example pause/unpause/quit python script

check.py

#!/usr/bin/python

import sys, os, time
import tty
from select import select

class TerminalFile:
    """Adapted from http://code.activestate.com/recipes/203830/"""
    def __init__(self,infile):
        if not infile.isatty():
            raise Exception()
        self.file = infile
        
        # prepare for getch:
        self.save_attr=tty.tcgetattr(self.file)
        newattr=self.save_attr[:]
        newattr[3] &= ~tty.ECHO & ~tty.ICANON
        tty.tcsetattr(self.file, tty.TCSANOW, newattr)
    
    def __del__(self):
        # restoring stdin:
        import tty  # required this import here
        tty.tcsetattr(self.file, tty.TCSADRAIN, self.save_attr)
    
    def getch(self):
        if select([self.file],[],[],0)[0]:
            return self.file.read(1)
        return ""


if __name__=="__main__":
    print "Press p to pause/unpause and q to quit..."
    s = TerminalFile( sys.stdin )
    paused = False
    
    i = 0
    while True:
        char = s.getch()
        
        if char == 'q':
            sys.stdout.write("\n")
            sys.exit(0)
        elif char == 'p':
            paused = (not paused)
        
        if not paused:
            sys.stdout.write("\r%06d" % i)
            sys.stdout.flush()
            i += 1
        
        time.sleep(0.01)