package IO::Stringy;

use vars qw($VERSION);
$VERSION = substr q$Revision: 2.108 $, 10;

1;
__END__


=head1 NAME

IO-stringy - I/O on in-core objects like strings and arrays


=head1 SYNOPSIS

    IO::
    ::AtomicFile   adpO  Write a file which is updated atomically     ERYQ
    ::Lines        bdpO  I/O handle to read/write to array of lines   ERYQ
    ::Scalar       RdpO  I/O handle to read/write to a string         ERYQ
    ::ScalarArray  RdpO  I/O handle to read/write to array of scalars ERYQ
    ::Wrap         RdpO  Wrap old-style FHs in standard OO interface  ERYQ
    ::WrapTie      adpO  Tie your handles & retain full OO interface  ERYQ


=head1 DESCRIPTION

This toolkit primarily provides modules for performing both traditional 
and object-oriented i/o) on things I<other> than normal filehandles; 
in particular, L<IO::Scalar|IO::Scalar>, L<IO::ScalarArray|IO::ScalarArray>, 
and L<IO::Lines|IO::Lines>.

In the more-traditional IO::Handle front, we 
have L<IO::AtomicFile|IO::AtomicFile>
which may be used to painlessly create files which are updated
atomically.

And in the "this-may-prove-useful" corner, we have L<IO::Wrap|IO::Wrap>, 
whose exported wraphandle() function will clothe anything that's not
a blessed object in an IO::Handle-like wrapper... so you can just
use OO syntax and stop worrying about whether your function's caller
handed you a string, a globref, or a FileHandle.


=head1 WARNINGS

Perl's TIEHANDLE spec was incomplete prior to 5.005_57;
it was missing support for C<seek()>, C<tell()>, and C<eof()>.
Attempting to use these functions with an IO::Scalar, IO::ScalarArray,
IO::Lines, etc. B<will not work> prior to 5.005_57.  
None of the relevant methods will be invoked by Perl; 
and even worse, this kind of bug can lie dormant for a while.
If you turn warnings on (via C<$^W> or C<perl -w>), and you see 
something like this...

    seek() on unopened file

...then you are probably trying to use one of these functions
on one of our IO:: classes with an old Perl.  The remedy is to simply
use the OO version; e.g.:

    $SH->seek(0,0);    ### GOOD: will work on any 5.005
    seek($SH,0,0);     ### WARNING: will only work on 5.005_57 and beyond



=head1 INSTALLATION


=head2 Requirements

As of version 2.x, this toolkit requires Perl 5.005 for 
the IO::Handle subclasses, and 5.005_57 or better is
B<strongly> recommended.  See L<"WARNINGS"> for details.


=head2 Directions

Most of you already know the drill...

    perl Makefile.PL
    make
    make test
    make install

For everyone else out there...
if you've never installed Perl code before, or you're trying to use
this in an environment where your sysadmin or ISP won't let you do
interesting things, B<relax:> since this module contains no binary 
extensions, you can cheat.  That means copying the directory tree
under my "./lib" directory into someplace where your script can "see" 
it.  For example, under Linux:

    cp -r IO-stringy-1.234/lib/* /path/to/my/perl/

Now, in your Perl code, do this:

    use lib "/path/to/my/perl";
    use IO::Scalar;                   ### or whatever

Ok, now you've been told.  At this point, anyone who whines about
not being given enough information gets an unflattering haiku 
written about them in the next change log.  I'll do it.  
Don't think I won't.



=head1 VERSION

$Id: Stringy.pm,v 2.108 2001/08/20 20:36:15 eryq Exp $



=head1 TO DO

=over 4

=item (2000/08/02)  Finalize $/ support

Graham Barr submitted this patch half a I<year> ago; 
Like a moron, I lost his message under a ton of others,
and only now have the experimental implementation done.

Will the sudden sensitivity to $/ hose anyone out there?
I'm worried, so you have to enable it explicitly in 1.x.
It will be on by default in 2.x, though only IO::Scalar
has been implemented.


=item (2000/09/28)  Separate read/write cursors?

Binkley sent me a very interesting variant of IO::Scalar which
maintains two separate cursors on the data, one for reading
and one for writing.  Quoth he:

    Isn't it the case that real operating system file descriptors 
    maintain an independent read and write file position (and 
    seek(2) resets them both)? 

(My answer: perhaps, but stdio's fseek/ftell manpages seem to
imply a single file position indicator, and I'm trying to be IO::-ish.)
Binkley also pointed out some issues with his implementation:  

    For example, what does eof or tell return?  The read position or 
    the write position?  (I assumed read position was more important). 

Your opinions on this are most welcome.
(Me, I'm just squeamish that this will break some code
which depends on the existing behavior, and that attempts to
maintain backwards-compatibility will slow down the code.)


=item (2001/08/08)  Remove IO::WrapTie from new IO:: classes

It's not needed.  Backwards compatibility could be maintained
by having new_tie() be identical to new().  Heck, I'll bet
that IO::WrapTie should be reimplemented so the returned 
object is just like an IO::Scalar in its use of globrefs.
 

=back



=head1 CHANGE LOG 

=over 4


=item Version 2.108   (2001/08/20)

The terms-of-use have been placed in the distribution file "COPYING".  
Also, small documentation tweaks were made.


=item Version 2.105   (2001/08/09)

Added support for various seek() whences to IO::ScalarArray.

Added support for consulting $/ in IO::Scalar and IO::ScalarArray.
The old C<use_RS()> is not even an option.  
Unsupported record separators will cause a croak().

Added a lot of regression tests to supoprt the above.

Better on-line docs (hyperlinks to individual functions).


=item Version 2.103   (2001/08/08)

After sober consideration I have reimplemented IO::Scalar::print() 
so that it once again always seeks to the end of the string.
Benchmarks show the new implementation to be just as fast as
Juergen's contributed patch; until someone can convince me otherwise,
the current, safer implementation stays.

I thought more about giving IO::Scalar two separate handles,
one for reading and one for writing, as suggested by Binkley.
His points about what tell() and eof() return are, I think,
show-stoppers for this feature.  Even the manpages for stdio's fseek()
seem to imply a I<single> file position indicator, not two.
So I think I will take this off the TO DO list.  
B<Remedy:> you can always have two handles open on the same
scalar, one which you only write to, and one which you only read from.
That should give the same effect.


=item Version 2.101   (2001/08/07)

B<Alpha release.>
This is the initial release of the "IO::Scalar and friends are
now subclasses of IO::Handle".  I'm flinging it against the wall.  
Please tell me if the banana sticks.  When it does, the banana
will be called 2.2x. 

First off, I<many many thanks to Doug Wilson>, who
has provided an I<invaluable> service by patching IO::Scalar
and friends so that they (1) inherit from IO::Handle, (2) automatically
tie themselves so that the C<new()> objects can be used in native i/o
constructs, and (3) doing it so that the whole damn thing passes
its regression tests.  As Doug knows, my globref Kung-Fu was not
up to the task; he graciously provided the patches.  This has earned
him a seat at the L<Co-Authors|"AUTHOR"> table, and the 
right to have me address him as I<sensei>.

Performance of IO::Scalar::print() has been improved by as much as 2x
for lots of little prints, with the cost of forcing those
who print-then-seek-then-print to explicitly seek to end-of-string
before printing again.
I<Thanks to Juergen Zeller for this patch.>

Added the COPYING file, which had been missing from prior versions.  
I<Thanks to Albert Chin-A-Young for pointing this out.>

IO::Scalar consults $/ by default (1.x ignored it by default).
Yes, I still need to support IO::ScalarArray.


=item Version 1.221   (2001/08/07)

I threatened in L<"INSTALLATION"> to write an unflattering haiku
about anyone who whined that I gave them insufficient information...
but it turns out that I left out a crucial direction.  D'OH!
I<Thanks to David Beroff for the "patch" and the haiku...>

       Enough info there?
         Here's unflattering haiku:
       Forgot the line, "make"!  ;-)



=item Version 1.220   (2001/04/03)

Added untested SEEK, TELL, and EOF methods to IO::Scalar 
and IO::ScalarArray to support corresponding functions for
tied filehandles: untested, because I'm still running 5.00556 
and Perl is complaining about "tell() on unopened file".
I<Thanks to Graham Barr for the suggestion.>

Removed not-fully-blank lines from modules; these were causing
lots of POD-related warnings.  
I<Thanks to Nicolas Joly for the suggestion.>


=item Version 1.219   (2001/02/23)

IO::Scalar objects can now be made sensitive to $/ .
Pains were taken to keep the fast code fast while adding this feature.
I<Cheers to Graham Barr for submitting his patch; 
jeers to me for losing his email for 6 months.>


=item Version 1.218   (2001/02/23)

IO::Scalar has a new sysseek() method.
I<Thanks again to Richard Jones.>

New "TO DO" section, because people who submit patches/ideas should 
at least know that they're in the system... and that I won't lose
their stuff.  Please read it.  

New entries in L<"AUTHOR">.  
Please read those too.



=item Version 1.216   (2000/09/28)

B<IO::Scalar and IO::ScalarArray now inherit from IO::Handle.>
I thought I'd remembered a problem with this ages ago, related to
the fact that these IO:: modules don't have "real" filehandles,
but the problem apparently isn't surfacing now.  
If you suddenly encounter Perl warnings during global destruction
(especially if you're using tied filehandles), then please let me know!
I<Thanks to B. K. Oxley (binkley) for this.>

B<Nasty bug fixed in IO::Scalar::write().>
Apparently, the offset and the number-of-bytes arguments were,
for all practical purposes, I<reversed.>  You were okay if
you did all your writing with print(), but boy was I<this> a stupid bug!  
I<Thanks to Richard Jones for finding this one.  
For you, Rich, a double-length haiku:>

       Newspaper headline
          typeset by dyslexic man
       loses urgency

       BABY EATS FISH is
          simply not equivalent   
       to FISH EATS BABY

B<New sysread and syswrite methods for IO::Scalar.>
I<Thanks again to Richard Jones for this.>


=item Version 1.215   (2000/09/05)

Added 'bool' overload to '""' overload, so object always evaluates 
to true.  (Whew.  Glad I caught this before it went to CPAN.)


=item Version 1.214   (2000/09/03)

Evaluating an IO::Scalar in a string context now yields
the underlying string.
I<Thanks to B. K. Oxley (binkley) for this.>


=item Version 1.213   (2000/08/16)

Minor documentation fixes.


=item Version 1.212   (2000/06/02)

Fixed IO::InnerFile incompatibility with Perl5.004.
I<Thanks to many folks for reporting this.>


=item Version 1.210   (2000/04/17)

Added flush() and other no-op methods.
I<Thanks to Doru Petrescu for suggesting this.>


=item Version 1.209   (2000/03/17)

Small bug fixes.


=item Version 1.208   (2000/03/14)

Incorporated a number of contributed patches and extensions,
mostly related to speed hacks, support for "offset", and
WRITE/CLOSE methods.
I<Thanks to Richard Jones, Doru Petrescu, and many others.>



=item Version 1.206   (1999/04/18)

Added creation of ./testout when Makefile.PL is run.


=item Version 1.205   (1999/01/15)

Verified for Perl5.005.


=item Version 1.202   (1998/04/18)

New IO::WrapTie and IO::AtomicFile added.


=item Version 1.110   

Added IO::WrapTie.


=item Version 1.107   

Added IO::Lines, and made some bug fixes to IO::ScalarArray. 
Also, added getc().


=item Version 1.105   

No real changes; just upgraded IO::Wrap to have a $VERSION string.

=back




=head1 AUTHOR

=over 4

=item Primary Maintainer 

Eryq (F<eryq@zeegee.com>).
President, ZeeGee Software Inc (F<http://www.zeegee.com>).

=item Co-Authors

For all their bug reports and patch submissions, the following
are officially recognized:

     Richard Jones
     B. K. Oxley (binkley) 
     Doru Petrescu 
     Doug Wilson (for picking up the ball I dropped, and doing tie() right)


=back

Go to F<http://www.zeegee.com> for the latest downloads
and on-line documentation for this module. 

Enjoy.  Yell if it breaks.


=cut

