Read one key press.

[Carel Fellinger]

Gerrit Holl <gerrit.holl at pobox.com> wrote:
> if I have the following program:

> key = raw_input("press a key: ")
> if key == 'a':
>     print "you pressed 'a'"
> elif key == '^['
>     print "you pressed escape"

> it doesn't work. Well, it works but it itsn't what I'm looking for. I want
> ONE key input. Can this me done easyly?

as you are running linux it sure can be done:) though not as easily as
in Windows. For a better understanding try reading the libc info pages,
menu "Low-Level Terminal Interface". You can find the example I recoded
in python in its submenu "Noncanon Example". Also have a look at the
termios module.


import termios, TERMIOS, sys

fd = sys.stdin.fileno()
def getch():
    saved_attributes = termios.tcgetattr(fd)
    try:
        attributes = termios.tcgetattr(fd)            #get a fresh copy!
        attributes[3] = attributes[3] & ~(TERMIOS.ICANON | TERMIOS.ECHO)
        attributes[6][TERMIOS.VMIN] = 1
        attributes[6][TERMIOS.VTIME] = 0
        termios.tcsetattr(fd, TERMIOS.TCSANOW, attributes)

        a = sys.stdin.read(1)
    finally:            #be sure to reset the attributes no matter what!
        termios.tcsetattr(fd, TERMIOS.TCSANOW, saved_attributes)
    return a
    
-- 
groetjes, carel