Go语言daemon启动的解决方法.linux平台

1、使用nohup ./commond & 这种方法最简单.

2、这种方法可以使用信号.

<pre name="code" class="html">package main

import (
"fmt"
"os"
"os/signal"
"syscall"
"time"
)

func main() {
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
}
go func() {
var c chan os.Signal = make(chan os.Signal, 1)
go signal.Notify(c, os.Kill, os.Interrupt, syscall.SIGHUP, syscall.SIGUSR2)
File, err := os.Create("/tmp/收到的信号.")
defer File.Close()
for {
s := <-c
File.WriteString(s.String())
}
}()
F, err := os.Create("/tmp/log")
if err != nil {
fmt.Println(err)
return
}
defer F.Close()
for {
fmt.Fprintln(F, "Hello World")
time.Sleep(3e9)
}
}

3、这种方法比较底层,但是不能使用信号.

package main

import (
"fmt"
"log"
"os"
"os/signal"
"runtime"
"syscall"
"time"
)

func daemon(nochdir, noclose int) int {
var ret, ret2 uintptr
var err syscall.Errno
darwin := runtime.GOOS == "darwin"
// already a daemon
if syscall.Getppid() == 1 {
return 0
}
// fork off the parent process
ret, ret2, err = syscall.RawSyscall(syscall.SYS_FORK, 0, 0, 0)
if err != 0 {
return -1
}
// failure
if ret2 < 0 {
os.Exit(-1)
}
// handle exception for darwin
if darwin && ret2 == 1 {
ret = 0
}
// if we got a good PID, then we call exit the parent process.
if ret > 0 {
os.Exit(0)
}
/* Change the file mode mask */
_ = syscall.Umask(0)

// create a new SID for the child process
s_ret, s_errno := syscall.Setsid()
if s_errno != nil {
log.Printf("Error: syscall.Setsid errno: %d", s_errno)
}
if s_ret < 0 {
return -1
}
if nochdir == 0 {
os.Chdir("/")
}
if noclose == 0 {
f, e := os.OpenFile("/dev/null", os.O_RDWR, 0)
if e == nil {
fd := f.Fd()
syscall.Dup2(int(fd), int(os.Stdin.Fd()))
syscall.Dup2(int(fd), int(os.Stdout.Fd()))
syscall.Dup2(int(fd), int(os.Stderr.Fd()))
}
}
return 0
}

func main() {
daemon(0, 1)
for {
fmt.Println("hello")
time.Sleep(1 * time.Second)
}
}