metasploit-framework/lib/rex/ui/text/input/readline.rb

require 'rex/ui'

module Rex
module Ui
module Text

begin 

	###
	#
	# This class implements standard input using readline against
	# standard input.  It supports tab completion.
	#
	###
	class Input::Readline < Rex::Ui::Text::Input
		
		#
		# Initializes the readline-aware Input instance for text.
		#
		def initialize(tab_complete_proc = nil)
			if(not Object.const_defined?('Readline'))
				begin 
					require 'readline'
				rescue ::LoadError
					require 'readline_compatible'
				end
			end
			
			self.extend(::Readline)
			
			if (tab_complete_proc)
				::Readline.basic_word_break_characters = "\x00"
				::Readline.completion_proc = tab_complete_proc
				@rl_saved_proc = tab_complete_proc
			end
		end

		#
		# Reattach the original completion proc
		#
		def reset_tab_completion(tab_complete_proc = nil)
			::Readline.basic_word_break_characters = "\x00"
			::Readline.completion_proc = tab_complete_proc || @rl_saved_proc
		end
		
		#
		# Whether or not the input medium supports readline.
		#
		def supports_readline
			true
		end
		
		#
		# Calls sysread on the standard input handle.
		#
		def sysread(len = 1)
			begin
				self.fd.sysread(len)
			rescue ::Errno::EINTR
				retry
			end
		end
		
		#
		# Read a line from stdin
		#
		def gets()
			begin
				self.fd.gets()
			rescue ::Errno::EINTR
				retry
			end
		end

		#
		# Stick readline into a low-priority thread so that the scheduler doesn't slow
		# down other background threads. This is important when there are many active
		# background jobs, such as when the user is running Karmetasploit
		#
		def pgets()
		
			line = nil
			orig = Thread.current.priority
			
			begin
				Thread.current.priority = -20

				output.prompting
				line = ::Readline.readline(prompt, true)
				::Readline::HISTORY.pop if (line and line.empty?)
			ensure
				Thread.current.priority = orig || 0
			end
			
			line
		end

		#
		# Returns the output pipe handle
		#
		def fd
			$stdin
		end
		
		#
		# Indicates that this input medium as a shell builtin, no need 
		# to extend.
		#
		def intrinsic_shell?
			true
		end

		#
		# The prompt that is to be displayed.
		#
		attr_accessor :prompt
		#
		# The output handle to use when displaying the prompt.
		#
		attr_accessor :output

	end
rescue LoadError
end

end
end
end