1. 字符处理

1) strings

1. 命令行参数

1.1 os.Args包

  1. func main() {
  2.     fmt.Println(os.Args)
  3.     for k,v :=range os.Args{
  4.         fmt.Println(k,v)
  5.     }
  6. }

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1.2 flag包

  1. func main() {
  2.     var host string
  3.     var port int
  4.     var help bool
  5.     // 第1个是传入值参数，第2个是命令参数，第3个是默认值，第4个是提示帮助信息
  6.     flag.IntVar(&port,"P",22,"ssh port")
  7.     flag.StringVar(&host,"h","127.0.0.1","ssh -h 127.0.0.1")
  8.     flag.BoolVar(&help,"-help",false,"help")
  10.     flag.Usage = func() {
  11.         fmt.Println("usage: flagargs [-h 127.0.0.1] [-P 22] [--help] [args01 args02]")
  12.         flag.PrintDefaults()
  13.     }
  14.     // 解析命令行参数
  15.     flag.Parse()
  16.     if help {
  17.         flag.Usage()
  18.     }else {
  19.         fmt.Println(host,port)
  20.         fmt.Println(flag.Args())
  21.     }
  22. }
  1. package main
  3. import (
  4.     "flag"
  5.     "fmt"
  6. )
  8. func main() {
  10.     // 第1个是命令参数，第2个是默认值，第3个是提示帮助信息
  11.     port:=flag.Int("P",22,"ssh port")
  12.     host:=flag.String("h","127.0.0.1","ssh -h 127.0.0.1")
  13.     help:=flag.Bool("-help",false,"help")
  15.     flag.Usage = func() {
  16.         fmt.Println("usage: flagargs [-h 127.0.0.1] [-P 22] [--help] [args01 args02]")
  17.         flag.PrintDefaults()
  18.     }
  19.     // 解析命令行参数
  20.     flag.Parse()
  21.     if *help {
  22.         flag.Usage()
  23.     }else {
  24.         fmt.Println(*host,*port)
  25.         fmt.Println(flag.Args())
  26.     }
  27. }

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2. time模块

  1. package main
  3. import (
  4.     "fmt"
  5.     "time"
  6. )
  8. func main() {
  9.     // 获取当前时间
  10.     now := time.Now()
  11.     fmt.Println(now)
  13.     fmt.Println(now.Format("2006/01/02 15:04:05"))
  14.     fmt.Println(now.Format("2006-01-02 15:04:05"))
  15.     fmt.Println(now.Format("2006/01/02"))
  16.     fmt.Println(now.Format("15:04:05"))
  18.     fmt.Println(now.Unix())
  19.     fmt.Println(now.UnixNano())
  21.     t, err := time.Parse("2006-01-02 15:04:05", "2020-02-02 14:22:22")
  22.     fmt.Println(t, err)
  24.     fmt.Println(time.Now())
  25.     time.Sleep(time.Second * 5)
  26.     fmt.Println(time.Now())
  27.     // 查看3小时后的时间
  28.     t = now.Add(time.Hour * 3)
  29.     fmt.Println(t)
  31.     // 时间转换
  32.     d, err := time.ParseDuration("3h2m4s")
  33.     fmt.Println(d, err)
  34.     fmt.Println(d.Hours(),"小时")
  35.     fmt.Println(d.Minutes(),"分钟")
  36.     fmt.Println(d.Seconds(),"秒")
  37. }

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3. md5值

  1. func main()  {
  2.     bytes:=md5.Sum([]byte("dadong"))
  3.     x:=fmt.Sprintf("%X",bytes)
  5.     fmt.Println(hex.EncodeToString(bytes[:]))
  6.     fmt.Println(x)
  8.     m:=md5.New()
  9.     m.Write([]byte("da"))
  10.     m.Write([]byte("dong"))
  11.     fmt.Printf("%x\n",m.Sum(nil))
  12. }

4. log

  1. func main()  {
  2.     log.SetPrefix("我的作用：给日志加前缀\t")
  3.     log.Println("我是println日志")
  4.     log.Fatal("我是fatal日志，打印完后退出状态为1")
  5. }

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5. 设置加密密码

  • 字符串转换为字节切片 []byte(string)
  • 字节切片转换字符串 string([]byte)
    1. func main()  {
    2.   const passwd = "E10ADC3949BA59ABBE56E057F20F883E"
    3.   fmt.Printf("请输入密码：")
    4.   bytes,_:=gopass.GetPasswd()
    5.   if fmt.Sprintf("%X",md5.Sum(bytes)) == passwd{
    6.       fmt.Println("密码输入正确")
    7.   }else {
    8.       fmt.Println("密码输入错误，程序退出")
    9.   }
    10. }