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 *
-
+
The printf() and sprintf() now support parameter reordering using the
C<%\d+\$> and C<*\d+\$> syntaxes. For example
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 Modules and Pragmata
+=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 back end for walking the Perl syntax tree,
-printing concise info about ops. The output is highly customizable,
-so customizable 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 *
=item *
-Digest, a front end module for calculating digests (checksums),
+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.
-NOTE: the MD5 backward compatibility module is purposefully not
+ use Digest::MD5 'md5_hex';
+
+ $digest = md5_hex("Thirsty Camel");
+
+ print $digest, "\n"; # 01d19d9d2045e005c3f1b80e8b164de1
+
+NOTE: the MD5 backward compatibility module is deliberately not
included since its use is discouraged.
+See L<Digest::MD5> for more information.
+
=item *
-Encode provides a mechanism to translate between different character
-encodings. Support for Unicode, ISO-8859-*, ASCII, CP*, KOI8-R, and
-three variants of EBCDIC are compiled in to the module. Several other
-encodings (like Japanese, Chinese, and MacIntosh encodings) are
-included and will be loaded at runtime.
+Encode, by Nick Ing-Simmons, provides a mechanism to translate
+between different character encodings. Support for Unicode,
+ISO-8859-*, ASCII, CP*, KOI8-R, and three variants of EBCDIC are
+compiled in to the module. Several other encodings (like Japanese,
+Chinese, and MacIntosh encodings) are included and will be loaded at
+runtime.
Any encoding supported by Encode module is also available to the
":encoding()" layer if PerlIO is used.
+See L<Encode> for more information.
+
=item *
-Filter::Simple is an easy-to-use front end to Filter::Util::Call,
+Filter::Simple is an easy-to-use frontend to Filter::Util::Call,
from Damian Conway.
+ # in MyFilter.pm:
+
+ package MyFilter;
+
+ use Filter::Simple sub {
+ while (my ($from, $to) = splice @_, 0, 2) {
+ s/$from/$to/g;
+ }
+ };
+
+ 1;
+
+ # in user's code:
+
+ use MyFilter qr/red/ => 'green';
+
+ print "red\n"; # this code is filtered, will print "green\n"
+ print "bored\n"; # this code is filtered, will print "bogreen\n"
+
+ no MyFilter;
+
+ 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 front end Filter::Simple is to be preferred.
+the frontend Filter::Simple is to be preferred.
+See L<Filter::Util::Call> for more information.
=item *
locale standards, such as "fr" for France, "usd" for US Dollar, and
"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;
+
+ $encoded = encode_base64('Aladdin:open sesame');
+ $decoded = decode_base64($encoded);
+
+ 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;
+
+ $encoded = encode_qp("Smiley in Unicode: \x{263a}");
+ $decoded = decode_qp($encoded);
+
+ print $encoded, "\n"; # "Smiley in Unicode: =263A"
+
MIME::QuotedPrint has been enhanced to provide the basic methods
necessary to use it with PerlIO::Via as in :
- use MIME::QuotedPrint;
- open($fh,">Via(MIME::QuotedPrint)",$path)
+ use MIME::QuotedPrint;
+ open($fh,">Via(MIME::QuotedPrint)",$path)
+
+See L<MIME::QuotedPrint> for more information.
=item *
-PerlIO::Scalar provides the IO to "in memory" perl scalars discussed
-above. It also serves as an example of a loadable layer.
+PerlIO::Scalar, by Nick Ing-Simmons, provides the implementation of
+IO to "in memory" Perl scalars as discussed above. It also serves as
+an example of a loadable layer. Other future possibilities include
+PerlIO::Array and PerlIO::Code. See L<PerlIO::Scalar> for more
+information.
=item *
-PerlIO::Via acts as a PerlIO layer and wraps PerlIO layer
-functionality provided by a class (typically implemented in
-perl code).
+PerlIO::Via, by Nick Ing-Simmons, acts as a PerlIO layer and wraps
+PerlIO layer functionality provided by a class (typically implemented
+in perl code).
+
+ use MIME::QuotedPrint;
+ open($fh,">Via(MIME::QuotedPrint)",$path)
+
+This will automatically convert everything output to C<$fh>
+to Quoted-Printable. 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 *
you have C<switch> and C<case> available in Perl.
+ use Switch;
+
+ switch ($val) {
+
+ case 1 { print "number 1" }
+ case "a" { print "string a" }
+ case [1..10,42] { print "number in list" }
+ case (@array) { print "number in list" }
+ case /\w+/ { print "pattern" }
+ case qr/\w+/ { print "pattern" }
+ case (%hash) { print "entry in hash" }
+ case (\%hash) { print "entry in hash" }
+ case (\&sub) { print "arg to subroutine" }
+ else { print "previous case not true" }
+ }
+
+See L<Switch> for more information.
+
=item *
Text::Balanced from Damian Conway has been added, for
extracting delimited text sequences from strings.
+ use Text::Balanced 'extract_delimited';
+
+ ($a, $b) = extract_delimited("'never say never', he never said", "'", '');
+
+$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(). 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 (still far from providing a full
-round trip for any random piece of Perl code).
+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 under active
+development: expect more robustness in 5.7.2.
=item *
-Class::Struct has now compile-time features.
+Class::Struct can now define the classes in compile time.
=item *
-Math::BigFloat has undergone much fixing. (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/)
+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/)
=item *
is positioned at the out-of-band mark. The method is also exportable
as a sockatmark() function.
-=item
+=item *
IO::Socket::INET has support for ReusePort option (if your platform
-supports it). The Reuse option has now an alias, ReuseAddr.
+supports it). The Reuse option now has an alias, ReuseAddr. For clarity
+you may want to prefer ReuseAddr.
=item *
-Net::Ping has been greatly enhanced.
+Net::Ping has been enhanced. There is now "external" protocol which
+uses Net::Ping::External module which runs external ping(1) and parses
+the output. An alpha version of Net::Ping::External is available in
+CPAN and in 5.7.2 the Net::Ping::External may be integrated to Perl.
=item *
=item *
POSIX::sigaction() is now much more flexible and robust.
+You can now install coderef handlers, 'DEFAULT', and 'IGNORE'
+handlers, installing new handlers was not atomic.
=item *
=back
The following modules have been upgraded from the versions at CPAN:
-CPAN, CGI, DB::File, Getopt::Long, Pod::Man, Pod::Text, Storable,
-Text-Tabs+Wrap.
+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 *
=head2 README.macos
In perl 5.7.1 (and in the 5.6.1) the MacPerl sources have been
-synchronized with the standard Perl sources. To compile MacPerl
+synchronised with the standard Perl sources. To compile MacPerl
some additional steps are required, and this file documents those
steps. On install README.macos will be installed as L<perlmacos>.
Documentation on how to use the Perl source repository has been added.
-=head1 Performance Enhancements
-
=head1 Installation and Configuration Improvements
=over 4
=item *
Another change related to the architecture name is that "-64all"
-(-Duse64bitall, or "maximally 64-bit") is appended only if your pointers
-are 64 bits wide.
+(-Duse64bitall, or "maximally 64-bit") is appended only if your
+pointers are 64 bits wide. (To be exact, the use64bitall is ignored.)
=item *
=item *
If you are on IRIX or Tru64 platforms, new profiling/debugging options
-have been added, see L</perlhack> for more information about pixie and
+have been added, see L<perlhack> for more information about pixie and
Third Degree.
=back
=item *
-In HP-UX 10.20 Perl threading is now working with the various threading
-packages available fror 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 *
MacOS Classic (MacPerl has of course been available since
perl 5.004 but now the source code bases of standard Perl
-and MacPerl have been synchronized)
+and MacPerl have been synchronised)
=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 *
=item *
-Some new Configure symbols, useful for extension writers: d_cmsghdr
-(for struct cmsgdhr), d_fcntl_can_lock (whether fcntl() can be used
-for file locking), d_fsync, d_getitimer(), d_getpagsz (for getpagesize(),
-though you should prefer POSIX::sysconf(_SC_PAGE_SIZE)), d_msghdr_s
-(for struct msgdhr), need_va_copy (whether one needs to use Perl_va_copy()
-to copy varargs), d_readv, d_recvmsg, d_sendmsg, sig_size (the number
-of elements in an array needed to hold all the available signals),
-d_sockatmark, d_strtoq, d_u32align (whether one needs to access
-character data aligned by U32 sized pointers), d_ualarm, d_usleep,
-d_writev.
+Some new Configure symbols, useful for extension writers:
+
+=over 8
+
+=item d_cmsghdr
+
+For struct cmsghdr.
+
+=item d_fcntl_can_lock
+
+Whether fcntl() can be used for file locking.
+
+=item d_fsync
+
+=item d_getitimer
+
+=item d_getpagsz
+
+For getpagesize(), though you should prefer POSIX::sysconf(_SC_PAGE_SIZE))
+
+=item d_msghdr_s
+
+For struct msghdr.
+
+=item need_va_copy
+
+Whether one needs to use Perl_va_copy() to copy varargs.
+
+=item d_readv
+
+=item d_recvmsg
+
+=item d_sendmsg
+
+=item sig_size
+
+The number of elements in an array needed to hold all the available signals.
+
+=item d_sockatmark
+
+=item d_strtoq
+
+=item d_u32align
+
+Whether one needs to access character data aligned by U32 sized pointers.
+
+=item d_ualarm
+
+=item d_usleep
+
+=back
=item *
If your file system supports symbolic links you can build Perl outside
of the source directory by
-
+
mkdir /tmp/perl/build/directory
cd /tmp/perl/build/directory
sh /path/to/perl/source/Configure -Dmksymlinks ...
=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
Two new debugging options have been added: if you have compiled your
Perl with debugging, you can use the -DT and -DR options to trace
-tokenizing and to add reference counts to displaying variables,
+tokenising and to add reference counts to displaying variables,
respectively.
=over 4
=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 Localizing 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
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 perlbug@perl.org to be
-analyzed by the Perl porting team.
+analysed by the Perl porting team.
=head1 SEE ALSO
projects / p5sagit/p5-mst-13.2.git / blobdiff