Translate a string to "sendkey" commands for QEMU.

sendkeys

#!/usr/bin/env ruby
# Translate a string to "sendkey" commands for QEMU.
# Martin Vidner, MIT License

# https://en.wikibooks.org/wiki/QEMU/Monitor#sendkey_keys
# sendkey keys
#
# You can emulate keyboard events through sendkey command. The syntax is: sendkey keys. To get a list of keys, type sendkey [tab]. Examples:
#
#     sendkey a
#     sendkey shift-a
#     sendkey ctrl-u
#     sendkey ctrl-alt-f1
#
# As of QEMU 0.12.5 there are:
# shift 	shift_r 	alt 	alt_r 	altgr 	altgr_r
# ctrl 	ctrl_r 	menu 	esc 	1 	2
# 3 	4 	5 	6 	7 	8
# 9 	0 	minus 	equal 	backspace 	tab
# q 	w 	e 	r 	t 	y
# u 	i 	o 	p 	ret 	a
# s 	d 	f 	g 	h 	j
# k 	l 	z 	x 	c 	v
# b 	n 	m 	comma 	dot 	slash
# asterisk 	spc 	caps_lock 	f1 	f2 	f3
# f4 	f5 	f6 	f7 	f8 	f9
# f10 	num_lock 	scroll_lock 	kp_divide 	kp_multiply 	kp_subtract
# kp_add 	kp_enter 	kp_decimal 	sysrq 	kp_0 	kp_1
# kp_2 	kp_3 	kp_4 	kp_5 	kp_6 	kp_7
# kp_8 	kp_9 	< 	f11 	f12 	print
# home 	pgup 	pgdn 	end 	left 	up
# down 	right 	insert 	delete

require "optparse"

# incomplete! only what I need now.
KEYS = {
  "%" => "shift-5",
  "/" => "slash",
  ":" => "shift-semicolon",
  "=" => "equal",
  "." => "dot",
  " " => "spc"
}

class Main
  attr_accessor :command
  attr_accessor :delay_s
  attr_accessor :keystring

  def initialize
    self.command = nil
    self.delay_s = 0.1

    OptionParser.new do |opts|
      opts.banner = "Usage: sendkeys [-c command_to_pipe_to] STRING\n" +
        "Where STRING can be 'ls<enter>ls<gt>/dev/null<enter>'"

      opts.on("-c", "--command COMMAND",
              "Pipe sendkeys to this commands, individually") do |v|
        self.command = v
      end
      opts.on("-d", "--delay SECONDS", Float,
              "Delay SECONDS after each key (default: 0.1)") do |v|
        self.delay_s = v
      end
    end.parse!
    self.keystring = ARGV[0]
  end

  def sendkey(qemu_key_name)
    qemu_cmd = "sendkey #{qemu_key_name}"
    if command
      system "echo '#{qemu_cmd}' | #{command}"
    else
      puts qemu_cmd
      $stdout.flush             # important when we are piped
    end
    sleep delay_s
  end

  PATTERN = /
              \G  # where last match ended
              < [^>]+ >
            |
              \G
              .
            /x
  def run
    keystring.scan(PATTERN) do |match|
      if match[0] == "<"
        key_name = match.slice(1..-2)
        sendkey case key_name
                when "lt" then "shift-comma"
                when "gt" then "shift-dot"
                else key_name
                end
      else
        sendkey KEYS.fetch(match, match)
      end
    end
  end
end

Main.new.run

Documentation you've based your code upon doesn't mention several key names,. which are really supported
by qemu:

; -> semicolon
' -> apostrophe
\ -> backslash

There should also be names for right bracket and left bracket keys, but I haven't be able to just guess them. Probably I should resort
to RTFS.

RTFS (qapi/ui.json in qemu 3.1 sources) gives bracket_left and bracket_right for these keys.

@vbwagner oops, sorry, I should have linked to a version which can do all the ASCII characters: https://github.com/mvidner/sendkeys