subcommands

Subcommands is a Go package that implements a simple way for a single command to have many subcommands, each of which takes arguments and so forth.

This is not an official Google product.

Usage

Set up a ‘print’ subcommand:

import ( "context" "flag" "fmt" "os" "strings" "github.com/google/subcommands" ) type printCmd struct { capitalize bool } func (*printCmd) Name() string { return "print" } func (*printCmd) Synopsis() string { return "Print args to stdout." } func (*printCmd) Usage() string { return `print [-capitalize] <some text>: Print args to stdout. ` } func (p *printCmd) SetFlags(f *flag.FlagSet) { f.BoolVar(&p.capitalize, "capitalize", false, "capitalize output") } func (p *printCmd) Execute(_ context.Context, f *flag.FlagSet, _ ...interface{}) subcommands.ExitStatus { for _, arg := range f.Args() { if p.capitalize { arg = strings.ToUpper(arg) } fmt.Printf("%s ", arg) } fmt.Println() return subcommands.ExitSuccess } 

Register using the default Commander, also use some built in subcommands, finally run Execute using ExitStatus as the exit code:

func main() { subcommands.Register(subcommands.HelpCommand(), "") subcommands.Register(subcommands.FlagsCommand(), "") subcommands.Register(subcommands.CommandsCommand(), "") subcommands.Register(&printCmd{}, "") flag.Parse() ctx := context.Background() os.Exit(int(subcommands.Execute(ctx))) }