quicli

README

🏃⌨️ quicli

Build CLI in one line

^{..or two}

cli := quicli.Cli{Usage:"SayToTheWorld [flags]",Description: "Say Hello... or not. If you want to make the world aware of it you also could",Flags: quicli.Flags{{Name: "count", Default: 1, Description: "how many times I want to say it. Sometimes repetition is the key"},{Name: "say", Default: "hello", Description: "say something. If you are polite start with a greeting"},{Name: "world", Description: "announce it to the world"},},}
cfg := cli.Parse()

With this code you obtain the following help message:

Say Hello... or not. If you want to make the world aware of it you also could

Usage: SayToTheWorld [flags]

--count -c              how many times I want to say it. Sometimes repetition is the key. (default: 1)
--say   -s              say something. If you are polite start with a greeting. (default: "hello")
--world -w              announce it to the world. (default: false)

Use "./sayhello --help" for more information about the command.

Pretty indented version

cli := quicli.Cli{
  Usage:       "SayToTheWorld [flags]",
  Description: "Say Hello... or not. If you want to make the world aware of it you also could",
  Flags: quicli.Flags{
    {Name: "count", Default: 1, Description: "how many times I want to say it. Sometimes repetition is the key"},
    {Name: "say", Default: "hello", Description: "say something. If you are polite start with a greeting"},
    {Name: "world", Description: "announce it to the world"},
  },
}
cfg := cli.Parse()

Real one-liner (Parse and run)

quicli.Run(quicli.Cli{Usage:"SayToTheWorld [flags]",Description: "Say Hello... or not. If you want to make the world aware of it you also could",Flags: quicli.Flags{{Name: "count", Default: 1, Description: "how many times I want to say it. Sometimes repetition is the key"},{Name: "say", Default: "hello", Description: "say something. If you are polite start with a greeting"},{Name: "world", Description: "announce it to the world"},},Function: SayHello,})

You want a subcommand pattern?! okay

	cli := quicli.Cli{
		Usage:       "SayToTheWorld [command] [flags]",
		Description: "Say Hello... or not. If you want to make the world aware of it you also could",
		Flags: quicli.Flags{
			{Name: "count", Default: 1, Description: "how many times I want to say it. Sometimes repetition is the key"},
			{Name: "foreground", Description: "change foreground background", SharedSubcommand: quicli.SubcommandSet{"color"}},
			{Name: "say", Default: "hello", Description: "say something. If you are polite start with a greeting"},
			{Name: "world", Description: "announce it to the world"},
			{Name: "surprise", Description: "you will see my friend", SharedSubcommand: quicli.SubcommandSet{"toto", "color"}, NotForRootCommand: true},
		},
		Function: Main,
		Subcommands: quicli.Subcommands{
			{Name: "color", Description: "print coloured message", Function: Color},
			{Name: "toto", Description: "??", Function: Toto},
		},
	}
	cli.RunWithSubcommand()

Use flag values in code

cfg.GetIntFlag("count")    // --count  (int)
cfg.GetStringFlag("say")   // --say    (string)
cfg.GetBoolFlag("world")   // --world  (bool)
cfg.GetFloatFlag("ratio")  // --ratio  (float64)
cfg.GetStringSliceFlag("tags") // --tags a,b --tags c  ([]string)
// or use the short name: cfg.GetIntFlag("c")

Custom short name — override the auto-derived first letter:

{Name: "config", ShortName: "C", Default: "", Description: "config file"}
// registers --config and -C

Per-subcommand exclusive flags — flags that only exist for one subcommand:

Subcommands: quicli.Subcommands{
    {
        Name: "push", Description: "push changes", Function: Push,
        Flags: quicli.Flags{
            {Name: "force", Description: "force push"},
        },
    },
},

Typo detection — if a user types an unknown subcommand, quicli automatically suggests the closest match:

$ mytool pish
quicli error: unknown subcommand 'pish', did you mean 'push'?

Env vars

Every flag automatically reads from an env var as fallback before using the default. Auto-derived name: PROGNAME_FLAGNAME (uppercase, non-alphanumeric → _).

SAY_HELLO_COUNT=5 ./say-hello   # same as --count 5

Override the env var name per flag:

{Name: "token", Default: "", Description: "API token", EnvVar: "MY_API_TOKEN"}

Opt a flag out of env var lookup:

{Name: "secret", Default: "", Description: "...", EnvVar: "-"}

The env var name is shown in help output: (default: 0) [env: SAY_HELLO_COUNT]

Shell completion

Every CLI built with quicli gets --completion <shell> for free:

./mycli --completion bash >> ~/.bash_completion
./mycli --completion zsh  > ~/.zsh/completions/_mycli
./mycli --completion fish > ~/.config/fish/completions/mycli.fish

Get more examples

Disclaimer

The library is a wrapper of the built-in go flag package. It should only be used to quickly built CLI and it is not intented for complex CLI usage.