HelloWorldCommand) UsageLine() string {
	return HelloWorldCommandUsageLine
}

func (c *HelloWorldCommand) ShortHelpText() string {
	return HelloWorldCommandShortHelpText
}

func (c *HelloWorldCommand) HelpText() string {
	return HelloWorldCommandHelpText
}

func (c *HelloWorldCommand) main() string {
	return HelloWorldCommandExamples
}

Output:

hello-world: [from cmder]

package main

import (
	"context"
	"fmt"

	"github.com/brandon1024/cmder"
)

func main() {
	args := []string{}

	cmd := &LifecycleCommand{}

	if err := cmder.Execute(context.Background(), cmd, cmder.WithArgs(args)); err != nil {
		fmt.Printf("unexpected error occurred: %v", err)
	}
}

const LifecycleCommandUsageLine = `lifecycle [<args>...]`

const LifecycleCommandShortHelpText = `Example command with lifecycle routines`

const LifecycleCommandHelpText = `
'lifecycle' demonstrates a command that implements the Initializer and Destroyer interfaces, defining initialization and
destroy routines.
`

const LifecycleCommandExamples = `
# demonstrate initialization and teardown
lifecycle
`

type LifecycleCommand struct{}

func (c *LifecycleCommand) Name() string {
	return "lifecycle"
}

func (c *LifecycleCommand) Initialize(ctx context.Context, args []string) error {
	fmt.Println("lifecycle: initializing")
	return nil
}

func (c *LifecycleCommand) Run(ctx context.Context, args []string) error {
	fmt.Println("lifecycle: running")
	return nil
}

func (c *LifecycleCommand) Destroy(ctx context.Context, args []string) error {
	fmt.Println("lifecycle: shutting down")
	return nil
}

func (c *LifecycleCommand) UsageLine() string {
	return LifecycleCommandUsageLine
}

func (c *LifecycleCommand) ShortHelpText() string {
	return LifecycleCommandShortHelpText
}

func (c *LifecycleCommand) HelpText() string {
	return LifecycleCommandHelpText
}

func (c *LifecycleCommand) ExampleText() string {
	return LifecycleCommandExamples
}

Output:

lifecycle: initializing
lifecycle: running
lifecycle: shutting down

This example demonstrates how to register command flags. The flags and documentation were borrowed from 'kubectl apply' to showcase what a real-world example woud look like.

package main

import (
	"context"
	"flag"
	"fmt"
	"time"

	"github.com/brandon1024/cmder"
	"github.com/brandon1024/cmder/getopt"
)

// This example demonstrates how to register command flags. The flags and documentation were borrowed from 'kubectl
// apply' to showcase what a real-world example woud look like.
func main() {
	var cmd KubectlApply

	args := []string{"-h"}

	if err := cmder.Execute(context.Background(), &cmd, cmder.WithArgs(args)); err != nil {
		fmt.Printf("unexpected error occurred: %v", err)
	}
}

const KubectlApplyDesc = `
Apply a configuration to a resource by file name or stdin. The resource name must be specified. This resource will be
created if it doesn't exist yet. To use 'apply', always create the resource initially with either 'apply' or
'create --save-config'.

JSON and YAML formats are accepted.
`

const KubectlApplyExamples = `
# Apply the configuration in pod.json to a pod
kubectl apply -f ./pod.json

# Apply resources from a directory containing kustomization.yaml - e.g. dir/kustomization.yaml
kubectl apply -k dir/

# Apply the JSON passed into stdin to a pod
cat pod.json | kubectl apply -f -

# Apply the configuration from all files that end with '.json'
kubectl apply -f '*.json'

# Note: --prune is still in Alpha
# Apply the configuration in manifest.yaml that matches label app=nginx and delete all other resources that are not in the file and match label app=nginx
kubectl apply --prune -f manifest.yaml -l app=nginx

# Apply the configuration in manifest.yaml and delete all the other config maps that are not in the file
kubectl apply --prune -f manifest.yaml --all --prune-allowlist=core/v1/ConfigMap
`

type KubectlApply struct {
	all                      bool
	allowMissingTemplateKeys bool
	cascade                  string
	dryRun                   string
	fieldManager             string
	filename                 getopt.StringsVar
	force                    bool
	forceConflicts           bool
	gracePeriod              int
	kustomize                string
	openapiPatch             bool
	output                   string
	overwrite                bool
	prune                    bool
	pruneAllowlist           getopt.StringsVar
	recursive                bool
	selector                 string
	serverSide               bool
	showManagedFields        bool
	subresource              string
	template                 string
	timeout                  time.Duration
	validate                 string
	wait                     bool
}

func (a *KubectlApply) InitializeFlags(fs *flag.FlagSet) {
	fs.BoolVar(&a.all, "all", false,
		"Select all resources in the namespace of the specified resource types.")
	fs.BoolVar(&a.allowMissingTemplateKeys, "allow-missing-template-keys", true,
		"If true, ignore any errors in templates when a field or map key is missing in the template. Only applies to golang and jsonpath output formats.")
	fs.StringVar(&a.cascade, "cascade", "background",
		"Must be \"background\", \"orphan\", or \"foreground\". Selects the deletion cascading strategy for the dependents (e.g. Pods created by a ReplicationController). Defaults to background.")
	fs.StringVar(&a.dryRun, "dry-run", "none",
		"Must be \"none\", \"server\", or \"client\". If client strategy, only print the object that would be sent, without sending it. If server strategy, submit server-side request without persisting the resource.")
	fs.StringVar(&a.fieldManager, "field-manager", "kubectl-client-side-apply",
		"Name of the manager used to track field ownership.")
	fs.Var(&a.filename, "filename",
		"The files that contain the configurations to apply.")
	fs.Var(&a.filename, "f",
		"The files that contain the configurations to apply.")
	fs.BoolVar(&a.force, "force", false,
		"If true, immediately remove resources from API and bypass graceful deletion. Note that immediate deletion of some resources may result in inconsistency or data loss and requires confirmation.")
	fs.BoolVar(&a.forceConflicts, "force-conflicts", false,
		"If true, server-side apply will force the changes against conflicts.")
	fs.IntVar(&a.gracePeriod, "grace-period", -1,
		"Period of time in seconds given to the resource to terminate gracefully. Ignored if negative. Set to 1 for immediate shutdown. Can only be set to 0 when --force is true (force deletion).")
	fs.StringVar(&a.kustomize, "kustomize", "",
		"Process a kustomization directory. This flag can't be used together with -f or -R.")
	fs.BoolVar(&a.openapiPatch, "openapi-patch", true,
		"If true, use openapi to calculate diff when the openapi presents and the resource can be found in the openapi spec. Otherwise, fall back to use baked-in types.")
	fs.StringVar(&a.output, "output", "",
		"Output format. One of: (json, yaml, kyaml, name, go-template, go-template-file, template, templatefile, jsonpath, jsonpath-as-json, jsonpath-file).")
	fs.StringVar(&a.output, "o", "",
		"Output format. One of: (json, yaml, kyaml, name, go-template, go-template-file, template, templatefile, jsonpath, jsonpath-as-json, jsonpath-file).")
	fs.BoolVar(&a.overwrite, "overwrite", true,
		"Automatically resolve conflicts between the modified and live configuration by using values from the modified configuration.")
	fs.BoolVar(&a.prune, "prune", false,
		"Automatically delete resource objects, that do not appear in the configs and are created by either apply or create --save-config. Should be used with either -l or --all.")
	fs.Var(&a.pruneAllowlist, "prune-allowlist",
		"Overwrite the default allowlist with <group/version/kind> for --prune.")
	fs.BoolVar(&a.recursive, "recursive", false,
		"Process the directory used in -f, --filename recursively. Useful when you want to manage related manifests organized within the same directory.")
	fs.BoolVar(&a.recursive, "R", false,
		"Process the directory used in -f, --filename recursively. Useful when you want to manage related manifests organized within the same directory.")
	fs.StringVar(&a.selector, "selector", "",
		"Selector (label query) to filter on, supports '=', '==', '!=', 'in', 'notin'.(e.g. -l key1=value1,key2=value2,key3 in (value3)). Matching objects must satisfy all of the specified label constraints.")
	fs.StringVar(&a.selector, "l", "",
		"Selector (label query) to filter on, supports '=', '==', '!=', 'in', 'notin'.(e.g. -l key1=value1,key2=value2,key3 in (value3)). Matching objects must satisfy all of the specified label constraints.")
	fs.BoolVar(&a.serverSide, "server-side", false,
		"If true, apply runs in the server instead of the client.")
	fs.BoolVar(&a.showManagedFields, "show-managed-fields", false,
		"If true, keep the managedFields when printing objects in JSON or YAML format.")
	fs.StringVar(&a.subresource, "subresource", "",
		"If specified, apply will operate on the subresource of the requested object. Only allowed when using --server-side.")
	fs.StringVar(&a.template, "template", "",
		"Template string or path to template file to use when -o=go-template, -o=go-template-file. The template format is golang templates [http://golang.org/pkg/text/template/#pkg-overview].")
	fs.DurationVar(&a.timeout, "timeout", time.Duration(0),
		"The length of time to wait before giving up on a delete, zero means determine a timeout from the size of the object.")
	fs.StringVar(&a.validate, "validate", "strict",
		"Must be one of: strict (or true), warn, ignore (or false). \"true\" or \"strict\" will use a schema to validate the input and fail the request if invalid. It will perform server side validation if ServerSideFieldValidation is enabled on the api-server, but will fall back to less reliable client-side validation if not. \"warn\" will warn about unknown or duplicate fields without blocking the request if server-side field validation is enabled on the API server, and behave as \"ignore\" otherwise. \"false\" or \"ignore\" will not perform any schema validation, silently dropping any unknown or duplicate fields.")
	fs.BoolVar(&a.wait, "wait", false, "If true, wait for resources to be gone before returning. This waits for finalizers.")
}

func (a *KubectlApply) Run(ctx context.Context, args []string) error {
	// left as an exercise for the reader...
	return nil
}

func (a *KubectlApply) Name() string {
	return "apply"
}

func (a *KubectlApply) UsageLine() string {
	return "kubectl apply (-f FILENAME | -k DIRECTORY)"
}

func (a *KubectlApply) ShortHelpText() string {
	return "Apply a configuration change to a resource from a file or stdin."
}

func (a *KubectlApply) HelpText() string {
	return KubectlApplyDesc
}

func (a *KubectlApply) main() string {
	return KubectlApplyExamples
}

package main

import (
	"context"
	"fmt"

	"github.com/brandon1024/cmder"
)

func main() {
	args := []string{}

	cmd := &LifecycleCommand{}

	if err := cmder.Execute(context.Background(), cmd, cmder.WithArgs(args)); err != nil {
		fmt.Printf("unexpected error occurred: %v", err)
	}
}

const LifecycleCommandUsageLine = `lifecycle [<args>...]`

const LifecycleCommandShortHelpText = `Example command with lifecycle routines`

const LifecycleCommandHelpText = `
'lifecycle' demonstrates a command that implements the Initializer and Destroyer interfaces, defining initialization and
destroy routines.
`

const LifecycleCommandExamples = `
# demonstrate initialization and teardown
lifecycle
`

type LifecycleCommand struct{}

func (c *LifecycleCommand) Name() string {
	return "lifecycle"
}

func (c *LifecycleCommand) Initialize(ctx context.Context, args []string) error {
	fmt.Println("lifecycle: initializing")
	return nil
}

func (c *LifecycleCommand) Run(ctx context.Context, args []string) error {
	fmt.Println("lifecycle: running")
	return nil
}

func (c *LifecycleCommand) Destroy(ctx context.Context, args []string) error {
	fmt.Println("lifecycle: shutting down")
	return nil
}

func (c *LifecycleCommand) UsageLine() string {
	return LifecycleCommandUsageLine
}

func (c *LifecycleCommand) ShortHelpText() string {
	return LifecycleCommandShortHelpText
}

func (c *LifecycleCommand) HelpText() string {
	return LifecycleCommandHelpText
}

func (c *LifecycleCommand) ExampleText() string {
	return LifecycleCommandExamples
}

Output:

lifecycle: initializing
lifecycle: running
lifecycle: shutting down

package main

import (
	"context"
	"fmt"

	"github.com/brandon1024/cmder"
)

func main() {
	cmd := &ParentCommand{
		subcommands: []cmder.Command{&ChildCommand{}},
	}

	args := []string{"child", "hello-world"}
	if err := cmder.Execute(context.Background(), cmd, cmder.WithArgs(args)); err != nil {
		fmt.Printf("unexpected error occurred: %v", err)
	}
}

// === PARENT COMMAND ===

const ParentCommandUsageLine = `parent [<subcommand>] [<args>...]`

const ParentCommandShortHelpText = `Example of parent command`

const ParentCommandHelpText = `
'parent' demonstrates an example of a command with subcommands. When executed without any arguments, the parent's Run
routine is executed, but if the child subcommand is provided the child subcommand Run routine will be exeuted instead.

The parent implements RootCommand indicating that it is a root command with runnable subcommands. The child does not
implement RootCommand, indicating it is a leaf command.

In this example, the parent and child commands implement RunnableLifecycle, and their respective init/destroy routines
are invoked in this order:

  1. parent Initialize
  2. child Initialize
  3. child Run
  4. child Destroy
  5. parent Destroy
`

const ParentCommandExamples = `
# run the parent 'Run' routine
parent

# run the child 'Run' routine
parent child

# run with some additional args
parent hello-world
parent child hello-world
`

type ParentCommand struct {
	subcommands []cmder.Command
}

func (c *ParentCommand) Name() string {
	return "parent"
}

func (c *ParentCommand) Initialize(ctx context.Context, args []string) error {
	fmt.Printf("%s: init %v\n", c.Name(), args)
	return nil
}

func (c *ParentCommand) Run(ctx context.Context, args []string) error {
	fmt.Printf("%s: run %v\n", c.Name(), args)
	return nil
}

func (c *ParentCommand) Destroy(ctx context.Context, args []string) error {
	fmt.Printf("%s: destroy %v\n", c.Name(), args)
	return nil
}

func (c *ParentCommand) UsageLine() string {
	return ParentCommandUsageLine
}

func (c *ParentCommand) ShortHelpText() string {
	return ParentCommandShortHelpText
}

func (c *ParentCommand) HelpText() string {
	return ParentCommandHelpText
}

func (c *ParentCommand) main() string {
	return ParentCommandExamples
}

func (c *ParentCommand) Subcommands() []cmder.Command {
	return c.subcommands
}

// === CHILD COMMAND ===

const ChildCommandUsageLine = `child [<args>...]`

const ChildCommandShortHelpText = `Example of child command`

const ChildCommandHelpText = `
'child' is the subcommand of 'parent'.
`

const ChildCommandExamples = `
# run the child 'Run' routine
parent child

# run with some additional args
parent child hello-world
`

type ChildCommand struct{}

func (c *ChildCommand) Name() string {
	return "child"
}

func (c *ChildCommand) Initialize(ctx context.Context, args []string) error {
	fmt.Printf("%s: init %v\n", c.Name(), args)
	return nil
}

func (c *ChildCommand) Run(ctx context.Context, args []string) error {
	fmt.Printf("%s: run %v\n", c.Name(), args)
	return nil
}

func (c *ChildCommand) Destroy(ctx context.Context, args []string) error {
	fmt.Printf("%s: destroy %v\n", c.Name(), args)
	return nil
}

func (c *ChildCommand) UsageLine() string {
	return ChildCommandUsageLine
}

func (c *ChildCommand) ShortHelpText() string {
	return ChildCommandShortHelpText
}

func (c *ChildCommand) HelpText() string {
	return ChildCommandHelpText
}

func (c *ChildCommand) main() string {
	return ChildCommandExamples
}

Output:

parent: init [child hello-world]
child: init [hello-world]
child: run [hello-world]
child: destroy [hello-world]
parent: destroy [child hello-world]