Like `wc -l` but for `tail -f`. Example: tail -f some.log | grep ERROR | ./runningwc.py -i 5

runningwc.py

#!/usr/bin/python -u
from twilio.rest import TwilioRestClient
import sys
import time
import threading
import argparse
 
total = 0
 
class Reporter(threading.Thread):
    def __init__(self, interval, lower_limit, alert_cb):
        super(Reporter, self).__init__()
        self.last_time = time.time()
        self.last_count = 0
        self.interval = interval
        self.lower_limit = lower_limit
        self.alert_cb = alert_cb
    def run(self):
        while True:
            time.sleep(self.interval)
            lines = total - self.last_count
            print("Last {0} seconds: {1} lines".format(self.interval, lines))
            if lines < self.lower_limit:
                self.alert_cb()
            self.last_count += lines
 
 
class Counter(threading.Thread):
    def run(self):
        global total
        for line in sys.stdin:
            total += 1


class SmsAlertFactory(object):

    def __init__(self, time_between_messages, to, from_, body):
        self.max_tbm = time_between_messages
        self.to = to if isinstance(to, list) else [to]
        self.from_ = from_
        self.body = body
        self.last_message = 0

    def __call__(self):
        print("ALERT!")
        if self.max_tbm < (time.time() - self.last_message):
            self.last_message = time.time()
            client = TwilioRestClient()
            for n in self.to:
                client.sms.messages.create(to=n, from_=self.from_, body=self.body)
 
 
if __name__ == "__main__":
    # example using SMS notifier
    nums = ["+155512341231"]
    sms_alert = SmsAlertFactory(60 * 15, nums, "+15553421412", "process dead?!")
    parser = argparse.ArgumentParser(description="Count lines from a streaming stdio")
    parser.add_argument('-i', '--interval', default=10, type=int)
    parser.add_argument('-b', '--below', default=-1, type=int)
    opts = parser.parse_args()
    Counter().start()
    Reporter(opts.interval, opts.below, sms_alert).start()