class Reline::ANSI - reline: Ruby Standard Library Documentation

# class Reline::ANSI

### Constants

ANSI_CURSOR_KEY_BINDINGS
CAPNAME_KEY_BINDINGS
END_BRACKETED_PASTE
START_BRACKETED_PASTE

### Attributes

input[W]
output[W]

### Public Class Methods

new() click to toggle source

    # File reline/io/ansi.rb, line 34
    def initialize
      @input = STDIN
      @output = STDOUT
      @buf = []
      @output_buffer = nil
      @old_winch_handler = nil
    end

### Public Instance Methods

both_tty?() click to toggle source

    # File reline/io/ansi.rb, line 232
    def both_tty?
      @input.tty? && @output.tty?
    end

buffered_output() { || ... } click to toggle source

    # File reline/io/ansi.rb, line 244
    def buffered_output
      @output_buffer = +''
      yield
      @output.write(@output_buffer)
    ensure
      @output_buffer = nil
    end

clear_screen() click to toggle source

    # File reline/io/ansi.rb, line 292
    def clear_screen
      write "\e[2J"
      write "\e[1;1H"
    end

cursor_pos() click to toggle source

    # File reline/io/ansi.rb, line 227
    def cursor_pos
      col, row = cursor_pos_internal(timeout: 0.5) if both_tty?
      Reline::CursorPos.new(col || 0, row || 0)
    end

deprep(otio) click to toggle source

    # File reline/io/ansi.rb, line 319
    def deprep(otio)
      # Disable bracketed paste
      write "\e[?2004l" if Reline.core.config.enable_bracketed_paste && both_tty?
      Signal.trap('WINCH', @old_winch_handler) if @old_winch_handler
      Signal.trap('CONT', @old_cont_handler) if @old_cont_handler
    end

empty_buffer?() click to toggle source

    # File reline/io/ansi.rb, line 167
    def empty_buffer?
      unless @buf.empty?
        return false
      end
      !@input.wait_readable(0)
    end

encoding() click to toggle source

    # File reline/io/ansi.rb, line 42
    def encoding
      @input.external_encoding || Encoding.default_external
    rescue IOError
      # STDIN.external_encoding raises IOError in Ruby <= 3.0 when STDIN is closed
      Encoding.default_external
    end

erase_after_cursor() click to toggle source

    # File reline/io/ansi.rb, line 280
    def erase_after_cursor
      write "\e[K"
    end

get_screen_size() click to toggle source

    # File reline/io/ansi.rb, line 189
    def get_screen_size
      s = @input.winsize
      return s if s[0] > 0 && s[1] > 0
      s = [ENV["LINES"].to_i, ENV["COLUMNS"].to_i]
      return s if s[0] > 0 && s[1] > 0
      [24, 80]
    rescue Errno::ENOTTY, Errno::ENODEV
      [24, 80]
    end

getc(timeout_second) click to toggle source

if the usage expects to wait indefinitely, use Float::INFINITY for timeout_second

    # File reline/io/ansi.rb, line 159
    def getc(timeout_second)
      inner_getc(timeout_second)
    end

hide_cursor() click to toggle source

    # File reline/io/ansi.rb, line 272
    def hide_cursor
      write "\e[?25l"
    end

in_pasting?() click to toggle source

    # File reline/io/ansi.rb, line 163
    def in_pasting?
      not empty_buffer?
    end

inner_getc(timeout_second) click to toggle source

    # File reline/io/ansi.rb, line 128
    def inner_getc(timeout_second)
      unless @buf.empty?
        return @buf.shift
      end
      until @input.wait_readable(0.01)
        timeout_second -= 0.01
        return nil if timeout_second <= 0

        Reline.core.line_editor.handle_signal
      end
      c = @input.getbyte
      (c == 0x16 && @input.tty? && @input.raw(min: 0, time: 0, &:getbyte)) || c
    rescue Errno::EIO
      # Maybe the I/O has been closed.
      nil
    end

move_cursor_column(x) click to toggle source

    # File reline/io/ansi.rb, line 252
    def move_cursor_column(x)
      write "\e[#{x + 1}G"
    end

move_cursor_down(x) click to toggle source

    # File reline/io/ansi.rb, line 264
    def move_cursor_down(x)
      if x > 0
        write "\e[#{x}B"
      elsif x < 0
        move_cursor_up(-x)
      end
    end

move_cursor_up(x) click to toggle source

    # File reline/io/ansi.rb, line 256
    def move_cursor_up(x)
      if x > 0
        write "\e[#{x}A"
      elsif x < 0
        move_cursor_down(-x)
      end
    end

prep() click to toggle source

    # File reline/io/ansi.rb, line 312
    def prep
      # Enable bracketed paste
      write "\e[?2004h" if Reline.core.config.enable_bracketed_paste && both_tty?
      retrieve_keybuffer
      nil
    end

read_bracketed_paste() click to toggle source

    # File reline/io/ansi.rb, line 147
    def read_bracketed_paste
      buffer = String.new(encoding: Encoding::ASCII_8BIT)
      until buffer.end_with?(END_BRACKETED_PASTE)
        c = inner_getc(Float::INFINITY)
        break unless c
        buffer << c
      end
      string = buffer.delete_suffix(END_BRACKETED_PASTE).force_encoding(encoding)
      string.valid_encoding? ? string : ''
    end

retrieve_keybuffer() click to toggle source

    # File reline/io/ansi.rb, line 178
    def retrieve_keybuffer
      begin
        return unless @input.wait_readable(0.001)
        str = @input.read_nonblock(1024)
        str.bytes.each do |c|
          @buf.push(c)
        end
      rescue EOFError
      end
    end

scroll_down(x) click to toggle source

This only works when the cursor is at the bottom of the scroll range For more details, see github.com/ruby/reline/pull/577#issuecomment-1646679623

    # File reline/io/ansi.rb, line 286
    def scroll_down(x)
      return if x.zero?
      # We use `\n` instead of CSI + S because CSI + S would cause https://github.com/ruby/reline/issues/576
      write "\n" * x
    end

set_bracketed_paste_key_bindings(config) click to toggle source

    # File reline/io/ansi.rb, line 68
    def set_bracketed_paste_key_bindings(config)
      [:emacs, :vi_insert, :vi_command].each do |keymap|
        config.add_default_key_binding_by_keymap(keymap, START_BRACKETED_PASTE.bytes, :bracketed_paste_start)
      end
    end

set_default_key_bindings(config) click to toggle source

    # File reline/io/ansi.rb, line 49
    def set_default_key_bindings(config)
      set_bracketed_paste_key_bindings(config)
      set_default_key_bindings_ansi_cursor(config)
      set_default_key_bindings_comprehensive_list(config)
      {
        [27, 91, 90] => :completion_journey_up, # S-Tab
      }.each_pair do |key, func|
        config.add_default_key_binding_by_keymap(:emacs, key, func)
        config.add_default_key_binding_by_keymap(:vi_insert, key, func)
      end
      {
        # default bindings
        [27, 32] => :em_set_mark,             # M-<space>
        [24, 24] => :em_exchange_mark,        # C-x C-x
      }.each_pair do |key, func|
        config.add_default_key_binding_by_keymap(:emacs, key, func)
      end
    end

set_default_key_bindings_ansi_cursor(config) click to toggle source

    # File reline/io/ansi.rb, line 74
    def set_default_key_bindings_ansi_cursor(config)
      ANSI_CURSOR_KEY_BINDINGS.each do |char, (default_func, modifiers)|
        bindings = [
          ["\e[#{char}", default_func], # CSI + char
          ["\eO#{char}", default_func] # SS3 + char, application cursor key mode
        ]
        if modifiers[:ctrl]
          # CSI + ctrl_key_modifier + char
          bindings << ["\e[1;5#{char}", modifiers[:ctrl]]
        end
        if modifiers[:meta]
          # CSI + meta_key_modifier + char
          bindings << ["\e[1;3#{char}", modifiers[:meta]]
          # Meta(ESC) + CSI + char
          bindings << ["\e\e[#{char}", modifiers[:meta]]
        end
        bindings.each do |sequence, func|
          key = sequence.bytes
          config.add_default_key_binding_by_keymap(:emacs, key, func)
          config.add_default_key_binding_by_keymap(:vi_insert, key, func)
          config.add_default_key_binding_by_keymap(:vi_command, key, func)
        end
      end
    end

set_default_key_bindings_comprehensive_list(config) click to toggle source

    # File reline/io/ansi.rb, line 99
    def set_default_key_bindings_comprehensive_list(config)
      {
        # xterm
        [27, 91, 51, 126] => :key_delete, # kdch1
        [27, 91, 53, 126] => :ed_search_prev_history, # kpp
        [27, 91, 54, 126] => :ed_search_next_history, # knp

        # Console (80x25)
        [27, 91, 49, 126] => :ed_move_to_beg, # Home
        [27, 91, 52, 126] => :ed_move_to_end, # End

        # urxvt / exoterm
        [27, 91, 55, 126] => :ed_move_to_beg, # Home
        [27, 91, 56, 126] => :ed_move_to_end, # End
      }.each_pair do |key, func|
        config.add_default_key_binding_by_keymap(:emacs, key, func)
        config.add_default_key_binding_by_keymap(:vi_insert, key, func)
        config.add_default_key_binding_by_keymap(:vi_command, key, func)
      end
    end

set_screen_size(rows, columns) click to toggle source

    # File reline/io/ansi.rb, line 199
    def set_screen_size(rows, columns)
      @input.winsize = [rows, columns]
      self
    rescue Errno::ENOTTY, Errno::ENODEV
      self
    end

set_winch_handler(&handler) click to toggle source

    # File reline/io/ansi.rb, line 297
    def set_winch_handler(&handler)
      @old_winch_handler = Signal.trap('WINCH') do |arg|
        handler.call
        @old_winch_handler.call(arg) if @old_winch_handler.respond_to?(:call)
      end
      @old_cont_handler = Signal.trap('CONT') do |arg|
        @input.raw!(intr: true) if @input.tty?
        # Rerender the screen. Note that screen size might be changed while suspended.
        handler.call
        @old_cont_handler.call(arg) if @old_cont_handler.respond_to?(:call)
      end
    rescue ArgumentError
      # Signal.trap may raise an ArgumentError if the platform doesn't support the signal.
    end

show_cursor() click to toggle source

    # File reline/io/ansi.rb, line 276
    def show_cursor
      write "\e[?25h"
    end

ungetc(c) click to toggle source

    # File reline/io/ansi.rb, line 174
    def ungetc(c)
      @buf.unshift(c)
    end

with_raw_input() { || ... } click to toggle source

    # File reline/io/ansi.rb, line 120
    def with_raw_input
      if @input.tty?
        @input.raw(intr: true) { yield }
      else
        yield
      end
    end

write(string) click to toggle source

    # File reline/io/ansi.rb, line 236
    def write(string)
      if @output_buffer
        @output_buffer << string
      else
        @output.write(string)
      end
    end

### Private Instance Methods

cursor_pos_internal(timeout:) click to toggle source

    # File reline/io/ansi.rb, line 206
            def cursor_pos_internal(timeout:)
      match = nil
      @input.raw do |stdin|
        @output << "\e[6n"
        @output.flush
        timeout_at = Time.now + timeout
        buf = +''
        while (wait = timeout_at - Time.now) > 0 && stdin.wait_readable(wait)
          buf << stdin.readpartial(1024)
          if (match = buf.match(/\e\[(?<row>\d+);(?<column>\d+)R/))
            buf = match.pre_match + match.post_match
            break
          end
        end
        buf.chars.reverse_each do |ch|
          stdin.ungetc ch
        end
      end
      [match[:column].to_i - 1, match[:row].to_i - 1] if match
    end