আপডেট: আমি অনেক উন্নতি করে একটি আপডেট সংস্করণ দিয়ে মূল কোডটি প্রতিস্থাপন করেছি। আসুন এটিকে (আসল?) আলফা-গুণযুক্ত বলা যাক।
এই সংস্করণ অন্তর্ভুক্ত:
- কমান্ড-লাইন বিকল্প হ্যান্ডলিং
- কমান্ড-লাইন তারিখ বিন্যাসের বৈধতা
- কিছু
tryব্লক
- লাইন পঠন একটি ফাংশন সরানো
মূল পাঠ্য:
ভাল, তুমি কি জানো? "সন্ধান করুন" এবং আপনি পাবেন! এখানে একটি পাইথন প্রোগ্রাম রয়েছে যা ফাইলটির সন্ধান করে এবং আরও বা কম বাইনারি অনুসন্ধান ব্যবহার করে। এটি অন্য বালকটি লিখেছিল যে এইডব্লিউকে স্ক্রিপ্টের চেয়ে যথেষ্ট দ্রুত ।
এটি (প্রাক?) আলফা-গুণমান। এটা তোলে থাকা উচিত tryব্লক এবং ইনপুট বৈধতা এবং পরীক্ষা প্রচুর এবং কোন সন্দেহ নেই আরও Pythonic হতে পারে। তবে এখানে এটি আপনার বিনোদনের জন্য। ওহ, এবং এটি পাইথন ২.6 এর জন্য লেখা হয়েছে।
নতুন কোড:
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# timegrep.py by Dennis Williamson 20100113
# in response to http://serverfault.com/questions/101744/fast-extraction-of-a-time-range-from-syslog-logfile
# thanks to serverfault user http://serverfault.com/users/1545/mike
# for the inspiration
# Perform a binary search through a log file to find a range of times
# and print the corresponding lines
# tested with Python 2.6
# TODO: Make sure that it works if the seek falls in the middle of
# the first or last line
# TODO: Make sure it's not blind to a line where the sync read falls
# exactly at the beginning of the line being searched for and
# then gets skipped by the second read
# TODO: accept arbitrary date
# done: add -l long and -s short options
# done: test time format
version = "0.01a"
import os, sys
from stat import *
from datetime import date, datetime
import re
from optparse import OptionParser
# Function to read lines from file and extract the date and time
def getdata():
"""Read a line from a file
Return a tuple containing:
the date/time in a format such as 'Jan 15 20:14:01'
the line itself
The last colon and seconds are optional and
not handled specially
"""
try:
line = handle.readline(bufsize)
except:
print("File I/O Error")
exit(1)
if line == '':
print("EOF reached")
exit(1)
if line[-1] == '\n':
line = line.rstrip('\n')
else:
if len(line) >= bufsize:
print("Line length exceeds buffer size")
else:
print("Missing newline")
exit(1)
words = line.split(' ')
if len(words) >= 3:
linedate = words[0] + " " + words[1] + " " + words[2]
else:
linedate = ''
return (linedate, line)
# End function getdata()
# Set up option handling
parser = OptionParser(version = "%prog " + version)
parser.usage = "\n\t%prog [options] start-time end-time filename\n\n\
\twhere times are in the form hh:mm[:ss]"
parser.description = "Search a log file for a range of times occurring yesterday \
and/or today using the current time to intelligently select the start and end. \
A date may be specified instead. Seconds are optional in time arguments."
parser.add_option("-d", "--date", action = "store", dest = "date",
default = "",
help = "NOT YET IMPLEMENTED. Use the supplied date instead of today.")
parser.add_option("-l", "--long", action = "store_true", dest = "longout",
default = False,
help = "Span the longest possible time range.")
parser.add_option("-s", "--short", action = "store_true", dest = "shortout",
default = False,
help = "Span the shortest possible time range.")
parser.add_option("-D", "--debug", action = "store", dest = "debug",
default = 0, type = "int",
help = "Output debugging information.\t\t\t\t\tNone (default) = %default, Some = 1, More = 2")
(options, args) = parser.parse_args()
if not 0 <= options.debug <= 2:
parser.error("debug level out of range")
else:
debug = options.debug # 1 = print some debug output, 2 = print a little more, 0 = none
if options.longout and options.shortout:
parser.error("options -l and -s are mutually exclusive")
if options.date:
parser.error("date option not yet implemented")
if len(args) != 3:
parser.error("invalid number of arguments")
start = args[0]
end = args[1]
file = args[2]
# test for times to be properly formatted, allow hh:mm or hh:mm:ss
p = re.compile(r'(^[2][0-3]|[0-1][0-9]):[0-5][0-9](:[0-5][0-9])?$')
if not p.match(start) or not p.match(end):
print("Invalid time specification")
exit(1)
# Determine Time Range
yesterday = date.fromordinal(date.today().toordinal()-1).strftime("%b %d")
today = datetime.now().strftime("%b %d")
now = datetime.now().strftime("%R")
if start > now or start > end or options.longout or options.shortout:
searchstart = yesterday
else:
searchstart = today
if (end > start > now and not options.longout) or options.shortout:
searchend = yesterday
else:
searchend = today
searchstart = searchstart + " " + start
searchend = searchend + " " + end
try:
handle = open(file,'r')
except:
print("File Open Error")
exit(1)
# Set some initial values
bufsize = 4096 # handle long lines, but put a limit them
rewind = 100 # arbitrary, the optimal value is highly dependent on the structure of the file
limit = 75 # arbitrary, allow for a VERY large file, but stop it if it runs away
count = 0
size = os.stat(file)[ST_SIZE]
beginrange = 0
midrange = size / 2
oldmidrange = midrange
endrange = size
linedate = ''
pos1 = pos2 = 0
if debug > 0: print("File: '{0}' Size: {1} Today: '{2}' Now: {3} Start: '{4}' End: '{5}'".format(file, size, today, now, searchstart, searchend))
# Seek using binary search
while pos1 != endrange and oldmidrange != 0 and linedate != searchstart:
handle.seek(midrange)
linedate, line = getdata() # sync to line ending
pos1 = handle.tell()
if midrange > 0: # if not BOF, discard first read
if debug > 1: print("...partial: (len: {0}) '{1}'".format((len(line)), line))
linedate, line = getdata()
pos2 = handle.tell()
count += 1
if debug > 0: print("#{0} Beg: {1} Mid: {2} End: {3} P1: {4} P2: {5} Timestamp: '{6}'".format(count, beginrange, midrange, endrange, pos1, pos2, linedate))
if searchstart > linedate:
beginrange = midrange
else:
endrange = midrange
oldmidrange = midrange
midrange = (beginrange + endrange) / 2
if count > limit:
print("ERROR: ITERATION LIMIT EXCEEDED")
exit(1)
if debug > 0: print("...stopping: '{0}'".format(line))
# Rewind a bit to make sure we didn't miss any
seek = oldmidrange
while linedate >= searchstart and seek > 0:
if seek < rewind:
seek = 0
else:
seek = seek - rewind
if debug > 0: print("...rewinding")
handle.seek(seek)
linedate, line = getdata() # sync to line ending
if debug > 1: print("...junk: '{0}'".format(line))
linedate, line = getdata()
if debug > 0: print("...comparing: '{0}'".format(linedate))
# Scan forward
while linedate < searchstart:
if debug > 0: print("...skipping: '{0}'".format(linedate))
linedate, line = getdata()
if debug > 0: print("...found: '{0}'".format(line))
if debug > 0: print("Beg: {0} Mid: {1} End: {2} P1: {3} P2: {4} Timestamp: '{5}'".format(beginrange, midrange, endrange, pos1, pos2, linedate))
# Now that the preliminaries are out of the way, we just loop,
# reading lines and printing them until they are
# beyond the end of the range we want
while linedate <= searchend:
print line
linedate, line = getdata()
if debug > 0: print("Start: '{0}' End: '{1}'".format(searchstart, searchend))
handle.close()