Module: Terminal

Defined in:
lib/terminal.rb,
lib/terminal/ansi.rb,
lib/terminal/text.rb,
lib/terminal/input.rb,
lib/terminal/shell.rb,
lib/terminal/detect.rb,
lib/terminal/version.rb,
lib/terminal/input/key_event.rb,
lib/terminal/text/char_width.rb,
lib/terminal/ansi/named_colors.rb

Overview

Terminal access with support for ANSI control codes and BBCode-like embedded text attribute syntax (see Ansi.bbcode). It automagically detects whether your terminal supports ANSI features, like coloring (see Terminal.colors) or the CSIu protocol support (see Terminal.read_key_event, Terminal.on_key_event and Terminal.input_mode). It calculates the display width for Unicode chars (see Text.width) and help you to display text with word-wise line breaks (see Text.each_line).

Defined Under Namespace

Modules: Ansi, Text Classes: KeyEvent

Constant Summary collapse

VERSION =

The version number of the gem.

'0.16.0'

Class Attribute Summary collapse

Class Method Summary collapse

Class Attribute Details

.ansi? ⇒ Boolean (readonly)

Return true if the current terminal supports ANSI control codes. When the terminal does not support it, colors will return 2 (two) and all output methods (<<, print, puts) will not forward ANSI control codes to the terminal, read_key_event and on_key_event will not support extended key codes and/or mouse events.

Returns:

  • (Boolean) —

    whether ANSI control codes are supported



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# File 'lib/terminal.rb', line 27

def ansi? = @ansi

.application ⇒ Symbol? (readonly)

Terminal application identifier.

The detection supports a wide range of terminal emulators but may return nil if an unsupported terminal was found. These are the supported application IDs: :alacritty, :amiga, :code_edit, :dg_unix, :docker, :fluent, :hpterm, :hyper, :iterm, :macos, :mintty, :ms_terminal, :ncr260, :nsterm, :terminator, :terminology, :termite, :vt100, :warp, :wezterm, :wyse, :xnuppc

Returns:

  • (Symbol, nil) —

    the application identifier



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# File 'lib/terminal.rb', line 41

def application = (@application ||= Detect.application)

.colors ⇒ Integer (readonly)

Number of supported colors. The detection checks various conditions to find the correct value. The most common values are

  • 16_777_216 for 24-bit encoding (true_color? return true)
  • 256 for 8-Bit encoding
  • 52 for some Unix terminals with an extended color palette
  • 8 for 3-/4-bit encoding
  • 2 if ANSI is not supported in general (ansi? return false)

Returns:

  • (Integer) —

    number of supported colors



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# File 'lib/terminal.rb', line 55

def colors = (@colors ||= ansi? ? Detect.colors : 2)

.columns ⇒ Integer

Screen column count. See size for support and detection details.

Returns:

  • (Integer) —

    number of available columns



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# File 'lib/terminal.rb', line 62

def columns = size[1]

.input_mode ⇒ :csi_u, ... (readonly)

Supported input mode.

Returns:

  • (:csi_u) —

    when CSIu protocol supported

  • (:legacy) —

    for standard terminal

  • (:dumb) —

    for non-interactive input (pipes etc.)

  • (:error) —

    when input device is not avail (closed)



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# File 'lib/terminal/input.rb', line 20

def input_mode
  @input_mode ||= find_input_mode
end

.pos ⇒ [Integer, Integer]?

Current cursor position. This is only available when ANSI is supported (ansi? return true).

Returns:

  • ([Integer, Integer]) —

    cursor position as rows and columns

  • (nil) —

    for incompatible terminals



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# File 'lib/terminal.rb', line 75

def pos
  @con&.cursor
rescue IOError
  @con = nil
end

.rows ⇒ Integer

Screen row count. See size for support and detection details.

Returns:

  • (Integer) —

    number of available rows



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# File 'lib/terminal.rb', line 93

def rows = size[0]

.size ⇒ [Integer, Integer]

Screen size as a tuple of rows and columns.

If the terminal does not support the report of it's dimension or ANSI is not supported in general then environment variables COLUMNS and LINES will be used. If this failed [25, 80] will be returned as default.

Setting the terminal size is not widely supported.

Returns:

  • ([Integer, Integer]) —

    available screen size as rows and columns

See Also:



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# File 'lib/terminal.rb', line 114

def size
  @size ||= @inf&.winsize || _default_size
rescue IOError
  @inf = nil
  @size = _default_size
end

.true_color? ⇒ Boolean (readonly)

Returns whether true colors are supported.

Returns:

  • (Boolean) —

    whether true colors are supported

See Also:



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# File 'lib/terminal.rb', line 131

def true_color? = (colors == 16_777_216)

Class Method Details

.<<(object) ⇒ Terminal

Writes the given object to the terminal. Interprets embedded BBCode.

Parameters:

  • object (#to_s) —

    object to write

Returns:



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# File 'lib/terminal.rb', line 186

def <<(object)
  @out.write(Ansi.bbcode(object)) if @out && object != nil
  self
rescue IOError
  @out = nil
  self
end

.hide_alt_screen ⇒ Terminal

Hide the alternate screen. Will not send the control code if the alternate screen is not used.

When you called show_alt_screen n-times you need to call hide_alt_screen n-times to show the default screen again.

Returns:



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# File 'lib/terminal.rb', line 176

def hide_alt_screen
  raw_write(Ansi::SCREEN_ALTERNATE_OFF) if @as > 0 && (@as -= 1).zero?
  self
end

.hide_cursor ⇒ Terminal

Hide the cursor. Will not send the control code if the cursor is already hidden.

When you called hide_cursor n-times you need to call show_cursor n-times to show the cursor again.

Returns:



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# File 'lib/terminal.rb', line 140

def hide_cursor
  raw_write(Ansi::CURSOR_HIDE) if ansi? && (@cc += 1) == 1
  self
end

.on_key_event(mouse: false, mouse_move: false, focus: false) {|event| ... } ⇒ true, ...

Event loop for key and mouse events.

Parameters:

  • mouse (true, false) (defaults to: false) —

    whether mouse buttons should be reported

  • mouse_move (true, false) (defaults to: false) —

    whether mouse movement should be reported

  • focus (true, false) (defaults to: false) —

    whether focus/unfocus of terminal window should be reported

Yield Parameters:

Yield Returns:

  • (true, false) —

    whether the loop should be continued

Returns:

  • (true) —

    when the loop was started

  • (false) —

    when the current input device is not available

  • (nil) —

    when no block was given



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# File 'lib/terminal/input.rb', line 81

def on_key_event(mouse: false, mouse_move: false, focus: false, &block)
  return unless block
  case input_mode
  when :dumb
    on_bumb_key_event(&block)
    true
  when :csi_u, :legacy
    on_tty_key_event(mouse, mouse_move, focus, &block)
    true
  else
    false
  end
end

.print(*objects, bbcode: true) ⇒ nil

Writes the given objects to the terminal. Optionally interprets embedded BBCode.

Parameters:

  • objects (Array<#to_s>) —

    any number of objects to write

  • bbcode (true|false) (defaults to: true) —

    whether to interpret embedded BBCode

Returns:

  • (nil) 


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# File 'lib/terminal.rb', line 200

def print(*objects, bbcode: true)
  return unless @out
  return @out.print(*objects) unless bbcode
  objects.each { @out.write(Ansi.bbcode(_1)) }
  nil
rescue IOError
  @out = nil
end

.puts(*objects, bbcode: true) ⇒ nil

Writes the given objects to the terminal. Writes a newline after each object that does not already end with a newline sequence in it's String represenation. If called without any arguments, writes a newline only.

Optionally interprets embedded BBCode.

Parameters:

  • objects (Array<#to_s>) —

    any number of objects to write

  • bbcode (true|false) (defaults to: true) —

    whether to interpret embedded BBCode

Returns:

  • (nil) 


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# File 'lib/terminal.rb', line 218

def puts(*objects, bbcode: true)
  return unless @out
  return @out.puts if objects.empty?
  return @out.puts(objects) unless bbcode
  objects.flatten!
  objects.empty? ? @out.puts : @out.puts(objects.map! { Ansi.bbcode(_1) })
rescue IOError
  @out = nil
end

.read_key(mode: :named) ⇒ String, ...

Deprecated.

Use rather read_key_event for better input handling.

Read next keyboard input.

The input will be returned as named key codes like "Ctrl+c" by default. This can be changed by mode.

Parameters:

  • mode (:named, :raw, :both) (defaults to: :named) —

    modifies the result

Returns:

  • (String) —

    key code ("as is") in :raw mode

  • (String) —

    key name in :named mode

  • ([String, String]) —

    key code and key name in :both mode

  • (nil) —

    in error case



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# File 'lib/terminal/input.rb', line 36

def read_key(mode: :named)
  warn(
    'Terminal.read_key is deprecaded; use Terminal.read_key_event instead.',
    uplevel: 1
  )
  event = read_key_event or return
  return event.raw if mode == :raw
  key, name = event
  mode == :both ? [key, name] : name || key
end

.read_key_event ⇒ KeyEvent?

Read next KeyEvent from standard input.

Returns:

  • (KeyEvent) —

    next event

  • (nil) —

    in error case



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# File 'lib/terminal/input.rb', line 51

def read_key_event
  case input_mode
  when :dumb
    raw = read_dumb or return
    opts = @dumb_keys[raw.ord] if raw.size == 1
    KeyEvent.new(raw, *opts)
  when :csi_u, :legacy
    raw = read_tty or return
    KeyEvent[raw]
  end
end

.sh(*cmd, **options) ⇒ [Process::Status, output, error]? .sh(*cmd, **options) {|line, type| ... } ⇒ Process::Status?

Execute a command and report command output line by line or capture the output.

Examples:

Execute a command wih arguments

ret, out, = Terminal.sh('curl', '--version')
raise('command not found - curl') unless ret
puts out

Execute shell commands and print error

ret, _, err = Terminal.sh("mkdir '/test' && cd '/test'")
raise('unable to execute') unless ret
puts("error #{ret.exitstatus}: #{err.join}") unless ret.success?

Copy a file content to clipboard

command = ENV.fetch('CLIP_COPY', 'pbcopy')
File.open(__FILE__) do |file|
  ret, = Terminal.sh(*command, input: file)
  raise("command not found - #{command}") unless ret
end

Overloads:

  • .sh(*cmd, **options) ⇒ [Process::Status, output, error]?

    Returns:

    • ([Process::Status, output, error]) —

      the status of the process successfully executed, the captured output, the captured error output,

    • (nil) —

      when the command was not executable

  • .sh(*cmd, **options) {|line, type| ... } ⇒ Process::Status?

    Yield Parameters:

    • line (String) —

      next received line from the process

    • type (:output, :error) —

      whether the received line is standard output or error

    Returns:

    • (Process::Status) —

      the status of the process successfully executed

    • (nil) —

      when the command was not executable

Parameters:

  • cmd (Array<#to_s>) —

    command line or command with arguments

  • options (Hash) —

    options how to execute the new process; see Process.spawn for default execution options provided by Ruby

Options Hash (**options):

  • :env (Hash<String,String>) —

    key/value pairs added to the ENV of the process; with option :unsetenv_others set to true it replaces the ENV

  • :shell (true, false) —

    whether to create a seperate shell or not

  • :input (#readpartial, #to_io, Array, #each, #to_a, #to_s) —

    piped to the command as input



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# File 'lib/terminal.rb', line 278

def sh(*cmd, **options, &block)
  return Shell.exec(cmd, **options, &block) if block_given?
  out = []
  err = []
  [
    Shell.exec(cmd, **options) do |line, type|
      (type == :error ? err : out) << line
    end,
    out,
    err
  ]
end

.show_alt_screen ⇒ Terminal

Show the alternate screen. Will not send the control code if the alternate screen is already used.

When you called show_alt_screen n-times you need to call hide_alt_screen n-times to show the default screen again.

Returns:



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# File 'lib/terminal.rb', line 164

def show_alt_screen
  raw_write(Ansi::SCREEN_ALTERNATE) if ansi? && (@as += 1) == 1
  self
end

.show_cursor ⇒ Terminal

Show the cursor. Will not send the control code if the cursor is not hidden.

When you called hide_cursor n-times you need to call show_cursor n-times to show the cursor again.

Returns:



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# File 'lib/terminal.rb', line 152

def show_cursor
  raw_write(Ansi::CURSOR_SHOW) if @cc > 0 && (@cc -= 1).zero?
  self
end