systemd.go

package systemd

import (
        "os"
        "strconv"
        "syscall"
)

const (
        listenFdsStart = 3
)

func ListenFds() []*os.File {
        pid, err := strconv.Atoi(os.Getenv("LISTEN_PID"))
        if err != nil || pid != os.Getpid() {
                return nil
        }
        nfds, err := strconv.Atoi(os.Getenv("LISTEN_FDS"))
        if err != nil || nfds == 0 {
                return nil
        }
        files := []*os.File(nil)
        for fd := listenFdsStart; fd < listenFdsStart+nfds; fd++ {
                syscall.CloseOnExec(fd)
                files = append(files, os.NewFile(uintptr(fd), ""))
        }
        return files
}

Good point. I just did a direct translation of sd_listen_fds long ago. I'll update this.