PID of running process

gistfile1.go

package main

import (
	"fmt"
	"os"
)

func main() {

	os.Create("a.txt")

	argv := []string{"-f", "a.txt"}
	files := []*os.File{nil, os.Stdout, os.Stderr}
	attr := &os.ProcAttr{Dir: "./", Files: files}
	pro, _ := os.StartProcess("/usr/bin/tail", argv, attr)

	fmt.Println(pro.Pid)
}