GCli

A simple and easy-to-use command-line application and tool library written in Golang. Including running commands, color styles, data display, progress display, interactive methods, etc.

中文说明

Features

Rich in functions and easy to use. Highlights grouped by area:

Commands

• Multi-level (nested) commands, each level binds its own options
• Command aliases and similar-command tips on typo (alias-aware)
• Command/App middleware via Use(handlers ...RunnerFunc)
• A single command can run as a stand-alone application

Option binding

• Code-style binders: BoolOpt / IntOpt / StrOpt / Float64Opt / VarOpt ...
• Generic, type-safe binders: gflag.Opt[T] / gflag.BindVar[T] — one call covers bool/int/uint/float/string, time.Duration, []string/[]int/[]bool, map[string]string
• Struct-tag binding via FromStruct:
  • three tag rules: named(default) / simple / field(field name as option name); anonymous embedded structs auto-expand under any rule
  • field types: bool/int/uint/float/string, native []string/[]int/[]bool (repeatable), time.Duration, map[string]string (repeatable --meta k=v)
  • enum:"a,b,c" tag for value candidates(completion) + membership validation
• Required / Validator / Choices per option; option Category for grouped help display

Three-level option model

• Global (App-level) options
• Shared (inherited) options via Command.SharedOpts() (≈ cobra PersistentFlags): inherited by the command and all its sub-commands (sharing the same variable), grouped under Inherited Options in help
• Local (per-command) options

Parse enhancements

• Options written after arguments are auto-reordered: cmd arg --name tom == cmd --name tom arg (on by default; disable via gflag.WithReorderArgs(false))
• POSIX short-flag combining (-ab = -a -b) via opt-in EnhanceShort; EnhanceShort=2 also supports attached-value form -Ostdout = -O stdout. Only all-bool groups are split, off by default for compatibility
• Declarative interactive collect by Question when the option value is empty

Arguments

• Bind named argument, with required / optional / array settings
• Auto-detected and collected when the command is run

Tooling

• Generate zsh / bash / pwsh command completion scripts (incl. dynamic completion)
• Generate markdown / man page command documentation (docgen package + builtin GenDoc command)
• Auto-generated, color-rendered command help information
• Event hook system (gevent, with gcli.Evt* aliases)

Extras

• Color output, interactive input and progress/data display, provided by gookit/color and gookit/cliui

GoDoc

• godoc

Install

go get github.com/gookit/gcli/v3

Upgrade note: the event package gcli/v3/events was renamed to gcli/v3/gevent. Update your imports, or reference event names directly via the gcli.Evt* aliases (e.g. gcli.EvtCmdRunBefore) to avoid the import entirely. See CHANGELOG for details.

Quick start

an example for quick start:

package main

import (
    "github.com/gookit/gcli/v3"
    "github.com/gookit/gcli/v3/_examples/cmd"
)

// for test run: go build ./_examples/cliapp.go && ./cliapp
func main() {
    app := gcli.NewApp()
    app.Version = "1.0.3"
    app.Desc = "this is my cli application"
    // app.SetVerbose(gcli.VerbDebug)

    // TIP: Add binding app-level option settings (same level as the built-in -h/--help)
    app.Flags().BoolOpt(...)
    app.Flags().StrOpt(...)

    app.Add(cmd.Example)
    app.Add(&gcli.Command{
        Name: "demo",
        // allow color tag and {$cmd} will be replace to 'demo'
        Desc: "this is a description <info>message</> for {$cmd}", 
        Subs: []*gcli.Command {
            // ... allow add subcommands
        },
        Aliases: []string{"dm"},
        Func: func (cmd *gcli.Command, args []string) error {
            gcli.Print("hello, in the demo command\n")
            return nil
        },
    })

    // .... add more ...

    app.Run(nil)
}

Binding flags

flags binding and manage by builtin gflag.go, allow binding flag options and arguments.

Bind options

gcli support multi method to binding flag options.

Use flag methods

Available methods:

BoolOpt(p *bool, name, shorts string, defValue bool, desc string)
BoolVar(p *bool, meta FlagMeta)
Float64Opt(p *float64, name, shorts string, defValue float64, desc string)
Float64Var(p *float64, meta FlagMeta)
Int64Opt(p *int64, name, shorts string, defValue int64, desc string)
Int64Var(p *int64, meta FlagMeta)
IntOpt(p *int, name, shorts string, defValue int, desc string)
IntVar(p *int, meta FlagMeta)
StrOpt(p *string, name, shorts, defValue, desc string)
StrVar(p *string, meta FlagMeta)
Uint64Opt(p *uint64, name, shorts string, defValue uint64, desc string)
Uint64Var(p *uint64, meta FlagMeta)
UintOpt(p *uint, name, shorts string, defValue uint, desc string)
UintVar(p *uint, meta FlagMeta)
Var(p flag.Value, meta FlagMeta)
VarOpt(p flag.Value, name, shorts, desc string)

Usage examples:

var id int
var b bool
var opt, dir string
var f1 float64
var names gcli.Strings

// bind options
cmd.IntOpt(&id, "id", "", 2, "the id option")
cmd.BoolOpt(&b, "bl", "b", false, "the bool option")
// notice `DIRECTORY` will replace to option value type
cmd.StrOpt(&dir, "dir", "d", "", "the `DIRECTORY` option")
// setting option name and short-option name
cmd.StrOpt(&opt, "opt", "o", "", "the option message")
// setting a special option var, it must implement the flag.Value interface
cmd.VarOpt(&names, "names", "n", "the option message")

Use generic binders

gflag.Opt[T] / gflag.BindVar[T] bind a typed pointer in one type-safe call, covering scalars, time.Duration, slices and map[string]string:

var name string
var tags []string

gflag.Opt(cmd.Flags(), &name, "name", "n", "tom", "the user name")
// slice option, repeatable: --tag php --tag go
gflag.Opt(cmd.Flags(), &tags, "tag", "t", nil, "the tags, repeatable")

Use struct tags

package main

import (
	"github.com/gookit/gcli/v3"
)

type userOpts struct {
	Int  int    `flag:"name=int0;shorts=i;required=true;desc=int option message"`
	Bol  bool   `flag:"name=bol;shorts=b;desc=bool option message"`
	Str1 string `flag:"name=str1;shorts=o;required=true;desc=str1 message"`
	// use ptr
	Str2 *string `flag:"name=str2;required=true;desc=str2 message"`
	// custom type and implement flag.Value
	Verb0 gcli.VerbLevel `flag:"name=verb0;shorts=v0;desc=verb0 message"`
	// use ptr
	Verb1 *gcli.VerbLevel `flag:"name=verb1;desc=verb1 message"`
}

// run: go run ./_examples/issues/iss157.go
func main() {
	astr := "xyz"
	verb := gcli.VerbWarn

	cmd := gcli.NewCommand("test", "desc")
	cmd.Config = func(c *gcli.Command) {
		c.MustFromStruct(&userOpts{
			Str2:  &astr,
			Verb1: &verb,
		})
	}

	// disable auto bind global options: verbose,version, progress...
	gcli.GOpts().SetDisable()

	// direct run
	if err := cmd.Run(nil); err != nil {
		colorp.Errorln( err)
	}
}

Struct tag rules

FromStruct supports three tag rules, selected by c.FromStruct(ptr, ruleType):

• gcli.TagRuleNamed (default): flag:"name=int0;shorts=i;required=true;desc=message"
• gcli.TagRuleSimple: flag:"desc;required;default;shorts"
• gcli.TagRuleField: use the field name (SnakeCase) as the option name, read meta from independent tag keys.

Anonymous embedded structs are expanded automatically under all three rules — each inner field is read using whichever rule is active. This also works for embedded unexported types (e.g. commonOpts below).

type commonOpts struct {
	Verbose bool `flag:"v" desc:"enable verbose output"`
}
type demoOpts struct {
	commonOpts        // anonymous: expands to a --verbose/-v option
	UserName string `flag:"u" desc:"the user name" required:"true"`
	Age      int    `desc:"the user age" default:"18"`
}

c.MustFromStruct(&demoOpts{}, gcli.TagRuleField)
// => options: --user-name/-u (required), --age (default 18), --verbose/-v

Interactive collect by Question

When an option value is empty, you can auto-collect it via an interactive question (a built-in default collector). Collector has higher priority than Question.

c.StrOpt2(&token, "token", "the access token",
	gflag.WithQuestion("Please input your access token: "))
// run without --token will prompt: "Please input your access token: "

POSIX short option enhance

Combined short options are disabled by default. Enable via Config.EnhanceShort:

c.ParserCfg().EnhanceShort = gcli.EnhanceShortMerge  // 1: -aux => -a -u -x (all bool)
c.ParserCfg().EnhanceShort = gcli.EnhanceShortAttach // 2: also -Ostdout => -O stdout

Or enable it globally for all commands with one call — a command's own setting (if any) still takes priority:

gcli.SetEnhanceShort(gcli.EnhanceShortMerge) // applies to every command

Only groups where all members are bool short options are split; mixed forms are kept as-is to avoid mis-parsing value-taking short options.

Runnable demos in _examples/cmd: struct-flag (B6), short-merge (B4+B5), ask-demo (B7).

Command/Option category

Both commands and options support a Category for grouped display in the help message. When no category is set, the output is the same as before (commands go to Available Commands, options are listed directly under Options:).

// command category
app.Add(&gcli.Command{Name: "migrate", Desc: "run db migrate", Category: "database"})
app.Add(&gcli.Command{Name: "serve", Desc: "start http server"}) // default group

// option category
cmd.StrVar(&dsn, &gcli.CliOpt{Name: "db-dsn", Desc: "database dsn", Category: "database"})
cmd.StrOpt2(&port, "port", "bind port", gflag.WithCategory("network"))

Groups keep the order of first appearance; commands inside a group are sorted by name.

NOTE: the log level is no longer controlled by a global --verbose option. Use the env GCLI_VERBOSE (eg GCLI_VERBOSE=debug) or gcli.SetVerbose() instead, so it won't pollute the option list of the host application.

Bind arguments

About arguments:

• Required argument cannot be defined after optional argument
• Support binding array argument
• The (array)argument of multiple values can only be defined at the end

Available methods:

Add(arg Argument) *Argument
AddArg(name, desc string, requiredAndArrayed ...bool) *Argument
AddArgByRule(name, rule string) *Argument
AddArgument(arg *Argument) *Argument
BindArg(arg Argument) *Argument

Usage examples:

cmd.AddArg("arg0", "the first argument, is required", true)
cmd.AddArg("arg1", "the second argument, is required", true)
cmd.AddArg("arg2", "the optional argument, is optional")
cmd.AddArg("arrArg", "the array argument, is array", false, true)

can also use Arg()/BindArg() add a gcli.Argument object:

cmd.Arg("arg0", gcli.Argument{
	Name: "ag0",
	Desc: "the first argument, is required",
	Require: true,
})
cmd.BindArg("arg2", gcli.Argument{
	Name: "ag0",
	Desc: "the third argument, is is optional",
})
cmd.BindArg("arrArg", gcli.Argument{
	Name: "arrArg",
	Desc: "the third argument, is is array",
	Arrayed: true,
})

use AddArgByRule:

cmd.AddArgByRule("arg2", "add an arg by string rule;required;23")

New application

app := gcli.NewApp()
app.Version = "1.0.3"
app.Desc = "this is my cli application"
// app.SetVerbose(gcli.VerbDebug)

Add commands

app.Add(cmd.Example)
app.Add(&gcli.Command{
    Name: "demo",
    // allow color tag and {$cmd} will be replace to 'demo'
    Desc: "this is a description <info>message</> for {$cmd}", 
    Subs: []*gcli.Command {
        // level1: sub commands...
    	{
            Name:    "remote",
            Desc:    "remote command for git",
            Aliases: []string{"rmt"},
            Func: func(c *gcli.Command, args []string) error {
                dump.Println(c.Path())
                return nil
            },
            Subs: []*gcli.Command{
                // level2: sub commands...
                // {}
            }
        },
        // ... allow add subcommands
    },
    Aliases: []string{"dm"},
    Func: func (cmd *gcli.Command, args []string) error {
        gcli.Print("hello, in the demo command\n")
        return nil
    },
})

Run application

Build the example application as demo

$ go build ./_examples/cliapp                                                         

Display version

$ ./cliapp --version      
# or use -V                                                 
$ ./cliapp -V                                                     

Display app help

by ./cliapp or ./cliapp -h or ./cliapp --help

Examples:

./cliapp
./cliapp -h # can also
./cliapp --help # can also

Run command

Format:

./cliapp COMMAND [--OPTION VALUE -S VALUE ...] [ARGUMENT0 ARGUMENT1 ...]
./cliapp COMMAND [--OPTION VALUE -S VALUE ...] SUBCOMMAND [--OPTION ...] [ARGUMENT0 ARGUMENT1 ...]

Run example:

$ ./cliapp example -c some.txt -d ./dir --id 34 -n tom -n john val0 val1 val2 arrVal0 arrVal1 arrVal2

You can see:

Display command help

by ./cliapp example -h or ./cliapp example --help

Error command tips

Generate Auto Completion Scripts

There are two ways to generate command completion scripts:

• Directly use the global option ./cliapp --gen-completion bash|zsh > ~/.cliapp-completion.sh to generate
• Register the built-in GenAutoComplete command and then generate it using ./cliapp genac -o ~/.cliapp-completion.sh

import  "github.com/gookit/gcli/v3/builtin"

    // ...
    // add gen command(gen successful you can remove it)
    app.Add(builtin.GenAutoComplete())

Build and run command(This command can be deleted after success.)：

$ go build ./_examples/cliapp.go && ./cliapp genac -h // display help
$ go build ./_examples/cliapp.go && ./cliapp genac // run gen command

will see:

INFO: 
  {shell:zsh binName:cliapp output:auto-completion.zsh}

Now, will write content to file auto-completion.zsh
Continue? [yes|no](default yes): y

OK, auto-complete file generate successful

After running, it will generate an auto-completion.{zsh|bash} file in the current directory, and the shell environment name is automatically obtained. Of course, you can specify it manually at runtime

Preview:

Shared (inherited) options

Command.SharedOpts() (≈ cobra PersistentFlags) binds options that are inherited by the command and all of its sub-commands, sharing the same variable. They can be written at any position in the sub-command segment and are grouped under Inherited Options in the help output.

var gitDir string

top := &gcli.Command{Name: "git", Desc: "git tools"}
// bind on SharedOpts: inherited by every sub-command
top.SharedOpts().StrOpt(&gitDir, "git-dir", "", ".git", "the git dir path")

top.Add(&gcli.Command{
    Name: "status",
    Func: func(c *gcli.Command, _ []string) error {
        // --git-dir is usable here even though it is declared on the parent
        gcli.Printf("git dir: %s\n", gitDir)
        return nil
    },
})

// usage: ./app git status --git-dir /path/to/.git

Generate command docs

Add the builtin GenDoc command, then export markdown / man documentation for all commands:

import "github.com/gookit/gcli/v3/builtin"

app.Add(builtin.GenDoc())
// ./cliapp gendoc -f md  -o ./docs   # export markdown (default)
// ./cliapp gendoc -f man -o ./docs   # export man pages

You can also call it programmatically:

import "github.com/gookit/gcli/v3/docgen"

docgen.MarkdownTree(app, "./docs") // one .md per command + index.md
docgen.ManTree(app, "./docs")      // man pages

Write a command

command allow setting fields:

• Name the command name.
• Desc the command description.
• Aliases the command alias names.
• Config the command config func, will call it on init.
• Subs add subcommands, allow multi level subcommands
• Func the command handle callback func
• More, please see godoc

Quick create

var MyCmd = &gcli.Command{
    Name: "demo",
    // allow color tag and {$cmd} will be replace to 'demo'
    Desc: "this is a description <info>message</> for command {$cmd}", 
    Aliases: []string{"dm"},
    Func: func (cmd *gcli.Command, args []string) error {
        gcli.Print("hello, in the demo command\n")
        return nil
    },
    // allow add multi level subcommands
    Subs: []*gcli.Command{},
}

Write go file

the source file at: example.go

package main

import (
	"fmt"

	"github.com/gookit/color"
	"github.com/gookit/gcli/v3"
	"github.com/gookit/goutil/dump"
)

// options for the command
var exampleOpts = struct {
	id  int
	c   string
	dir string
	opt string
	names gcli.Strings
}{}

// ExampleCommand command definition
var ExampleCommand = &gcli.Command{
	Name: "example",
	Desc: "this is a description message",
	Aliases: []string{"exp", "ex"}, // 命令别名
	// {$binName} {$cmd} is help vars. '{$cmd}' will replace to 'example'
	Examples: `{$binName} {$cmd} --id 12 -c val ag0 ag1
<cyan>{$fullCmd} --names tom --names john -n c</> test use special option`,
	Config: func(c *gcli.Command) {
	    // binding options
        // ...
        c.IntOpt(&exampleOpts.id, "id", "", 2, "the id option")
		c.StrOpt(&exampleOpts.c, "config", "c", "value", "the config option")
		// notice `DIRECTORY` will replace to option value type
		c.StrOpt(&exampleOpts.dir, "dir", "d", "", "the `DIRECTORY` option")
		// 支持设置选项短名称
		c.StrOpt(&exampleOpts.opt, "opt", "o", "", "the option message")
		// 支持绑定自定义变量, 但必须实现 flag.Value 接口
		c.VarOpt(&exampleOpts.names, "names", "n", "the option message")

      // binding arguments
		c.AddArg("arg0", "the first argument, is required", true)
		// ...
	},
	Func:  exampleExecute,
}

// 命令执行主逻辑代码
// example run:
// 	go run ./_examples/cliapp.go ex -c some.txt -d ./dir --id 34 -n tom -n john val0 val1 val2 arrVal0 arrVal1 arrVal2
func exampleExecute(c *gcli.Command, args []string) error {
	color.Infoln("hello, in example command")

	if exampleOpts.showErr {
		return c.NewErrf("OO, An error has occurred!!")
	}

	magentaln := color.Magenta.Println

	color.Cyanln("All Aptions:")
	// fmt.Printf("%+v\n", exampleOpts)
	dump.V(exampleOpts)

	color.Cyanln("Remain Args:")
	// fmt.Printf("%v\n", args)
	dump.P(args)

	magentaln("Get arg by name:")
	arr := c.Arg("arg0")
	fmt.Printf("named arg '%s', value: %#v\n", arr.Name, arr.Value)

	magentaln("All named args:")
	for _, arg := range c.Args() {
		fmt.Printf("- named arg '%s': %+v\n", arg.Name, arg.Value)
	}

	return nil
}

• display the command help：

go build ./_examples/cliapp.go && ./cliapp example -h

Extras: color, interactive & progress

gcli ships with color output, interactive input (Confirm / Select / ReadLine ...), progress display (Bar / Spinner / Loading ...) and data display (table / list / tree), provided by gookit/color and gookit/cliui.

color.Info.Tips("processing...")              // colored output

ok := interact.Confirm("ensure continue?")    // interactive confirm
if !ok {
    return nil
}

p := progress.Bar(100)                        // progress bar
p.Start();
/* p.Advance() in loop */
p.Finish()

For more usage see gookit/color and gookit/cliui.

Gookit packages

• gookit/ini Go config management, use INI files
• gookit/rux Simple and fast request router for golang HTTP
• gookit/gcli build CLI application, tool library, running CLI commands
• gookit/event Lightweight event manager and dispatcher implements by Go
• gookit/config Go config management. support JSON, YAML, TOML, INI, HCL, ENV and Flags
• gookit/color A command-line color library with true color support, universal API methods and Windows support
• gookit/filter Provide filtering, sanitizing, and conversion of golang data
• gookit/validate Use for data validation and filtering. support Map, Struct, Form data
• gookit/goutil Some utils for the Go: string, array/slice, map, format, cli, env, filesystem, test and more
• More please see https://github.com/gookit

See also

• inhere/console https://github/inhere/php-console
• issue9/term https://github.com/issue9/term
• ANSI escape code

License

MIT