Module: Kramdown::ANSI::Pager

Defined in:
lib/kramdown/ansi/pager.rb

Class Method Summary collapse

Class Method Details

.pager(command: nil, lines: nil) {|IO| ... } ⇒ NilClass

If called without a block returns either the provided command for paging if the given number of lines are exceeding the available number of terminal lines or nil. If a block was provided it yields to an IO handle for the pager command in the latter case or STDOUT in the former.

Parameters:

  • command (String) (defaults to: nil) —

    the pager command (optional)

  • lines (Integer) (defaults to: nil) —

    the number of lines in the output (optional)

Yields:

  • (IO) —

    yields the output IO handle for further processing

Returns:

  • (NilClass) —

    returns nil if STDOUT is used or STDOUT is not a TTY.



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# File 'lib/kramdown/ansi/pager.rb', line 15

def pager(command: nil, lines: nil, &block)
  if block
    if my_pager = pager(command:, lines:)
      IO.popen(my_pager, 'w') do |output|
        output.sync = true
        yield output
        output.close
      end
    else
      yield STDOUT
    end
  else
    return unless STDOUT.tty?
    if lines
      if lines >= Tins::Terminal.lines
        pager(command:)
      end
    else
      command
    end
  end
end