diff --git a/aos/linux_code/logging/log_displayer.cc b/aos/linux_code/logging/log_displayer.cc
index 805267c..8141cd4 100644
--- a/aos/linux_code/logging/log_displayer.cc
+++ b/aos/linux_code/logging/log_displayer.cc
@@ -38,7 +38,7 @@
     "LEVEL must be DEBUG, INFO, WARNING, ERROR, or FATAL.\n"
     "  It defaults to INFO.\n"
     "\n"
-    "TODO(brians) implement the commented out ones and changing FILE\n";
+    "TODO(brians) implement the commented out ones.\n";
 
 void PrintHelpAndExit() {
   fprintf(stderr, "Usage: %s %s", program_invocation_name, kArgsHelp);
@@ -135,8 +135,10 @@
     }
   }
 
-  fprintf(stderr, "displaying down to level %s from file '%s'\n",
-          ::aos::logging::log_str(filter_level), filename);
+  if (optind < argc) {
+    // We got a filename.
+    filename = argv[optind++];
+  }
   if (optind < argc) {
     fprintf(stderr, "non-option ARGV-elements: ");
     while (optind < argc) {
@@ -144,7 +146,11 @@
     }
   }
 
+  fprintf(stderr, "displaying down to level %s from file '%s'\n",
+      ::aos::logging::log_str(filter_level), filename);
+
   int fd = open(filename, O_RDONLY);
+
   if (fd == -1) {
     PLOG(FATAL, "couldn't open file '%s' for reading", filename);
   }