+type Multi map[string]Handler
+
+func (m Multi) RunCommand(prog string, args []string, stdin io.Reader, stdout, stderr io.Writer) int {
+ _, basename := filepath.Split(prog)
+ if i := strings.Index(basename, "~"); i >= 0 {
+ // drop "~anything" suffix (arvados-dispatch-cloud's
+ // DeployRunnerBinary feature relies on this)
+ basename = basename[:i]
+ }
+ cmd, ok := m[basename]
+ if !ok {
+ // "controller" command exists, and binary is named "arvados-controller"
+ cmd, ok = m[strings.TrimPrefix(basename, "arvados-")]
+ }
+ if !ok {
+ // "dispatch-slurm" command exists, and binary is named "crunch-dispatch-slurm"
+ cmd, ok = m[strings.TrimPrefix(basename, "crunch-")]
+ }
+ if ok {
+ return cmd.RunCommand(prog, args, stdin, stdout, stderr)
+ } else if len(args) < 1 {
+ fmt.Fprintf(stderr, "usage: %s command [args]\n", prog)
+ m.Usage(stderr)
+ return 2
+ } else if cmd, ok = m[args[0]]; ok {
+ return cmd.RunCommand(prog+" "+args[0], args[1:], stdin, stdout, stderr)
+ } else {
+ fmt.Fprintf(stderr, "%s: unrecognized command %q\n", prog, args[0])
+ m.Usage(stderr)
+ return 2
+ }
+}
+
+func (m Multi) Usage(stderr io.Writer) {
+ fmt.Fprintf(stderr, "\nAvailable commands:\n")
+ m.listSubcommands(stderr, "")
+}
+
+func (m Multi) listSubcommands(out io.Writer, prefix string) {
+ var subcommands []string
+ for sc := range m {
+ if strings.HasPrefix(sc, "-") {
+ // Some subcommands have alternate versions
+ // like "--version" for compatibility. Don't
+ // clutter the subcommand summary with those.
+ continue