Support expressions for the irb command

Author: zeroSteiner

lib/msf/ui/console/command_dispatcher/core.rb

@@ -94,6 +94,10 @@ class Core
   @@go_pro_opts = Rex::Parser::Arguments.new(
     "-h" => [ false, "Help banner."                                   ])
 
+  @@irb_opts = Rex::Parser::Arguments.new(
+    "-h" => [ false, "Help banner."                                   ],
+    "-e" => [ true,  "Expression to evaluate."                        ])
+
   # The list of data store elements that cannot be set when in defanged
   # mode.
   DefangedProhibitedDataStoreElements = [ "MsfModulePaths" ]
@@ -759,8 +763,8 @@ def cmd_info_tabs(str, words)
   def cmd_irb_help
     print_line "Usage: irb"
     print_line
-    print_line "Drop into an interactive Ruby environment"
-    print_line
+    print_line "Execute commands in a Ruby environment"
+    print @@irb_opts.usage()
   end
 
   #
@@ -769,6 +773,26 @@ def cmd_irb_help
   def cmd_irb(*args)
     defanged?
 
+    expressions = []
+
+    # Parse the command options
+    @@irb_opts.parse(args) do |opt, idx, val|
+      case opt
+        when '-e'
+          expressions << val
+        when '-h'
+          cmd_irb_help
+          return false
+      end
+    end
+
+    if !expressions.empty?
+      expressions.each do |expression|
+        eval(expression, binding)
+      end
+      return
+    end
+
     print_status("Starting IRB shell...\n")
 
     begin