add base files

lib/common/utils.go

@@ -0,0 +1,14 @@
+package common
+
+import (
+  "os"
+)
+
+// check if a file is there and writeable
+func FileExists(fname string) (exists bool) {
+  _, err := os.Stat(fname)
+  if err == nil {
+    exists = true
+  }
+  return
+}