4 files changed, 19 insertions, 5 deletions
diff --git a/lib/irb/context.rb b/lib/irb/context.rb
index e6c993d423..b74cae1223 100644
--- a/lib/irb/context.rb
+++ b/lib/irb/context.rb
@@ -115,6 +115,10 @@ module IRB
         end
         @io = StdioInputMethod.new unless @io
 
+      when '-'
+        @io = FileInputMethod.new($stdin)
+        @irb_name = '-'
+        @irb_path = '-'
       when String
         @io = FileInputMethod.new(input_method)
         @irb_name = File.basename(input_method)
diff --git a/lib/irb/init.rb b/lib/irb/init.rb
index d2baee2017..d9c4353f39 100644
--- a/lib/irb/init.rb
+++ b/lib/irb/init.rb
@@ -289,6 +289,10 @@ module IRB # :nodoc:
         @CONF[:PROMPT_MODE] = prompt_mode
       when "--noprompt"
         @CONF[:PROMPT_MODE] = :NULL
+      when "--script"
+        noscript = false
+      when "--noscript"
+        noscript = true
       when "--inf-ruby-mode"
         @CONF[:PROMPT_MODE] = :INF_RUBY
       when "--sample-book-mode", "--simple-prompt"
@@ -309,16 +313,20 @@ module IRB # :nodoc:
         IRB.print_usage
         exit 0
       when "--"
-        if opt = argv.shift
+        if !noscript && (opt = argv.shift)
           @CONF[:SCRIPT] = opt
           $0 = opt
         end
         break
-      when /^-/
+      when /^-./
         fail UnrecognizedSwitch, opt
       else
-        @CONF[:SCRIPT] = opt
-        $0 = opt
+        if noscript
+          argv.unshift(opt)
+        else
+          @CONF[:SCRIPT] = opt
+          $0 = opt
+        end
         break
       end
     end
diff --git a/lib/irb/input-method.rb b/lib/irb/input-method.rb
index b77fd3207d..eec2daa549 100644
--- a/lib/irb/input-method.rb
+++ b/lib/irb/input-method.rb
@@ -137,7 +137,7 @@ module IRB
     # Creates a new input method object
     def initialize(file)
       super
-      @io = IRB::MagicFile.open(file)
+      @io = file.is_a?(IO) ? file : IRB::MagicFile.open(file)
       @external_encoding = @io.external_encoding
     end
     # The file name of this input method, usually given during initialization.
diff --git a/lib/irb/lc/help-message b/lib/irb/lc/help-message
index 3405fa775f..5b23f4c41e 100644
--- a/lib/irb/lc/help-message
+++ b/lib/irb/lc/help-message
@@ -38,6 +38,8 @@ Usage:  irb.rb [options] [programfile] [arguments]
   --sample-book-mode, --simple-prompt
                     Set prompt mode to 'simple'.
   --noprompt        Don't output prompt.
+  --script          Script mode (default, treat first argument as script)
+  --noscript        No script mode (leave arguments in argv)
   --single-irb      Share self with sub-irb.
   --tracer          Show stack trace for each command.
   --back-trace-limit n[=16]