getkey

[Ulli Horlacher]

I have an application which runs on Windows and UNIX where I need to get
one keypress from the user (without ENTER). 
Keys which sends escape sequences (e.g. cursor or function keys) should be
ignored. 

I have a solution for Windows, but not for UNIX:
The first byte of an escape sequence (example: ^[[21~ for F10) is
recognized, but the trailing bytes then are not discarded by
clear_keyboard_buffer() and get_key() returns the second byte of the
escape sequence.

My code:

try:
  import msvcrt
except ImportError:
  import tty
  import select
  import termios


def get_key():
  try:
    k = msvcrt.getch()
  except:
    fd = sys.stdin.fileno()
    old_settings = termios.tcgetattr(fd)
    try:
      tty.setraw(fd)
      k = sys.stdin.read(1)
    finally:
      termios.tcsetattr(fd,termios.TCSADRAIN,old_settings)

  if k == '\033': 
    clear_keyboard_buffer()
    return get_key()
  else:
    return k


def clear_keyboard_buffer():
  try:
    while msvcrt.kbhit(): msvcrt.getwch()
  except:
    fd = sys.stdin.fileno()
    while len(select.select([fd],[],[],0.0)[0]) > 0: os.read(fd,1)
    termios.tcflush(sys.stdin,termios.TCIOFLUSH)


-- 
Ullrich Horlacher              Server und Virtualisierung
Rechenzentrum IZUS/TIK         E-Mail: horlacher at tik.uni-stuttgart.de
Universitaet Stuttgart         Tel:    ++49-711-68565868
Allmandring 30a                Fax:    ++49-711-682357
70550 Stuttgart (Germany)      WWW:    http://www.tik.uni-stuttgart.de/