console.rb

# This implementation of io/console is a little hacky. It shells out to `stty`
# for most operations, which does not work on Windows, in secured environments,
# and so on. In addition, because on Java 6 we can't actually launch
# subprocesses with tty control, stty will not actually manipulate the
# controlling terminal.
#
# For platforms where shelling to stty does not work, most operations will
# just be pass-throughs. This allows them to function, but does not actually
# change any tty flags.
#
# Finally, since we're using stty to shell out, we can only manipulate stdin/
# stdout tty rather than manipulating whatever terminal is actually associated
# with the IO we're calling against. This will produce surprising results if
# anyone is actually using io/console against non-stdio ttys...but that case
# seems like it would be pretty rare.
#
# Note: we are incorporating this into 1.7.0 since RubyGems uses io/console
# when pushing gems, in order to mask the password entry. Worst case is that
# we don't actually disable echo and the password is shown...we will try to
# do a better version of this in 1.7.1.

# attempt to call stty; if failure, fall back on stubbed version

if RbConfig::CONFIG['host_os'].downcase =~ /darwin|openbsd|freebsd|netbsd|linux/
  require 'java'

  result = begin
    if RbConfig::CONFIG['host_os'].downcase =~ /darwin|openbsd|freebsd|netbsd/
      require File.join(File.dirname(__FILE__), 'bsd_console')

    elsif RbConfig::CONFIG['host_os'].downcase =~ /linux/
      require File.join(File.dirname(__FILE__), 'linux_console')

    else
      raise LoadError.new("no native io/console support")
    end

    class IO
      def ttymode
        termios = LibC::Termios.new
        if LibC.tcgetattr(self.fileno, termios) != 0
          raise SystemCallError.new("tcgetattr", FFI.errno)
        end

        if block_given?
          yield tmp = termios.dup
          if LibC.tcsetattr(self.fileno, LibC::TCSADRAIN, tmp) != 0
            raise SystemCallError.new("tcsetattr", FFI.errno)
          end
        end
        termios
      end

      def ttymode_yield(block, &setup)
        begin
          orig_termios = ttymode { |t| setup.call(t) }
          block.call(self)
        ensure
          if orig_termios && LibC.tcsetattr(self.fileno, LibC::TCSADRAIN, orig_termios) != 0
            raise SystemCallError.new("tcsetattr", FFI.errno)
          end
        end
      end

      TTY_RAW = Proc.new do |t|
        LibC.cfmakeraw(t)
        t[:c_lflag] &= ~(LibC::ECHOE|LibC::ECHOK)
      end

      def raw(*, &block)
        ttymode_yield(block, &TTY_RAW)
      end

      def raw!(*)
        ttymode(&TTY_RAW)
      end

      TTY_COOKED = Proc.new do |t|
        t[:c_iflag] |= (LibC::BRKINT|LibC::ISTRIP|LibC::ICRNL|LibC::IXON)
        t[:c_oflag] |= LibC::OPOST
        t[:c_lflag] |= (LibC::ECHO|LibC::ECHOE|LibC::ECHOK|LibC::ECHONL|LibC::ICANON|LibC::ISIG|LibC::IEXTEN)
      end

      def cooked(*, &block)
        ttymode_yield(block, &TTY_COOKED)
      end

      def cooked!(*)
        ttymode(&TTY_COOKED)
      end

      TTY_ECHO = LibC::ECHO | LibC::ECHOE | LibC::ECHOK | LibC::ECHONL
      def echo=(echo)
        ttymode do |t|
          if echo
            t[:c_lflag] |= TTY_ECHO
          else
            t[:c_lflag] &= ~TTY_ECHO
          end
        end
      end

      def echo?
        (ttymode[:c_lflag] & (LibC::ECHO | LibC::ECHONL)) != 0
      end

      def noecho(&block)
        ttymode_yield(block) { |t| t[:c_lflag] &= ~(TTY_ECHO) }
      end

      def getch(*)
        raw do
          getc
        end
      end

      def winsize
        ws = LibC::Winsize.new
        if LibC.ioctl(self.fileno, LibC::TIOCGWINSZ, :pointer, ws.pointer) != 0
          raise SystemCallError.new("ioctl(TIOCGWINSZ)", FFI.errno)
        end
        [ ws[:ws_row], ws[:ws_col] ]
      end

      def winsize=(size)
        ws = LibC::Winsize.new
        if LibC.ioctl(self.fileno, LibC::TIOCGWINSZ, :pointer, ws.pointer) != 0
          raise SystemCallError.new("ioctl(TIOCGWINSZ)", FFI.errno)
        end

        ws[:ws_row] = size[0]
        ws[:ws_col] = size[1]
        if LibC.ioctl(self.fileno, LibC::TIOCSWINSZ, :pointer, ws.pointer) != 0
          raise SystemCallError.new("ioctl(TIOCSWINSZ)", FFI.errno)
        end
      end

      def iflush
        raise SystemCallError.new("tcflush(TCIFLUSH)", FFI.errno) unless LibC.tcflush(self.fileno, LibC::TCIFLUSH) == 0
      end

      def oflush
        raise SystemCallError.new("tcflush(TCOFLUSH)", FFI.errno) unless LibC.tcflush(self.fileno, LibC::TCOFLUSH) == 0
      end

      def ioflush
        raise SystemCallError.new("tcflush(TCIOFLUSH)", FFI.errno) unless LibC.tcflush(self.fileno, LibC::TCIOFLUSH) == 0
      end

      # TODO: Windows version uses "conin$" and "conout$" instead of /dev/tty
      def self.console(sym = nil)
        raise TypeError, "expected Symbol, got #{sym.class}" unless sym.nil? || sym.kind_of?(Symbol)
        klass = self == IO ? File : self

        if defined?(@console) # using ivar instead of hidden const as in MRI
          con = @console
        end

        if !con.kind_of?(File) || !con.open? || !con.readable? # MRI checks IO internals here
          remove_instance_variable :@console if defined?(@console)
          con = nil
        end

        if sym
          if sym == :close
            if con
              con.close
              remove_instance_variable :@console if defined?(@console)
              con = nil
            end
            return nil
          end
        end

        if con.nil?
          con = File.open('/dev/tty', 'r+')
          @console = con
        end

        return con
      end
    end
    true
  rescue Exception => ex
    warn "failed to load native console support: #{ex}" if $VERBOSE
    begin
      `stty 2> /dev/null`
      $?.exitstatus != 0
    rescue Exception
      nil
    end
  end
elsif RbConfig::CONFIG['host_os'] !~ /(mswin)|(win32)|(ming)/
  result = begin
    old_stderr = $stderr.dup
    $stderr.reopen('/dev/null')
    `stty -a`
    $?.exitstatus != 0
  rescue Exception
    nil
  ensure
    $stderr.reopen(old_stderr)
  end
end

if !result || RbConfig::CONFIG['host_os'] =~ /(mswin)|(win32)|(ming)/
  warn "io/console not supported; tty will not be manipulated" if $VERBOSE

  # Windows version is always stubbed for now
  class IO
    def raw(*)
      yield self
    end

    def raw!(*)
    end

    def cooked(*)
      yield self
    end

    def cooked!(*)
    end

    def getch(*)
      getc
    end

    def echo=(echo)
    end

    def echo?
      true
    end

    def noecho
      yield self
    end

    def winsize
      [25, 80]
    end

    def winsize=(size)
    end

    def iflush
    end

    def oflush
    end

    def ioflush
    end
  end
elsif !IO.method_defined?:ttymode
  warn "io/console on JRuby shells out to stty for most operations"

  # Non-Windows assumes stty command is available
  class IO
    if RbConfig::CONFIG['host_os'].downcase =~ /linux/ && File.exists?("/proc/#{Process.pid}/fd")
      def stty(*args)
        `stty #{args.join(' ')} < /proc/#{Process.pid}/fd/#{fileno}`
      end
    else
      def stty(*args)
        `stty #{args.join(' ')}`
      end
    end

    def raw(*)
      saved = stty('-g')
      stty('raw')
      yield self
    ensure
      stty(saved)
    end

    def raw!(*)
      stty('raw')
    end

    def cooked(*)
      saved = stty('-g')
      stty('-raw')
      yield self
    ensure
      stty(saved)
    end

    def cooked!(*)
      stty('-raw')
    end

    def getch(*)
      getc
    end

    def echo=(echo)
      stty(echo ? 'echo' : '-echo')
    end

    def echo?
      (stty('-a') =~ / -echo /) ? false : true
    end

    def noecho
      saved = stty('-g')
      stty('-echo')
      yield self
    ensure
      stty(saved)
    end

    # Not all systems return same format of stty -a output
    IEEE_STD_1003_2 = '(?<rows>\d+) rows; (?<columns>\d+) columns'
    UBUNTU = 'rows (?<rows>\d+); columns (?<columns>\d+)'

    def winsize
      match = stty('-a').match(/#{IEEE_STD_1003_2}|#{UBUNTU}/)
      [match[:rows].to_i, match[:columns].to_i]
    end

    def winsize=(size)
      stty("rows #{size[0]} cols #{size[1]}")
    end

    def iflush
    end

    def oflush
    end

    def ioflush
    end
  end
end