Move in code from netconf and docker-from-scratch

dfs/one.go

@@ -0,0 +1,24 @@
+// +build linux
+
+package dfs
+
+import (
+	"os"
+	"os/signal"
+	"syscall"
+)
+
+func PidOne() error {
+	c := make(chan os.Signal, 2048)
+	signal.Notify(c, syscall.SIGCHLD)
+
+	for range c {
+		for {
+			if pid, err := syscall.Wait4(-1, nil, syscall.WNOHANG, nil); err != nil || pid <= 0 {
+				break
+			}
+		}
+	}
+
+	return nil
+}