daemon function for Go language

package mainimport (
“syscall”
“os”
“log”
)

func daemon (nochdir, noclose int) int {
var ret uintptr
var err uintptr

// already a daemon
if syscall.Getppid() == 1 { return 0 }

// fork off the parent process
ret, _, err = syscall.RawSyscall(syscall.SYS_FORK, 0, 0, 0)
if err != 0 { return -1 }

// failure
if ret < 0 { os.Exit(-1) }

// 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 != 0 {
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(fd, os.Stdin.Fd())
syscall.Dup2(fd, os.Stdout.Fd())
syscall.Dup2(fd, os.Stderr.Fd())
}
}

return 0
}
// usage example: daemon(0, 0)