Re: CLI Java Glitch

From	Bent C Dalager <bcd@pvv.ntnu.no>
Newsgroups	comp.lang.java.programmer
Subject	Re: CLI Java Glitch
Date	2011-06-24 22:49 +0000
Organization	Norwegian university of science and technology
Message-ID	<slrnj0a544.64t.bcd@microbel.pvv.ntnu.no> (permalink)
References	(2 earlier) <4dffe2ea$0$57121$c30e37c6@exi-reader.telstra.net> <alpine.DEB.2.00.1106212245430.6476@urchin.earth.li> <TL-dnR5jfceDipzTnZ2dnUVZ_t6dnZ2d@posted.palinacquisition> <itvq8g82avs@news2.newsguy.com> <caf4475a-03ef-444b-8eba-9899232227d4@l14g2000pro.googlegroups.com>

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The below program creates two distinct files on the file system of my
OSX 10.6.7, one with a regular hyphen and one with the non-breaking
hyphen. Other OS/FS combinations may behave differently. Of course,
the two files look exactly the same. In my opinion this is a lot more
subtle than a case difference and just underscores that string
comparison is a very complicated topic. (This particular sort of
subtelty used to be phishing gold, but I believe browser vendors have
since implemented countermeasures against that.)

I can't offhand think of any characters that are legal in Java symbols
and that might also have similarly subtle issues.


import java.io.File;
import java.io.IOException;

public class TestCase
{
   public static void main(String[] args)
      throws IOException
   {
      File fileHyphen = new File("test-file.tmp");
      File fileNbrkHyphen = new File("test\u2011file.tmp");

      createFile(fileHyphen);
      createFile(fileNbrkHyphen);
   }

   static void createFile(File file)
      throws IOException
   {
      if (!file.createNewFile())
      {
         System.out.println("Could not create " + file);
      }
   }
}


$ javac TestCase.java
$ java TestCase
$ ls test*
test-file.tmp	test‑file.tmp
$ java TestCase
Could not create test-file.tmp
Could not create test?file.tmp

(not sure what I have misconfigured that bollocksed up the Unicode on
that last line)

Cheers,
	Bent D
-- 
Bent Dalager - bcd@pvv.org - http://www.pvv.org/~bcd
                                    powered by emacs

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Thread

CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-20 14:24 -0700
  Re: CLI Java Glitch Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-06-20 14:48 -0700
  Re: CLI Java Glitch Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-06-20 18:49 -0300
  Re: CLI Java Glitch Martin Gregorie <martin@address-in-sig.invalid> - 2011-06-20 22:09 +0000
    Re: CLI Java Glitch Esmond Pitt <esmond.pitt@bigpond.com> - 2011-06-21 10:16 +1000
      Re: CLI Java Glitch Tom Anderson <twic@urchin.earth.li> - 2011-06-21 22:49 +0100
        Re: CLI Java Glitch Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2011-06-21 15:11 -0700
          Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-21 16:37 -0700
            Re: CLI Java Glitch Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2011-06-21 17:54 -0700
            Re: CLI Java Glitch lewbloch <lewbloch@gmail.com> - 2011-06-22 09:02 -0700
              Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-22 10:12 -0700
                Re: CLI Java Glitch Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-06-22 10:39 -0700
          Re: CLI Java Glitch Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-06-22 09:50 -0700
          Re: CLI Java Glitch Tom Anderson <twic@urchin.earth.li> - 2011-06-22 19:44 +0100
            Re: CLI Java Glitch Michael Wojcik <mwojcik@newsguy.com> - 2011-06-23 12:31 -0400
              Re: CLI Java Glitch Tom Anderson <twic@urchin.earth.li> - 2011-06-23 23:04 +0100
                Re: CLI Java Glitch Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2011-06-23 21:40 -0700
                Re: CLI Java Glitch Michael Wojcik <mwojcik@newsguy.com> - 2011-06-24 09:43 -0400
          Re: CLI Java Glitch Michael Wojcik <mwojcik@newsguy.com> - 2011-06-23 12:24 -0400
            Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-23 14:32 -0700
            Re: CLI Java Glitch lewbloch <lewbloch@gmail.com> - 2011-06-24 09:12 -0700
              Re: CLI Java Glitch Bent C Dalager <bcd@pvv.ntnu.no> - 2011-06-24 22:49 +0000
                Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-26 20:29 -0700
        Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-21 16:29 -0700
        Re: CLI Java Glitch Nigel Wade <nmw-news@ion.le.ac.uk> - 2011-06-22 11:54 +0100
          Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-22 10:16 -0700
            Re: CLI Java Glitch Patricia Shanahan <pats@acm.org> - 2011-06-22 11:06 -0700
              Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-22 11:46 -0700
                Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-22 12:50 -0700
                Re: CLI Java Glitch Nigel Wade <nmw-news@ion.le.ac.uk> - 2011-06-23 15:23 +0100
                Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-23 08:58 -0700
                Re: CLI Java Glitch lewbloch <lewbloch@gmail.com> - 2011-06-24 08:58 -0700
                Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-24 11:36 -0700
                Re: CLI Java Glitch Paul Cager <paul.cager@googlemail.com> - 2011-06-22 14:45 -0700
                Re: CLI Java Glitch Tom Anderson <twic@urchin.earth.li> - 2011-06-22 23:29 +0100
                Re: CLI Java Glitch Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-06-22 18:08 -0700
                Re: CLI Java Glitch Tom Anderson <twic@urchin.earth.li> - 2011-06-23 23:20 +0100
                Re: CLI Java Glitch Esmond Pitt <esmond.pitt@bigpond.com> - 2011-06-24 10:28 +1000
                Re: CLI Java Glitch Tom Anderson <twic@urchin.earth.li> - 2011-06-25 22:58 +0100
                Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-26 20:31 -0700
                Re: CLI Java Glitch lewbloch <lewbloch@gmail.com> - 2011-06-24 09:00 -0700
          Re: CLI Java Glitch Tom Anderson <twic@urchin.earth.li> - 2011-06-22 20:00 +0100
            Re: CLI Java Glitch Nigel Wade <nmw-news@ion.le.ac.uk> - 2011-06-23 15:18 +0100
        Re: CLI Java Glitch Esmond Pitt <esmond.pitt@bigpond.com> - 2011-06-23 11:40 +1000
          Re: CLI Java Glitch Esmond Pitt <esmond.pitt@bigpond.com> - 2011-06-23 20:21 +1000
          Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-23 09:00 -0700
            Re: CLI Java Glitch Esmond Pitt <esmond.pitt@bigpond.com> - 2011-06-24 10:24 +1000
    Re: CLI Java Glitch Tom Anderson <twic@urchin.earth.li> - 2011-06-21 22:52 +0100
  Re: CLI Java Glitch Jeff Higgins <jeff@invalid.invalid> - 2011-06-20 19:11 -0400
    Re: CLI Java Glitch Lew Bloch <lewisbloch@google.com> - 2011-06-20 16:25 -0700
      Re: CLI Java Glitch Jeff Higgins <jeff@invalid.invalid> - 2011-06-20 19:45 -0400
        Re: CLI Java Glitch Lew Bloch <lewisbloch@google.com> - 2011-06-20 18:28 -0700
        Ping: Lew Bloch Jeff Higgins <jeff@invalid.invalid> - 2011-06-20 23:26 -0400
          Re: Ping: Lew Bloch Lew Bloch <lewisbloch@google.com> - 2011-06-21 10:25 -0700
            Re: Ping: Lew Bloch Jeff Higgins <jeff@invalid.invalid> - 2011-06-21 14:36 -0400
      Re: CLI Java Glitch Patricia Shanahan <pats@acm.org> - 2011-06-20 17:02 -0700
        Re: CLI Java Glitch Jeff Higgins <jeff@invalid.invalid> - 2011-06-20 20:37 -0400
          Re: CLI Java Glitch Jeff Higgins <jeff@invalid.invalid> - 2011-06-20 20:44 -0400
            Re: CLI Java Glitch Tom Anderson <twic@urchin.earth.li> - 2011-06-21 22:45 +0100
  Re: CLI Java Glitch Roedy Green <see_website@mindprod.com.invalid> - 2011-06-20 16:55 -0700
    Re: CLI Java Glitch Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-06-20 20:44 -0400
      Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-20 19:26 -0700
      Re: CLI Java Glitch Paul Cager <paul.cager@googlemail.com> - 2011-06-21 02:34 -0700
        Re: CLI Java Glitch Silvio <silvio@moc.com> - 2011-06-21 16:50 +0200
        Re: CLI Java Glitch "Gavino" <invalid@invalid.invalid> - 2011-06-21 21:35 +0200
      Re: CLI Java Glitch Roedy Green <see_website@mindprod.com.invalid> - 2011-06-21 11:59 -0700
        Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-21 13:03 -0700
          Re: CLI Java Glitch BGB <cr88192@hotmail.com> - 2011-06-21 14:21 -0700
  Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-20 19:29 -0700
  Re: CLI Java Glitch Tom Anderson <twic@urchin.earth.li> - 2011-06-21 22:42 +0100
    Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-21 14:48 -0700
  Re: CLI Java Glitch Jeff Higgins <jeff@invalid.invalid> - 2011-06-21 21:52 -0400
    Re: CLI Java Glitch Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-06-22 07:56 -0300
      Re: CLI Java Glitch Jeff Higgins <jeff@invalid.invalid> - 2011-06-22 08:02 -0400
        Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-22 10:18 -0700
          Re: CLI Java Glitch Jeff Higgins <jeff@invalid.invalid> - 2011-06-22 15:01 -0400
            Re: CLI Java Glitch Gene Wirchenko <genew@ocis.net> - 2011-06-22 12:54 -0700
          Re: CLI Java Glitch Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-06-22 18:52 -0300
          Re: CLI Java Glitch Michael Wojcik <mwojcik@newsguy.com> - 2011-06-23 15:13 -0400

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