5.7.1 release.
(To view the differences between the 5.6.0 release and the 5.7.0
-release, see L<perl570delta>).
+release, see L<perl570delta>.)
=head1 Security Vulnerability Closed
=head1 Core Enhancements
-=over 4
-
-=item *
+=head2 AUTOLOAD Is Now Lvaluable
AUTOLOAD is now lvaluable, meaning that you can add the :lvalue attribute
to AUTOLOAD subroutines and you can assign to the AUTOLOAD return value.
+=head2 PerlIO is Now The Default
+
+=over 4
+
=item *
IO is now by default done via PerlIO rather than system's "stdio".
open($fh,">:utf8","Uni.txt");
-Note for EBCDIC users: the pseudo layer ":utf8" is badly named for you
-since it's not UTF-8 what you will be getting but instead UTF-EBCDIC.
-See http://www.unicode.org/unicode/reports/tr16/ for more information.
-In future release this naming issue may or may not change.
+Note for EBCDIC users: the pseudo layer ":utf8" is erroneously named
+for you since it's not UTF-8 what you will be getting but instead
+UTF-EBCDIC. See L<perlunicode>, L<utf8>, and
+http://www.unicode.org/unicode/reports/tr16/ for more information.
+In future releases this naming may change.
=item *
=item *
-The following builtin functions are now overrideable: chop(), chomp(),
+The following builtin functions are now overridable: chop(), chomp(),
each(), keys(), pop(), push(), shift(), splice(), unshift().
=item *
and basic arithmetics (+ - * /) if the arguments are integers, and
tries also to keep the results stored internally as integers.
This change leads into often slightly faster and always less lossy
-arithmetics (previously Perl always preferred floating point numbers
-in its math)
+arithmetics. (Previously Perl always preferred floating point numbers
+in its math.)
=item *
to Unicode 3.1. For more information, see http://www.unicode.org/,
and http://www.unicode.org/unicode/reports/tr27/
-For developers interested in enhanching Perl's Unicode capabilities:
+For developers interested in enhancing Perl's Unicode capabilities:
almost all the UCD files are included with the Perl distribution in
the lib/unicode subdirectory. The most notable omission, for space
considerations, is the Unihan database.
=back
+=head2 Signals Are Now Safe
+
+Perl used to be fragile in that signals arriving at inopportune moments
+could corrupt Perl's internal state.
+
=head1 Modules and Pragmata
=head2 New Modules
=item *
-B::Concise is a new compiler backend for walking the Perl syntax tree,
-printing concise info about ops. The output is highly customisable,
-so customisable that B::Terse has been re-implemented in terms of
-B::Concise.
+B::Concise, by Stephen McCamant, is a new compiler backend for
+walking the Perl syntax tree, printing concise info about ops.
+The output is highly customisable.
+
+See L<B::Concise> for more information.
=item *
-Class::ISA for reporting the search path for a class's ISA tree,
-from Sean Burke, has been added.
+Class::ISA, by Sean Burke, for reporting the search path for a
+class's ISA tree, has been added.
+
+See L<Class::ISA> for more information.
=item *
Digest, a frontend module for calculating digests (checksums),
from Gisle Aas, has been added.
+See L<Digest> for more information.
+
=item *
-Digest::MD5 for calculating MD5 digests (checksums), from Gisle Aas,
+Digest::MD5 for calculating MD5 digests (checksums), by Gisle Aas,
has been added.
use Digest::MD5 'md5_hex';
print $digest, "\n"; # 01d19d9d2045e005c3f1b80e8b164de1
-NOTE: the MD5 backward compatibility module is purposefully not
+NOTE: the MD5 backward compatibility module is deliberately not
included since its use is discouraged.
+See L<Digest::MD5> for more information.
+
=item *
-Encode provides a mechanism to translate between different character
-encodings. Support for Unicode, ISO-8859-*, ASCII, CP*, KOI8-R, and
-three variants of EBCDIC are compiled in to the module. Several other
-encodings (like Japanese, Chinese, and MacIntosh encodings) are
-included and will be loaded at runtime.
+Encode, by Nick Ing-Simmons, provides a mechanism to translate
+between different character encodings. Support for Unicode,
+ISO-8859-*, ASCII, CP*, KOI8-R, and three variants of EBCDIC are
+compiled in to the module. Several other encodings (like Japanese,
+Chinese, and MacIntosh encodings) are included and will be loaded at
+runtime.
Any encoding supported by Encode module is also available to the
":encoding()" layer if PerlIO is used.
+See L<Encode> for more information.
+
=item *
Filter::Simple is an easy-to-use frontend to Filter::Util::Call,
print "red\n"; # this code is not filtered, will print "red\n"
+See L<Filter::Simple> for more information.
+
=item *
-Filter::Util::Call, from Paul Marquess, provides you with the
+Filter::Util::Call, by Paul Marquess, provides you with the
framework to write I<Source Filters> in Perl. For most uses
the frontend Filter::Simple is to be preferred.
+See L<Filter::Util::Call> for more information.
=item *
"jp" for Japanese.
use Locale::Country;
-
+
$country = code2country('jp'); # $country gets 'Japan'
$code = country2code('Norway'); # $code gets 'no'
+See L<Locale::Constants>, L<Locale::Country>, L<Locale::Currency>,
+and L<Locale::Language> for more information.
+
=item *
-MIME::Base64, from Gisle Aas, allows you to encode data in base64.
+MIME::Base64, by Gisle Aas, allows you to encode data in base64.
use MIME::Base64;
print $encoded, "\n"; # "QWxhZGRpbjpvcGVuIHNlc2FtZQ=="
+See L<MIME::Base64> for more information.
+
=item *
-MIME::QuotedPrint, from Gisle Aas, allows you to encode data in
+MIME::QuotedPrint, by Gisle Aas, allows you to encode data in
quoted-printable encoding.
use MIME::QuotedPrint;
use MIME::QuotedPrint;
open($fh,">Via(MIME::QuotedPrint)",$path)
+See L<MIME::QuotedPrint> for more information.
+
=item *
-PerlIO::Scalar provides the implementation of IO to "in memory" Perl
-scalars as discussed above. It also serves as an example of
-a loadable layer. Other future possibilities include PerlIO::Array
-and PerlIO::Code.
+PerlIO::Scalar, by Nick Ing-Simmons, provides the implementation of
+IO to "in memory" Perl scalars as discussed above. It also serves as
+an example of a loadable layer. Other future possibilities include
+PerlIO::Array and PerlIO::Code. See L<PerlIO::Scalar> for more
+information.
=item *
-PerlIO::Via acts as a PerlIO layer and wraps PerlIO layer
-functionality provided by a class (typically implemented in
-perl code).
+PerlIO::Via, by Nick Ing-Simmons, acts as a PerlIO layer and wraps
+PerlIO layer functionality provided by a class (typically implemented
+in perl code).
use MIME::QuotedPrint;
open($fh,">Via(MIME::QuotedPrint)",$path)
This will automatically convert everything output to C<$fh>
-to Quoted-Printable.
+to Quoted-Printable. See L<PerlIO::Via> for more information.
=item *
-Pod::Text::Overstrike, from Joe Smith, has been added.
+Pod::Text::Overstrike, by Joe Smith, has been added.
It converts POD data to formatted overstrike text.
+See L<Pod::Text::Overstrike> for more information.
=item *
else { print "previous case not true" }
}
+See L<Switch> for more information.
+
=item *
Text::Balanced from Damian Conway has been added, for
extracting delimited text sequences from strings.
use Text::Balanced 'extract_delimited';
-
+
($a, $b) = extract_delimited("'never say never', he never said", "'", '');
-C<$a> will be "'never say never'", C<$b> will be ', he never said'.
+$a will be "'never say never'", $b will be ', he never said'.
In addition to extract_delimited() there are also extract_bracketed(),
extract_quotelike(), extract_codeblock(), extract_variable(),
extract_tagged(), extract_multiple(), gen_delimited_pat(), and
-gen_extract_tagged().
+gen_extract_tagged(). With these you can implement rather advanced
+parsing algorithms. See L<Text::Balanced> for more information.
=item *
-Tie::RefHash::Nestable, from Edward Avis, allows storing hash references
-(unlike the standard Tie::Refhash)
+Tie::RefHash::Nestable, by Edward Avis, allows storing hash references
+(unlike the standard Tie::Refhash) The module is contained within
+Tie::RefHash.
=item *
-XS::Typemap is a test extension that exercises XS typemaps.
-Nothing gets installed but for extension writers the code is
-worth studying.
+XS::Typemap, by Tim Jenness, is a test extension that exercises XS
+typemaps. Nothing gets installed but for extension writers the code
+is worth studying.
=back
=item *
B::Deparse should be now more robust. It still far from providing a full
-round trip for any random piece of Perl code, though, and is unde active
+round trip for any random piece of Perl code, though, and is under active
development: expect more robustness in 5.7.2.
=item *
=item *
-Math::BigFloat has undergone much fixing.
+Math::BigFloat has undergone much fixing, and in addition the fmod()
+function now supports modulus operations.
(The fixed Math::BigFloat module is also available in CPAN for those
who can't upgrade their Perl: http://www.cpan.org/authors/id/J/JP/JPEACOCK/)
=back
The following modules have been upgraded from the versions at CPAN:
-CPAN, CGI, DB::File, File::Temp, Getopt::Long, Pod::Man, Pod::Text,
+CPAN, CGI, DB_File, File::Temp, Getopt::Long, Pod::Man, Pod::Text,
Storable, Text-Tabs+Wrap.
=head1 Performance Enhancements
=item *
Hashes now use Bob Jenkins "One-at-a-Time" hashing key algorithm
-(http://burtleburtle.net/bob/hash/doobs.html).
-This algorithm is reasonably fast while producing a much better spread
-of values. Hash values output from the algorithm on a hash of all
-3-char printable ASCII keys comes much closer to passing the DIEHARD
-random number generation tests. According to perlbench, this change
-has not affected the overall speed of Perl.
+(http://burtleburtle.net/bob/hash/doobs.html). This algorithm is
+reasonably fast while producing a much better spread of values than
+the old hashing algorithm (originally by Chris Torek, later tweaked by
+Ilya Zakharevich). Hash values output from the algorithm on a hash of
+all 3-char printable ASCII keys comes much closer to passing the
+DIEHARD random number generation tests. According to perlbench, this
+change has not affected the overall speed of Perl.
=item *
=item *
-In HP-UX 10.20 Perl threading is now working with the various threading
-packages available for HP-UX. See L<perlhpux> (or in the source
-distribution, README.hpux) for more information.
+Building perl with -Duseithreads or -Duse5005threads now works under
+HP-UX 10.20 (previously it only worked under 10.30 or later). You will
+need a thread library package installed. See README.hpux.
=item *
=item *
-NCR MP-RAS
+NCR MP-RAS is now supported.
=item *
-NonStop-UX
+NonStop-UX is now supported.
=item *
-Amdahl UTS
+Amdahl UTS is now supported.
=item *
=head1 Selected Bug Fixes
-Numerous memory leaks have been hunted down. Most importantly anonymous
-subs used to leak quite a bit.
+Numerous memory leaks and uninitialized memory accesses have been hunted down.
+Most importantly anonymous subs used to leak quite a bit.
=over 4
=item *
-The order of DESTROYS has been made more predictable.
+chop(@list) in list context returned the characters chopped in
+reverse order. This has been reversed to be in the right order.
+
+=item *
+
+The order of DESTROYs has been made more predictable.
=item *
=item *
+The tainting behaviour of sprintf() has been rationalized. It does
+not taint the result of floating point formats anymore, making the
+behaviour consistent with that of string interpolation.
+
+=item *
+
All but the first argument of the IO syswrite() method are now optional.
=item *
Previously DYNIX/ptx had problems in its Configure probe for non-blocking I/O.
+=item *
+
+Windows
+
+=over 8
+
+=item *
+
+Borland C++ v5.5 is now a supported compiler that can build Perl.
+However, the generated binaries continue to be incompatible with those
+generated by the other supported compilers (GCC and Visual C++).
+
+=item *
+
+Win32::GetCwd() correctly returns C:\ instead of C: when at the drive root.
+Other bugs in chdir() and Cwd::cwd() have also been fixed.
+
+=item *
+
+Duping socket handles with open(F, ">&MYSOCK") now works under Windows 9x.
+
+=item *
+
+HTML files will be installed in c:\perl\html instead of c:\perl\lib\pod\html
+
+=item *
+
+The makefiles now provide a single switch to bulk-enable all the features
+enabled in ActiveState ActivePerl (a popular binary distribution).
+
+=back
+
=back
=head1 New or Changed Diagnostics
=item *
-If an attempt to use a (non-blessed) reference as an array element
+If an attempt to use a (non-blessed) reference as an array index
is made, a warning is given.
=item *
=item *
-Perl now uses system malloc instead of Perl malloc in all 64-bit
-platforms. This change breaks backward compatibility but Perl's
-malloc has problems with large address spaces and also the speed of
-vendors' malloc is generally better in large address space machines
-(Perl's malloc is mostly tuned for space).
+Perl now uses system malloc instead of Perl malloc on all 64-bit
+platforms, and even in some not-always-64-bit platforms like AIX,
+IRIX, and Solaris. This change breaks backward compatibility but
+Perl's malloc has problems with large address spaces and also the
+speed of vendors' malloc is generally better in large address space
+machines (Perl's malloc is mostly tuned for space).
=back
+=head1 New Tests
+
+Many new tests have been added. The most notable is probably the
+lib/1_compile: it is very notable because running it takes quite a
+long time -- it test compiles all the Perl modules in the distribution.
+Please be patient.
+
=head1 Known Problems
-=head2 lib/b test 19
+Note that unlike other sections in this document (which describe
+changes since 5.7.0) this section is cumulative containing known
+problems for all the 5.7 releases.
-The test fails in various platforms (PA64 and IA64 are known), but the
-exact cause is still being investigated.
+=head2 AIX vac 5.0.0.0 May Produce Buggy Code For Perl
-=head2 Localising a Tied Variable Leaks Memory
+The AIX C compiler vac version 5.0.0.0 may produce buggy code,
+resulting in few random tests failing, but when the failing tests
+are run by hand, they succeed. We suggest upgrading to at least
+vac version 5.0.1.0, that has been known to compile Perl correctly.
+"lslpp -L|grep vac.C" will tell you the vac version.
- use Tie::Hash;
- tie my %tie_hash => 'Tie::StdHash';
+=head2 lib/ftmp-security tests warn 'system possibly insecure'
- ...
+Don't panic. Read INSTALL 'make test' section instead.
- local($tie_hash{Foo}) = 1; # leaks
+=head2 lib/io_multihomed Fails In LP64-Configured HP-UX
-Code like the above is known to leak memory every time the local()
-is executed.
+The lib/io_multihomed test may hang in HP-UX if Perl has been
+configured to be 64-bit. Because other 64-bit platforms do not hang in
+this test, HP-UX is suspect. All other tests pass in 64-bit HP-UX. The
+test attempts to create and connect to "multihomed" sockets (sockets
+which have multiple IP addresses).
+
+=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 lib/b test 19
+
+The test fails on various platforms (PA64 and IA64 are known), but the
+exact cause is still being investigated.
+
+=head2 Linux With Sfio Fails op/misc Test 48
+
+No known fix.
=head2 sigaction test 13 in VMS
-The test is known to fail, whether it's because of VMS of because
-of faulty test, is not known.
+The test is known to fail; whether it's because of VMS of because
+of faulty test is not known.
=head2 sprintf tests 129 and 130
-The op/sprintf tests 129 and 130 are known to fail in some platforms.
-Examples include any platform using sfio, and Tandem's NonStop-UX.
+The op/sprintf tests 129 and 130 are known to fail on some platforms.
+Examples include any platform using sfio, and Compaq/Tandem's NonStop-UX.
The failing platforms do not comply with the ANSI C Standard, line
19ff on page 134 of ANSI X3.159 1989 to be exact. (They produce
something else than "1" and "-1" when formatting 0.6 and -0.6 using
the printf format "%.0f", most often they produce "0" and "-0".)
+=head2 Failure of Thread tests
+
+The subtests 19 and 20 of lib/thr5005.t test are known to fail due to
+fundamental problems in the 5.005 threading implementation. These are
+not new failures--Perl 5.005_0x has the same bugs, but didn't have
+these tests. (Note that support for 5.005-style threading remains
+experimental.)
+
+=head2 Localising a Tied Variable Leaks Memory
+
+ use Tie::Hash;
+ tie my %tie_hash => 'Tie::StdHash';
+
+ ...
+
+ local($tie_hash{Foo}) = 1; # leaks
+
+Code like the above is known to leak memory every time the local()
+is executed.
+
=head2 Self-tying of Arrays and Hashes Is Forbidden
Self-tying of arrays and hashes is broken in rather deep and
frustrated at the mysterious results (core dumps, most often) it is
for now forbidden (you will get a fatal error even from an attempt).
+=head2 Building Extensions Can Fail Because Of Largefiles
+
+Some extensions like mod_perl 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 The Compiler Suite Is Still Experimental
+
+The compiler suite is slowly getting better but is nowhere near
+working order yet.
+
=head1 Reporting Bugs
If you find what you think is a bug, you might check the articles