Rename sendSig to sendUsr1

This matches waitForUsr1 in daemonize()

main.go

@@ -184,7 +184,7 @@ func main() {
 
 	fmt.Println("Filesystem ready.")
 	// Send notification to our parent
-	sendSig()
+	sendUsr1()
 	// Jump into server loop
 	srv.Serve()
 }

sendusr1.go

@@ -8,33 +8,31 @@ import (
 	"syscall"
 )
 
-// cmdline looks like this: /bin/bash \0 /path/to/gocryptfs \0 --zerokey \0 ...
 const (
-	WRAPPER_PREFIX   = "/bin/bash\000"
 	WRAPPER_CONTAINS = "gocryptfs\000"
 )
 
-// Send USR1 to the "gocryptfs" wrapper shell script. This notifies it that the
+// Send USR1 to the parent process. This notifies it that the
 // mounting has completed sucessfully.
 //
 // Checks /proc/$PPID/cmdline to make sure we do not kill an unrelated process.
-func sendSig() {
+func sendUsr1() {
 	ppid := os.Getppid()
 	fn := fmt.Sprintf("/proc/%d/cmdline", ppid)
 	cmdline, err := ioutil.ReadFile(fn)
 	if err != nil {
-		fmt.Printf("sendSig: ReadFile: %v\n", err)
+		fmt.Printf("sendUsr1: ReadFile: %v\n", err)
 		return
 	}
-	if bytes.HasPrefix(cmdline, []byte(WRAPPER_PREFIX)) && bytes.Contains(cmdline, []byte(WRAPPER_CONTAINS)) {
+	if bytes.Contains(cmdline, []byte(WRAPPER_CONTAINS)) {
 		p, err := os.FindProcess(ppid)
 		if err != nil {
-			fmt.Printf("sendSig: FindProcess: %v\n", err)
+			fmt.Printf("sendUsr1: FindProcess: %v\n", err)
 			return
 		}
 		err = p.Signal(syscall.SIGUSR1)
 		if err != nil {
-			fmt.Printf("sendSig: Signal: %v\n", err)
+			fmt.Printf("sendUsr1: Signal: %v\n", err)
 		}
 	} else {
 		fmt.Printf("Not running under the gocryptfs wrapper - will not daemonize\n")