Go 没有将完整的数据写入文本文件

Question

我正在尝试探索 Go 并发性。这里Grabber()打印并写入执行结果。程序打印预期结果，但不将其写入urls.txt. 谁能向我解释我在这里缺少什么？

main.go

package main

import (

    "bufio"

    "fmt"

    "io/ioutil"

    "log"

    "net/http"

    "os"

    "regexp"

    "strings"

    "sync"

)

var wg sync.WaitGroup

var mt sync.Mutex

// Final Literation

func main() {

    file, err := os.Open("ip.txt")

    if err != nil {

        log.Fatal(err)

    }

    defer file.Close()

    scanner := bufio.NewScanner(file)

    for scanner.Scan() {

        go Grabber(scanner.Text())

        wg.Add(1)

    }

    wg.Wait()

    if err := scanner.Err(); err != nil {

        log.Fatal(err)

    }

}

// stringInArray do If string in list return true false otherwise.

func stringInArray(a string, list []string) bool {

    for _, b := range list {

        if b == a {

            return true

        }

    }

    return false

}

// Grabber Do Search the bing and collect array of sitelist

func Grabber(ip string) {

    defer wg.Done()

    var output []string

    outfile, err := os.Create("urls.txt")

    if err != nil {

        log.Fatal(err)

    }

    defer outfile.Close()

    if ip == "" {

    }

    page := 1

    for page < 251 {

        client := &http.Client{}

        req, err := http.NewRequest(

            http.MethodGet,

            fmt.Sprintf(

                "http://www.bing.com/search?q=ip:%s+&count=50&first=1",

                ip,

            ),

            nil,

        )

        if err != nil {

        }

        req.Header.Set("User-Agent", "Mozilla/5.0 (Windows NT 6.1; rv:57.0) Gecko/20100101 Firefox/57.0")

        res, err := client.Do(req)

        if err != nil {

            fmt.Println("Invalid Request")

        }

        defer res.Body.Close()

        body, err := ioutil.ReadAll(res.Body)

        if err != nil {

            fmt.Println("Couldn't Read")

        }

ip.txt 作为输入

103.253.145.129

103.253.146.125

103.253.146.239

103.253.147.72

146.185.176.79

146.185.176.45

146.185.179.250

146.185.180.35

146.185.180.185

146.185.180.113

146.185.181.51

146.185.183.107

146.185.183.202

146.185.183.248

146.185.183.219

146.185.184.69

146.185.185.169

Answer 1

您正在调用create每个 goroutine，这将截断文件。相反，在外部创建文件，并使用另一个 goroutine 序列化对其的写入：&nbsp; &nbsp; outfile, err := os.Create("urls.txt")&nbsp; &nbsp; results:=make(chan []string)&nbsp; &nbsp; go func() {&nbsp; &nbsp; &nbsp; &nbsp;for output:=range results {&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; for _, links := range output {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; fmt.Fprintln(outfile, links)&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp;&nbsp;&nbsp; &nbsp; &nbsp; &nbsp;}&nbsp; &nbsp; }()&nbsp; &nbsp; scanner := bufio.NewScanner(file)&nbsp; &nbsp; for scanner.Scan() {&nbsp; &nbsp; &nbsp; &nbsp; go Grabber(scanner.Text(), results)&nbsp; &nbsp; &nbsp; &nbsp; wg.Add(1)&nbsp; &nbsp; }&nbsp; &nbsp; wg.Wait()&nbsp; &nbsp; close(results)在 Grabber 中获取结果时，不要将其写入文件，而是将其写入通道：&nbsp; &nbsp; results<-output&nbsp; &nbsp; for _, links := range output {&nbsp; &nbsp; &nbsp; &nbsp; fmt.Println(links)&nbsp; &nbsp; }