Add support for staging and purging

cmds/updatemgr/confirm.go

@@ -0,0 +1,20 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strings"
+)
+
+func confirm(msg string) bool {
+	fmt.Printf("%s: [y|n] ", msg)
+
+	scanner := bufio.NewScanner(os.Stdin)
+	ok := scanner.Scan()
+	if ok && strings.TrimSpace(scanner.Text()) == "y" {
+		return true
+	}
+
+	return false
+}