Go语言daemon启动本身.实现

package main

import (

    "fmt"

    "log"

    "net/http"

    "os"

    "os/signal"

    "syscall"

)

func main() {

    File, err := os.Create("log")

    if err != nil {

        fmt.Println("创建日志文件错误", err)

        return

    }

    log.SetOutput(File)

    ce("pid")

}

func ce(pid string) {

    File, err := os.OpenFile(pid, os.O_RDWR|os.O_CREATE, 0644)

    if err != nil {

        log.Println(err)

        return

    }

    info, _ := File.Stat()

    if info.Size() != 0 {

        log.Println("pid file is exist")

        return

    }

    if os.Getppid() != 1 {

        args := append([]string{os.Args[0]}, os.Args[1:]...)

        os.StartProcess(os.Args[0], args, &os.ProcAttr{Files: []*os.File{os.Stdin, os.Stdout, os.Stderr}})

        return

    }

    File.WriteString(fmt.Sprint(os.Getpid()))

    c := make(chan os.Signal, 1)

    signal.Notify(c, os.Interrupt, syscall.SIGUSR2)

    go HttpServer()

    for {

        s := <-c

        switch s {

        case syscall.SIGUSR2:

            fmt.Println("自定义型号.")

        case os.Interrupt:

            fmt.Println("安全退出")

            Exit(File)

        }

    }

}

func HttpServer() {

    http.HandleFunc("/", route)

    http.ListenAndServe(":1789", nil)

}

func route(w http.ResponseWriter, r *http.Request) {

    log.Println(r.URL.Path)

    fmt.Fprint(w, "Hello World\n")

}

func Exit(F *os.File) {

    F.Close()

    os.Remove(F.Name())

    fmt.Println("bye")

}