func Stack(buf []byte, all bool) int
Stack formats a stack trace of the calling goroutine into buf and returns the number of bytes written to buf. If all is true, Stack formats stack traces of all other goroutines into buf after the trace for the current goroutine.

package main
import (
    "runtime"
    "time"
    "fmt"
)
func main() {
    go power1()
    for {
        time.Sleep(time.Duration(1)*time.Minute)
    }
}


func power1(){
    var buf [1024]byte
    fmt.Println("power1.....")
    n := runtime.Stack(buf[:], true)
    fmt.Println(string(buf[:]), n)
}

power1.....
goroutine 5 [running]:
main.power1()
/home/lanyang/src/t.go:29 +0xec
created by main.main
/home/lanyang/src/t.go:14 +0x3c

goroutine 1 [sleep]:
time.Sleep(0xdf8475800)
/home/lanyang/src/t.go:59 +0x107
main.main()
/home/lanyang/src/t.go:17 +0x4f
303