perl570delta.pod

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=item *

scalar() now forces scalar context even when used in void context.

=item *

sort() arguments are now compiled in the right wantarray context
(they were accidentally using the context of the sort() itself).

=item *

Changed the POSIX character class C<[[:space:]]> to include the (very
rare) vertical tab character.  Added a new POSIX-ish character class
C<[[:blank:]]> which stands for horizontal whitespace (currently,
the space and the tab).

=item *

$AUTOLOAD, sort(), lock(), and spawning subprocesses
in multiple threads simultaneously are now thread-safe.

=item *

Allow read-only string on left hand side of non-modifying tr///.

=item *

Several Unicode fixes (but still not perfect).

=over 8

=item *

BOMs (byte order marks) in the beginning of Perl files
(scripts, modules) should now be transparently skipped.
UTF-16 (UCS-2) encoded Perl files should now be read correctly.

=item *

The character tables have been updated to Unicode 3.0.1.

=item *

chr() for values greater than 127 now create utf8 when under use
utf8.

=item *

Comparing with utf8 data does not magically upgrade non-utf8 data into
utf8.

=item *

C<IsAlnum>, C<IsAlpha>, and C<IsWord> now match titlecase.

=item *

Concatenation with the C<.> operator or via variable interpolation,
C<eq>, C<substr>, C<reverse>, C<quotemeta>, the C<x> operator,
substitution with C<s///>, single-quoted UTF-8, should now work--in
theory.

=item *

The C<tr///> operator now works I<slightly> better but is still rather
broken.  Note that the C<tr///CU> functionality has been removed (but
see pack('U0', ...)).

=item *

vec() now refuses to deal with characters >255.

=item *

Zero entries were missing from the Unicode classes like C<IsDigit>.

=back

=item *

UNIVERSAL::isa no longer caches methods incorrectly.  (This broke
the Tk extension with 5.6.0.)

=back

=head2 Platform Specific Changes and Fixes

=over 4

=item *

BSDI 4.*

Perl now works on post-4.0 BSD/OSes.

=item *

All BSDs

Setting C<$0> now works (as much as possible; see perlvar for details).

=item *

Cygwin

Numerous updates; currently synchronised with Cygwin 1.1.4.

=item *

EPOC

EPOC update after Perl 5.6.0.  See README.epoc.

=item *

FreeBSD 3.*

Perl now works on post-3.0 FreeBSDs.

=item *

HP-UX

README.hpux updated; C<Configure -Duse64bitall> now almost works.

=item *

IRIX

Numerous compilation flag and hint enhancements; accidental mixing
of 32-bit and 64-bit libraries (a doomed attempt) made much harder.

=item *

Linux

Long doubles should now work (see INSTALL).

=item *

Mac OS Classic

Compilation of the standard Perl distribution in Mac OS Classic should
now work if you have the Metrowerks development environment and the
missing Mac-specific toolkit bits.  Contact the macperl mailing list
for details.

=item *

MPE/iX

MPE/iX update after Perl 5.6.0.  See README.mpeix.

=item *

NetBSD/sparc

Perl now works on NetBSD/sparc.

=item *

OS/2

Now works with usethreads (see INSTALL).

=item *

Solaris

64-bitness using the Sun Workshop compiler now works.

=item *

Tru64 (aka Digital UNIX, aka DEC OSF/1)

The operating system version letter now recorded in $Config{osvers}.
Allow compiling with gcc (previously explicitly forbidden).  Compiling
with gcc still not recommended because buggy code results, even with
gcc 2.95.2.

=item *

Unicos

Fixed various alignment problems that lead into core dumps either
during build or later; no longer dies on math errors at runtime;
now using full quad integers (64 bits), previously was using 
only 46 bit integers for speed.

=item *

VMS

chdir() now works better despite a CRT bug; now works with MULTIPLICITY
(see INSTALL); now works with Perl's malloc.

=item *

Windows

=over 8

=item *

accept() no longer leaks memory.

=item *

Better chdir() return value for a non-existent directory.

=item *

New %ENV entries now propagate to subprocesses.

=item *

$ENV{LIB} now used to search for libs under Visual C.

=item *

A failed (pseudo)fork now returns undef and sets errno to EAGAIN.

=item *

Allow REG_EXPAND_SZ keys in the registry.

=item *

Can now send() from all threads, not just the first one.

=item *

Fake signal handling reenabled, bugs and all.

=item *

Less stack reserved per thread so that more threads can run
concurrently. (Still 16M per thread.)

=item *

C<< File::Spec->tmpdir() >> now prefers C:/temp over /tmp
(works better when perl is running as service).

=item *

Better UNC path handling under ithreads.

=item *

wait() and waitpid() now work much better.

=item *

winsock handle leak fixed.

=back

=back

=head1 New or Changed Diagnostics

All regular expression compilation error messages are now hopefully
easier to understand both because the error message now comes before
the failed regex and because the point of failure is now clearly
marked.

The various "opened only for", "on closed", "never opened" warnings
drop the C<main::> prefix for filehandles in the C<main> package,
for example C<STDIN> instead of <main::STDIN>. 

The "Unrecognized escape" warning has been extended to include C<\8>,
C<\9>, and C<\_>.  There is no need to escape any of the C<\w> characters.

=head1 Changed Internals

=over 4

=item *

perlapi.pod (a companion to perlguts) now attempts to document the
internal API.

=item *

You can now build a really minimal perl called microperl.
Building microperl does not require even running Configure;
C<make -f Makefile.micro> should be enough.  Beware: microperl makes
many assumptions, some of which may be too bold; the resulting
executable may crash or otherwise misbehave in wondrous ways.
For careful hackers only.

=item *

Added rsignal(), whichsig(), do_join() to the publicised API.

=item *

Made possible to propagate customised exceptions via croak()ing.

=item *

Added is_utf8_char(), is_utf8_string(), bytes_to_utf8(), and utf8_to_bytes().

=item *

Now xsubs can have attributes just like subs.

=back

=head1 Known Problems

=head2 Unicode Support Still Far From Perfect

We're working on it.  Stay tuned.

=head2 EBCDIC Still A Lost Platform

The plan is to bring them back.

=head2 Building Extensions Can Fail Because Of Largefiles

Certain extensions like mod_perl and BSD::Resource are known to have
issues with `largefiles', a change brought by Perl 5.6.0 in which file
offsets default to 64 bits wide, where supported.  Modules may fail to
compile at all or compile and work incorrectly.  Currently there is no
good solution for the problem, but Configure now provides appropriate
non-largefile ccflags, ldflags, libswanted, and libs in the %Config
hash (e.g., $Config{ccflags_nolargefiles}) so the extensions that are
having problems can try configuring themselves without the
largefileness.  This is admittedly not a clean solution, and the
solution may not even work at all.  One potential failure is whether
one can (or, if one can, whether it's a good idea) link together at
all binaries with different ideas about file offsets, all this is
platform-dependent.

=head2 ftmp-security tests warn 'system possibly insecure'

Don't panic.  Read INSTALL 'make test' section instead. 

=head2 Test lib/posix Subtest 9 Fails In LP64-Configured HP-UX

If perl is configured with -Duse64bitall, the successful result of the
subtest 10 of lib/posix may arrive before the successful result of the
subtest 9, which confuses the test harness so much that it thinks the
subtest 9 failed.

=head2 Long Doubles Still Don't Work In Solaris

The experimental long double support is still very much so in Solaris.
(Other platforms like Linux and Tru64 are beginning to solidify in
this area.)

=head2 Linux With Sfio Fails op/misc Test 48

No known fix.

=head2 Storable tests fail in some platforms

If any Storable tests fail the use of Storable is not advisable.

=over 4

=item *

Many Storable tests fail on AIX configured with 64 bit integers.

So far unidentified problems break Storable in AIX if Perl is
configured to use 64 bit integers.  AIX in 32-bit mode works and
other 64-bit platforms work with Storable.

=item *

DOS DJGPP may hang when testing Storable.

=item *

st-06compat fails in UNICOS and UNICOS/mk.

This means that you cannot read old (pre-Storable-0.7) Storable images
made in other platforms.

=item *

st-store.t and st-retrieve may fail with Compaq C 6.2 on OpenVMS Alpha 7.2.

=back

=head2 Threads Are Still Experimental

Multithreading is still an experimental feature.  Some platforms
emit the following message for lib/thr5005

    #
    # This is a KNOWN FAILURE, and one of the reasons why threading
    # is still an experimental feature.  It is here to stop people
    # from deploying threads in production. ;-)
    #

and another known thread-related warning is

   pragma/overload......Unbalanced saves: 3 more saves than restores
   panic: magic_mutexfree during global destruction.
   ok
   lib/selfloader.......Unbalanced saves: 3 more saves than restores
   panic: magic_mutexfree during global destruction.
   ok
   lib/st-dclone........Unbalanced saves: 3 more saves than restores
   panic: magic_mutexfree during global destruction.
   ok

=head2 The Compiler Suite Is Still Experimental

The compiler suite is slowly getting better but is nowhere near
working order yet.  The backend part that has seen perhaps the most
progress is the bytecode compiler.

=head1 Reporting Bugs

If you find what you think is a bug, you might check the articles
recently posted to the comp.lang.perl.misc newsgroup and the perl
bug database at http://bugs.perl.org/  There may also be
information at http://www.perl.com/perl/ , the Perl Home Page.

If you believe you have an unreported bug, please run the B<perlbug>
program included with your release.  Be sure to trim your bug down
to a tiny but sufficient test case.  Your bug report, along with the
output of C<perl -V>, will be sent off to [e-mail] to be
analysed by the Perl porting team.

=head1 SEE ALSO

The F<Changes> file for exhaustive details on what changed.

The F<INSTALL> file for how to build Perl.

The F<README> file for general stuff.

The F<Artistic> and F<Copying> files for copyright information.

=head1 HISTORY

Written by Jarkko Hietaniemi <F<[e-mail]>>, with many contributions
from The Perl Porters and Perl Users submitting feedback and patches.

Send omissions or corrections to <F<[e-mail]>>.

=cut