#!/usr/bin/env python## show_deltas: Read list of printk messages instrumented with# time data, and format with time deltas.## Also, you can show the times relative to a fixed point.## Copyright 2003 Sony Corporation## GPL 2.0 applies. import sysimport string def usage():	print """usage: show_delta [<options>] <filename> This program parses the output from a set of printk message lines whichhave time data prefixed because the CONFIG_PRINTK_TIME option is set, orthe kernel command line option "time" is specified. When run with nooptions, the time information is converted to show the time delta betweeneach printk line and the next.  When run with the '-b' option, all timesare relative to a single (base) point in time. Options:  -h            Show this usage help.  -b <base>	Specify a base for time references.		<base> can be a number or a string.		If it is a string, the first message line		which matches (at the beginning of the		line) is used as the time reference. ex: $ dmesg >timefile    $ show_delta -b NET4 timefile will show times relative to the line in the kernel outputstarting with "NET4"."""	sys.exit(1) # returns a tuple containing the seconds and text for each message line# seconds is returned as a float# raise an exception if no timing data was founddef get_time(line):	if line[0]!="[":		raise ValueError 	# split on closing bracket	(time_str, rest) = string.split(line[1:],']',1)	time = string.atof(time_str) 	#print "time=", time	return (time, rest)  # average line looks like:# [    0.084282] VFS: Mounted root (romfs filesystem) readonly# time data is expressed in seconds.useconds,# convert_line adds a delta for each linelast_time = 0.0def convert_line(line, base_time):	global last_time 	try:		(time, rest) = get_time(line)	except:		# if any problem parsing time, don't convert anything		return line 	if base_time:		# show time from base		delta = time - base_time	else:		# just show time from last line		delta = time - last_time		last_time = time 	return ("[%5.6f < %5.6f >]" % (time, delta)) + rest def main():	base_str = ""	filein = ""	for arg in sys.argv[1:]:		if arg=="-b":			base_str = sys.argv[sys.argv.index("-b")+1]		elif arg=="-h":			usage()		else:			filein = arg 	if not filein:		usage() 	try:		lines = open(filein,"r").readlines()	except:		print "Problem opening file: %s" % filein		sys.exit(1) 	if base_str:		print 'base= "%s"' % base_str		# assume a numeric base.  If that fails, try searching		# for a matching line.		try:			base_time = float(base_str)		except:			# search for line matching <base> string			found = 0			for line in lines:				try:					(time, rest) = get_time(line)				except:					continue				if string.find(rest, base_str)==1:					base_time = time					found = 1					# stop at first match					break			if not found:				print 'Couldn\'t find line matching base pattern "%s"' % base_str				sys.exit(1)	else:		base_time = 0.0 	for line in lines:		print convert_line(line, base_time), main()