enable frozen_string_literal for Ruby 2.3+

No changes for older Rubies, but this reduces garbage under 2.3

1 files changed, 2 insertions, 1 deletions

diff --git a/bin/posix-mq-rb b/bin/posix-mq-rb
index 8c77aea..45efb7b 100755
--- a/bin/posix-mq-rb
+++ b/bin/posix-mq-rb
@@ -1,5 +1,6 @@
 #!/usr/bin/env ruby
 # -*- encoding: binary -*-
+# -*- frozen_string_literal: true -*-
 $stderr.sync = $stdout.sync = true
 $stdout.binmode
 $stderr.binmode
@@ -100,7 +101,7 @@ begin
   when :create
     exit
   when :receive
-    buf, prio = mq.receive("", timeout)
+    buf, prio = mq.receive(nil, timeout)
     $stderr.write("priority=#{prio}\n") if priority
     $stdout.write(buf)
   when :send