From: Robert Klemme <bob.news@...>
Date: 2003-07-23T18:02:48+09:00
Subject: Re: Should String#strip take a parameter?


"daz" <dooby@d10.karoo.co.uk> schrieb im Newsbeitrag
news:vhs8osad38h515@corp.supernews.com...
>
> "Xiangrong Fang" <xrfang@hotmail.com> wrote:
>
> > Hi,
> >
> > I have a question regarding strip. I wrote a DLL in other language,
and
> > used the following  to call the dll function in ruby:
> >
> > arg = " " * 100
> > myfunc.Call(arg)
> >
> > after that arg may contain a string such as:
> >
> > "return value\000"
> >
> > I used strip, but the strip does not strip away terminating null
> > character...
> >
> > Am I doing something wrong? If I suggest that strip should also strip
> > the \000, is it a good idea or not?
> >
> > Shannon
> >
>
> The only reason for thinking #strip might be relevant
> in this situation is that you initialised your buffer
> with spaces.
>
>
> class String
>   def sz_cut!   #  cut at string-zero terminator
>     replace(self[/\A[^\0]*/])
>   end
> end
>
> p "return value\000  garbage".sz_cut!

There is a more efficient implementation of sz_cut!:

class String
  def sz_cut!   #  cut at string-zero terminator
    gsub!( /\0.*$/, '' )
  end
end

Cheers

    robert


                user     system      total        real
test1   change  5.235000   0.031000   5.266000 (  5.281000)
test2   change  5.828000   0.032000   5.860000 (  5.875000)
test1 no change  1.891000   0.000000   1.891000 (  1.922000)
test2 no change  7.078000   0.000000   7.078000 (  7.125000)

require 'benchmark'

REP=500000

STR1="foo\0garbage"
STR1.freeze

STR2="foo.garbage"
STR2.freeze

def test1(s)
  s.gsub!( /\0.*$/, '' )
end

def test2(s)
  s.replace(s[/\A[^\0]*/])
end

Benchmark.bm(10) do |x|
  x.report "test1   change" do
    REP.times { test1 STR1.dup }
  end

  x.report "test2   change" do
    REP.times { test2 STR1.dup }
  end

  x.report "test1 no change" do
    REP.times { test1 STR2.dup }
  end

  x.report "test2 no change" do
    REP.times { test2 STR2.dup }
  end
end