popen = subprocess.Popen(cmd, stdout=subprocess.PIPE, universal_newlines=True)

yield from iter(popen.stdout.readline, '')

popen.stdout.close()

return_code = popen.wait()

if return_code:

def __init__(self, stdscr):

self.stdscr = stdscr

curses.curs_set(0)

stdscr.timeout(0)

self.char = '▓'

self.limit = 1000

self.height, self.width = stdscr.getmaxyx()

self.pad = curses.newpad(self.height+1, self.width+1)

curses.init_pair(1, 1, 1)

stdscr.clear()

data = ping_stream(['ping', '-t', *(sys.argv[1:] or ['www.google.com'])])

# test data:

#data = [f'time={t}ms' for t in range(0,1501, 100)]; data.insert(6, 'timed out')

self.process(data)

def process(self, data):

for datum in data:

if self.stdscr.getch() != -1:

break

self.pad.clear()

if 'time=' in datum:

ping = int(datum.partition('time=')[2].partition('ms')[0])

half = self.limit/2

green,red = 1000,1000-int(1000*abs(min(ping, self.limit) - half)/half)

if ping > self.limit/2:

green,red = red,green

curses.init_color(1, red, green, 0) # color #1, up to 1000 of each channel

fill = self.char * int(self.width * min(ping, self.limit) / self.limit) + '\n'

self.pad.addstr((fill * self.height).strip(), curses.color_pair(1))

self.pad.refresh(0,0, 0,0, self.height-1,self.width-1)

elif 'timed out' in datum:

curses.init_pair(1, curses.COLOR_WHITE, curses.COLOR_BLACK)

self.pad.refresh(0,0, 0,0, self.height-1,self.width-1)

for _ in range(3):

curses.flash()

curses.napms(50)

curses.init_pair(1, 1, 1)

# with test data:

# curses.napms(1500)

#self.stdscr.timeout(-1)