code.go

package main

import (
	"bytes"
	"io/ioutil"
	"log"
	"os"
	"path/filepath"
	"time"
)

func main() {
	num_files := 0
	num_lines := 0
	go func() {
		t := time.NewTicker(1)
		defer t.Stop()
		for {
			<-t.C
			log.Print("progress: files=%s; lines=%s", num_files, num_lines)
		}
	}()
	e := filepath.Walk(os.Args[1], func(path string, info os.FileInfo, err error) error {
		go func() error {
			num_files++
			file, err := ioutil.ReadFile(path)
			if err != nil {
				return err
			}
			num_lines += bytes.Count(file, []byte("\n"))
			return nil
		}()
		return nil
	})
	if e != nil {
		print(e.Error())
		os.Exit(1)
	}
	log.Print("files=%s; lines=%s", num_files, num_lines)
}