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Re: [cc2-dev-l] Re: FCW compressed files

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  • Bradd W. Szonye
    ... Hi! ... I m not sure I understand -- could you please explain what you re getting at? Maybe it s just the context that has me confused; I m not sure what
    Message 1 of 10 , Mar 23, 2001
      On Thu, Mar 22, 2001 at 08:12:11PM -1000, Linda Kekumu wrote:
      > Hi :)

      Hi!

      > Can you link from HTML to CC2? or from Word to CC2 - or from other
      > programs that support hyper linking? I know we can do the reverse, I
      > just wanted to know if other programs were as progressive?

      I'm not sure I understand -- could you please explain what you're
      getting at? Maybe it's just the context that has me confused; I'm not
      sure what this has to do with the subject.

      Do you mean, can you click on a link to a CC2 file in an HTML doc and
      have it fire up CC2 to open the map? Yeah, I'm pretty sure that's
      possible. Most browsers will let you configure them so that they can
      open files with different applications (instead of simply asking you to
      save the file to disk). For Netscape Navigator, you do this in the
      Applications panel of the Edit>>Preferences dialog.
      --
      Bradd W. Szonye Work: bradd@...
      Software Design Engineer Home: bradds@...
      Hewlett-Packard Cupertino Site, iFL Phone: 408-447-4832
    • Bradd W. Szonye
      ... That s right. That s why you need a script and not just PKZIP to do it. The easiest way to uncompress an FCW is with the PKWare library, but I don t have
      Message 2 of 10 , Mar 23, 2001
        >> On Wed, Mar 21, 2001 at 08:45:27PM -0000, bradds@... wrote:
        >>> However, the basics are there, so now I can convert a compressed FCW
        >>> to an uncompressed FCW on a Unix machine.

        On Fri, Mar 23, 2001 at 01:28:25AM -0700, Mike Riddle wrote:
        > Note that a compressed FCW file is NOT a PKZIP file - the file, after
        > the 128-byte file id block, is compressed using the same algorithms
        > used by PKZIP, but does not have a ZIP file's internal directory
        > structure.

        That's right. That's why you need a script and not just PKZIP to do it.
        The easiest way to uncompress an FCW is with the PKWare library, but I
        don't have $700 to buy the libraries for Windows and Unix for what is
        basically a hobby project. Fortunately, with a little extra work, PKZIP
        can do the job (for decompression anyway).

        The steps involved are:
        1. Extract and save the FCW file ID header.
        2. Wrap the compressed stream with a ZIP header and central directory.
        3. Decompress with PKZIP.
        4. Re-attach the data to the FCW header.

        The tricky part is to do it in such a way that PKZIP doesn't leave
        droppings all over the place.

        > As to PKZIP in UNIX being awful, I can't say, but I have always liked
        > and used PkWare's programs (and Data Compression Library) and have
        > found them stable and fast. And I've *never* had bugs in their
        > products cause me trouble. I really respect their products.

        Oh, PKZIP for Unix seems to work well enough -- it's not buggy or
        anything. It's just that it has some quirks that are acceptable in a
        Windows/DOS environment that are inappropriate on a Unix system. For
        example, every time you run it, it writes a configuration file in the
        current directory. In Unix, that sort of thing belongs in a hidden
        file in your home directory -- dropping files in the current directory
        is not only not always possible, but it's a data integrity and security
        risk.

        I was also going to complain that there's no way to decompress to
        standard output (instead of to a file), but I just found that one! I
        still haven't figured out whether it's possible to supply the ZIP file
        on standard input instead of as a filename.

        In short, it's not that it's a poor program, it's that it has an
        extremely poor Unix command interface. Now, for somebody who's
        accustomed to using PKZIP-DOS, that's an advantage, but it makes it very
        difficult for seasoned Unix users, especially if you're trying to write
        a script.
        --
        Bradd W. Szonye Work: bradd@...
        Software Design Engineer Home: bradds@...
        Hewlett-Packard Cupertino Site, iFL Phone: 408-447-4832
      • Bradd W. Szonye
        ... Well, that turned out not to be the tricky part after all. On the surface, the files appear to decompress correctly, but when I try to actually read the FC
        Message 3 of 10 , Mar 24, 2001
          On Fri, Mar 23, 2001 at 09:50:01AM -0800, Bradd W. Szonye wrote:
          > The steps [to decompress an FCW] are:
          > 1. Extract and save the FCW file ID header.
          > 2. Wrap the compressed stream with a ZIP header and central directory.
          > 3. Decompress with PKZIP.
          > 4. Re-attach the data to the FCW header.
          >
          > The tricky part is to do it in such a way that PKZIP doesn't leave
          > droppings all over the place.

          Well, that turned out not to be the tricky part after all. On the
          surface, the files appear to decompress correctly, but when I try to
          actually read the FC chunks, it falls apart. There are corrupted bits
          here and there, and the files appear to get truncated slightly. Unless I
          make some sort of radical breakthrough, it looks like I'm going to need
          to leave this alone for now. Oh well -- I have lots of other projects
          I'm working on.

          Sorry if I got anyone's hopes up! (Assuming, of course, that anyone
          other than me is interested in this.)
          --
          Bradd W. Szonye Hewlett-Packard: Home:
          Software Engineer bradd@... bradds@...
          408-447-4832 http://www.concentric.net/~Bradds
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