main.go

package main

import (
	"fmt"
	"io"
	"io/ioutil"
	"log"
	"os"
	"path/filepath"
)

func main() {
	srcDir := os.Args[1]
	dstDir := os.Args[2]

	files, err := ioutil.ReadDir(srcDir)
	if err != nil {
		log.Println(err)
	}

	for _, file := range files {
		//fmt.Println(file.Name())

		srcName := srcDir + "/" + file.Name()
		ex := filepath.Ext(srcName)

		if ex == ".zip" {
			src, err := os.Open(srcName)
			if err != nil {
				log.Println(err)
			}

			dstName := dstDir + "/" + file.Name()
			dst, err := os.Create(dstName)
			if err != nil {
				log.Println(err)
			}

			_, err = io.Copy(dst, src)
			if err != nil {
				log.Println(err)
			} else {
				fmt.Println("--> " + file.Name())
			}

			src.Close()
			dst.Close()

			r := os.Remove(srcName)
			if r != nil {
				log.Println(r)
			}
		}
	}
}

zipだけコピーするようにした