netlogserve

#!/usr/bin/env -S python3 -u

import datetime
import time
import sys

if len(sys.argv) < 2:
    print("Syntax: netlogserve [-v] <filename>", file=sys.stderr)
    exit(-1)

verbose = False
fn = sys.argv[1]
if fn == "-v":
    verbose = True
    fn = sys.argv[2]

f = open(fn)
lines = [line.strip() for line in f.readlines()]
f.close()

logs = {}

month = {"Jan": 1, "Feb": 2, "Mar": 3, "Apr": 4, "May": 5, "Jun": 6, "Jul": 7, "Aug": 8, "Sep": 9, "Oct": 10, "Nov": 11, "Dec": 12}

year = 2019
firststamp = None
laststamp = None
for line in lines:
    try:
        m, d, hms, *rest = line.split()
        hms_h, hms_m, hms_s = hms.split(":")
        dt = datetime.datetime(year, month[m], int(d), int(hms_h), int(hms_m), int(hms_s))
    except:
        print("Parse error - incorrect log format (lines need to begin with MMM DD hh:mm:ss)", file=sys.stderr)
        exit(-1)
    if verbose:
        print("load", m, d, hms, "→", dt)
    laststamp = int(dt.timestamp())
    logs[laststamp] = logs.get(laststamp, []) + [line]
    if not firststamp:
        firststamp = laststamp

realstamp = int(time.time())
delta = realstamp - firststamp
if verbose:
    print("delta", delta, "s")
quit = False
for i in range(firststamp, laststamp + 1):
    while int(time.time()) - i < delta:
        time.sleep(0.5)
    if i in logs:
        for line in logs[i]:
            try:
                print(line)
            except:
                quit = True
                if verbose:
                    print("discarding remaining lines")
                break
    if quit:
        break