libgocryptfs/daemonize.go
2016-11-01 19:04:49 +01:00

51 lines
1.2 KiB
Go

package main
import (
"fmt"
"os"
"os/exec"
"os/signal"
"syscall"
"github.com/rfjakob/gocryptfs/internal/tlog"
)
// The child sends us USR1 if the mount was successful
func exitOnUsr1() {
c := make(chan os.Signal, 1)
signal.Notify(c, syscall.SIGUSR1)
<-c
os.Exit(0)
}
// forkChild - execute ourselves once again, this time with the "-fg" flag, and
// wait for SIGUSR1 or child exit.
// This is a workaround for the missing true fork function in Go.
func forkChild() int {
go exitOnUsr1()
name := os.Args[0]
newArgs := []string{"-fg", fmt.Sprintf("-notifypid=%d", os.Getpid())}
newArgs = append(newArgs, os.Args[1:]...)
c := exec.Command(name, newArgs...)
c.Stdout = os.Stdout
c.Stderr = os.Stderr
c.Stdin = os.Stdin
err := c.Start()
if err != nil {
tlog.Fatal.Printf("forkChild: starting %s failed: %v\n", name, err)
return 1
}
err = c.Wait()
if err != nil {
if exiterr, ok := err.(*exec.ExitError); ok {
if waitstat, ok := exiterr.Sys().(syscall.WaitStatus); ok {
os.Exit(waitstat.ExitStatus())
}
}
tlog.Fatal.Printf("forkChild: wait returned an unknown error: %v\n", err)
return 1
}
// The child exited with 0 - let's do the same.
return 0
}