Go语言标准包之用io包模拟curl

package main

import (
	"bytes"
	"fmt"
	"os"
	"io"
	"log"
	"net/http"
)

	
func main() {
	var b bytes.Buffer
	b.Write([]byte("Hello "))
	
	fmt.Fprintf(&b, "World")
	
	b.WriteTo(os.Stdout)
	
	resp, err := http.Get(os.Args[1])
	if err != nil {
		log.Fatalln(err)
	}
	
	file, err := os.Create(os.Args[2])
	if err != nil {
		log.Fatalln(err)
	}
	defer file.Close()
	
	dest := io.MultiWriter(os.Stdout, file)
	
	io.Copy(dest, resp.Body)
	if err := resp.Body.Close(); err != nil {
		log.Println(err)
	}
}