package main 
import (
    "os"
    "os/exec"
)

func main() {
    c := exec.Command("cls")
    c.Stdout = os.Stdout
    c.Run()
}

C.system(C.CString("cls"))

package main

import (
"os"
"os/exec"
)

func main() {
    cmd := exec.Command("cmd","/c","cls")
    cmd.Stdout = os.Stdout
    cmd.Run()
}