golang 錯誤 too many open files

問題 too many open files錯誤

最近在看golang，寫了個掃描title的腳本，發現打開文件的時候會報錯，記錄下。

too many open files

https://github.com/Stu2014/go

package main

import (
	"bufio"
	"crypto/tls"
	"encoding/csv"
	"flag"
	"fmt"
	"io/ioutil"
	"net/http"
	"os"
	"regexp"
	"strconv"
	"sync"
	"time"
)

/*

用的colly模塊，-f指定文件名

*/
var wg sync.WaitGroup

func scnafile(file string, url chan string)  {
	files, err := os.Open(file)
	if err != nil {
		fmt.Println("open error")
	}
	defer files.Close()
	//n := bufio.NewReader(files)
	//for {
	//	a, _, c := n.ReadLine()
	//	if c == io.EOF {
	//		break
	//	}
	//	fmt.Println(string(a),"aaa")
	//	url <- string(a)
	//}
	n := bufio.NewScanner(files)
	for n.Scan(){
		fmt.Println(n.Text())
		url <- n.Text()
		continue
	}
	err_ := n.Err()
	if err_ != nil {
		fmt.Println("Error scanner")
	}
	close(url)

}

func reurl(url chan string)  {
	timeUnix := time.Now().Format("2006-01-02 15:04:05")+".csv"
	for{
		select {
		case xdd, ok := <-url:
			if !ok {
				wg.Done()
				return
			}
		tr := &http.Transport{
			TLSClientConfig: &tls.Config{InsecureSkipVerify:true},
		}
		client := &http.Client{Transport:tr}
		url := xdd
		req, err := http.NewRequest("GET", url, nil)
		if err != nil {
			fmt.Println("url2 error")
			continue
		}
		resp, err := client.Do(req)
		if err != nil {
			fmt.Printf("url: %s error\n", url)
			continue
		}
		defer resp.Body.Close()

		content, _ := ioutil.ReadAll(resp.Body)
		r := regexp.MustCompile(`<title>(.*)</title>`)
		ret := r.FindAllStringSubmatch(string(content),-1)
		//fmt.Println(ret)
		for _, substr := range ret  {
			fmt.Printf("[%d+] %s %s %s \n",resp.StatusCode, substr[1], xdd, resp.Header.Get("Server"))
			writeurl(timeUnix, strconv.Itoa(resp.StatusCode), xdd, substr[1], resp.Header.Get("Server"))
		}
		case <- time.After(time.Duration(2) * time.Second):
			wg.Done()
			return


		}
	}
}

//寫文件
func writeurl(time_ string, code string, url string, title string, serverver string)  {
	file , err := os.OpenFile(time_, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666)
	_, _ = file.WriteString("\xEF\xBB\xBF")
	if err != nil {
		fmt.Println("open file err:", err)
	}
	defer file.Close()
	w := csv.NewWriter(file)
	_ = w.Write([]string{url, title, code, serverver})
	w.Flush()
}

func main() {
	url :=make(chan string)
	var filename string

	flag.StringVar(&filename, "f", "", "請輸入url文件名字")
	flag.Parse()
	if filename == ""{
		fmt.Println(`
 _____  _  _____  _    ____    ___   ___   __   _   _ 
(_   _)( )(_   _)( )  (  __)  /  _) (  _) (  ) ( \ ( )
  | |  | |  | |  | |  | |_    \_"-. | |   /o \ | \\| |
  ( )  ( )  ( )  ( )_ (  _)    __) )( )_ ( __ )( )\\ )
  /_\  /_\  /_\  /___\/____\  /___/ /___\/_\/_\/_\ \_\
                                               v1.0
`)
		os.Exit(1)
	}

	go scnafile(filename, url)
	for i := 0; i < 10; i++ {
		wg.Add(1)
		go reurl(url)
	}
	wg.Wait()

}

解決（mac版本）

修改linux 最大文件限制數ulimit

ulimit -a

> 修改限制
ulimit -n 2048

完美解決

俺也不知道咋回事，這玩意還須要字數限制，咋回事咧。我真的不知道啊。
那我就講個故事吧，從前有一隻蚊子，嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡嗡～