Share a go auxiliary command line

package ctl
 
import (
    "bufio"
    "errors"
    "os"
    "strings"
)
 
type cmdinfo struct {
    cmd string
    desc string
    fn func(str string)
}
 
var cbmap map[string]*cmdinfo
 
func init() {
    go run()
 
    cbmap = make(map[string]*cmdinfo)
    Register("test", "This is a test", func(arg string) {
        println("Test callback of test command.")
    })
 
    Register("help", "Show all commands", func(arg string) {help()})
}
 
func Register(key string, desc string, fn func(string)) error {
    if _, ok := cbmap[key];ok{
        return errors.New("Repeat register cb of ctl:"+ key)
    }
    cbmap[key] = &cmdinfo{key, desc, fn}
    return nil
}
 
func help(){
    for key, cmd := range(cbmap) {
        println("*\t", key, "\t\t ", cmd.desc)
    }
}
 
func run() {
    for {
        input := bufio.NewScanner(os.Stdin)
        input.Scan()
        in := input.Text()
 
        //  Commands and parameters are separated by spaces 
        strs := strings.Split(in, " ")
        cmd := strs[0]
        arg := ""
        if len(strs)==2{
            arg = strs[1]
        }
        if cmd, ok := cbmap[cmd];ok{
            cmd.fn(arg)
        } else {
            println("Invalid command, input ‘help’ to get more information.")
        }
    }
}