Re-write pattern_create layout and options

Updated pattern_create.rb to be more consistent other tools and modules in Metasploit.  Provided a usage example for undocumented custom set feature that allows removal of bad characters.

Usage: ./pattern_create.rb [options]
Example: ./pattern_create.rb -l 50 -s ABC,def,123
Ad1Ad2Ad3Ae1Ae2Ae3Af1Af2Af3Bd1Bd2Bd3Be1Be2Be3Bf1Bf

Specific options:
    -l, --length <length>            The length of the pattern
    -s, --sets <ABC,def,123>         Custom Pattern Sets
    -h, --help                       Show this message

tools/exploit/pattern_create.rb

@@ -2,7 +2,6 @@
 #
 # $Id$
 # $Revision$
-#
 
 msfbase = __FILE__
 while File.symlink?(msfbase)
@@ -11,18 +10,71 @@ end
 
 $:.unshift(File.expand_path(File.join(File.dirname(msfbase), '..', '..', 'lib')))
 require 'msfenv'
-
-$:.unshift(ENV['MSF_LOCAL_LIB']) if ENV['MSF_LOCAL_LIB']
-
+require 'msf/core'
+require 'msf/base'
 require 'rex'
+require 'optparse'
 
-if (!(length = ARGV.shift))
-  $stderr.puts("Usage: #{File.basename($0)} length [set a] [set b] [set c]\n")
-  exit
+module PatternCreate
+  class OptsConsole
+    def self.parse(args)
+      options = {}
+      parser = OptionParser.new do |opt|
+        opt.banner = "Usage: #{__FILE__} [options]\nExample: #{__FILE__} -l 50 -s ABC,def,123\nAd1Ad2Ad3Ae1Ae2Ae3Af1Af2Af3Bd1Bd2Bd3Be1Be2Be3Bf1Bf"
+        opt.separator ''
+        opt.separator 'Specific options:'
+        opt.on('-l', '--length <length>', Integer, "The length of the pattern") do |len| 
+          options[:length] = len
+         end
+
+        opt.on('-s', '--sets <ABC,def,123>', Array, "Custom Pattern Sets") do |sets| 
+         options[:sets] = sets
+        end
+
+        opt.on_tail('-h', '--help', 'Show this message') do
+          $stdout.puts opt
+          exit
+        end
+      end
+
+      parser.parse!(args)
+
+      if options.empty?
+        raise OptionParser::MissingArgument, 'No options set, try -h for usage'
+      end
+
+      options[:sets] = nil unless options[:sets]
+
+      options
+    end
+  end
+
+class Driver
+    def initialize
+      begin
+        @opts = OptsConsole.parse(ARGV)
+      rescue OptionParser::ParseError => e
+        $stderr.puts "[x] #{e.message}"
+        exit
+      end
+    end
+    
+    def run
+      pattern = Rex::Text.pattern_create(@opts[:length], @opts[:sets])
+      puts pattern
+    end
+
+  end
 end
 
-# If the user supplied custom sets, use those.  Otherwise, use the default
-# sets.
-sets = ARGV.length > 0 ? ARGV : Rex::Text::DefaultPatternSets
+if __FILE__ == $PROGRAM_NAME
+  driver = PatternCreate::Driver.new
+  begin
+    driver.run
+  rescue ::Exception => e
+    elog("#{e.class}: #{e.message}\n#{e.backtrace * "\n"}")
+    $stderr.puts "[x] #{e.class}: #{e.message}"
+    $stderr.puts "[*] If necessary, please refer to framework.log for more details."
+  end
+end
 
-puts Rex::Text.pattern_create(length.to_i, sets)