Zhong__Go并发实例

时间：2021.06.22

环境：Windows

目的：批量通过ssh连接远程主机执行命令

说明：

作者：Zhong QQ交流群：121160124 欢迎加入！

ip_info.txt文件内容如下:

192.168.40.66
192.168.40.67
192.168.40.68
192.168.40.69
192.168.40.70
192.168.40.71
192.168.40.72
192.168.40.73
192.168.40.74
192.168.40.75
192.168.40.76
192.168.40.77
192.168.40.78
192.168.40.79
192.168.40.80
192.168.40.81
192.168.40.82
192.168.40.83
192.168.40.84
192.168.40.85
192.168.40.86
192.168.40.87
192.168.40.88
           

代码如下：

package main

import (
	"fmt"
	"sync"
	"strings"
	"golang.org/x/crypto/ssh"
	"log"
	"os"
	"bufio"
	"io"
	"time"
	"flag"
)

// 定义ip列表
var ip_list = []string{}

var user, passwd, port, ip_info string
var n int


type Glimit struct {
	n int
	c chan struct{}
}


// initialization Glimit struct
func New(n int) *Glimit {
	return &Glimit{
		n: n,
		c: make(chan struct{}, n),
	}
}
// Run f in a new goroutine but with limit.
func (g *Glimit) Run(f func()) {
	g.c <- struct{}{}
	go func() {
		f()
		<-g.c
	}()
}

var wg sync.WaitGroup

//判断文件是否存在  存在返回 true 不存在返回false
func checkFileIsExist(filename string) bool {
	var exist = true
	if _, err := os.Stat(filename); os.IsNotExist(err) {
		exist = false
	}
	return exist
}

func read_txt(ip_info string) {
	file, err := os.Open(ip_info)
	if err != nil {
		fmt.Printf("系统无法找到指定的文件,请检查%v是否存在!\n", ip_info)
		log.Fatal(err)
	}
	defer file.Close()

	br := bufio.NewReader(file)
	for {
		a, _, c := br.ReadLine()
		if c == io.EOF {
			break
		}
		ip_list = append(ip_list, string(a))
	}

}

func main(){
	flag.StringVar(&ip_info, "t", "ip_info.txt", "ip地址数据文件")  //获取string类型参数
	flag.StringVar(&user, "u", "root", "用户名")  //获取string类型参数
	flag.StringVar(&passwd, "p", "", "密码")
	flag.StringVar(&port, "port", "22", "端口")
	flag.IntVar(&n, "n", 10, "Max exec number")

	flag.Parse()

	read_txt(ip_info)

	txt_ls := len(ip_list)
	fmt.Println(txt_ls)

	t := time.Now()

	number := txt_ls
	g := New(n)
	for i := 0; i < number; i++ {
		wg.Add(1)
		value :=i
		goFunc := func() {
			client, err := ssh.Dial("tcp", strings.Join([]string{ip_list[value], port}, ":"), &ssh.ClientConfig{
				User:            user,
				Auth:            []ssh.AuthMethod{ssh.Password(passwd)},
				HostKeyCallback: ssh.InsecureIgnoreHostKey(),
			})
			if err != nil {
				//log.Fatalf("SSH dial error: %s", err.Error())
				fmt.Printf("SSH dial error: %s\n", err.Error())
				//ch <- fmt.Sprintf("ip : %s error! SSH dial error: %s", ip, err.Error())
				wg.Done()
				return
			}

			// 建立新会话
			session, err := client.NewSession()
			defer session.Close()
			if err != nil {
				log.Fatalf("new session error: %s\n", err.Error())
			}

			result, err := session.Output("ls -a")
			if err != nil {
				fmt.Fprintf(os.Stdout, "Failed to run command, Err:%s\n", err.Error())
				//ch <- fmt.Sprintf("ip : %s error! Failed to run command, Err:%s", ip, err.Error())
				wg.Done()
				return
				//os.Exit(0)
			}
			fmt.Println(string(result))
			//time.Sleep(time.Second)
			wg.Done()
			return
		}
		g.Run(goFunc)
	}
	wg.Wait()

	elapsed := time.Since(t)
	fmt.Println("app elapsed:", elapsed)
}

/*
go run main.go  -u root -p 2021Zhong... -port 22 -n 20

*/
           

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