From: "Florian Aßmann" <florian.assmann@...>
Date: 2007-07-11T05:48:25+09:00
Subject: Re: Help: Efficient regular expression

Divya Badrinath schrieb:
> string = "root     14051 14033  3 08:39 pts/2    00:00:00 /bin/bash"
> 
> i need to fetch 14051 and /bin/bash from the string
> 
> can someone  help me to write an efficient regular expression for that.
> 
> i am a beginner, i wrote
> string =~ /(\d+)\s+(\d+)\s+\d+\s+\d+:\d+\s+.*\s+\d+:\d+:\d+\s+(.*)\s/
> 
> i know this is not the efficient way of doing it.
> 
> Please help.
> 
talking about efficient, I was just curious...

#!/usr/bin/env ruby -w
#
#  Created by Florian Aßmann on 2007-07-10.
#  Copyright (c) 2007. All rights reserved.

string = "root     14051 14033  3 08:39 pts/2    00:00:00 /bin/bash"
require 'profiler'

puts <<-EOS

pid = string[/\s(\d+)/, 1]
cmd = string[/\s(\S+)$/, 1]

EOS
Profiler__::start_profile

10000.times do
  pid = string[/\s(\d+)/, 1]
  cmd = string[/\s(\S+)$/, 1]
end

Profiler__::stop_profile
Profiler__::print_profile STDOUT

puts <<-EOS

cols      = string.split
sec, last = cols.values_at(1, -1)

EOS
Profiler__::start_profile

10000.times do
  cols      = string.split
  sec, last = cols.values_at(1, -1)
end

Profiler__::stop_profile
Profiler__::print_profile STDOUT

puts <<-EOS

number  = string.split[1]
program = string.split.last

EOS
Profiler__::start_profile

10000.times do
  number  = string.split[1]
  program = string.split.last
end

Profiler__::stop_profile
Profiler__::print_profile STDOUT

*grin*

Florian