Tricking modules into thinking scalars are globs. (code)

deprecated has asked for the wisdom of the Perl Monks concerning the following question:

Lets start with some code:

    my $handle = gensym;
    open $handle, ref ($file) ? ">&". fileno ($file) : ">" . $file
  and binmode ($handle)
      or goto &_drat;
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This is from Archive::Tar, around line 750, for those who like to read along. This has been my absolute arch nemesis in this project. It wants a steenkin' file. And it will not accept anything but a file. Some of you may have read Self Extracting Archives with Perl (almost) a while ago. I had at the time abandoned using Archive::Tar. However, I am doing a similar thing now and I must use tar. So I'm going over my code again, and updating it with the knowledge I've learned since then, and I switched to IO::String from IO::Scalar due to this bit in the IO::Scalar pod:

       the IO::String manpage, which is quite similar but which
       was designed more-recently and with an IO::Handle-like
       interface in mind, so you can mix OO- and native-
       filehandle usage without using tied().  Note: if anyone
       can make IO::Scalar do that without breaking the
       regression tests, I'm all ears.
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and this bit from the Archive::Tar pod:

       write ($file, $compressed)
           Write the in-memory archive to disk.  The first
           argument can either be the name of a file or a
           reference to an already open file handle (be a GLOB
           reference).  If the second argument is true, the
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So in theory, IO::String allows me to create a pseudofile in memory that I can then print stuff to as if it were a file. My hope was that Archive::Tar wouldn't know any better, and would happily print to it, and I could then steal its tarball and do cool stuff to it (like MIME::Base64 or Convert::UU or Compress::Gzip, et cetera), followed by even more cool stuff (like Mail::Mailer, among other things)

Mmmmkay, let's look at some errors.

Can't locate object method "FETCH" via package "IO::String" at /home/p
+erl/lib/5.6.0/ppc-linux-thread-multi/Data/Dumper.pm line 150.
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is gleaned from the following code:

tie *IOST, 'IO::String';
print Dumper \*IOST;
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So that's kind of sucky. But I found out that the FETCH thing I'm looking for is over in perldoc perltie, and it seems like a real pain in the ass.

       FETCH
            This method will be triggered every time the tied
            variable is accessed (read).  It takes no arguments
            beyond its self reference, which is the object
            representing the scalar we're dealing with.  Because
            in this case we're using just a SCALAR ref for the
            tied scalar object, a simple $$self allows the method
            to get at the real value stored there.  In our
            example below, that real value is the process ID to
            which we've tied our variable.
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So this all boils down to one thing. I have a module that wants to write to a filehandle. But I dont want to write to the disk at all. I am just going to pass it to something else, and I dont see why I should have to write out a file and read it back in. That just seems stupid. But all the seemingly close-enough-to-be-useful methods are a) very complicated or b) not the solution.

If Larry were to fix this for me today, it would be thusly:

open TRICKERY, \$stringamabob;
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Which 'works', but actually doesnt. (try it and see).

I guess the other solution would be to steal Archive::Tar's data. That doesnt seem particularly elegant, and I'd rather have a perl solution to this.

Finally, since this was rather information-rich, I pondered putting it in Meditations. However, I didnt really produce anything worth meditating on, so it resides in SoPW for now. Feel free to edit if if you feel the urge.

whiiiiiiiiine,
brother dep.

--
Laziness, Impatience, Hubris, and Generosity.

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