pod/perl570delta.pod Changes from 5.6 to 5.7.0
pod/perl571delta.pod Changes from 5.7.0 to 5.7.1
pod/perl572delta.pod Changes from 5.7.1 to 5.7.2
+pod/perl58delta.pod Changes from 5.6 to 5.8.0
pod/perlapi.pod Perl API documentation (autogenerated)
pod/perlapio.pod PerlIO IO API info
pod/perlbook.pod Perl book information
--- /dev/null
+=head1 NAME
+
+perldelta - what is new for perl v5.8.0
+
+=head1 DESCRIPTION
+
+This document describes differences between the 5.6.0 release and
+the 5.8.0 release.
+
+Many of the bug fixes in 5.8.0 were already seen in the 5.6.1
+maintenance release since the two releases were kept closely
+coordinated (while 5.8.0 was still called 5.7.something).
+
+Changes that were integrated into the 5.6.1 release are marked C<[561]>.
+Many of these changes have been further developed since 5.6.1 was released,
+those are marked C<[561+]>.
+
+You can see the list of changes in the 5.6.1 release (both from the
+5.005_03 release and the 5.6.0 release) by reading L<perl561delta>.
+
+=head1 Highlights In 5.8.0
+
+=over 4
+
+=item *
+
+Better Unicode support
+
+=item *
+
+New IO Implementation
+
+=item *
+
+New Thread Implementation
+
+=item *
+
+Better Numeric Accuracy
+
+=item *
+
+Safe Signals
+
+=item *
+
+Many New Modules
+
+=item *
+
+More Extensive Regression Testing
+
+=back
+
+=head1 Incompatible Changes
+
+=head2 Binary Incompatibility
+
+B<Perl 5.8 is not binary compatible with earlier releases of Perl.>
+
+B<You have to recompile your XS modules.>
+
+(Pure Perl modules should continue to work.)
+
+The major reason for the discontinuity is the new IO architecture
+called PerlIO. PerlIO is the default configuration because without
+it many new features of Perl 5.8 cannot be used. In other words:
+you just have to recompile your modules containing XS code, sorry
+about that.
+
+In future releases of Perl, non-PerlIO aware XS modules may become
+completely unsupported. This shouldn't be too difficult for module
+authors, however: PerlIO has been designed as a drop-in replacement
+(at the source code level) for the stdio interface.
+
+Depending on your platform, there are also other reasons why
+we decided to break binary compatibility, please read on.
+
+=head2 64-bit platforms and malloc
+
+If your pointers are 64 bits wide, the Perl malloc is no longer being
+used because it does not work well with 8-byte pointers. Also,
+usually the system mallocs on such platforms are much better optimized
+for such large memory models than the Perl malloc. Some memory-hungry
+Perl applications like the PDL don't work well with Perl's malloc.
+Finally, other applications than Perl (such as mod_perl) tend to prefer
+the system malloc. Such platforms include Alpha and 64-bit HPPA,
+MIPS, PPC, and Sparc.
+
+=head2 AIX Dynaloading
+
+The AIX dynaloading now uses in AIX releases 4.3 and newer the native
+dlopen interface of AIX instead of the old emulated interface. This
+change will probably break backward compatibility with compiled
+modules. The change was made to make Perl more compliant with other
+applications like mod_perl which are using the AIX native interface.
+
+=head2 Attributes for C<my> variables now handled at run-time
+
+The C<my EXPR : ATTRS> syntax now applies variable attributes at
+run-time. (Subroutine and C<our> variables still get attributes applied
+at compile-time.) See L<attributes> for additional details. In particular,
+however, this allows variable attributes to be useful for C<tie> interfaces,
+which was a deficiency of earlier releases. Note that the new semantics
+doesn't work with the Attribute::Handlers module (as of version 0.76).
+
+=head2 Socket Extension Dynamic in VMS
+
+The Socket extension is now dynamically loaded instead of being
+statically built in. This may or may not be a problem with ancient
+TCP/IP stacks of VMS: we do not know since we weren't able to test
+Perl in such configurations.
+
+=head2 IEEE-format Floating Point Default on OpenVMS Alpha
+
+Perl now uses IEEE format (T_FLOAT) as the default internal floating
+point format on OpenVMS Alpha, potentially breaking binary compatibility
+with external libraries or existing data. G_FLOAT is still available as
+a configuration option. The default on VAX (D_FLOAT) has not changed.
+
+=head2 New Unicode Semantics (no more C<use utf8>, almost)
+
+Previously in Perl 5.6 to use Unicode one would say "use utf8" and
+then the operations (like string concatenation) were Unicode-aware
+in that lexical scope.
+
+This was found to be an inconvenient interface, and in Perl 5.8 the
+Unicode model has completely changed: now the "Unicodeness" is bound
+to the data itself, and for most of the time "use utf8" is not needed
+at all. The only remaining use of "use utf8" is when the Perl script
+itself has been written in the UTF-8 encoding of Unicode. (UTF-8 has
+not been made the default since there are many Perl scripts out there
+that are using various national eight-bit character sets, which would
+be illegal in UTF-8.)
+
+See L<perluniintro> for the explanation of the current model,
+and L<utf8> for the current use of the utf8 pragma.
+
+=head2 New Unicode Properties
+
+Unicode I<scripts> are now supported. Scripts are similar to (and superior
+to) Unicode I<blocks>. The difference between scripts and blocks is that
+scripts are the glyphs used by a language or a group of languages, while
+the blocks are more artificial groupings of (mostly) 256 characters based
+on the Unicode numbering.
+
+In general, scripts are more inclusive, but not universally so. For
+example, while the script C<Latin> includes all the Latin characters and
+their various diacritic-adorned versions, it does not include the various
+punctuation or digits (since they are not solely C<Latin>).
+
+A number of other properties are now supported, including C<\p{L&}>,
+C<\p{Any}> C<\p{Assigned}>, C<\p{Unassigned}>, C<\p{Blank}> [561] and
+C<\p{SpacePerl}> [561] (along with their C<\P{...}> versions, of course).
+See L<perlunicode> for details, and more additions.
+
+The C<In> or C<Is> prefix to names used with the C<\p{...}> and C<\P{...}>
+are now almost always optional. The only exception is that a C<In> prefix
+is required to signify a Unicode block when a block name conflicts with a
+script name. For example, C<\p{Tibetan}> refers to the script, while
+C<\p{InTibetan}> refers to the block. When there is no name conflict, you
+can omit the C<In> from the block name (e.g. C<\p{BraillePatterns}>), but
+to be safe, it's probably best to always use the C<In>).
+
+=head2 REF(...) Instead Of SCALAR(...)
+
+A reference to a reference now stringifies as "REF(0x81485ec)" instead
+of "SCALAR(0x81485ec)" in order to be more consistent with the return
+value of ref().
+
+=head2 pack/unpack D/F recycled
+
+The undocumented pack/unpack template letters D/F have been recycled
+for better use: now they stand for long double (if supported by the
+platform) and NV (Perl internal floating point type). (They used
+to be aliases for d/f, but you never knew that.)
+
+=head2 glob() now returns filenames in alphabetical order
+
+The list of filenames from glob() (or <...>) is now by default sorted
+alphabetically to be csh-compliant (which is what happened before
+in most UNIX platforms). (bsd_glob() does still sort platform
+natively, ASCII or EBCDIC, unless GLOB_ALPHASORT is specified.) [561]
+
+=head2 Deprecations
+
+=over 4
+
+=item *
+
+The semantics of bless(REF, REF) were unclear and until someone proves
+it to make some sense, it is forbidden.
+
+=item *
+
+The obsolete chat2 library that should never have been allowed
+to escape the laboratory has been decommissioned.
+
+=item *
+
+Using chdir("") or chdir(undef) instead of explicit chdir() is
+doubtful. A failure (think chdir(some_function()) can lead into
+unintended chdir() to the home directory, therefore this behaviour
+is deprecated.
+
+=item *
+
+The builtin dump() function has probably outlived most of its
+usefulness. The core-dumping functionality will remain in future
+available as an explicit call to C<CORE::dump()>, but in future
+releases the behaviour of an unqualified C<dump()> call may change.
+
+=item *
+
+The very dusty examples in the eg/ directory have been removed.
+Suggestions for new shiny examples welcome but the main issue is that
+the examples need to be documented, tested and (most importantly)
+maintained.
+
+=item *
+
+The (bogus) escape sequences \8 and \9 now give an optional warning
+("Unrecognized escape passed through"). There is no need to \-escape
+any C<\w> character.
+
+=item *
+
+The *glob{FILEHANDLE} is deprecated, use *glob{IO} instead.
+
+=item *
+
+The C<package;> syntax (C<package> without an argument) has been
+deprecated. Its semantics were never that clear and its
+implementation even less so. If you have used that feature to
+disallow all but fully qualified variables, C<use strict;> instead.
+
+=item *
+
+The unimplemented POSIX regex features [[.cc.]] and [[=c=]] are still
+recognised but now cause fatal errors. The previous behaviour of
+ignoring them by default and warning if requested was unacceptable
+since it, in a way, falsely promised that the features could be used.
+
+=item *
+
+In future releases, non-PerlIO aware XS modules may become completely
+unsupported. Since PerlIO is a drop-in replacement for stdio at the
+source code level, this shouldn't be that drastic a change.
+
+=item *
+
+Previous versions of perl and some readings of some sections of Camel
+III implied that the C<:raw> "discipline" was the inverse of C<:crlf>.
+Turning off "clrfness" is no longer enough to make a stream truly
+binary. So the PerlIO C<:raw> layer (or "discipline", to use the Camel
+book's older terminology) is now formally defined as being equivalent
+to binmode(FH) - which is in turn defined as doing whatever is
+necessary to pass each byte as-is without any translation. In
+particular binmode(FH) - and hence C<:raw> - will now turn off both
+CRLF and UTF-8 translation and remove other layers (e.g. :encoding())
+which would modify byte stream.
+
+=item *
+
+The current user-visible implementation of pseudo-hashes (the weird
+use of the first array element) is deprecated starting from Perl 5.8.0
+and will be removed in Perl 5.10.0, and the feature will be
+implemented differently. Not only is the current interface rather
+ugly, but the current implementation slows down normal array and hash
+use quite noticeably. The C<fields> pragma interface will remain
+available. The I<restricted hashes> interface is expected to
+be the replacement interface (see L<Hash::Util>). If your existing
+programs depends on the underlying implementation, consider using
+L<Class::PseudoHash> from CPAN.
+
+=item *
+
+The syntaxes C<< @a->[...] >> and C<< %h->{...} >> have now been deprecated.
+
+=item *
+
+After years of trying, suidperl is considered to be too complex to
+ever be considered truly secure. The suidperl functionality is likely
+to be removed in a future release.
+
+=item *
+
+The 5.005 threads model (module C<Thread>) is deprecated and expected
+to be removed in Perl 5.10. Multithreaded code should be migrated to
+the new ithreads model (see L<threads>, L<threads::shared> and
+L<perlthrtut>).
+
+=item *
+
+The long deprecated uppercase aliases for the string comparison
+operators (EQ, NE, LT, LE, GE, GT) have now been removed.
+
+=item *
+
+The tr///C and tr///U features have been removed and will not return;
+the interface was a mistake. Sorry about that. For similar
+functionality, see pack('U0', ...) and pack('C0', ...). [561]
+
+=item *
+
+Earlier Perls treated "sub foo (@bar)" as equivalent to "sub foo (@)".
+The prototypes are now checked better at compile-time for invalid
+syntax. An optional warning is generated ("Illegal character in
+prototype...") but this may be upgraded to a fatal error in a future
+release.
+
+=item *
+
+The C<exec LIST> and C<system LIST> operations now produce warnings on
+tainted data and in some future release they will produce fatal errors.
+
+=item *
+
+The existing behaviour when localising tied arrays and hashes is wrong,
+and will be changed in a future release, so do not rely on the existing
+behaviour. See L<"Localising Tied Arrays and Hashes Is Broken">.
+
+=back
+
+=head1 Core Enhancements
+
+=head2 Unicode Overhaul
+
+Unicode in general should be now much more usable than in Perl 5.6.0
+(or even in 5.6.1). Unicode can be used in hash keys, Unicode in
+regular expressions should work now, Unicode in tr/// should work now,
+Unicode in I/O should work now. See L<perluniintro> for introduction
+and L<perlunicode> for details.
+
+=over 4
+
+=item *
+
+The Unicode Character Database coming with Perl has been upgraded
+to Unicode 3.2.0. For more information, see http://www.unicode.org/ .
+[561+] (5.6.1 has UCD 3.0.1.)
+
+=item *
+
+For developers interested in enhancing Perl's Unicode capabilities:
+almost all the UCD files are included with the Perl distribution in
+the F<lib/unicore> subdirectory. The most notable omission, for space
+considerations, is the Unihan database.
+
+=item *
+
+The properties \p{Blank} and \p{SpacePerl} have been added. "Blank" is like
+C isblank(), that is, it contains only "horizontal whitespace" (the space
+character is, the newline isn't), and the "SpacePerl" is the Unicode
+equivalent of C<\s> (\p{Space} isn't, since that includes the vertical
+tabulator character, whereas C<\s> doesn't.)
+
+See "New Unicode Properties" earlier in this document for additional
+information on changes with Unicode properties.
+
+=back
+
+=head2 PerlIO is Now The Default
+
+=over 4
+
+=item *
+
+IO is now by default done via PerlIO rather than system's "stdio".
+PerlIO allows "layers" to be "pushed" onto a file handle to alter the
+handle's behaviour. Layers can be specified at open time via 3-arg
+form of open:
+
+ open($fh,'>:crlf :utf8', $path) || ...
+
+or on already opened handles via extended C<binmode>:
+
+ binmode($fh,':encoding(iso-8859-7)');
+
+The built-in layers are: unix (low level read/write), stdio (as in
+previous Perls), perlio (re-implementation of stdio buffering in a
+portable manner), crlf (does CRLF <=> "\n" translation as on Win32,
+but available on any platform). A mmap layer may be available if
+platform supports it (mostly UNIXes).
+
+Layers to be applied by default may be specified via the 'open' pragma.
+
+See L</"Installation and Configuration Improvements"> for the effects
+of PerlIO on your architecture name.
+
+=item *
+
+If your platform supports fork(), you can use the list form of C<open>
+for pipes. For example:
+
+ open KID_PS, "-|", "ps", "aux" or die $!;
+
+forks the ps(1) command (without spawning a shell, as there are more
+than three arguments to open()), and reads its standard output via the
+C<KID_PS> filehandle. See L<perlipc>.
+
+=item *
+
+File handles can be marked as accepting Perl's internal encoding of Unicode
+(UTF-8 or UTF-EBCDIC depending on platform) by a pseudo layer ":utf8" :
+
+ open($fh,">:utf8","Uni.txt");
+
+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. See L<perluniintro>
+for more information about UTF-8.
+
+=item *
+
+If your environment variables (LC_ALL, LC_CTYPE, LANG, LANGUAGE) look
+like you want to use UTF-8 (any of the the variables match C</utf-?8/i>),
+your STDIN, STDOUT, STDERR handles and the default open layer
+(see L<open>) are marked as UTF-8. (This feature, like other new
+features that combine Unicode and I/O, work only if you are using
+PerlIO, but that's the default.)
+
+Note that after this Perl really does assume that everything is UTF-8:
+for example if some input handle is not, Perl will probably very soon
+complain about the input data like this "Malformed UTF-8 ..." since
+any old eight-bit data is not legal UTF-8.
+
+Note for code authors: if you want to enable your users to use UTF-8
+as their default encoding but in your code still have eight-bit I/O streams
+(such as images or zip files), you need to explicitly open() or binmode()
+with C<:bytes> (see L<perlfunc/open> and L<perlfunc/binmode>), or you
+can just use C<binmode(FH)> (nice for pre-5.8.0 backward compatibility).
+
+=item *
+
+File handles can translate character encodings from/to Perl's internal
+Unicode form on read/write via the ":encoding()" layer.
+
+=item *
+
+File handles can be opened to "in memory" files held in Perl scalars via:
+
+ open($fh,'>', \$variable) || ...
+
+=item *
+
+Anonymous temporary files are available without need to
+'use FileHandle' or other module via
+
+ open($fh,"+>", undef) || ...
+
+That is a literal undef, not an undefined value.
+
+=back
+
+=head2 ithreads
+
+The new interpreter threads ("ithreads" for short) implementation of
+multithreading, by Arthur Bergman, replaces the old "5.005 threads"
+implementation. In the ithreads model any data sharing between
+threads must be explicit, as opposed to the model where data sharing
+was implicit. See L<threads> and L<threads::shared>, and
+L<perlthrtut>.
+
+As a part of the ithreads implementation Perl will also use
+any necessary and detectable reentrant libc interfaces.
+
+=head2 Restricted Hashes
+
+A restricted hash is restricted to a certain set of keys, no keys
+outside the set can be added. Also individual keys can be restricted
+so that the key cannot be deleted and the value cannot be changed.
+No new syntax is involved: the Hash::Util module is the interface.
+
+=head2 Safe Signals
+
+Perl used to be fragile in that signals arriving at inopportune moments
+could corrupt Perl's internal state. Now Perl postpones handling of
+signals until it's safe (between opcodes).
+
+This change may have surprising side effects because signals no longer
+interrupt Perl instantly. Perl will now first finish whatever it was
+doing, like finishing an internal operation (like sort()) or an
+external operation (like an I/O operation), and only then look at any
+arrived signals (and before starting the next operation). No more corrupt
+internal state since the current operation is always finished first,
+but the signal may take more time to get heard. Note that breaking
+out from potentially blocking operations should still work, though.
+
+=head2 Understanding of Numbers
+
+In general a lot of fixing has happened in the area of Perl's
+understanding of numbers, both integer and floating point. Since in
+many systems the standard number parsing functions like C<strtoul()>
+and C<atof()> seem to have bugs, Perl tries to work around their
+deficiencies. This results hopefully in more accurate numbers.
+
+Perl now tries internally to use integer values in numeric conversions
+and basic arithmetics (+ - * /) if the arguments are integers, and
+tries also to keep the results stored internally as integers.
+This change leads to often slightly faster and always less lossy
+arithmetics. (Previously Perl always preferred floating point numbers
+in its math.)
+
+=head2 Arrays now always interpolate into double-quoted strings [561]
+
+In double-quoted strings, arrays now interpolate, no matter what. The
+behavior in earlier versions of perl 5 was that arrays would interpolate
+into strings if the array had been mentioned before the string was
+compiled, and otherwise Perl would raise a fatal compile-time error.
+In versions 5.000 through 5.003, the error was
+
+ Literal @example now requires backslash
+
+In versions 5.004_01 through 5.6.0, the error was
+
+ In string, @example now must be written as \@example
+
+The idea here was to get people into the habit of writing
+C<"fred\@example.com"> when they wanted a literal C<@> sign, just as
+they have always written C<"Give me back my \$5"> when they wanted a
+literal C<$> sign.
+
+Starting with 5.6.1, when Perl now sees an C<@> sign in a
+double-quoted string, it I<always> attempts to interpolate an array,
+regardless of whether or not the array has been used or declared
+already. The fatal error has been downgraded to an optional warning:
+
+ Possible unintended interpolation of @example in string
+
+This warns you that C<"fred@example.com"> is going to turn into
+C<fred.com> if you don't backslash the C<@>.
+See http://www.plover.com/~mjd/perl/at-error.html for more details
+about the history here.
+
+=head2 Miscellaneous Changes
+
+=over 4
+
+=item *
+
+AUTOLOAD is now lvaluable, meaning that you can add the :lvalue attribute
+to AUTOLOAD subroutines and you can assign to the AUTOLOAD return value.
+
+=item *
+
+The $Config{byteorder} (and corresponding BYTEORDER in config.h) was
+previously wrong in platforms if sizeof(long) was 4, but sizeof(IV)
+was 8. The byteorder was only sizeof(long) bytes long (1234 or 4321),
+but now it is correctly sizeof(IV) bytes long, (12345678 or 87654321).
+(This problem didn't affect Windows platforms.)
+
+Also, $Config{byteorder} is now computed dynamically--this is more
+robust with "fat binaries" where an executable image contains binaries
+for more than one binary platform, and when cross-compiling.
+
+=item *
+
+C<perl -d:Module=arg,arg,arg> now works (previously one couldn't pass
+in multiple arguments.)
+
+=item *
+
+C<do> followed by a bareword now ensures that this bareword isn't
+a keyword (to avoid a bug where C<do q(foo.pl)> tried to call a
+subroutine called C<q>). This means that for example instead of
+C<do format()> you must write C<do &format()>.
+
+=item *
+
+The builtin dump() now gives an optional warning
+C<dump() better written as CORE::dump()>,
+meaning that by default C<dump(...)> is resolved as the builtin
+dump() which dumps core and aborts, not as (possibly) user-defined
+C<sub dump>. To call the latter, qualify the call as C<&dump(...)>.
+(The whole dump() feature is to considered deprecated, and possibly
+removed/changed in future releases.)
+
+=item *
+
+chomp() and chop() are now overridable. Note, however, that their
+prototype (as given by C<prototype("CORE::chomp")> is undefined,
+because it cannot be expressed and therefore one cannot really write
+replacements to override these builtins.
+
+=item *
+
+END blocks are now run even if you exit/die in a BEGIN block.
+Internally, the execution of END blocks is now controlled by
+PL_exit_flags & PERL_EXIT_DESTRUCT_END. This enables the new
+behaviour for Perl embedders. This will default in 5.10. See
+L<perlembed>.
+
+=item *
+
+Formats now support zero-padded decimal fields.
+
+=item *
+
+Although "you shouldn't do that", it was possible to write code that
+depends on Perl's hashed key order (Data::Dumper does this). The new
+algorithm "One-at-a-Time" produces a different hashed key order.
+More details are in L</"Performance Enhancements">.
+
+=item *
+
+lstat(FILEHANDLE) now gives a warning because the operation makes no sense.
+In future releases this may become a fatal error.
+
+=item *
+
+Spurious syntax errors generated in certain situations, when glob()
+caused File::Glob to be loaded for the first time, have been fixed. [561]
+
+=item *
+
+Lvalue subroutines can now return C<undef> in list context. However,
+the lvalue subroutine feature still remains experimental. [561+]
+
+=item *
+
+A lost warning "Can't declare ... dereference in my" has been
+restored (Perl had it earlier but it became lost in later releases.)
+
+=item *
+
+A new special regular expression variable has been introduced:
+C<$^N>, which contains the most-recently closed group (submatch).
+
+=item *
+
+C<no Module;> does not produce an error even if Module does not have an
+unimport() method. This parallels the behavior of C<use> vis-a-vis
+C<import>. [561]
+
+=item *
+
+The numerical comparison operators return C<undef> if either operand
+is a NaN. Previously the behaviour was unspecified.
+
+=item *
+
+C<our> can now have an experimental optional attribute C<unique> that
+affects how global variables are shared among multiple interpreters,
+see L<perlfunc/our>.
+
+=item *
+
+The following builtin functions are now overridable: each(), keys(),
+pop(), push(), shift(), splice(), unshift(). [561]
+
+=item *
+
+C<pack() / unpack()> can now group template letters with C<()> and then
+apply repetition/count modifiers on the groups.
+
+=item *
+
+C<pack() / unpack()> can now process the Perl internal numeric types:
+IVs, UVs, NVs-- and also long doubles, if supported by the platform.
+The template letters are C<j>, C<J>, C<F>, and C<D>.
+
+=item *
+
+C<pack('U0a*', ...)> can now be used to force a string to UTF8.
+
+=item *
+
+my __PACKAGE__ $obj now works. [561]
+
+=item *
+
+POSIX::sleep() now returns the number of I<unslept> seconds
+(as the POSIX standard says), as opposed to CORE::sleep() which
+returns the number of slept seconds.
+
+=item *
+
+The printf() and sprintf() now support parameter reordering using the
+C<%\d+\$> and C<*\d+\$> syntaxes. For example
+
+ print "%2\$s %1\$s\n", "foo", "bar";
+
+will print "bar foo\n". This feature helps in writing
+internationalised software, and in general when the order
+of the parameters can vary.
+
+=item *
+
+The (\&) prototype now works properly. [561]
+
+=item *
+
+prototype(\[$@%&]) is now available to implicitly create references
+(useful for example if you want to emulate the tie() interface).
+
+=item *
+
+A new command-line option, C<-t> is available. It is the
+little brother of C<-T>: instead of dying on taint violations,
+lexical warnings are given. B<This is only meant as a temporary
+debugging aid while securing the code of old legacy applications.
+This is not a substitute for -T.>
+
+=item *
+
+In other taint news, the C<exec LIST> and C<system LIST> have now been
+considered too risky (think C<exec @ARGV>: it can start any program
+with any arguments), and now the said forms cause a warning under
+lexical warnings. You should carefully launder the arguments to
+guarantee their validity. In future releases of Perl the forms will
+become fatal errors so consider starting laundering now.
+
+=item *
+
+Tied hash interfaces are now required to have the EXISTS and DELETE
+methods (either own or inherited).
+
+=item *
+
+If tr/// is just counting characters, it doesn't attempt to
+modify its target.
+
+=item *
+
+untie() will now call an UNTIE() hook if it exists. See L<perltie>
+for details. [561]
+
+=item *
+
+L<utime> now supports C<utime undef, undef, @files> to change the
+file timestamps to the current time.
+
+=item *
+
+The rules for allowing underscores (underbars) in numeric constants
+have been relaxed and simplified: now you can have an underscore
+simply B<between digits>.
+
+=item *
+
+Rather than relying on C's argv[0] (which may not contain a full pathname)
+where possible $^X is now set by asking the operating system.
+(eg by reading F</proc/self/exe> on Linux, F</proc/curproc/file> on FreeBSD)
+
+=item *
+
+A new variable, C<${^TAINT}>, indicates whether taint mode is enabled.
+
+=item *
+
+You can now override the readline() builtin, and this overrides also
+the <FILEHANDLE> angle bracket operator.
+
+=item *
+
+The command-line options -s and -F are now recognized on the shebang
+(#!) line.
+
+=item *
+
+Use of the C</c> match modifier without an accompanying C</g> modifier
+elicits a new warning: C<Use of /c modifier is meaningless without /g>.
+
+Use of C</c> in substitutions, even with C</g>, elicits
+C<Use of /c modifier is meaningless in s///>.
+
+Use of C</g> with C<split> elicits C<Use of /g modifier is meaningless
+in split>.
+
+=item *
+
+Support for the C<CLONE> special subroutine had been added.
+With ithreads, when a new thread is created, all Perl data is cloned,
+however non-Perl data cannot be cloned automatically. In C<CLONE> you
+can do whatever you need to do, like for example handle the cloning of
+non-Perl data, if necessary. C<CLONE> will be executed once for every
+package that has it defined or inherited. It will be called in the
+context of the new thread, so all modifications are made in the new area.
+
+See L<perlmod>
+
+=back
+
+=head1 Modules and Pragmata
+
+=head2 New Modules and Pragmata
+
+=over 4
+
+=item *
+
+C<Attribute::Handlers>, originally by Damian Conway and now maintained
+by Arthur Bergman, allows a class to define attribute handlers.
+
+ package MyPack;
+ use Attribute::Handlers;
+ sub Wolf :ATTR(SCALAR) { print "howl!\n" }
+
+ # later, in some package using or inheriting from MyPack...
+
+ my MyPack $Fluffy : Wolf; # the attribute handler Wolf will be called
+
+Both variables and routines can have attribute handlers. Handlers can
+be specific to type (SCALAR, ARRAY, HASH, or CODE), or specific to the
+exact compilation phase (BEGIN, CHECK, INIT, or END).
+See L<Attribute::Handlers>.
+
+=item *
+
+C<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>. [561+]
+
+=item *
+
+The new bignum, bigint, and bigrat pragmas, by Tels, implement
+transparent bignum support (using the Math::BigInt, Math::BigFloat,
+and Math::BigRat backends).
+
+=item *
+
+C<Class::ISA>, by Sean Burke, is a module for reporting the search
+path for a class's ISA tree. See L<Class::ISA>.
+
+=item *
+
+C<Cwd> now has a split personality: if possible, an XS extension is
+used, (this will hopefully be faster, more secure, and more robust)
+but if not possible, the familiar Perl implementation is used.
+
+=item *
+
+C<Devel::PPPort>, originally by Kenneth Albanowski and now
+maintained by Paul Marquess, has been added. It is primarily used
+by C<h2xs> to enhance portability of XS modules between different
+versions of Perl. See L<Devel::PPPort>.
+
+=item *
+
+C<Digest>, frontend module for calculating digests (checksums), from
+Gisle Aas, has been added. See L<Digest>.
+
+=item *
+
+C<Digest::MD5> for calculating MD5 digests (checksums) as defined in
+RFC 1321, from Gisle Aas, has been added. See L<Digest::MD5>.
+
+ use Digest::MD5 'md5_hex';
+
+ $digest = md5_hex("Thirsty Camel");
+
+ print $digest, "\n"; # 01d19d9d2045e005c3f1b80e8b164de1
+
+NOTE: the C<MD5> backward compatibility module is deliberately not
+included since its further use is discouraged.
+
+See also L<PerlIO::via::QuotedPrint>.
+
+=item *
+
+C<Encode>, originally by Nick Ing-Simmons and now maintained by Dan
+Kogai, provides a mechanism to translate between different character
+encodings. Support for Unicode, ISO-8859-1, and ASCII are compiled in
+to the module. Several other encodings (like the rest of the
+ISO-8859, CP*/Win*, Mac, KOI8-R, three variants EBCDIC, Chinese,
+Japanese, and Korean encodings) are included and can be loaded at
+runtime. (For space considerations, the largest Chinese encodings
+have been separated into their own CPAN module, Encode::HanExtra,
+which Encode will use if available). See L<Encode>.
+
+Any encoding supported by Encode module is also available to the
+":encoding()" layer if PerlIO is used.
+
+=item *
+
+C<Hash::Util> is the interface to the new I<restricted hashes>
+feature. (Implemented by Jeffrey Friedl, Nick Ing-Simmons, and
+Michael Schwern.) See L<Hash::Util>.
+
+=item *
+
+C<I18N::Langinfo> can be used to query locale information.
+See L<I18N::Langinfo>.
+
+=item *
+
+C<I18N::LangTags>, by Sean Burke, has functions for dealing with
+RFC3066-style language tags. See L<I18N::LangTags>.
+
+=item *
+
+C<ExtUtils::Constant>, by Nicholas Clark, is a new tool for extension
+writers for generating XS code to import C header constants.
+See L<ExtUtils::Constant>.
+
+=item *
+
+C<Filter::Simple>, by Damian Conway, is an easy-to-use frontend to
+Filter::Util::Call. See L<Filter::Simple>.
+
+ # in MyFilter.pm:
+
+ package MyFilter;
+
+ use Filter::Simple sub {
+ while (my ($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"
+
+=item *
+
+C<File::Temp>, by Tim Jenness, allows one to create temporary files
+and directories in an easy, portable, and secure way. See L<File::Temp>.
+[561+]
+
+=item *
+
+C<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>.
+
+=item *
+
+C<if>, by Ilya Zakharevich, is a new pragma for conditional inclusion
+of modules.
+
+=item *
+
+L<libnet>, by Graham Barr, is a collection of perl5 modules related
+to network programming. See L<Net::FTP>, L<Net::NNTP>, L<Net::Ping>
+(not part of libnet, but related), L<Net::POP3>, L<Net::SMTP>,
+and L<Net::Time>.
+
+Perl installation leaves libnet unconfigured; use F<libnetcfg>
+to configure it.
+
+=item *
+
+C<List::Util>, by Graham Barr, is a selection of general-utility
+list subroutines, such as sum(), min(), first(), and shuffle().
+See L<List::Util>.
+
+=item *
+
+C<Locale::Constants>, C<Locale::Country>, C<Locale::Currency>
+C<Locale::Language>, and L<Locale::Script>, by Neil Bowers, have
+been added. They provide the codes for various locale standards, such
+as "fr" for France, "usd" for US Dollar, and "ja" 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>.
+
+=item *
+
+C<Locale::Maketext>, by Sean Burke, is a localization framework. See
+L<Locale::Maketext>, and L<Locale::Maketext::TPJ13>. The latter is an
+article about software localization, originally published in The Perl
+Journal #13, and republished here with kind permission.
+
+=item *
+
+C<Math::BigRat> for big rational numbers, to accompany Math::BigInt and
+Math::BigFloat, from Tels. See L<Math::BigRat>.
+
+=item *
+
+C<Memoize> can make your functions faster by trading space for time,
+from Mark-Jason Dominus. See L<Memoize>.
+
+=item *
+
+C<MIME::Base64>, by Gisle Aas, allows you to encode data in base64,
+as defined in RFC 2045 - I<MIME (Multipurpose Internet Mail
+Extensions)>.
+
+ use MIME::Base64;
+
+ $encoded = encode_base64('Aladdin:open sesame');
+ $decoded = decode_base64($encoded);
+
+ print $encoded, "\n"; # "QWxhZGRpbjpvcGVuIHNlc2FtZQ=="
+
+See L<MIME::Base64>.
+
+=item *
+
+C<MIME::QuotedPrint>, by Gisle Aas, allows you to encode data
+in quoted-printable encoding, as defined in RFC 2045 - I<MIME
+(Multipurpose Internet Mail Extensions)>.
+
+ use MIME::QuotedPrint;
+
+ $encoded = encode_qp("Smiley in Unicode: \x{263a}");
+ $decoded = decode_qp($encoded);
+
+ print $encoded, "\n"; # "Smiley in Unicode: =263A"
+
+See also L<PerlIO::via::QuotedPrint>.
+
+=item *
+
+C<NEXT>, by Damian Conway, is a pseudo-class for method redispatch.
+See L<NEXT>.
+
+=item *
+
+C<open> is a new pragma for setting the default I/O layers
+for open().
+
+=item *
+
+C<PerlIO::scalar>, by Nick Ing-Simmons, provides the implementation
+of IO to "in memory" Perl scalars as discussed above. It also serves
+as an example of a loadable PerlIO layer. Other future possibilities
+include PerlIO::Array and PerlIO::Code. See L<PerlIO::scalar>.
+
+=item *
+
+C<PerlIO::via>, by Nick Ing-Simmons, acts as a PerlIO layer and wraps
+PerlIO layer functionality provided by a class (typically implemented
+in Perl code).
+
+=item *
+
+C<PerlIO::via::QuotedPrint>, by Elizabeth Mattijsen, is an example
+of a C<PerlIO::via> class:
+
+ use PerlIO::via::QuotedPrint;
+ open($fh,">:via(QuotedPrint)",$path);
+
+This will automatically convert everything output to C<$fh> to
+Quoted-Printable. See L<PerlIO::via> and L<PerlIO::via::QuotedPrint>.
+
+=item *
+
+C<Pod::ParseLink>, by Russ Allbery, has been added,
+to parse LZ<><> links in pods as described in the new
+perlpodspec.
+
+=item *
+
+C<Pod::Text::Overstrike>, by Joe Smith, has been added.
+It converts POD data to formatted overstrike text.
+See L<Pod::Text::Overstrike>. [561+]
+
+=item *
+
+C<Scalar::Util> is a selection of general-utility scalar subroutines,
+such as blessed(), reftype(), and tainted(). See L<Scalar::Util>.
+
+=item *
+
+C<sort> is a new pragma for controlling the behaviour of sort().
+
+=item *
+
+C<Storable> gives persistence to Perl data structures by allowing the
+storage and retrieval of Perl data to and from files in a fast and
+compact binary format. Because in effect Storable does serialisation
+of Perl data structures, with it you can also clone deep, hierarchical
+datastructures. Storable was originally created by Raphael Manfredi,
+but it is now maintained by Abhijit Menon-Sen. Storable has been
+enhanced to understand the two new hash features, Unicode keys and
+restricted hashes. See L<Storable>.
+
+=item *
+
+C<Switch>, by Damian Conway, has been added. Just by saying
+
+ use Switch;
+
+you have C<switch> and C<case> available in Perl.
+
+ use Switch;
+
+ switch ($val) {
+
+ case 1 { print "number 1" }
+ case "a" { print "string a" }
+ case [1..10,42] { print "number in list" }
+ case (@array) { print "number in list" }
+ case /\w+/ { print "pattern" }
+ case qr/\w+/ { print "pattern" }
+ case (%hash) { print "entry in hash" }
+ case (\%hash) { print "entry in hash" }
+ case (\&sub) { print "arg to subroutine" }
+ else { print "previous case not true" }
+ }
+
+See L<Switch>.
+
+=item *
+
+C<Test::More>, by Michael Schwern, is yet another framework for writing
+test scripts, more extensive than Test::Simple. See L<Test::More>.
+
+=item *
+
+C<Test::Simple>, by Michael Schwern, has basic utilities for writing
+tests. See L<Test::Simple>.
+
+=item *
+
+C<Text::Balanced>, by Damian Conway, has been added, for extracting
+delimited text sequences from strings.
+
+ use Text::Balanced 'extract_delimited';
+
+ ($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>.
+
+=item *
+
+C<threads>, by Arthur Bergman, is an interface to interpreter threads.
+Interpreter threads (ithreads) is the new thread model introduced in
+Perl 5.6 but only available as an internal interface for extension
+writers (and for Win32 Perl for C<fork()> emulation). See L<threads>,
+L<threads::shared>, and L<perlthrtut>.
+
+=item *
+
+C<threads::shared>, by Arthur Bergman, allows data sharing for
+interpreter threads. See L<threads::shared>.
+
+=item *
+
+C<Tie::File>, by Mark-Jason Dominus, associates a Perl array with the
+lines of a file. See L<Tie::File>.
+
+=item *
+
+C<Tie::Memoize>, by Ilya Zakharevich, provides on-demand loaded hashes.
+See L<Tie::Memoize>.
+
+=item *
+
+C<Tie::RefHash::Nestable>, by Edward Avis, allows storing hash
+references (unlike the standard Tie::RefHash) The module is contained
+within Tie::RefHash. See L<Tie::RefHash>.
+
+=item *
+
+C<Time::HiRes>, by Douglas E. Wegscheid, provides high resolution
+timing (ualarm, usleep, and gettimeofday). See L<Time::HiRes>.
+
+=item *
+
+C<Unicode::UCD> offers a querying interface to the Unicode Character
+Database. See L<Unicode::UCD>.
+
+=item *
+
+C<Unicode::Collate>, by SADAHIRO Tomoyuki, implements the UCA
+(Unicode Collation Algorithm) for sorting Unicode strings.
+See L<Unicode::Collate>.
+
+=item *
+
+C<Unicode::Normalize>, by SADAHIRO Tomoyuki, implements the various
+Unicode normalization forms. See L<Unicode::Normalize>.
+
+=item *
+
+C<XS::APItest>, by Tim Jenness, is a test extension that exercises XS
+APIs. Currently only C<printf()> is tested: how to output various
+basic data types from XS.
+
+=item *
+
+C<XS::Typemap>, by Tim Jenness, is a test extension that exercises
+XS typemaps. Nothing gets installed, but the code is worth studying
+for extension writers.
+
+=back
+
+=head2 Updated And Improved Modules and Pragmata
+
+=over 4
+
+=item *
+
+The following independently supported modules have been updated to the
+newest versions from CPAN: CGI, CPAN, DB_File, File::Spec, File::Temp,
+Getopt::Long, Math::BigFloat, Math::BigInt, the podlators bundle
+(Pod::Man, Pod::Text), Pod::LaTeX [561+], Pod::Parser, Storable,
+Term::ANSIColor, Test, Text-Tabs+Wrap.
+
+=item *
+
+attributes::reftype() now works on tied arguments.
+
+=item *
+
+AutoLoader can now be disabled with C<no AutoLoader;>.
+
+=item *
+
+B::Deparse has been significantly enhanced by Robin Houston. It can
+now deparse almost all of the standard test suite (so that the tests
+still succeed). There is a make target "test.deparse" for trying this
+out.
+
+=item *
+
+Carp now has better interface documentation, and the @CARP_NOT
+interface has been added to get optional control over where errors
+are reported independently of @ISA, by Ben Tilly.
+
+=item *
+
+Class::Struct can now define the classes in compile time.
+
+=item *
+
+Class::Struct now assigns the array/hash element if the accessor
+is called with an array/hash element as the B<sole> argument.
+
+=item *
+
+The return value of Cwd::fastcwd() is now tainted.
+
+=item *
+
+Data::Dumper now has an option to sort hashes.
+
+=item *
+
+Data::Dumper now has an option to dump code references
+using B::Deparse.
+
+=item *
+
+DB_File now supports newer Berkeley DB versions, among
+other improvements.
+
+=item *
+
+Devel::Peek now has an interface for the Perl memory statistics
+(this works only if you are using perl's malloc, and if you have
+compiled with debugging).
+
+=item *
+
+The English module can now be used without the infamous performance
+hit by saying
+
+ use English '-no_match_vars';
+
+(Assuming, of course, that you don't need the troublesome variables
+C<$`>, C<$&>, or C<$'>.) Also, introduced C<@LAST_MATCH_START> and
+C<@LAST_MATCH_END> English aliases for C<@-> and C<@+>.
+
+=item *
+
+ExtUtils::MakeMaker has been significantly cleaned up and fixed.
+The enhanced version has also been backported to earlier releases
+of Perl and submitted to CPAN so that the earlier releases can
+enjoy the fixes.
+
+=item *
+
+The arguments of WriteMakefile() in Makefile.PL are now checked
+for sanity much more carefully than before. This may cause new
+warnings when modules are being installed. See L<ExtUtils::MakeMaker>
+for more details.
+
+=item *
+
+ExtUtils::MakeMaker now uses File::Spec internally, which hopefully
+leads to better portability.
+
+=item *
+
+Fcntl, Socket, and Sys::Syslog have been rewritten by Nicholas Clark
+to use the new-style constant dispatch section (see L<ExtUtils::Constant>).
+This means that they will be more robust and hopefully faster.
+
+=item *
+
+File::Find now chdir()s correctly when chasing symbolic links. [561]
+
+=item *
+
+File::Find now has pre- and post-processing callbacks. It also
+correctly changes directories when chasing symbolic links. Callbacks
+(naughtily) exiting with "next;" instead of "return;" now work.
+
+=item *
+
+File::Find is now (again) reentrant. It also has been made
+more portable.
+
+=item *
+
+The warnings issued by File::Find now belong to their own category.
+You can enable/disable them with C<use/no warnings 'File::Find';>.
+
+=item *
+
+File::Glob::glob() has been renamed to File::Glob::bsd_glob()
+because the name clashes with the builtin glob(). The older
+name is still available for compatibility, but is deprecated. [561]
+
+=item *
+
+File::Glob now supports C<GLOB_LIMIT> constant to limit the size of
+the returned list of filenames.
+
+=item *
+
+IPC::Open3 now allows the use of numeric file descriptors.
+
+=item *
+
+IO::Socket now has an atmark() method, which returns true if the socket
+is positioned at the out-of-band mark. The method is also exportable
+as a sockatmark() function.
+
+=item *
+
+IO::Socket::INET failed to open the specified port if the service name
+was not known. It now correctly uses the supplied port number as is. [561]
+
+=item *
+
+IO::Socket::INET has support for the ReusePort option (if your
+platform supports it). The Reuse option now has an alias, ReuseAddr.
+For clarity, you may want to prefer ReuseAddr.
+
+=item *
+
+IO::Socket::INET now supports a value of zero for C<LocalPort>
+(usually meaning that the operating system will make one up.)
+
+=item *
+
+'use lib' now works identically to @INC. Removing directories
+with 'no lib' now works.
+
+=item *
+
+Math::BigFloat and Math::BigInt have undergone a full rewrite by Tels.
+They are now magnitudes faster, and they support various bignum
+libraries such as GMP and PARI as their backends.
+
+=item *
+
+Math::Complex handles inf, NaN etc., better.
+
+=item *
+
+Net::Ping has been considerably enhanced by Rob Brown: multihoming is
+now supported, Win32 functionality is better, there is now time
+measuring functionality (optionally high-resolution using
+Time::HiRes), and there is now "external" protocol which uses
+Net::Ping::External module which runs your external ping utility and
+parses the output. A version of Net::Ping::External is available in
+CPAN.
+
+Note that some of the Net::Ping tests are disabled when running
+under the Perl distribution since one cannot assume one or more
+of the following: enabled echo port at localhost, full Internet
+connectivity, or sympathetic firewalls. You can set the environment
+variable PERL_TEST_Net_Ping to "1" (one) before running the Perl test
+suite to enable all the Net::Ping tests.
+
+=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 *
+
+In Safe, C<%INC> is now localised in a Safe compartment so that
+use/require work.
+
+=item *
+
+In SDBM_File on dosish platforms, some keys went missing because of
+lack of support for files with "holes". A workaround for the problem
+has been added.
+
+=item *
+
+In Search::Dict one can now have a pre-processing hook for the
+lines being searched.
+
+=item *
+
+The Shell module now has an OO interface.
+
+=item *
+
+In Sys::Syslog there is now a failover mechanism that will go
+through alternative connection mechanisms until the message
+is successfully logged.
+
+=item *
+
+The Test module has been significantly enhanced.
+
+=item *
+
+Time::Local::timelocal() does not handle fractional seconds anymore.
+The rationale is that neither does localtime(), and timelocal() and
+localtime() are supposed to be inverses of each other.
+
+=item *
+
+The vars pragma now supports declaring fully qualified variables.
+(Something that C<our()> does not and will not support.)
+
+=item *
+
+The C<utf8::> name space (as in the pragma) provides various
+Perl-callable functions to provide low level access to Perl's
+internal Unicode representation. At the moment only length()
+has been implemented.
+
+=back
+
+=head1 Utility Changes
+
+=over 4
+
+=item *
+
+Emacs perl mode (emacs/cperl-mode.el) has been updated to version
+4.31.
+
+=item *
+
+F<emacs/e2ctags.pl> is now much faster.
+
+=item *
+
+C<enc2xs> is a tool for people adding their own encodings to the
+Encode module.
+
+=item *
+
+C<h2ph> now supports C trigraphs.
+
+=item *
+
+C<h2xs> now produces a template README.
+
+=item *
+
+C<h2xs> now uses C<Devel::PPPort> for better portability between
+different versions of Perl.
+
+=item *
+
+C<h2xs> uses the new L<ExtUtils::Constant|ExtUtils::Constant> module
+which will affect newly created extensions that define constants.
+Since the new code is more correct (if you have two constants where the
+first one is a prefix of the second one, the first constant B<never>
+got defined), less lossy (it uses integers for integer constant,
+as opposed to the old code that used floating point numbers even for
+integer constants), and slightly faster, you might want to consider
+regenerating your extension code (the new scheme makes regenerating
+easy). L<h2xs> now also supports C trigraphs.
+
+=item *
+
+C<libnetcfg> has been added to configure libnet.
+
+=item *
+
+C<perlbug> is now much more robust. It also sends the bug report to
+perl.org, not perl.com.
+
+=item *
+
+C<perlcc> has been rewritten and its user interface (that is,
+command line) is much more like that of the UNIX C compiler, cc.
+(The perlbc tools has been removed. Use C<perlcc -B> instead.)
+B<Note that perlcc is still considered very experimental and
+unsupported.> [561]
+
+=item *
+
+C<perlivp> is a new Installation Verification Procedure utility
+for running any time after installing Perl.
+
+=item *
+
+C<piconv> is an implementation of the character conversion utility
+C<iconv>, demonstrating the new Encode module.
+
+=item *
+
+C<pod2html> now allows specifying a cache directory.
+
+=item *
+
+C<pod2html> now produces XHTML 1.0.
+
+=item *
+
+C<pod2html> now understands POD written using different line endings
+(PC-like CRLF versus UNIX-like LF versus MacClassic-like CR).
+
+=item *
+
+C<s2p> has been completely rewritten in Perl. (It is in fact a full
+implementation of sed in Perl: you can use the sed functionality by
+using the C<psed> utility.)
+
+=item *
+
+C<xsubpp> now understands POD documentation embedded in the *.xs
+files. [561]
+
+=item *
+
+C<xsubpp> now supports the OUT keyword.
+
+=back
+
+=head1 New Documentation
+
+=over 4
+
+=item *
+
+perl56delta details the changes between the 5.005 release and the
+5.6.0 release.
+
+=item *
+
+perlclib documents the internal replacements for standard C library
+functions. (Interesting only for extension writers and Perl core
+hackers.) [561+]
+
+=item *
+
+perldebtut is a Perl debugging tutorial. [561+]
+
+=item *
+
+perlebcdic contains considerations for running Perl on EBCDIC
+platforms. [561+]
+
+=item *
+
+perlintro is a gentle introduction to Perl.
+
+=item *
+
+perliol documents the internals of PerlIO with layers.
+
+=item *
+
+perlmodstyle is a style guide for writing modules.
+
+=item *
+
+perlnewmod tells about writing and submitting a new module. [561+]
+
+=item *
+
+perlpacktut is a pack() tutorial.
+
+=item *
+
+perlpod has been rewritten to be clearer and to record the best
+practices gathered over the years.
+
+=item *
+
+perlpodspec is a more formal specification of the pod format,
+mainly of interest for writers of pod applications, not to
+people writing in pod.
+
+=item *
+
+perlretut is a regular expression tutorial. [561+]
+
+=item *
+
+perlrequick is a regular expressions quick-start guide.
+Yes, much quicker than perlretut. [561]
+
+=item *
+
+perltodo has been updated.
+
+=item *
+
+perltootc has been renamed as perltooc (to not to conflict
+with perltoot in filesystems restricted to "8.3" names).
+
+=item *
+
+perluniintro is an introduction to using Unicode in Perl.
+(perlunicode is more of a detailed reference and background
+information)
+
+=item *
+
+perlutil explains the command line utilities packaged with the Perl
+distribution. [561+]
+
+=back
+
+The following platform-specific documents are available before
+the installation as README.I<platform>, and after the installation
+as perlI<platform>:
+
+ perlaix perlamiga perlapollo perlbeos perlbs2000
+ perlce perlcygwin perldgux perldos perlepoc perlfreebsd perlhpux
+ perlhurd perlirix perlmachten perlmacos perlmint perlmpeix
+ perlnetware perlos2 perlos390 perlplan9 perlqnx perlsolaris
+ perltru64 perluts perlvmesa perlvms perlvos perlwin32
+
+These documents usually detail one or more of the following subjects:
+configuring, building, testing, installing, and sometimes also using
+Perl on the said platform.
+
+Eastern Asian Perl users are now welcomed in their own languages:
+README.jp (Japanese), README.ko (Korean), README.cn (simplified
+Chinese) and README.tw (traditional Chinese), which are written in
+normal pod but encoded in EUC-JP, EUC-KR, EUC-CN and Big5. These
+will get installed as
+
+ perljp perlko perlcn perltw
+
+=over 4
+
+=item *
+
+The documentation for the POSIX-BC platform is called "BS2000", to avoid
+confusion with the Perl POSIX module.
+
+=item *
+
+The documentation for the WinCE platform is called perlce (README.ce
+in the source code kit), to avoid confusion with the perlwin32
+documentation on 8.3-restricted filesystems.
+
+=back
+
+=head1 Performance Enhancements
+
+=over 4
+
+=item *
+
+map() could get pathologically slow when the result list it generates
+is larger than the source list. The performance has been improved for
+common scenarios. [561]
+
+=item *
+
+sort() is also fully reentrant, in the sense that the sort function
+can itself call sort(). This did not work reliably in previous
+releases. [561]
+
+=item *
+
+sort() has been changed to use primarily mergesort internally as
+opposed to the earlier quicksort. For very small lists this may
+result in slightly slower sorting times, but in general the speedup
+should be at least 20%. Additional bonuses are that the worst case
+behaviour of sort() is now better (in computer science terms it now
+runs in time O(N log N), as opposed to quicksort's Theta(N**2)
+worst-case run time behaviour), and that sort() is now stable
+(meaning that elements with identical keys will stay ordered as they
+were before the sort). See the C<sort> pragma for information.
+
+The story in more detail: suppose you want to serve yourself a little
+slice of Pi.
+
+ @digits = ( 3,1,4,1,5,9 );
+
+A numerical sort of the digits will yield (1,1,3,4,5,9), as expected.
+Which C<1> comes first is hard to know, since one C<1> looks pretty
+much like any other. You can regard this as totally trivial,
+or somewhat profound. However, if you just want to sort the even
+digits ahead of the odd ones, then what will
+
+ sort { ($a % 2) <=> ($b % 2) } @digits;
+
+yield? The only even digit, C<4>, will come first. But how about
+the odd numbers, which all compare equal? With the quicksort algorithm
+used to implement Perl 5.6 and earlier, the order of ties is left up
+to the sort. So, as you add more and more digits of Pi, the order
+in which the sorted even and odd digits appear will change.
+and, for sufficiently large slices of Pi, the quicksort algorithm
+in Perl 5.8 won't return the same results even if reinvoked with the
+same input. The justification for this rests with quicksort's
+worst case behavior. If you run
+
+ sort { $a <=> $b } ( 1 .. $N , 1 .. $N );
+
+(something you might approximate if you wanted to merge two sorted
+arrays using sort), doubling $N doesn't just double the quicksort time,
+it I<quadruples> it. Quicksort has a worst case run time that can
+grow like N**2, so-called I<quadratic> behaviour, and it can happen
+on patterns that may well arise in normal use. You won't notice this
+for small arrays, but you I<will> notice it with larger arrays,
+and you may not live long enough for the sort to complete on arrays
+of a million elements. So the 5.8 quicksort scrambles large arrays
+before sorting them, as a statistical defence against quadratic behaviour.
+But that means if you sort the same large array twice, ties may be
+broken in different ways.
+
+Because of the unpredictability of tie-breaking order, and the quadratic
+worst-case behaviour, quicksort was I<almost> replaced completely with
+a stable mergesort. I<Stable> means that ties are broken to preserve
+the original order of appearance in the input array. So
+
+ sort { ($a % 2) <=> ($b % 2) } (3,1,4,1,5,9);
+
+will yield (4,3,1,1,5,9), guaranteed. The even and odd numbers
+appear in the output in the same order they appeared in the input.
+Mergesort has worst case O(N log N) behaviour, the best value
+attainable. And, ironically, this mergesort does particularly
+well where quicksort goes quadratic: mergesort sorts (1..$N, 1..$N)
+in O(N) time. But quicksort was rescued at the last moment because
+it is faster than mergesort on certain inputs and platforms.
+For example, if you really I<don't> care about the order of even
+and odd digits, quicksort will run in O(N) time; it's very good
+at sorting many repetitions of a small number of distinct elements.
+The quicksort divide and conquer strategy works well on platforms
+with relatively small, very fast, caches. Eventually, the problem gets
+whittled down to one that fits in the cache, from which point it
+benefits from the increased memory speed.
+
+Quicksort was rescued by implementing a sort pragma to control aspects
+of the sort. The B<stable> subpragma forces stable behaviour,
+regardless of algorithm. The B<_quicksort> and B<_mergesort>
+subpragmas are heavy-handed ways to select the underlying implementation.
+The leading C<_> is a reminder that these subpragmas may not survive
+beyond 5.8. More appropriate mechanisms for selecting the implementation
+exist, but they wouldn't have arrived in time to save quicksort.
+
+=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 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 *
+
+unshift() should now be noticeably faster.
+
+=back
+
+=head1 Installation and Configuration Improvements
+
+=head2 Generic Improvements
+
+=over 4
+
+=item *
+
+INSTALL now explains how you can configure Perl to use 64-bit
+integers even on non-64-bit platforms.
+
+=item *
+
+Policy.sh policy change: if you are reusing a Policy.sh file
+(see INSTALL) and you use Configure -Dprefix=/foo/bar and in the old
+Policy $prefix eq $siteprefix and $prefix eq $vendorprefix, all of
+them will now be changed to the new prefix, /foo/bar. (Previously
+only $prefix changed.) If you do not like this new behaviour,
+specify prefix, siteprefix, and vendorprefix explicitly.
+
+=item *
+
+A new optional location for Perl libraries, otherlibdirs, is available.
+It can be used for example for vendor add-ons without disturbing Perl's
+own library directories.
+
+=item *
+
+In many platforms, the vendor-supplied 'cc' is too stripped-down to
+build Perl (basically, 'cc' doesn't do ANSI C). If this seems
+to be the case and 'cc' does not seem to be the GNU C compiler
+'gcc', an automatic attempt is made to find and use 'gcc' instead.
+
+=item *
+
+gcc needs to closely track the operating system release to avoid
+build problems. If Configure finds that gcc was built for a different
+operating system release than is running, it now gives a clearly visible
+warning that there may be trouble ahead.
+
+=item *
+
+Since Perl 5.8 is not binary-compatible with previous releases
+of Perl, Configure no longer suggests including the 5.005
+modules in @INC.
+
+=item *
+
+Configure C<-S> can now run non-interactively. [561]
+
+=item *
+
+Configure support for pdp11-style memory models has been removed due
+to obsolescence. [561]
+
+=item *
+
+configure.gnu now works with options with whitespace in them.
+
+=item *
+
+installperl now outputs everything to STDERR.
+
+=item *
+
+Because PerlIO is now the default on most platforms, "-perlio" doesn't
+get appended to the $Config{archname} (also known as $^O) anymore.
+Instead, if you explicitly choose not to use perlio (Configure command
+line option -Uuseperlio), you will get "-stdio" appended.
+
+=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. (To be exact, the use64bitall is ignored.)
+
+=item *
+
+In AFS installations, one can configure the root of the AFS to be
+somewhere else than the default F</afs> by using the Configure
+parameter C<-Dafsroot=/some/where/else>.
+
+=item *
+
+APPLLIB_EXP, a lesser-known configuration-time definition, has been
+documented. It can be used to prepend site-specific directories
+to Perl's default search path (@INC); see INSTALL for information.
+
+=item *
+
+The version of Berkeley DB used when the Perl (and, presumably, the
+DB_File extension) was built is now available as
+C<@Config{qw(db_version_major db_version_minor db_version_patch)}>
+from Perl and as C<DB_VERSION_MAJOR_CFG DB_VERSION_MINOR_CFG
+DB_VERSION_PATCH_CFG> from C.
+
+=item *
+
+Building Berkeley DB3 for compatibility modes for DB, NDBM, and ODBM
+has been documented in INSTALL.
+
+=item *
+
+If you have CPAN access (either network or a local copy such as a
+CD-ROM) you can during specify extra modules to Configure to build and
+install with Perl using the -Dextras=... option. See INSTALL for
+more details.
+
+=item *
+
+In addition to config.over, a new override file, config.arch, is
+available. This file is supposed to be used by hints file writers
+for architecture-wide changes (as opposed to config.over which is
+for site-wide changes).
+
+=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 ...
+
+This will create in /tmp/perl/build/directory a tree of symbolic links
+pointing to files in /path/to/perl/source. The original files are left
+unaffected. After Configure has finished, you can just say
+
+ make all test
+
+and Perl will be built and tested, all in /tmp/perl/build/directory.
+[561]
+
+=item *
+
+For Perl developers, several new make targets for profiling
+and debugging have been added; see L<perlhack>.
+
+=over 8
+
+=item *
+
+Use of the F<gprof> tool to profile Perl has been documented in
+L<perlhack>. There is a make target called "perl.gprof" for
+generating a gprofiled Perl executable.
+
+=item *
+
+If you have GCC 3, there is a make target called "perl.gcov" for
+creating a gcoved Perl executable for coverage analysis. See
+L<perlhack>.
+
+=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
+Third Degree.
+
+=back
+
+=item *
+
+Guidelines of how to construct minimal Perl installations have
+been added to INSTALL.
+
+=item *
+
+The Thread extension is now not built at all under ithreads
+(C<Configure -Duseithreads>) because it wouldn't work anyway (the
+Thread extension requires being Configured with C<-Duse5005threads>).
+
+B<Note that the 5.005 threads are unsupported and deprecated: if you
+have code written for the old threads you should migrate it to the
+new ithreads model.>
+
+=item *
+
+The Gconvert macro ($Config{d_Gconvert}) used by perl for stringifying
+floating-point numbers is now more picky about using sprintf %.*g
+rules for the conversion. Some platforms that used to use gcvt may
+now resort to the slower sprintf.
+
+=item *
+
+The obsolete method of making a special (e.g., debugging) flavor
+of perl by saying
+
+ make LIBPERL=libperld.a
+
+has been removed. Use -DDEBUGGING instead.
+
+=back
+
+=head2 New Or Improved Platforms
+
+For the list of platforms known to support Perl,
+see L<perlport/"Supported Platforms">.
+
+=over 4
+
+=item *
+
+AIX dynamic loading should be now better supported.
+
+=item *
+
+AIX should now work better with gcc, threads, and 64-bitness. Also the
+long doubles support in AIX should be better now. See L<perlaix>.
+
+=item *
+
+AtheOS ( http://www.atheos.cx/ ) is a new platform.
+
+=item *
+
+BeOS has been reclaimed.
+
+=item *
+
+The DG/UX platform now supports 5.005-style threads.
+See L<perldgux>.
+
+=item *
+
+The DYNIX/ptx platform (also known as dynixptx) is supported at or
+near osvers 4.5.2.
+
+=item *
+
+EBCDIC platforms (z/OS (also known as OS/390), POSIX-BC, and VM/ESA)
+have been regained. Many test suite tests still fail and the
+co-existence of Unicode and EBCDIC isn't quite settled, but the
+situation is much better than with Perl 5.6. See L<perlos390>,
+L<perlbs2000> (for POSIX-BC), and L<perlvmesa> for more information.
+
+=item *
+
+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. [561]
+
+=item *
+
+Mac OS Classic is now supported in the mainstream source package
+(MacPerl has of course been available since perl 5.004 but now the
+source code bases of standard Perl and MacPerl have been synchronised)
+[561]
+
+=item *
+
+Mac OS X (or Darwin) should now be able to build Perl even on HFS+
+filesystems. (The case-insensitivity used to confuse the Perl build
+process.)
+
+=item *
+
+NCR MP-RAS is now supported. [561]
+
+=item *
+
+All the NetBSD specific patches (except for the installation
+specific ones) have been merged back to the main distribution.
+
+=item *
+
+NetWare from Novell is now supported. See L<perlnetware>.
+
+=item *
+
+NonStop-UX is now supported. [561]
+
+=item *
+
+NEC SUPER-UX is now supported.
+
+=item *
+
+All the OpenBSD specific patches (except for the installation
+specific ones) have been merged back to the main distribution.
+
+=item *
+
+Perl has been tested with the GNU pth userlevel thread package
+( http://www.gnu.org/software/pth/pth.html ). All thread tests
+of Perl now work, but not without adding some yield()s to the tests,
+so while pth (and other userlevel thread implementations) can be
+considered to be "working" with Perl ithreads, keep in mind the
+possible non-preemptability of the underlying thread implementation.
+
+=item *
+
+Stratus VOS is now supported using Perl's native build method
+(Configure). This is the recommended method to build Perl on
+VOS. The older methods, which build miniperl, are still
+available. See L<perlvos>. [561+]
+
+=item *
+
+The Amdahl UTS UNIX mainframe platform is now supported. [561]
+
+=item *
+
+WinCE is now supported. See L<perlce>.
+
+=item *
+
+z/OS (formerly known as OS/390, formerly known as MVS OE) now has
+support for dynamic loading. This is not selected by default,
+however, you must specify -Dusedl in the arguments of Configure. [561]
+
+=back
+
+=head1 Selected Bug Fixes
+
+Numerous memory leaks and uninitialized memory accesses have been
+hunted down. Most importantly, anonymous subs used to leak quite
+a bit. [561]
+
+=over 4
+
+=item *
+
+The autouse pragma didn't work for Multi::Part::Function::Names.
+
+=item *
+
+caller() could cause core dumps in certain situations. Carp was
+sometimes affected by this problem. In particular, caller() now
+returns a subroutine name of C<(unknown)> for subroutines that have
+been removed from the symbol table.
+
+=item *
+
+chop(@list) in list context returned the characters chopped in
+reverse order. This has been reversed to be in the right order. [561]
+
+=item *
+
+Configure no longer includes the DBM libraries (dbm, gdbm, db, ndbm)
+when building the Perl binary. The only exception to this is SunOS 4.x,
+which needs them. [561]
+
+=item *
+
+The behaviour of non-decimal but numeric string constants such as
+"0x23" was platform-dependent: in some platforms that was seen as 35,
+in some as 0, in some as a floating point number (don't ask). This
+was caused by Perl's using the operating system libraries in a situation
+where the result of the string to number conversion is undefined: now
+Perl consistently handles such strings as zero in numeric contexts.
+
+=item *
+
+Several debugger fixes: exit code now reflects the script exit code,
+condition C<"0"> now treated correctly, the C<d> command now checks
+line number, C<$.> no longer gets corrupted, and all debugger output
+now goes correctly to the socket if RemotePort is set. [561]
+
+=item *
+
+The debugger (perl5db.pl) has been modified to present a more
+consistent commands interface, via (CommandSet=580). perl5db.t was
+also added to test the changes, and as a placeholder for further tests.
+
+See L<perldebug>.
+
+=item *
+
+The debugger has a new C<dumpDepth> option to control the maximum
+depth to which nested structures are dumped. The C<x> command has
+been extended so that C<x N EXPR> dumps out the value of I<EXPR> to a
+depth of at most I<N> levels.
+
+=item *
+
+The debugger can now show lexical variables if you have the CPAN
+module PadWalker installed.
+
+=item *
+
+The order of DESTROYs has been made more predictable.
+
+=item *
+
+Perl 5.6.0 could emit spurious warnings about redefinition of
+dl_error() when statically building extensions into perl.
+This has been corrected. [561]
+
+=item *
+
+L<dprofpp> -R didn't work.
+
+=item *
+
+C<*foo{FORMAT}> now works.
+
+=item *
+
+Infinity is now recognized as a number.
+
+=item *
+
+UNIVERSAL::isa no longer caches methods incorrectly. (This broke
+the Tk extension with 5.6.0.) [561]
+
+=item *
+
+Lexicals I: lexicals outside an eval "" weren't resolved
+correctly inside a subroutine definition inside the eval "" if they
+were not already referenced in the top level of the eval""ed code.
+
+=item *
+
+Lexicals II: lexicals leaked at file scope into subroutines that
+were declared before the lexicals.
+
+=item *
+
+Lexical warnings now propagating correctly between scopes
+and into C<eval "...">.
+
+=item *
+
+C<use warnings qw(FATAL all)> did not work as intended. This has been
+corrected. [561]
+
+=item *
+
+warnings::enabled() now reports the state of $^W correctly if the caller
+isn't using lexical warnings. [561]
+
+=item *
+
+Line renumbering with eval and C<#line> now works. [561]
+
+=item *
+
+Fixed numerous memory leaks, especially in eval "".
+
+=item *
+
+Localised tied variables no longer leak memory
+
+ use Tie::Hash;
+ tie my %tied_hash => 'Tie::StdHash';
+
+ ...
+
+ # Used to leak memory every time local() was called;
+ # in a loop, this added up.
+ local($tied_hash{Foo}) = 1;
+
+=item *
+
+Localised hash elements (and %ENV) are correctly unlocalised to not
+exist, if they didn't before they were localised.
+
+
+ use Tie::Hash;
+ tie my %tied_hash => 'Tie::StdHash';
+
+ ...
+
+ # Nothing has set the FOO element so far
+
+ { local $tied_hash{FOO} = 'Bar' }
+
+ # This used to print, but not now.
+ print "exists!\n" if exists $tied_hash{FOO};
+
+As a side effect of this fix, tied hash interfaces B<must> define
+the EXISTS and DELETE methods.
+
+=item *
+
+mkdir() now ignores trailing slashes in the directory name,
+as mandated by POSIX.
+
+=item *
+
+Some versions of glibc have a broken modfl(). This affects builds
+with C<-Duselongdouble>. This version of Perl detects this brokenness
+and has a workaround for it. The glibc release 2.2.2 is known to have
+fixed the modfl() bug.
+
+=item *
+
+Modulus of unsigned numbers now works (4063328477 % 65535 used to
+return 27406, instead of 27047). [561]
+
+=item *
+
+Some "not a number" warnings introduced in 5.6.0 eliminated to be
+more compatible with 5.005. Infinity is now recognised as a number. [561]
+
+=item *
+
+Numeric conversions did not recognize changes in the string value
+properly in certain circumstances. [561]
+
+=item *
+
+Attributes (such as :shared) didn't work with our().
+
+=item *
+
+our() variables will not cause bogus "Variable will not stay shared"
+warnings. [561]
+
+=item *
+
+"our" variables of the same name declared in two sibling blocks
+resulted in bogus warnings about "redeclaration" of the variables.
+The problem has been corrected. [561]
+
+=item *
+
+pack "Z" now correctly terminates the string with "\0".
+
+=item *
+
+Fix password routines which in some shadow password platforms
+(e.g. HP-UX) caused getpwent() to return every other entry.
+
+=item *
+
+The PERL5OPT environment variable (for passing command line arguments
+to Perl) didn't work for more than a single group of options. [561]
+
+=item *
+
+PERL5OPT with embedded spaces didn't work.
+
+=item *
+
+printf() no longer resets the numeric locale to "C".
+
+=item *
+
+C<qw(a\\b)> now parses correctly as C<'a\\b'>: that is, as three
+characters, not four. [561]
+
+=item *
+
+pos() did not return the correct value within s///ge in earlier
+versions. This is now handled correctly. [561]
+
+=item *
+
+Printing quads (64-bit integers) with printf/sprintf now works
+without the q L ll prefixes (assuming you are on a quad-capable platform).
+
+=item *
+
+Regular expressions on references and overloaded scalars now work. [561+]
+
+=item *
+
+Right-hand side magic (GMAGIC) could in many cases such as string
+concatenation be invoked too many times.
+
+=item *
+
+scalar() now forces scalar context even when used in void context.
+
+=item *
+
+SOCKS support is now much more robust.
+
+=item *
+
+sort() arguments are now compiled in the right wantarray context
+(they were accidentally using the context of the sort() itself).
+The comparison block is now run in scalar context, and the arguments
+to be sorted are always provided list context. [561]
+
+=item *
+
+Changed the POSIX character class C<[[:space:]]> to include the (very
+rarely used) vertical tab character. Added a new POSIX-ish character
+class C<[[:blank:]]> which stands for horizontal whitespace
+(currently, the space and the tab).
+
+=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. [561]
+
+=item *
+
+Some cases of inconsistent taint propagation (such as within hash
+values) have been fixed.
+
+=item *
+
+The RE engine found in Perl 5.6.0 accidentally pessimised certain kinds
+of simple pattern matches. These are now handled better. [561]
+
+=item *
+
+Regular expression debug output (whether through C<use re 'debug'>
+or via C<-Dr>) now looks better. [561]
+
+=item *
+
+Multi-line matches like C<"a\nxb\n" =~ /(?!\A)x/m> were flawed. The
+bug has been fixed. [561]
+
+=item *
+
+Use of $& could trigger a core dump under some situations. This
+is now avoided. [561]
+
+=item *
+
+The regular expression captured submatches ($1, $2, ...) are now
+more consistently unset if the match fails, instead of leaving false
+data lying around in them. [561]
+
+=item *
+
+readline() on files opened in "slurp" mode could return an extra
+"" (blank line) at the end in certain situations. This has been
+corrected. [561]
+
+=item *
+
+Autovivification of symbolic references of special variables described
+in L<perlvar> (as in C<${$num}>) was accidentally disabled. This works
+again now. [561]
+
+=item *
+
+Sys::Syslog ignored the C<LOG_AUTH> constant.
+
+=item *
+
+$AUTOLOAD, sort(), lock(), and spawning subprocesses
+in multiple threads simultaneously are now thread-safe.
+
+=item *
+
+Tie::Array's SPLICE method was broken.
+
+=item *
+
+Allow a read-only string on the left-hand side of a non-modifying tr///.
+
+=item *
+
+If C<STDERR> is tied, warnings caused by C<warn> and C<die> now
+correctly pass to it.
+
+=item *
+
+Several Unicode fixes.
+
+=over 8
+
+=item *
+
+BOMs (byte order marks) at the beginning of Perl files
+(scripts, modules) should now be transparently skipped.
+UTF-16 and UCS-2 encoded Perl files should now be read correctly.
+
+=item *
+
+The character tables have been updated to Unicode 3.2.0.
+
+=item *
+
+Comparing with utf8 data does not magically upgrade non-utf8 data
+into utf8. (This was a problem for example if you were mixing data
+from I/O and Unicode data: your output might have got magically encoded
+as UTF-8.)
+
+=item *
+
+Generating illegal Unicode code points such as U+FFFE, or the UTF-16
+surrogates, now also generates an optional warning.
+
+=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 UTF8, should now work.
+
+=item *
+
+The C<tr///> operator now works. Note that the C<tr///CU>
+functionality has been removed (but see pack('U0', ...)).
+
+=item *
+
+C<eval "v200"> now works.
+
+=item *
+
+Perl 5.6.0 parsed m/\x{ab}/ incorrectly, leading to spurious warnings.
+This has been corrected. [561]
+
+=item *
+
+Zero entries were missing from the Unicode classes such as C<IsDigit>.
+
+=back
+
+=item *
+
+Large unsigned numbers (those above 2**31) could sometimes lose their
+unsignedness, causing bogus results in arithmetic operations. [561]
+
+=item *
+
+The Perl parser has been stress tested using both random input and
+Markov chain input and the few found crashes and lockups have been
+fixed.
+
+=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 L<perlvar> for details).
+
+=item *
+
+Cygwin
+
+Numerous updates; currently synchronised with Cygwin 1.3.10.
+
+=item *
+
+Previously DYNIX/ptx had problems in its Configure probe for non-blocking I/O.
+
+=item *
+
+EPOC
+
+EPOC now better supported. See README.epoc. [561]
+
+=item *
+
+FreeBSD 3.*
+
+Perl now works on post-3.0 FreeBSDs.
+
+=item *
+
+HP-UX
+
+README.hpux updated; C<Configure -Duse64bitall> now works;
+now uses HP-UX malloc instead of Perl malloc.
+
+=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
+
+=over 8
+
+=item *
+
+Long doubles should now work (see INSTALL). [561]
+
+=item *
+
+Linux previously had problems related to sockaddrlen when using
+accept(), recvfrom() (in Perl: recv()), getpeername(), and
+getsockname().
+
+=back
+
+=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. [561]
+
+=item *
+
+NetBSD/threads: try installing the GNU pth (should be in the
+packages collection, or http://www.gnu.org/software/pth/),
+and Configure with -Duseithreads.
+
+=item *
+
+NetBSD/sparc
+
+Perl now works on NetBSD/sparc.
+
+=item *
+
+OS/2
+
+Now works with usethreads (see INSTALL). [561]
+
+=item *
+
+Solaris
+
+64-bitness using the Sun Workshop compiler now works.
+
+=item *
+
+Stratus VOS
+
+The native build method requires at least VOS Release 14.5.0
+and GNU C++/GNU Tools 2.0.1 or later. The Perl pack function
+now maps overflowed values to +infinity and underflowed values
+to -infinity.
+
+=item *
+
+Tru64 (aka Digital UNIX, aka DEC OSF/1)
+
+The operating system version letter now recorded in $Config{osvers}.
+Allow compiling with gcc (previously explicitly forbidden). Compiling
+with gcc still not recommended because buggy code results, even with
+gcc 2.95.2.
+
+=item *
+
+Unicos
+
+Fixed various alignment problems that lead into core dumps either
+during build or later; no longer dies on math errors at runtime;
+now using full quad integers (64 bits), previously was using
+only 46 bit integers for speed.
+
+=item *
+
+VMS
+
+See L</"Socket Extension Dynamic in VMS"> and L</"IEEE-format Floating Point
+Default on OpenVMS Alpha"> for important changes not otherwise listed here.
+
+chdir() now works better despite a CRT bug; now works with MULTIPLICITY
+(see INSTALL); now works with Perl's malloc.
+
+The tainting of C<%ENV> elements via C<keys> or C<values> was previously
+unimplemented. It now works as documented.
+
+The C<waitpid> emulation has been improved. The worst bug (now fixed)
+was that a pid of -1 would cause a wildcard search of all processes on
+the system.
+
+POSIX-style signals are now emulated much better on VMS versions prior
+to 7.0.
+
+The C<system> function and backticks operator have improved
+functionality and better error handling. [561]
+
+File access tests now use current process privileges rather than the
+user's default privileges, which could sometimes result in a mismatch
+between reported access and actual access. This improvement is only
+available on VMS v6.0 and later.
+
+There is a new C<kill> implementation based on C<sys$sigprc> that allows
+older VMS systems (pre-7.0) to use C<kill> to send signals rather than
+simply force exit. This implementation also allows later systems to
+call C<kill> from within a signal handler.
+
+Iterative logical name translations are now limited to 10 iterations in
+imitation of SHOW LOGICAL and other OpenVMS facilities.
+
+=item *
+
+Windows
+
+=over 8
+
+=item *
+
+Signal handling now works better than it used to. It is now implemented
+using a Windows message loop, and is therefore less prone to random
+crashes.
+
+=item *
+
+fork() emulation is now more robust, but still continues to have a few
+esoteric bugs and caveats. See L<perlfork> for details. [561+]
+
+=item *
+
+A failed (pseudo)fork now returns undef and sets errno to EAGAIN. [561]
+
+=item *
+
+The following modules now work on Windows:
+
+ ExtUtils::Embed [561]
+ IO::Pipe
+ IO::Poll
+ Net::Ping
+
+=item *
+
+IO::File::new_tmpfile() is no longer limited to 32767 invocations
+per-process.
+
+=item *
+
+Better chdir() return value for a non-existent directory.
+
+=item *
+
+Compiling perl using the 64-bit Platform SDK tools is now supported.
+
+=item *
+
+The Win32::SetChildShowWindow() builtin can be used to control the
+visibility of windows created by child processes. See L<Win32> for
+details.
+
+=item *
+
+Non-blocking waits for child processes (or pseudo-processes) are
+supported via C<waitpid($pid, &POSIX::WNOHANG)>.
+
+=item *
+
+The behavior of system() with multiple arguments has been rationalized.
+Each unquoted argument will be automatically quoted to protect whitespace,
+and any existing whitespace in the arguments will be preserved. This
+improves the portability of system(@args) by avoiding the need for
+Windows C<cmd> shell specific quoting in perl programs.
+
+Note that this means that some scripts that may have relied on earlier
+buggy behavior may no longer work correctly. For example,
+C<system("nmake /nologo", @args)> will now attempt to run the file
+C<nmake /nologo> and will fail when such a file isn't found.
+On the other hand, perl will now execute code such as
+C<system("c:/Program Files/MyApp/foo.exe", @args)> correctly.
+
+=item *
+
+The perl header files no longer suppress common warnings from the
+Microsoft Visual C++ compiler. This means that additional warnings may
+now show up when compiling XS code.
+
+=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++). [561]
+
+=item *
+
+Duping socket handles with open(F, ">&MYSOCK") now works under Windows 9x.
+[561]
+
+=item *
+
+Current directory entries in %ENV are now correctly propagated to child
+processes. [561]
+
+=item *
+
+New %ENV entries now propagate to subprocesses. [561]
+
+=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. [561]
+
+=item *
+
+The makefiles now default to the features enabled in ActiveState ActivePerl
+(a popular Win32 binary distribution). [561]
+
+=item *
+
+HTML files will now be installed in c:\perl\html instead of
+c:\perl\lib\pod\html
+
+=item *
+
+REG_EXPAND_SZ keys are now allowed in registry settings used by perl. [561]
+
+=item *
+
+Can now send() from all threads, not just the first one. [561]
+
+=item *
+
+ExtUtils::MakeMaker now uses $ENV{LIB} to search for libraries. [561]
+
+=item *
+
+Less stack reserved per thread so that more threads can run
+concurrently. (Still 16M per thread.) [561]
+
+=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. [561]
+
+=item *
+
+wait(), waitpid(), and backticks now return the correct exit status
+under Windows 9x. [561]
+
+=item *
+
+A socket handle leak in accept() has been fixed. [561]
+
+=back
+
+=back
+
+=head1 New or Changed Diagnostics
+
+Please see L<perldiag> for more details.
+
+=over 4
+
+=item *
+
+Ambiguous range in the transliteration operator (like a-z-9) now
+gives a warning.
+
+=item *
+
+chdir("") and chdir(undef) now give a deprecation warning because they
+cause a possible unintentional chdir to the home directory.
+Say chdir() if you really mean that.
+
+=item *
+
+Two new debugging options have been added: if you have compiled your
+Perl with debugging, you can use the -DT [561] and -DR options to trace
+tokenising and to add reference counts to displaying variables,
+respectively.
+
+=item *
+
+The lexical warnings category "deprecated" is no longer a sub-category
+of the "syntax" category. It is now a top-level category in its own
+right.
+
+=item *
+
+Unadorned dump() will now give a warning suggesting to
+use explicit CORE::dump() if that's what really is meant.
+
+=item *
+
+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.
+
+=item *
+
+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 by a C<E<lt>-- HERE> marker.
+
+=item *
+
+Various I/O (and socket) functions like binmode(), close(), and so
+forth now more consistently warn if they are used illogically either
+on a yet unopened or on an already closed filehandle (or socket).
+
+=item *
+
+Using lstat() on a filehandle now gives a warning. (It's a non-sensical
+thing to do.)
+
+=item *
+
+The C<-M> and C<-m> options now warn if you didn't supply the module name.
+
+=item *
+
+If you in C<use> specify a required minimum version, modules matching
+the name and but not defining a $VERSION will cause a fatal failure.
+
+=item *
+
+Using negative offset for vec() in lvalue context is now a warnable offense.
+
+=item *
+
+Odd number of arguments to oveload::constant now elicits a warning.
+
+=item *
+
+Odd number of elements to in anonymous hash now elicits a warning.
+
+=item *
+
+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 C<main::STDIN>.
+
+=item *
+
+Subroutine prototypes are now checked more carefully, you may
+get warnings for example if you have used non-prototype characters.
+
+=item *
+
+If an attempt to use a (non-blessed) reference as an array index
+is made, a warning is given.
+
+=item *
+
+C<push @a;> and C<unshift @a;> (with no values to push or unshift)
+now give a warning. This may be a problem for generated and evaled
+code.
+
+=item *
+
+If you try to L<perlfunc/pack> a number less than 0 or larger than 255
+using the C<"C"> format you will get an optional warning. Similarly
+for the C<"c"> format and a number less than -128 or more than 127.
+
+=item *
+
+pack C<P> format now demands an explicit size.
+
+=item *
+
+unpack C<w> now warns of unterminated compressed integers.
+
+=item *
+
+Warnings relating to the use of PerlIO have been added.
+
+=item *
+
+Certain regex modifiers such as C<(?o)> make sense only if applied to
+the entire regex. You will get an optional warning if you try to do
+otherwise.
+
+=item *
+
+Variable length lookbehind has not yet been implemented, trying to
+use it will tell that.
+
+=item *
+
+Using arrays or hashes as references (e.g. C<< %foo->{bar} >>
+has been deprecated for a while. Now you will get an optional warning.
+
+=item *
+
+Warnings relating to the use of the new restricted hashes feature
+have been added.
+
+=item *
+
+Self-ties of arrays and hashes are not supported and fatal errors
+will happen even at an attempt to do so.
+
+=item *
+
+Using C<sort> in scalar context now issues an optional warning.
+This didn't do anything useful, as the sort was not performed.
+
+=item *
+
+Using the /g modifier in split() is meaningless and will cause a warning.
+
+=item *
+
+Using splice() past the end of an array now causes a warning.
+
+=item *
+
+Malformed Unicode encodings (UTF-8 and UTF-16) cause a lot of warnings,
+ad doestrying to use UTF-16 surrogates (which are unimplemented).
+
+=item *
+
+Trying to use Unicode characters on an I/O stream without marking the
+stream's encoding (using open() or binmode()) will cause "Wide character"
+warnings.
+
+=item *
+
+Use of v-strings in use/require causes a (backward) portability warning.
+
+=item *
+
+Warnings relating to the use interpreter threads and their shared data
+have been added.
+
+=back
+
+=head1 Changed Internals
+
+=over 4
+
+=item *
+
+PerlIO is now the default.
+
+=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(), op_clear, op_null,
+ptr_table_clear(), ptr_table_free(), sv_setref_uv(), and several UTF-8
+interfaces to the publicised API. For the full list of the available
+APIs see L<perlapi>.
+
+=item *
+
+Made possible to propagate customised exceptions via croak()ing.
+
+=item *
+
+Now xsubs can have attributes just like subs. (Well, at least the
+built-in attributes.)
+
+=item *
+
+dTHR and djSP have been obsoleted; the former removed (because it's
+a no-op) and the latter replaced with dSP.
+
+=item *
+
+PERL_OBJECT has been completely removed.
+
+=item *
+
+The MAGIC constants (e.g. C<'P'>) have been macrofied
+(e.g. C<PERL_MAGIC_TIED>) for better source code readability
+and maintainability.
+
+=item *
+
+The regex compiler now maintains a structure that identifies nodes in
+the compiled bytecode with the corresponding syntactic features of the
+original regex expression. The information is attached to the new
+C<offsets> member of the C<struct regexp>. See L<perldebguts> for more
+complete information.
+
+=item *
+
+The C code has been made much more C<gcc -Wall> clean. Some warning
+messages still remain in some platforms, so if you are compiling with
+gcc you may see some warnings about dubious practices. The warnings
+are being worked on.
+
+=item *
+
+F<perly.c>, F<sv.c>, and F<sv.h> have now been extensively commented.
+
+=item *
+
+Documentation on how to use the Perl source repository has been added
+to F<Porting/repository.pod>.
+
+=item *
+
+There are now several profiling make targets.
+
+=back
+
+=head1 Security Vulnerability Closed [561]
+
+(This change was already made in 5.7.0 but bears repeating here.)
+(5.7.0 came out before 5.6.1: the development branch 5.7 released
+earlier than the maintenance branch 5.6)
+
+A potential security vulnerability in the optional suidperl component
+of Perl was identified in August 2000. suidperl is neither built nor
+installed by default. As of November 2001 the only known vulnerable
+platform is Linux, most likely all Linux distributions. CERT and
+various vendors and distributors have been alerted about the vulnerability.
+See http://www.cpan.org/src/5.0/sperl-2000-08-05/sperl-2000-08-05.txt
+for more information.
+
+The problem was caused by Perl trying to report a suspected security
+exploit attempt using an external program, /bin/mail. On Linux
+platforms the /bin/mail program had an undocumented feature which
+when combined with suidperl gave access to a root shell, resulting in
+a serious compromise instead of reporting the exploit attempt. If you
+don't have /bin/mail, or if you have 'safe setuid scripts', or if
+suidperl is not installed, you are safe.
+
+The exploit attempt reporting feature has been completely removed from
+Perl 5.8.0 (and the maintenance release 5.6.1, and it was removed also
+from all the Perl 5.7 releases), so that particular vulnerability
+isn't there anymore. However, further security vulnerabilities are,
+unfortunately, always possible. The suidperl functionality is most
+probably going to be removed in Perl 5.10. In any case, suidperl
+should only be used by security experts who know exactly what they are
+doing and why they are using suidperl instead of some other solution
+such as sudo ( see http://www.courtesan.com/sudo/ ).
+
+=head1 New Tests
+
+Several new tests have been added, especially for the F<lib> and
+F<ext> subsections. There are now about 69 000 individual tests
+(spread over about 700 test scripts), in the regression suite (5.6.1
+has about 11 700 tests, in 258 test scripts) The exact numbers depend
+on the platform and Perl configuration used. Many of the new tests
+are of course introduced by the new modules, but still in general Perl
+is now more thoroughly tested.
+
+Because of the large number of tests, running the regression suite
+will take considerably longer time than it used to: expect the suite
+to take up to 4-5 times longer to run than in perl 5.6. On a really
+fast machine you can hope to finish the suite in about 6-8 minutes
+(wallclock time).
+
+The tests are now reported in a different order than in earlier Perls.
+(This happens because the test scripts from under t/lib have been moved
+to be closer to the library/extension they are testing.)
+
+=head1 Known Problems
+
+=head2 The Compiler Suite Is Still Very Experimental
+
+The compiler suite is slowly getting better but it continues to be
+highly experimental. Use in production environments is discouraged.
+
+=head2 Localising Tied Arrays and Hashes Is Broken
+
+ local %tied_array;
+
+doesn't work as one would expect: the old value is restored
+incorrectly. This will be changed in a future release, but we don't
+know yet what the new semantics will exactly be. In any case, the
+change will break existing code that relies on the current
+(ill-defined) semantics, so just avoid doing this in general.
+
+=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 they may 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 to) link
+together at all binaries with different ideas about file offsets;
+all this is platform-dependent.
+
+=head2 Modifying $_ Inside for(..)
+
+ for (1..5) { $_++ }
+
+works without complaint. It shouldn't. (You should be able to
+modify only lvalue elements inside the loops.) You can see the
+correct behaviour by replacing the 1..5 with 1, 2, 3, 4, 5.
+
+=head2 mod_perl 1.26 Doesn't Build With Threaded Perl
+
+Use mod_perl 1.27 or higher.
+
+=head2 lib/ftmp-security tests warn 'system possibly insecure'
+
+Don't panic. Read the 'make test' section of INSTALL instead.
+
+=head2 libwww-perl (LWP) fails base/date #51
+
+Use libwww-perl 5.65 or later.
+
+=head2 PDL failing some tests
+
+Use PDL 2.3.4 or later.
+
+=head2 Perl_get_sv
+
+You may get errors like 'Undefined symbol "Perl_get_sv"' or "can't
+resolve symbol 'Perl_get_sv'", or the symbol may be "Perl_sv_2pv".
+This probably means that you are trying to use an older shared Perl
+library (or extensions linked with such) with Perl 5.8.0 executable.
+Perl used to have such a subroutine, but that is no more the case.
+Check your shared library path, and any shared Perl libraries in those
+directories.
+
+Sometimes this problem may also indicate a partial Perl 5.8.0
+installation, see L</"Mac OS X dyld undefined symbols"> for an
+example and how to deal with it.
+
+=head2 Self-tying Problems
+
+Self-tying of arrays and hashes is broken in rather deep and
+hard-to-fix ways. As a stop-gap measure to avoid people from getting
+frustrated at the mysterious results (core dumps, most often), it is
+forbidden for now (you will get a fatal error even from an attempt).
+
+A change to self-tying of globs has caused them to be recursively
+referenced (see: L<perlobj/"Two-Phased Garbage Collection">). You
+will now need an explicit untie to destroy a self-tied glob. This
+behaviour may be fixed at a later date.
+
+Self-tying of scalars and IO thingies works.
+
+=head2 ext/threads/t/libc
+
+If this test fails, it indicates that your libc (C library) is not
+threadsafe. This particular test stress tests the localtime() call to
+find out whether it is threadsafe. See L<perlthrtut> for more information.
+
+=head2 Failure of Thread (5.005-style) tests
+
+B<Note that support for 5.005-style threading is deprecated,
+experimental and practically unsupported. In 5.10, it is expected
+to be removed. You should migrate your code to ithreads.>
+
+The following tests 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.
+
+ ../ext/B/t/xref.t 255 65280 14 12 85.71% 3-14
+ ../ext/List/Util/t/first.t 255 65280 7 4 57.14% 2 5-7
+ ../lib/English.t 2 512 54 2 3.70% 2-3
+ ../lib/FileCache.t 5 1 20.00% 5
+ ../lib/Filter/Simple/t/data.t 6 3 50.00% 1-3
+ ../lib/Filter/Simple/t/filter_only. 9 3 33.33% 1-2 5
+ ../lib/Math/BigInt/t/bare_mbf.t 1627 4 0.25% 8 11 1626-1627
+ ../lib/Math/BigInt/t/bigfltpm.t 1629 4 0.25% 10 13 1628-
+ 1629
+ ../lib/Math/BigInt/t/sub_mbf.t 1633 4 0.24% 8 11 1632-1633
+ ../lib/Math/BigInt/t/with_sub.t 1628 4 0.25% 9 12 1627-1628
+ ../lib/Tie/File/t/31_autodefer.t 255 65280 65 32 49.23% 34-65
+ ../lib/autouse.t 10 1 10.00% 4
+ op/flip.t 15 1 6.67% 15
+
+These failures are unlikely to get fixed as 5.005-style threads
+are considered fundamentally broken. (Basically what happens is that
+competing threads can corrupt shared global state, one good example
+being regular expression engine's state.)
+
+=head2 Timing problems
+
+The following tests may fail intermittently because of timing
+problems, for example if the system is heavily loaded.
+
+ t/op/alarm.t
+ ext/Time/HiRes/HiRes.t
+ lib/Benchmark.t
+ lib/Memoize/t/expmod_t.t
+ lib/Memoize/t/speed.t
+
+In case of failure please try running them manually, for example
+
+ ./perl -Ilib ext/Time/HiRes/HiRes.t
+
+=head2 Tied/Magical Array/Hash Elements Do Not Autovivify
+
+For normal arrays C<$foo = \$bar[1]> will assign C<undef> to
+C<$bar[1]> (assuming that it didn't exist before), but for
+tied/magical arrays and hashes such autovivification does not happen
+because there is currently no way to catch the reference creation.
+The same problem affects slicing over non-existent indices/keys of
+a tied/magical array/hash.
+
+=head2 Unicode in package/class and subroutine names does not work
+
+One can have Unicode in identifier names, but not in package/class or
+subroutine names. While some limited functionality towards this does
+exist as of Perl 5.8.0, that is more accidental than designed; use of
+Unicode for the said purposes is unsupported.
+
+One reason of this unfinishedness is its (currently) inherent
+unportability: since both package names and subroutine names may
+need to be mapped to file and directory names, the Unicode capability
+of the filesystem becomes important-- and there unfortunately aren't
+portable answers.
+
+=head1 Platform Specific Problems
+
+=head2 AIX
+
+=over 4
+
+=item *
+
+If using the AIX native make command, instead of just "make" issue
+"make all". In some setups the former has been known to spuriously
+also try to run "make install". Alternatively, you may want to use
+GNU make.
+
+=item *
+
+In AIX 4.2, Perl extensions that use C++ functions that use statics
+may have problems in that the statics are not getting initialized.
+In newer AIX releases, this has been solved by linking Perl with
+the libC_r library, but unfortunately in AIX 4.2 the said library
+has an obscure bug where the various functions related to time
+(such as time() and gettimeofday()) return broken values, and
+therefore in AIX 4.2 Perl is not linked against libC_r.
+
+=item *
+
+vac 5.0.0.0 May Produce Buggy Code For Perl
+
+The AIX C compiler vac version 5.0.0.0 may produce buggy code,
+resulting in a few random tests failing when run as part of "make
+test", 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. See README.aix.
+
+=item *
+
+If building threaded Perl, you may get compilation warning from pp_sys.c:
+
+ "pp_sys.c", line 4651.39: 1506-280 (W) Function argument assignment between types "unsigned char*" and "const void*" is not allowed.
+
+This is harmless; it is caused by the getnetbyaddr() and getnetbyaddr_r()
+having slightly different types for their first argument.
+
+=back
+
+=head2 Alpha systems with old gccs fail several tests
+
+If you see op/pack, op/pat, op/regexp, or ext/Storable tests failing
+in a Linux/alpha or *BSD/Alpha, it's probably time to upgrade your gcc.
+gccs prior to 2.95.3 are definitely not good enough, and gcc 3.1 may
+be even better. (RedHat Linux/alpha with gcc 3.1 reported no problems,
+as did Linux 2.4.18 with gcc 2.95.4.) (In Tru64, it is preferable to
+use the bundled C compiler.)
+
+=head2 AmigaOS
+
+Perl 5.8.0 doesn't build in AmigaOS. It broke at some point during
+the ithreads work and we could not find Amiga experts to unbreak the
+problems. Perl 5.6.1 still works for AmigaOS (as does the the 5.7.2
+development release).
+
+=head2 BeOS
+
+The following tests fail on 5.8.0 Perl in BeOS Personal 5.03:
+
+ t/op/lfs............................FAILED at test 17
+ t/op/magic..........................FAILED at test 24
+ ext/Fcntl/t/syslfs..................FAILED at test 17
+ ext/File/Glob/t/basic...............FAILED at test 3
+ ext/POSIX/t/sigaction...............FAILED at test 13
+ ext/POSIX/t/waitpid.................FAILED at test 1
+
+See L<perlbeos> (README.beos) for more details.
+
+=head2 Cygwin "unable to remap"
+
+For example when building the Tk extension for Cygwin,
+you may get an error message saying "unable to remap".
+This is known problem with Cygwin, and a workaround is
+detailed in here: http://sources.redhat.com/ml/cygwin/2001-12/msg00894.html
+
+=head2 Cygwin ndbm tests fail on FAT
+
+One can build but not install (or test the build of) the NDBM_File
+on FAT filesystems. Installation (or build) on NTFS works fine.
+If one attempts the test on a FAT install (or build) the following
+failures are expected:
+
+ ../ext/NDBM_File/ndbm.t 13 3328 71 59 83.10% 1-2 4 16-71
+ ../ext/ODBM_File/odbm.t 255 65280 ?? ?? % ??
+ ../lib/AnyDBM_File.t 2 512 12 2 16.67% 1 4
+ ../lib/Memoize/t/errors.t 0 139 11 5 45.45% 7-11
+ ../lib/Memoize/t/tie_ndbm.t 13 3328 4 4 100.00% 1-4
+ run/fresh_perl.t 97 1 1.03% 91
+
+NDBM_File fails and ODBM_File just coredumps.
+
+=head2 DJGPP Failures
+
+ t/op/stat............................FAILED at test 29
+ lib/File/Find/t/find.................FAILED at test 1
+ lib/File/Find/t/taint................FAILED at test 1
+ lib/h2xs.............................FAILED at test 15
+ lib/Pod/t/eol........................FAILED at test 1
+ lib/Test/Harness/t/strap-analyze.....FAILED at test 8
+ lib/Test/Harness/t/test-harness......FAILED at test 23
+ lib/Test/Simple/t/exit...............FAILED at test 1
+
+The above failures are known as of 5.8.0 with native builds with long
+filenames, but there are a few more if running under dosemu because of
+limitations (and maybe bugs) of dosemu:
+
+ t/comp/cpp...........................FAILED at test 3
+ t/op/inccode.........................(crash)
+
+and a few lib/ExtUtils tests, and several hundred Encode/t/Aliases.t
+failures that work fine with long filenames. So you really might
+prefer native builds and long filenames.
+
+=head2 FreeBSD built with ithreads coredumps reading large directories
+
+This is a known bug in FreeBSD 4.5's readdir_r(), it has been fixed in
+FreeBSD 4.6 (see L<perlfreebsd> (README.freebsd)).
+
+=head2 FreeBSD Failing locale Test 117 For ISO 8859-15 Locales
+
+The ISO 8859-15 locales may fail the locale test 117 in FreeBSD.
+This is caused by the characters \xFF (y with diaeresis) and \xBE
+(Y with diaeresis) not behaving correctly when being matched
+case-insensitively. Apparently this problem has been fixed in
+the latest FreeBSD releases.
+( http://www.freebsd.org/cgi/query-pr.cgi?pr=34308 )
+
+=head2 IRIX fails ext/List/Util/t/shuffle.t or Digest::MD5
+
+IRIX with MIPSpro 7.3.1.2m or 7.3.1.3m compiler may fail the List::Util
+test ext/List/Util/t/shuffle.t by dumping core. This seems to be
+a compiler error since if compiled with gcc no core dump ensues, and
+no failures have been seen on the said test on any other platform.
+
+Similarly, building the Digest::MD5 extension has been
+known to fail with "*** Termination code 139 (bu21)".
+
+The cure is to drop optimization level (Configure -Doptimize=-O2).
+
+=head2 HP-UX lib/posix Subtest 9 Fails When LP64-Configured
+
+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 Linux with glibc 2.2.5 fails t/op/int subtest #6 with -Duse64bitint
+
+This is a known bug in the glibc 2.2.5 with long long integers.
+( http://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=65612 )
+
+=head2 Linux With Sfio Fails op/misc Test 48
+
+No known fix.
+
+=head2 Mac OS X
+
+Please remember to set your environment variable LC_ALL to "C"
+(setenv LC_ALL C) before running "make test" to avoid a lot of
+warnings about the broken locales of Mac OS X.
+
+The following tests are known to fail in Mac OS X 10.1.5 because of
+buggy (old) implementations of Berkeley DB included in Mac OS X:
+
+ Failed Test Stat Wstat Total Fail Failed List of Failed
+ -------------------------------------------------------------------------
+ ../ext/DB_File/t/db-btree.t 0 11 ?? ?? % ??
+ ../ext/DB_File/t/db-recno.t 149 3 2.01% 61 63 65
+
+If you are building on a UFS partition, you will also probably see
+t/op/stat.t subtest #9 fail. This is caused by Darwin's UFS not
+supporting inode change time.
+
+Also the ext/POSIX/t/posix.t subtest #10 fails but it is skipped for
+now because the failure is Apple's fault, not Perl's (blocked signals
+are lost).
+
+If you Configure with ithreads, ext/threads/t/libc.t will fail. Again,
+this is not Perl's fault-- the libc of Mac OS X is not threadsafe
+(in this particular test, the localtime() call is found to be
+threadunsafe.)
+
+=head2 Mac OS X dyld undefined symbols
+
+If after installing Perl 5.8.0 you are getting warnings about missing
+symbols, for example
+
+ dyld: perl Undefined symbols
+ _perl_sv_2pv
+ _perl_get_sv
+
+you probably have an old pre-Perl-5.8.0 installation (or parts of one)
+in /Library/Perl (the undefined symbols used to exist in pre-5.8.0 Perls).
+It seems that for some reason "make install" doesn't always completely
+overwrite the files in /Library/Perl. You can move the old Perl
+shared library out of the way like this:
+
+ cd /Library/Perl/darwin/CORE
+ mv libperl.dylib libperlold.dylib
+
+and then reissue "make install". Note that the above of course is
+extremely disruptive for anything using the /usr/local/bin/perl.
+If that doesn't help, you may have to try removing all the .bundle
+files from beneath /Library/Perl, and again "make install"-ing.
+
+=head2 OS/2 Test Failures
+
+The following tests are known to fail on OS/2 (for clarity
+only the failures are shown, not the full error messages):
+
+ ../lib/ExtUtils/t/Mkbootstrap.t 1 256 18 1 5.56% 8
+ ../lib/ExtUtils/t/Packlist.t 1 256 34 1 2.94% 17
+ ../lib/ExtUtils/t/basic.t 1 256 17 1 5.88% 14
+ lib/os2_process.t 2 512 227 2 0.88% 174 209
+ lib/os2_process_kid.t 227 2 0.88% 174 209
+ lib/rx_cmprt.t 255 65280 18 3 16.67% 16-18
+
+=head2 op/sprintf tests 91, 129, and 130
+
+The op/sprintf tests 91, 129, and 130 are known to fail on some platforms.
+Examples include any platform using sfio, and Compaq/Tandem's NonStop-UX.
+
+Test 91 is known to fail on QNX6 (nto), because C<sprintf '%e',0>
+incorrectly produces C<0.000000e+0> instead of C<0.000000e+00>.
+
+For tests 129 and 130, the failing platforms do not comply with
+the ANSI C Standard: lines 19ff on page 134 of ANSI X3.159 1989, to
+be exact. (They produce something other than "1" and "-1" when
+formatting 0.6 and -0.6 using the printf format "%.0f"; most often,
+they produce "0" and "-0".)
+
+=head2 Solaris 2.5
+
+In case you are still using Solaris 2.5 (aka SunOS 5.5), you may
+experience failures (the test core dumping) in lib/locale.t.
+The suggested cure is to upgrade your Solaris.
+
+=head2 Solaris x86 Fails Tests With -Duse64bitint
+
+The following tests are known to fail in Solaris x86 with Perl
+configured to use 64 bit integers:
+
+ ext/Data/Dumper/t/dumper.............FAILED at test 268
+ ext/Devel/Peek/Peek..................FAILED at test 7
+
+=head2 SUPER-UX (NEC SX)
+
+The following tests are known to fail on SUPER-UX:
+
+ op/64bitint...........................FAILED tests 29-30, 32-33, 35-36
+ op/arith..............................FAILED tests 128-130
+ op/pack...............................FAILED tests 25-5625
+ op/pow................................
+ op/taint..............................# msgsnd failed
+ ../ext/IO/lib/IO/t/io_poll............FAILED tests 3-4
+ ../ext/IPC/SysV/ipcsysv...............FAILED tests 2, 5-6
+ ../ext/IPC/SysV/t/msg.................FAILED tests 2, 4-6
+ ../ext/Socket/socketpair..............FAILED tests 12
+ ../lib/IPC/SysV.......................FAILED tests 2, 5-6
+ ../lib/warnings.......................FAILED tests 115-116, 118-119
+
+The op/pack failure ("Cannot compress negative numbers at op/pack.t line 126")
+is serious but as of yet unsolved. It points at some problems with the
+signedness handling of the C compiler, as do the 64bitint, arith, and pow
+failures. Most of the rest point at problems with SysV IPC.
+
+=head2 Term::ReadKey not working on Win32
+
+Use Term::ReadKey 2.20 or later.
+
+=head2 UNICOS/mk
+
+=over 4
+
+=item *
+
+During Configure, the test
+
+ Guessing which symbols your C compiler and preprocessor define...
+
+will probably fail with error messages like
+
+ CC-20 cc: ERROR File = try.c, Line = 3
+ The identifier "bad" is undefined.
+
+ bad switch yylook 79bad switch yylook 79bad switch yylook 79bad switch yylook 79#ifdef A29K
+ ^
+
+ CC-65 cc: ERROR File = try.c, Line = 3
+ A semicolon is expected at this point.
+
+This is caused by a bug in the awk utility of UNICOS/mk. You can ignore
+the error, but it does cause a slight problem: you cannot fully
+benefit from the h2ph utility (see L<h2ph>) that can be used to
+convert C headers to Perl libraries, mainly used to be able to access
+from Perl the constants defined using C preprocessor, cpp. Because of
+the above error, parts of the converted headers will be invisible.
+Luckily, these days the need for h2ph is rare.
+
+=item *
+
+If building Perl with interpreter threads (ithreads), the
+getgrent(), getgrnam(), and getgrgid() functions cannot return the
+list of the group members due to a bug in the multithreaded support of
+UNICOS/mk. What this means is that in list context the functions will
+return only three values, not four.
+
+=back
+
+=head2 UTS
+
+There are a few known test failures, see L<perluts> (README.uts).
+
+=head2 VOS (Stratus)
+
+When Perl is built using the native build process on VOS Release
+14.5.0 and GNU C++/GNU Tools 2.0.1, all attempted tests either
+pass or result in TODO (ignored) failures.
+
+=head2 VMS
+
+There should be no reported test failures with a default configuration,
+though there are a number of tests marked TODO that point to areas
+needing further debugging and/or porting work.
+
+=head2 Win32
+
+In multi-CPU boxes, there are some problems with the I/O buffering:
+some output may appear twice.
+
+=head2 XML::Parser not working
+
+Use XML::Parser 2.31 or later.
+
+=head2 z/OS (OS/390)
+
+z/OS has rather many test failures but the situation is actually much
+better than it was in 5.6.0; it's just that so many new modules and
+tests have been added.
+
+ Failed Test Stat Wstat Total Fail Failed List of Failed
+ ---------------------------------------------------------------------------
+ ../ext/Data/Dumper/t/dumper.t 357 8 2.24% 311 314 325 327
+ 331 333 337 339
+ ../ext/IO/lib/IO/t/io_unix.t 5 4 80.00% 2-5
+ ../ext/Storable/t/downgrade.t 12 3072 169 12 7.10% 14-15 46-47 78-79
+ 110-111 150 161
+ ../lib/ExtUtils/t/Constant.t 121 30976 48 48 100.00% 1-48
+ ../lib/ExtUtils/t/Embed.t 9 9 100.00% 1-9
+ op/pat.t 922 7 0.76% 665 776 785 832-
+ 834 845
+ op/sprintf.t 224 3 1.34% 98 100 136
+ op/tr.t 97 5 5.15% 63 71-74
+ uni/fold.t 780 6 0.77% 61 169 196 661
+ 710-711
+
+The failures in dumper.t and downgrade.t are problems in the tests,
+those in io_unix and sprintf are problems in the USS (UDP sockets and
+printf formats). The pat, tr, and fold failures are genuine Perl
+problems caused by EBCDIC (and in the pat and fold cases, combining
+that with Unicode). The Constant and Embed are probably problems in
+the tests (since they test Perl's ability to build extensions, and
+that seems to be working reasonably well.)
+
+=head2 Unicode Support on EBCDIC Still Spotty
+
+Though mostly working, Unicode support still has problem spots on
+EBCDIC platforms. One such known spot are the C<\p{}> and C<\P{}>
+regular expression constructs for code points less than 256: the
+C<pP> are testing for Unicode code points, not knowing about EBCDIC.
+
+=head2 Seen In Perl 5.7 But Gone Now
+
+C<Time::Piece> (previously known as C<Time::Object>) was removed
+because it was felt that it didn't have enough value in it to be a
+core module. It is still a useful module, though, and is available
+from the CPAN.
+
+Perl 5.8 unfortunately does not build anymore on AmigaOS; this broke
+accidentally at some point. Since there are not that many Amiga
+developers available, we could not get this fixed and tested in time
+for 5.8.0. Perl 5.6.1 still works for AmigaOS (as does the the 5.7.2
+development release).
+
+The C<PerlIO::Scalar> and C<PerlIO::Via> (capitalised) were renamed as
+C<PerlIO::scalar> and C<PerlIO::via> (all lowercase) just before 5.8.0.
+The main rationale was to have all core PerlIO layers to have all
+lowercase names. The "plugins" are named as usual, for example
+C<PerlIO::via::QuotedPrint>.
+
+The C<threads::shared::queue> and C<threads::shared::semaphore> were
+renamed as C<Thread::Queue> and C<Thread::Semaphore> just before 5.8.0.
+The main rationale was to have thread modules to obey normal naming,
+C<Thread::> (the C<threads> and C<threads::shared> themselves are
+more pragma-like, they affect compile-time, so they stay lowercase).
+
+=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/ , 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 perlbug@perl.org 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<jhi@iki.fi>>.
+
+=cut
=head1 NAME
-perldelta - what is new for perl v5.8.0
+perldelta - what is new for perl v5.9.0
=head1 DESCRIPTION
-This document describes differences between the 5.6.0 release and
-the 5.8.0 release.
+This document describes differences between the 5.8.0 release and
+the 5.9.0 release.
-Many of the bug fixes in 5.8.0 were already seen in the 5.6.1
-maintenance release since the two releases were kept closely
-coordinated (while 5.8.0 was still called 5.7.something).
-
-Changes that were integrated into the 5.6.1 release are marked C<[561]>.
-Many of these changes have been further developed since 5.6.1 was released,
-those are marked C<[561+]>.
-
-You can see the list of changes in the 5.6.1 release (both from the
-5.005_03 release and the 5.6.0 release) by reading L<perl561delta>.
-
-=head1 Highlights In 5.8.0
-
-=over 4
-
-=item *
-
-Better Unicode support
-
-=item *
-
-New IO Implementation
-
-=item *
-
-New Thread Implementation
-
-=item *
-
-Better Numeric Accuracy
-
-=item *
-
-Safe Signals
-
-=item *
-
-Many New Modules
-
-=item *
-
-More Extensive Regression Testing
-
-=back
-
-=head1 Incompatible Changes
-
-=head2 Binary Incompatibility
-
-B<Perl 5.8 is not binary compatible with earlier releases of Perl.>
-
-B<You have to recompile your XS modules.>
-
-(Pure Perl modules should continue to work.)
-
-The major reason for the discontinuity is the new IO architecture
-called PerlIO. PerlIO is the default configuration because without
-it many new features of Perl 5.8 cannot be used. In other words:
-you just have to recompile your modules containing XS code, sorry
-about that.
-
-In future releases of Perl, non-PerlIO aware XS modules may become
-completely unsupported. This shouldn't be too difficult for module
-authors, however: PerlIO has been designed as a drop-in replacement
-(at the source code level) for the stdio interface.
-
-Depending on your platform, there are also other reasons why
-we decided to break binary compatibility, please read on.
-
-=head2 64-bit platforms and malloc
-
-If your pointers are 64 bits wide, the Perl malloc is no longer being
-used because it does not work well with 8-byte pointers. Also,
-usually the system mallocs on such platforms are much better optimized
-for such large memory models than the Perl malloc. Some memory-hungry
-Perl applications like the PDL don't work well with Perl's malloc.
-Finally, other applications than Perl (such as mod_perl) tend to prefer
-the system malloc. Such platforms include Alpha and 64-bit HPPA,
-MIPS, PPC, and Sparc.
-
-=head2 AIX Dynaloading
-
-The AIX dynaloading now uses in AIX releases 4.3 and newer the native
-dlopen interface of AIX instead of the old emulated interface. This
-change will probably break backward compatibility with compiled
-modules. The change was made to make Perl more compliant with other
-applications like mod_perl which are using the AIX native interface.
-
-=head2 Attributes for C<my> variables now handled at run-time
-
-The C<my EXPR : ATTRS> syntax now applies variable attributes at
-run-time. (Subroutine and C<our> variables still get attributes applied
-at compile-time.) See L<attributes> for additional details. In particular,
-however, this allows variable attributes to be useful for C<tie> interfaces,
-which was a deficiency of earlier releases. Note that the new semantics
-doesn't work with the Attribute::Handlers module (as of version 0.76).
-
-=head2 Socket Extension Dynamic in VMS
-
-The Socket extension is now dynamically loaded instead of being
-statically built in. This may or may not be a problem with ancient
-TCP/IP stacks of VMS: we do not know since we weren't able to test
-Perl in such configurations.
-
-=head2 IEEE-format Floating Point Default on OpenVMS Alpha
-
-Perl now uses IEEE format (T_FLOAT) as the default internal floating
-point format on OpenVMS Alpha, potentially breaking binary compatibility
-with external libraries or existing data. G_FLOAT is still available as
-a configuration option. The default on VAX (D_FLOAT) has not changed.
-
-=head2 New Unicode Semantics (no more C<use utf8>, almost)
-
-Previously in Perl 5.6 to use Unicode one would say "use utf8" and
-then the operations (like string concatenation) were Unicode-aware
-in that lexical scope.
-
-This was found to be an inconvenient interface, and in Perl 5.8 the
-Unicode model has completely changed: now the "Unicodeness" is bound
-to the data itself, and for most of the time "use utf8" is not needed
-at all. The only remaining use of "use utf8" is when the Perl script
-itself has been written in the UTF-8 encoding of Unicode. (UTF-8 has
-not been made the default since there are many Perl scripts out there
-that are using various national eight-bit character sets, which would
-be illegal in UTF-8.)
-
-See L<perluniintro> for the explanation of the current model,
-and L<utf8> for the current use of the utf8 pragma.
-
-=head2 New Unicode Properties
-
-Unicode I<scripts> are now supported. Scripts are similar to (and superior
-to) Unicode I<blocks>. The difference between scripts and blocks is that
-scripts are the glyphs used by a language or a group of languages, while
-the blocks are more artificial groupings of (mostly) 256 characters based
-on the Unicode numbering.
-
-In general, scripts are more inclusive, but not universally so. For
-example, while the script C<Latin> includes all the Latin characters and
-their various diacritic-adorned versions, it does not include the various
-punctuation or digits (since they are not solely C<Latin>).
-
-A number of other properties are now supported, including C<\p{L&}>,
-C<\p{Any}> C<\p{Assigned}>, C<\p{Unassigned}>, C<\p{Blank}> [561] and
-C<\p{SpacePerl}> [561] (along with their C<\P{...}> versions, of course).
-See L<perlunicode> for details, and more additions.
-
-The C<In> or C<Is> prefix to names used with the C<\p{...}> and C<\P{...}>
-are now almost always optional. The only exception is that a C<In> prefix
-is required to signify a Unicode block when a block name conflicts with a
-script name. For example, C<\p{Tibetan}> refers to the script, while
-C<\p{InTibetan}> refers to the block. When there is no name conflict, you
-can omit the C<In> from the block name (e.g. C<\p{BraillePatterns}>), but
-to be safe, it's probably best to always use the C<In>).
-
-=head2 REF(...) Instead Of SCALAR(...)
-
-A reference to a reference now stringifies as "REF(0x81485ec)" instead
-of "SCALAR(0x81485ec)" in order to be more consistent with the return
-value of ref().
-
-=head2 pack/unpack D/F recycled
-
-The undocumented pack/unpack template letters D/F have been recycled
-for better use: now they stand for long double (if supported by the
-platform) and NV (Perl internal floating point type). (They used
-to be aliases for d/f, but you never knew that.)
-
-=head2 glob() now returns filenames in alphabetical order
-
-The list of filenames from glob() (or <...>) is now by default sorted
-alphabetically to be csh-compliant (which is what happened before
-in most UNIX platforms). (bsd_glob() does still sort platform
-natively, ASCII or EBCDIC, unless GLOB_ALPHASORT is specified.) [561]
-
-=head2 Deprecations
-
-=over 4
-
-=item *
-
-The semantics of bless(REF, REF) were unclear and until someone proves
-it to make some sense, it is forbidden.
-
-=item *
-
-The obsolete chat2 library that should never have been allowed
-to escape the laboratory has been decommissioned.
-
-=item *
-
-Using chdir("") or chdir(undef) instead of explicit chdir() is
-doubtful. A failure (think chdir(some_function()) can lead into
-unintended chdir() to the home directory, therefore this behaviour
-is deprecated.
-
-=item *
-
-The builtin dump() function has probably outlived most of its
-usefulness. The core-dumping functionality will remain in future
-available as an explicit call to C<CORE::dump()>, but in future
-releases the behaviour of an unqualified C<dump()> call may change.
-
-=item *
-
-The very dusty examples in the eg/ directory have been removed.
-Suggestions for new shiny examples welcome but the main issue is that
-the examples need to be documented, tested and (most importantly)
-maintained.
-
-=item *
-
-The (bogus) escape sequences \8 and \9 now give an optional warning
-("Unrecognized escape passed through"). There is no need to \-escape
-any C<\w> character.
-
-=item *
-
-The *glob{FILEHANDLE} is deprecated, use *glob{IO} instead.
-
-=item *
-
-The C<package;> syntax (C<package> without an argument) has been
-deprecated. Its semantics were never that clear and its
-implementation even less so. If you have used that feature to
-disallow all but fully qualified variables, C<use strict;> instead.
-
-=item *
-
-The unimplemented POSIX regex features [[.cc.]] and [[=c=]] are still
-recognised but now cause fatal errors. The previous behaviour of
-ignoring them by default and warning if requested was unacceptable
-since it, in a way, falsely promised that the features could be used.
-
-=item *
-
-In future releases, non-PerlIO aware XS modules may become completely
-unsupported. Since PerlIO is a drop-in replacement for stdio at the
-source code level, this shouldn't be that drastic a change.
-
-=item *
-
-Previous versions of perl and some readings of some sections of Camel
-III implied that the C<:raw> "discipline" was the inverse of C<:crlf>.
-Turning off "clrfness" is no longer enough to make a stream truly
-binary. So the PerlIO C<:raw> layer (or "discipline", to use the Camel
-book's older terminology) is now formally defined as being equivalent
-to binmode(FH) - which is in turn defined as doing whatever is
-necessary to pass each byte as-is without any translation. In
-particular binmode(FH) - and hence C<:raw> - will now turn off both
-CRLF and UTF-8 translation and remove other layers (e.g. :encoding())
-which would modify byte stream.
-
-=item *
-
-The current user-visible implementation of pseudo-hashes (the weird
-use of the first array element) is deprecated starting from Perl 5.8.0
-and will be removed in Perl 5.10.0, and the feature will be
-implemented differently. Not only is the current interface rather
-ugly, but the current implementation slows down normal array and hash
-use quite noticeably. The C<fields> pragma interface will remain
-available. The I<restricted hashes> interface is expected to
-be the replacement interface (see L<Hash::Util>). If your existing
-programs depends on the underlying implementation, consider using
-L<Class::PseudoHash> from CPAN.
-
-=item *
-
-The syntaxes C<< @a->[...] >> and C<< %h->{...} >> have now been deprecated.
-
-=item *
-
-After years of trying, suidperl is considered to be too complex to
-ever be considered truly secure. The suidperl functionality is likely
-to be removed in a future release.
-
-=item *
-
-The 5.005 threads model (module C<Thread>) is deprecated and expected
-to be removed in Perl 5.10. Multithreaded code should be migrated to
-the new ithreads model (see L<threads>, L<threads::shared> and
-L<perlthrtut>).
-
-=item *
-
-The long deprecated uppercase aliases for the string comparison
-operators (EQ, NE, LT, LE, GE, GT) have now been removed.
-
-=item *
-
-The tr///C and tr///U features have been removed and will not return;
-the interface was a mistake. Sorry about that. For similar
-functionality, see pack('U0', ...) and pack('C0', ...). [561]
-
-=item *
-
-Earlier Perls treated "sub foo (@bar)" as equivalent to "sub foo (@)".
-The prototypes are now checked better at compile-time for invalid
-syntax. An optional warning is generated ("Illegal character in
-prototype...") but this may be upgraded to a fatal error in a future
-release.
-
-=item *
-
-The C<exec LIST> and C<system LIST> operations now produce warnings on
-tainted data and in some future release they will produce fatal errors.
-
-=item *
-
-The existing behaviour when localising tied arrays and hashes is wrong,
-and will be changed in a future release, so do not rely on the existing
-behaviour. See L<"Localising Tied Arrays and Hashes Is Broken">.
-
-=back
-
-=head1 Core Enhancements
-
-=head2 Unicode Overhaul
-
-Unicode in general should be now much more usable than in Perl 5.6.0
-(or even in 5.6.1). Unicode can be used in hash keys, Unicode in
-regular expressions should work now, Unicode in tr/// should work now,
-Unicode in I/O should work now. See L<perluniintro> for introduction
-and L<perlunicode> for details.
-
-=over 4
-
-=item *
-
-The Unicode Character Database coming with Perl has been upgraded
-to Unicode 3.2.0. For more information, see http://www.unicode.org/ .
-[561+] (5.6.1 has UCD 3.0.1.)
-
-=item *
-
-For developers interested in enhancing Perl's Unicode capabilities:
-almost all the UCD files are included with the Perl distribution in
-the F<lib/unicore> subdirectory. The most notable omission, for space
-considerations, is the Unihan database.
-
-=item *
-
-The properties \p{Blank} and \p{SpacePerl} have been added. "Blank" is like
-C isblank(), that is, it contains only "horizontal whitespace" (the space
-character is, the newline isn't), and the "SpacePerl" is the Unicode
-equivalent of C<\s> (\p{Space} isn't, since that includes the vertical
-tabulator character, whereas C<\s> doesn't.)
-
-See "New Unicode Properties" earlier in this document for additional
-information on changes with Unicode properties.
-
-=back
-
-=head2 PerlIO is Now The Default
-
-=over 4
-
-=item *
-
-IO is now by default done via PerlIO rather than system's "stdio".
-PerlIO allows "layers" to be "pushed" onto a file handle to alter the
-handle's behaviour. Layers can be specified at open time via 3-arg
-form of open:
-
- open($fh,'>:crlf :utf8', $path) || ...
-
-or on already opened handles via extended C<binmode>:
-
- binmode($fh,':encoding(iso-8859-7)');
-
-The built-in layers are: unix (low level read/write), stdio (as in
-previous Perls), perlio (re-implementation of stdio buffering in a
-portable manner), crlf (does CRLF <=> "\n" translation as on Win32,
-but available on any platform). A mmap layer may be available if
-platform supports it (mostly UNIXes).
-
-Layers to be applied by default may be specified via the 'open' pragma.
-
-See L</"Installation and Configuration Improvements"> for the effects
-of PerlIO on your architecture name.
-
-=item *
-
-If your platform supports fork(), you can use the list form of C<open>
-for pipes. For example:
-
- open KID_PS, "-|", "ps", "aux" or die $!;
-
-forks the ps(1) command (without spawning a shell, as there are more
-than three arguments to open()), and reads its standard output via the
-C<KID_PS> filehandle. See L<perlipc>.
-
-=item *
-
-File handles can be marked as accepting Perl's internal encoding of Unicode
-(UTF-8 or UTF-EBCDIC depending on platform) by a pseudo layer ":utf8" :
-
- open($fh,">:utf8","Uni.txt");
-
-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. See L<perluniintro>
-for more information about UTF-8.
-
-=item *
-
-If your environment variables (LC_ALL, LC_CTYPE, LANG, LANGUAGE) look
-like you want to use UTF-8 (any of the the variables match C</utf-?8/i>),
-your STDIN, STDOUT, STDERR handles and the default open layer
-(see L<open>) are marked as UTF-8. (This feature, like other new
-features that combine Unicode and I/O, work only if you are using
-PerlIO, but that's the default.)
-
-Note that after this Perl really does assume that everything is UTF-8:
-for example if some input handle is not, Perl will probably very soon
-complain about the input data like this "Malformed UTF-8 ..." since
-any old eight-bit data is not legal UTF-8.
-
-Note for code authors: if you want to enable your users to use UTF-8
-as their default encoding but in your code still have eight-bit I/O streams
-(such as images or zip files), you need to explicitly open() or binmode()
-with C<:bytes> (see L<perlfunc/open> and L<perlfunc/binmode>), or you
-can just use C<binmode(FH)> (nice for pre-5.8.0 backward compatibility).
-
-=item *
-
-File handles can translate character encodings from/to Perl's internal
-Unicode form on read/write via the ":encoding()" layer.
-
-=item *
-
-File handles can be opened to "in memory" files held in Perl scalars via:
-
- open($fh,'>', \$variable) || ...
-
-=item *
-
-Anonymous temporary files are available without need to
-'use FileHandle' or other module via
-
- open($fh,"+>", undef) || ...
-
-That is a literal undef, not an undefined value.
-
-=back
-
-=head2 ithreads
-
-The new interpreter threads ("ithreads" for short) implementation of
-multithreading, by Arthur Bergman, replaces the old "5.005 threads"
-implementation. In the ithreads model any data sharing between
-threads must be explicit, as opposed to the model where data sharing
-was implicit. See L<threads> and L<threads::shared>, and
-L<perlthrtut>.
-
-As a part of the ithreads implementation Perl will also use
-any necessary and detectable reentrant libc interfaces.
-
-=head2 Restricted Hashes
-
-A restricted hash is restricted to a certain set of keys, no keys
-outside the set can be added. Also individual keys can be restricted
-so that the key cannot be deleted and the value cannot be changed.
-No new syntax is involved: the Hash::Util module is the interface.
-
-=head2 Safe Signals
-
-Perl used to be fragile in that signals arriving at inopportune moments
-could corrupt Perl's internal state. Now Perl postpones handling of
-signals until it's safe (between opcodes).
-
-This change may have surprising side effects because signals no longer
-interrupt Perl instantly. Perl will now first finish whatever it was
-doing, like finishing an internal operation (like sort()) or an
-external operation (like an I/O operation), and only then look at any
-arrived signals (and before starting the next operation). No more corrupt
-internal state since the current operation is always finished first,
-but the signal may take more time to get heard. Note that breaking
-out from potentially blocking operations should still work, though.
-
-=head2 Understanding of Numbers
-
-In general a lot of fixing has happened in the area of Perl's
-understanding of numbers, both integer and floating point. Since in
-many systems the standard number parsing functions like C<strtoul()>
-and C<atof()> seem to have bugs, Perl tries to work around their
-deficiencies. This results hopefully in more accurate numbers.
-
-Perl now tries internally to use integer values in numeric conversions
-and basic arithmetics (+ - * /) if the arguments are integers, and
-tries also to keep the results stored internally as integers.
-This change leads to often slightly faster and always less lossy
-arithmetics. (Previously Perl always preferred floating point numbers
-in its math.)
-
-=head2 Arrays now always interpolate into double-quoted strings [561]
-
-In double-quoted strings, arrays now interpolate, no matter what. The
-behavior in earlier versions of perl 5 was that arrays would interpolate
-into strings if the array had been mentioned before the string was
-compiled, and otherwise Perl would raise a fatal compile-time error.
-In versions 5.000 through 5.003, the error was
-
- Literal @example now requires backslash
-
-In versions 5.004_01 through 5.6.0, the error was
-
- In string, @example now must be written as \@example
-
-The idea here was to get people into the habit of writing
-C<"fred\@example.com"> when they wanted a literal C<@> sign, just as
-they have always written C<"Give me back my \$5"> when they wanted a
-literal C<$> sign.
-
-Starting with 5.6.1, when Perl now sees an C<@> sign in a
-double-quoted string, it I<always> attempts to interpolate an array,
-regardless of whether or not the array has been used or declared
-already. The fatal error has been downgraded to an optional warning:
-
- Possible unintended interpolation of @example in string
-
-This warns you that C<"fred@example.com"> is going to turn into
-C<fred.com> if you don't backslash the C<@>.
-See http://www.plover.com/~mjd/perl/at-error.html for more details
-about the history here.
-
-=head2 Miscellaneous Changes
-
-=over 4
-
-=item *
-
-AUTOLOAD is now lvaluable, meaning that you can add the :lvalue attribute
-to AUTOLOAD subroutines and you can assign to the AUTOLOAD return value.
-
-=item *
-
-The $Config{byteorder} (and corresponding BYTEORDER in config.h) was
-previously wrong in platforms if sizeof(long) was 4, but sizeof(IV)
-was 8. The byteorder was only sizeof(long) bytes long (1234 or 4321),
-but now it is correctly sizeof(IV) bytes long, (12345678 or 87654321).
-(This problem didn't affect Windows platforms.)
-
-Also, $Config{byteorder} is now computed dynamically--this is more
-robust with "fat binaries" where an executable image contains binaries
-for more than one binary platform, and when cross-compiling.
-
-=item *
-
-C<perl -d:Module=arg,arg,arg> now works (previously one couldn't pass
-in multiple arguments.)
-
-=item *
-
-C<do> followed by a bareword now ensures that this bareword isn't
-a keyword (to avoid a bug where C<do q(foo.pl)> tried to call a
-subroutine called C<q>). This means that for example instead of
-C<do format()> you must write C<do &format()>.
-
-=item *
-
-The builtin dump() now gives an optional warning
-C<dump() better written as CORE::dump()>,
-meaning that by default C<dump(...)> is resolved as the builtin
-dump() which dumps core and aborts, not as (possibly) user-defined
-C<sub dump>. To call the latter, qualify the call as C<&dump(...)>.
-(The whole dump() feature is to considered deprecated, and possibly
-removed/changed in future releases.)
-
-=item *
-
-chomp() and chop() are now overridable. Note, however, that their
-prototype (as given by C<prototype("CORE::chomp")> is undefined,
-because it cannot be expressed and therefore one cannot really write
-replacements to override these builtins.
-
-=item *
-
-END blocks are now run even if you exit/die in a BEGIN block.
-Internally, the execution of END blocks is now controlled by
-PL_exit_flags & PERL_EXIT_DESTRUCT_END. This enables the new
-behaviour for Perl embedders. This will default in 5.10. See
-L<perlembed>.
-
-=item *
-
-Formats now support zero-padded decimal fields.
-
-=item *
-
-Although "you shouldn't do that", it was possible to write code that
-depends on Perl's hashed key order (Data::Dumper does this). The new
-algorithm "One-at-a-Time" produces a different hashed key order.
-More details are in L</"Performance Enhancements">.
-
-=item *
-
-lstat(FILEHANDLE) now gives a warning because the operation makes no sense.
-In future releases this may become a fatal error.
-
-=item *
-
-Spurious syntax errors generated in certain situations, when glob()
-caused File::Glob to be loaded for the first time, have been fixed. [561]
-
-=item *
-
-Lvalue subroutines can now return C<undef> in list context. However,
-the lvalue subroutine feature still remains experimental. [561+]
-
-=item *
-
-A lost warning "Can't declare ... dereference in my" has been
-restored (Perl had it earlier but it became lost in later releases.)
-
-=item *
-
-A new special regular expression variable has been introduced:
-C<$^N>, which contains the most-recently closed group (submatch).
-
-=item *
-
-C<no Module;> does not produce an error even if Module does not have an
-unimport() method. This parallels the behavior of C<use> vis-a-vis
-C<import>. [561]
-
-=item *
-
-The numerical comparison operators return C<undef> if either operand
-is a NaN. Previously the behaviour was unspecified.
-
-=item *
-
-C<our> can now have an experimental optional attribute C<unique> that
-affects how global variables are shared among multiple interpreters,
-see L<perlfunc/our>.
-
-=item *
-
-The following builtin functions are now overridable: each(), keys(),
-pop(), push(), shift(), splice(), unshift(). [561]
-
-=item *
-
-C<pack() / unpack()> can now group template letters with C<()> and then
-apply repetition/count modifiers on the groups.
-
-=item *
-
-C<pack() / unpack()> can now process the Perl internal numeric types:
-IVs, UVs, NVs-- and also long doubles, if supported by the platform.
-The template letters are C<j>, C<J>, C<F>, and C<D>.
-
-=item *
-
-C<pack('U0a*', ...)> can now be used to force a string to UTF8.
-
-=item *
-
-my __PACKAGE__ $obj now works. [561]
-
-=item *
-
-POSIX::sleep() now returns the number of I<unslept> seconds
-(as the POSIX standard says), as opposed to CORE::sleep() which
-returns the number of slept seconds.
-
-=item *
-
-The printf() and sprintf() now support parameter reordering using the
-C<%\d+\$> and C<*\d+\$> syntaxes. For example
-
- print "%2\$s %1\$s\n", "foo", "bar";
-
-will print "bar foo\n". This feature helps in writing
-internationalised software, and in general when the order
-of the parameters can vary.
-
-=item *
-
-The (\&) prototype now works properly. [561]
-
-=item *
-
-prototype(\[$@%&]) is now available to implicitly create references
-(useful for example if you want to emulate the tie() interface).
-
-=item *
-
-A new command-line option, C<-t> is available. It is the
-little brother of C<-T>: instead of dying on taint violations,
-lexical warnings are given. B<This is only meant as a temporary
-debugging aid while securing the code of old legacy applications.
-This is not a substitute for -T.>
-
-=item *
-
-In other taint news, the C<exec LIST> and C<system LIST> have now been
-considered too risky (think C<exec @ARGV>: it can start any program
-with any arguments), and now the said forms cause a warning under
-lexical warnings. You should carefully launder the arguments to
-guarantee their validity. In future releases of Perl the forms will
-become fatal errors so consider starting laundering now.
-
-=item *
-
-Tied hash interfaces are now required to have the EXISTS and DELETE
-methods (either own or inherited).
-
-=item *
-
-If tr/// is just counting characters, it doesn't attempt to
-modify its target.
-
-=item *
-
-untie() will now call an UNTIE() hook if it exists. See L<perltie>
-for details. [561]
-
-=item *
-
-L<utime> now supports C<utime undef, undef, @files> to change the
-file timestamps to the current time.
-
-=item *
-
-The rules for allowing underscores (underbars) in numeric constants
-have been relaxed and simplified: now you can have an underscore
-simply B<between digits>.
-
-=item *
-
-Rather than relying on C's argv[0] (which may not contain a full pathname)
-where possible $^X is now set by asking the operating system.
-(eg by reading F</proc/self/exe> on Linux, F</proc/curproc/file> on FreeBSD)
-
-=item *
-
-A new variable, C<${^TAINT}>, indicates whether taint mode is enabled.
-
-=item *
-
-You can now override the readline() builtin, and this overrides also
-the <FILEHANDLE> angle bracket operator.
-
-=item *
-
-The command-line options -s and -F are now recognized on the shebang
-(#!) line.
-
-=item *
-
-Use of the C</c> match modifier without an accompanying C</g> modifier
-elicits a new warning: C<Use of /c modifier is meaningless without /g>.
-
-Use of C</c> in substitutions, even with C</g>, elicits
-C<Use of /c modifier is meaningless in s///>.
-
-Use of C</g> with C<split> elicits C<Use of /g modifier is meaningless
-in split>.
-
-=item *
-
-Support for the C<CLONE> special subroutine had been added.
-With ithreads, when a new thread is created, all Perl data is cloned,
-however non-Perl data cannot be cloned automatically. In C<CLONE> you
-can do whatever you need to do, like for example handle the cloning of
-non-Perl data, if necessary. C<CLONE> will be executed once for every
-package that has it defined or inherited. It will be called in the
-context of the new thread, so all modifications are made in the new area.
-
-See L<perlmod>
-
-=back
-
-=head1 Modules and Pragmata
-
-=head2 New Modules and Pragmata
-
-=over 4
-
-=item *
-
-C<Attribute::Handlers>, originally by Damian Conway and now maintained
-by Arthur Bergman, allows a class to define attribute handlers.
-
- package MyPack;
- use Attribute::Handlers;
- sub Wolf :ATTR(SCALAR) { print "howl!\n" }
-
- # later, in some package using or inheriting from MyPack...
-
- my MyPack $Fluffy : Wolf; # the attribute handler Wolf will be called
-
-Both variables and routines can have attribute handlers. Handlers can
-be specific to type (SCALAR, ARRAY, HASH, or CODE), or specific to the
-exact compilation phase (BEGIN, CHECK, INIT, or END).
-See L<Attribute::Handlers>.
-
-=item *
-
-C<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>. [561+]
-
-=item *
-
-The new bignum, bigint, and bigrat pragmas, by Tels, implement
-transparent bignum support (using the Math::BigInt, Math::BigFloat,
-and Math::BigRat backends).
-
-=item *
-
-C<Class::ISA>, by Sean Burke, is a module for reporting the search
-path for a class's ISA tree. See L<Class::ISA>.
-
-=item *
-
-C<Cwd> now has a split personality: if possible, an XS extension is
-used, (this will hopefully be faster, more secure, and more robust)
-but if not possible, the familiar Perl implementation is used.
-
-=item *
-
-C<Devel::PPPort>, originally by Kenneth Albanowski and now
-maintained by Paul Marquess, has been added. It is primarily used
-by C<h2xs> to enhance portability of XS modules between different
-versions of Perl. See L<Devel::PPPort>.
-
-=item *
-
-C<Digest>, frontend module for calculating digests (checksums), from
-Gisle Aas, has been added. See L<Digest>.
-
-=item *
-
-C<Digest::MD5> for calculating MD5 digests (checksums) as defined in
-RFC 1321, from Gisle Aas, has been added. See L<Digest::MD5>.
-
- use Digest::MD5 'md5_hex';
-
- $digest = md5_hex("Thirsty Camel");
-
- print $digest, "\n"; # 01d19d9d2045e005c3f1b80e8b164de1
-
-NOTE: the C<MD5> backward compatibility module is deliberately not
-included since its further use is discouraged.
-
-See also L<PerlIO::via::QuotedPrint>.
-
-=item *
-
-C<Encode>, originally by Nick Ing-Simmons and now maintained by Dan
-Kogai, provides a mechanism to translate between different character
-encodings. Support for Unicode, ISO-8859-1, and ASCII are compiled in
-to the module. Several other encodings (like the rest of the
-ISO-8859, CP*/Win*, Mac, KOI8-R, three variants EBCDIC, Chinese,
-Japanese, and Korean encodings) are included and can be loaded at
-runtime. (For space considerations, the largest Chinese encodings
-have been separated into their own CPAN module, Encode::HanExtra,
-which Encode will use if available). See L<Encode>.
-
-Any encoding supported by Encode module is also available to the
-":encoding()" layer if PerlIO is used.
-
-=item *
-
-C<Hash::Util> is the interface to the new I<restricted hashes>
-feature. (Implemented by Jeffrey Friedl, Nick Ing-Simmons, and
-Michael Schwern.) See L<Hash::Util>.
-
-=item *
-
-C<I18N::Langinfo> can be used to query locale information.
-See L<I18N::Langinfo>.
-
-=item *
-
-C<I18N::LangTags>, by Sean Burke, has functions for dealing with
-RFC3066-style language tags. See L<I18N::LangTags>.
-
-=item *
-
-C<ExtUtils::Constant>, by Nicholas Clark, is a new tool for extension
-writers for generating XS code to import C header constants.
-See L<ExtUtils::Constant>.
-
-=item *
-
-C<Filter::Simple>, by Damian Conway, is an easy-to-use frontend to
-Filter::Util::Call. See L<Filter::Simple>.
-
- # in MyFilter.pm:
-
- package MyFilter;
-
- use Filter::Simple sub {
- while (my ($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"
-
-=item *
-
-C<File::Temp>, by Tim Jenness, allows one to create temporary files
-and directories in an easy, portable, and secure way. See L<File::Temp>.
-[561+]
-
-=item *
-
-C<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>.
-
-=item *
-
-C<if>, by Ilya Zakharevich, is a new pragma for conditional inclusion
-of modules.
-
-=item *
-
-L<libnet>, by Graham Barr, is a collection of perl5 modules related
-to network programming. See L<Net::FTP>, L<Net::NNTP>, L<Net::Ping>
-(not part of libnet, but related), L<Net::POP3>, L<Net::SMTP>,
-and L<Net::Time>.
-
-Perl installation leaves libnet unconfigured; use F<libnetcfg>
-to configure it.
-
-=item *
-
-C<List::Util>, by Graham Barr, is a selection of general-utility
-list subroutines, such as sum(), min(), first(), and shuffle().
-See L<List::Util>.
-
-=item *
-
-C<Locale::Constants>, C<Locale::Country>, C<Locale::Currency>
-C<Locale::Language>, and L<Locale::Script>, by Neil Bowers, have
-been added. They provide the codes for various locale standards, such
-as "fr" for France, "usd" for US Dollar, and "ja" 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>.
-
-=item *
-
-C<Locale::Maketext>, by Sean Burke, is a localization framework. See
-L<Locale::Maketext>, and L<Locale::Maketext::TPJ13>. The latter is an
-article about software localization, originally published in The Perl
-Journal #13, and republished here with kind permission.
-
-=item *
-
-C<Math::BigRat> for big rational numbers, to accompany Math::BigInt and
-Math::BigFloat, from Tels. See L<Math::BigRat>.
-
-=item *
-
-C<Memoize> can make your functions faster by trading space for time,
-from Mark-Jason Dominus. See L<Memoize>.
-
-=item *
-
-C<MIME::Base64>, by Gisle Aas, allows you to encode data in base64,
-as defined in RFC 2045 - I<MIME (Multipurpose Internet Mail
-Extensions)>.
-
- use MIME::Base64;
-
- $encoded = encode_base64('Aladdin:open sesame');
- $decoded = decode_base64($encoded);
-
- print $encoded, "\n"; # "QWxhZGRpbjpvcGVuIHNlc2FtZQ=="
-
-See L<MIME::Base64>.
-
-=item *
-
-C<MIME::QuotedPrint>, by Gisle Aas, allows you to encode data
-in quoted-printable encoding, as defined in RFC 2045 - I<MIME
-(Multipurpose Internet Mail Extensions)>.
-
- use MIME::QuotedPrint;
-
- $encoded = encode_qp("Smiley in Unicode: \x{263a}");
- $decoded = decode_qp($encoded);
-
- print $encoded, "\n"; # "Smiley in Unicode: =263A"
-
-See also L<PerlIO::via::QuotedPrint>.
-
-=item *
-
-C<NEXT>, by Damian Conway, is a pseudo-class for method redispatch.
-See L<NEXT>.
-
-=item *
-
-C<open> is a new pragma for setting the default I/O layers
-for open().
-
-=item *
-
-C<PerlIO::scalar>, by Nick Ing-Simmons, provides the implementation
-of IO to "in memory" Perl scalars as discussed above. It also serves
-as an example of a loadable PerlIO layer. Other future possibilities
-include PerlIO::Array and PerlIO::Code. See L<PerlIO::scalar>.
-
-=item *
-
-C<PerlIO::via>, by Nick Ing-Simmons, acts as a PerlIO layer and wraps
-PerlIO layer functionality provided by a class (typically implemented
-in Perl code).
-
-=item *
-
-C<PerlIO::via::QuotedPrint>, by Elizabeth Mattijsen, is an example
-of a C<PerlIO::via> class:
-
- use PerlIO::via::QuotedPrint;
- open($fh,">:via(QuotedPrint)",$path);
-
-This will automatically convert everything output to C<$fh> to
-Quoted-Printable. See L<PerlIO::via> and L<PerlIO::via::QuotedPrint>.
-
-=item *
-
-C<Pod::ParseLink>, by Russ Allbery, has been added,
-to parse LZ<><> links in pods as described in the new
-perlpodspec.
-
-=item *
-
-C<Pod::Text::Overstrike>, by Joe Smith, has been added.
-It converts POD data to formatted overstrike text.
-See L<Pod::Text::Overstrike>. [561+]
-
-=item *
-
-C<Scalar::Util> is a selection of general-utility scalar subroutines,
-such as blessed(), reftype(), and tainted(). See L<Scalar::Util>.
-
-=item *
-
-C<sort> is a new pragma for controlling the behaviour of sort().
-
-=item *
-
-C<Storable> gives persistence to Perl data structures by allowing the
-storage and retrieval of Perl data to and from files in a fast and
-compact binary format. Because in effect Storable does serialisation
-of Perl data structures, with it you can also clone deep, hierarchical
-datastructures. Storable was originally created by Raphael Manfredi,
-but it is now maintained by Abhijit Menon-Sen. Storable has been
-enhanced to understand the two new hash features, Unicode keys and
-restricted hashes. See L<Storable>.
-
-=item *
-
-C<Switch>, by Damian Conway, has been added. Just by saying
-
- use Switch;
-
-you have C<switch> and C<case> available in Perl.
-
- use Switch;
-
- switch ($val) {
-
- case 1 { print "number 1" }
- case "a" { print "string a" }
- case [1..10,42] { print "number in list" }
- case (@array) { print "number in list" }
- case /\w+/ { print "pattern" }
- case qr/\w+/ { print "pattern" }
- case (%hash) { print "entry in hash" }
- case (\%hash) { print "entry in hash" }
- case (\&sub) { print "arg to subroutine" }
- else { print "previous case not true" }
- }
-
-See L<Switch>.
-
-=item *
-
-C<Test::More>, by Michael Schwern, is yet another framework for writing
-test scripts, more extensive than Test::Simple. See L<Test::More>.
-
-=item *
-
-C<Test::Simple>, by Michael Schwern, has basic utilities for writing
-tests. See L<Test::Simple>.
-
-=item *
-
-C<Text::Balanced>, by Damian Conway, has been added, for extracting
-delimited text sequences from strings.
-
- use Text::Balanced 'extract_delimited';
-
- ($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>.
-
-=item *
-
-C<threads>, by Arthur Bergman, is an interface to interpreter threads.
-Interpreter threads (ithreads) is the new thread model introduced in
-Perl 5.6 but only available as an internal interface for extension
-writers (and for Win32 Perl for C<fork()> emulation). See L<threads>,
-L<threads::shared>, and L<perlthrtut>.
-
-=item *
-
-C<threads::shared>, by Arthur Bergman, allows data sharing for
-interpreter threads. See L<threads::shared>.
-
-=item *
-
-C<Tie::File>, by Mark-Jason Dominus, associates a Perl array with the
-lines of a file. See L<Tie::File>.
-
-=item *
-
-C<Tie::Memoize>, by Ilya Zakharevich, provides on-demand loaded hashes.
-See L<Tie::Memoize>.
-
-=item *
-
-C<Tie::RefHash::Nestable>, by Edward Avis, allows storing hash
-references (unlike the standard Tie::RefHash) The module is contained
-within Tie::RefHash. See L<Tie::RefHash>.
-
-=item *
-
-C<Time::HiRes>, by Douglas E. Wegscheid, provides high resolution
-timing (ualarm, usleep, and gettimeofday). See L<Time::HiRes>.
-
-=item *
-
-C<Unicode::UCD> offers a querying interface to the Unicode Character
-Database. See L<Unicode::UCD>.
-
-=item *
-
-C<Unicode::Collate>, by SADAHIRO Tomoyuki, implements the UCA
-(Unicode Collation Algorithm) for sorting Unicode strings.
-See L<Unicode::Collate>.
-
-=item *
-
-C<Unicode::Normalize>, by SADAHIRO Tomoyuki, implements the various
-Unicode normalization forms. See L<Unicode::Normalize>.
-
-=item *
-
-C<XS::APItest>, by Tim Jenness, is a test extension that exercises XS
-APIs. Currently only C<printf()> is tested: how to output various
-basic data types from XS.
-
-=item *
-
-C<XS::Typemap>, by Tim Jenness, is a test extension that exercises
-XS typemaps. Nothing gets installed, but the code is worth studying
-for extension writers.
-
-=back
-
-=head2 Updated And Improved Modules and Pragmata
-
-=over 4
-
-=item *
-
-The following independently supported modules have been updated to the
-newest versions from CPAN: CGI, CPAN, DB_File, File::Spec, File::Temp,
-Getopt::Long, Math::BigFloat, Math::BigInt, the podlators bundle
-(Pod::Man, Pod::Text), Pod::LaTeX [561+], Pod::Parser, Storable,
-Term::ANSIColor, Test, Text-Tabs+Wrap.
-
-=item *
-
-attributes::reftype() now works on tied arguments.
-
-=item *
-
-AutoLoader can now be disabled with C<no AutoLoader;>.
-
-=item *
-
-B::Deparse has been significantly enhanced by Robin Houston. It can
-now deparse almost all of the standard test suite (so that the tests
-still succeed). There is a make target "test.deparse" for trying this
-out.
-
-=item *
-
-Carp now has better interface documentation, and the @CARP_NOT
-interface has been added to get optional control over where errors
-are reported independently of @ISA, by Ben Tilly.
-
-=item *
-
-Class::Struct can now define the classes in compile time.
-
-=item *
-
-Class::Struct now assigns the array/hash element if the accessor
-is called with an array/hash element as the B<sole> argument.
-
-=item *
-
-The return value of Cwd::fastcwd() is now tainted.
-
-=item *
-
-Data::Dumper now has an option to sort hashes.
-
-=item *
-
-Data::Dumper now has an option to dump code references
-using B::Deparse.
-
-=item *
-
-DB_File now supports newer Berkeley DB versions, among
-other improvements.
-
-=item *
-
-Devel::Peek now has an interface for the Perl memory statistics
-(this works only if you are using perl's malloc, and if you have
-compiled with debugging).
-
-=item *
-
-The English module can now be used without the infamous performance
-hit by saying
-
- use English '-no_match_vars';
-
-(Assuming, of course, that you don't need the troublesome variables
-C<$`>, C<$&>, or C<$'>.) Also, introduced C<@LAST_MATCH_START> and
-C<@LAST_MATCH_END> English aliases for C<@-> and C<@+>.
-
-=item *
-
-ExtUtils::MakeMaker has been significantly cleaned up and fixed.
-The enhanced version has also been backported to earlier releases
-of Perl and submitted to CPAN so that the earlier releases can
-enjoy the fixes.
-
-=item *
-
-The arguments of WriteMakefile() in Makefile.PL are now checked
-for sanity much more carefully than before. This may cause new
-warnings when modules are being installed. See L<ExtUtils::MakeMaker>
-for more details.
-
-=item *
-
-ExtUtils::MakeMaker now uses File::Spec internally, which hopefully
-leads to better portability.
-
-=item *
-
-Fcntl, Socket, and Sys::Syslog have been rewritten by Nicholas Clark
-to use the new-style constant dispatch section (see L<ExtUtils::Constant>).
-This means that they will be more robust and hopefully faster.
-
-=item *
-
-File::Find now chdir()s correctly when chasing symbolic links. [561]
-
-=item *
-
-File::Find now has pre- and post-processing callbacks. It also
-correctly changes directories when chasing symbolic links. Callbacks
-(naughtily) exiting with "next;" instead of "return;" now work.
-
-=item *
-
-File::Find is now (again) reentrant. It also has been made
-more portable.
-
-=item *
-
-The warnings issued by File::Find now belong to their own category.
-You can enable/disable them with C<use/no warnings 'File::Find';>.
-
-=item *
-
-File::Glob::glob() has been renamed to File::Glob::bsd_glob()
-because the name clashes with the builtin glob(). The older
-name is still available for compatibility, but is deprecated. [561]
-
-=item *
-
-File::Glob now supports C<GLOB_LIMIT> constant to limit the size of
-the returned list of filenames.
-
-=item *
-
-IPC::Open3 now allows the use of numeric file descriptors.
-
-=item *
-
-IO::Socket now has an atmark() method, which returns true if the socket
-is positioned at the out-of-band mark. The method is also exportable
-as a sockatmark() function.
-
-=item *
-
-IO::Socket::INET failed to open the specified port if the service name
-was not known. It now correctly uses the supplied port number as is. [561]
-
-=item *
-
-IO::Socket::INET has support for the ReusePort option (if your
-platform supports it). The Reuse option now has an alias, ReuseAddr.
-For clarity, you may want to prefer ReuseAddr.
-
-=item *
-
-IO::Socket::INET now supports a value of zero for C<LocalPort>
-(usually meaning that the operating system will make one up.)
-
-=item *
-
-'use lib' now works identically to @INC. Removing directories
-with 'no lib' now works.
-
-=item *
-
-Math::BigFloat and Math::BigInt have undergone a full rewrite by Tels.
-They are now magnitudes faster, and they support various bignum
-libraries such as GMP and PARI as their backends.
-
-=item *
-
-Math::Complex handles inf, NaN etc., better.
-
-=item *
-
-Net::Ping has been considerably enhanced by Rob Brown: multihoming is
-now supported, Win32 functionality is better, there is now time
-measuring functionality (optionally high-resolution using
-Time::HiRes), and there is now "external" protocol which uses
-Net::Ping::External module which runs your external ping utility and
-parses the output. A version of Net::Ping::External is available in
-CPAN.
-
-Note that some of the Net::Ping tests are disabled when running
-under the Perl distribution since one cannot assume one or more
-of the following: enabled echo port at localhost, full Internet
-connectivity, or sympathetic firewalls. You can set the environment
-variable PERL_TEST_Net_Ping to "1" (one) before running the Perl test
-suite to enable all the Net::Ping tests.
-
-=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 *
-
-In Safe, C<%INC> is now localised in a Safe compartment so that
-use/require work.
-
-=item *
-
-In SDBM_File on dosish platforms, some keys went missing because of
-lack of support for files with "holes". A workaround for the problem
-has been added.
-
-=item *
-
-In Search::Dict one can now have a pre-processing hook for the
-lines being searched.
-
-=item *
-
-The Shell module now has an OO interface.
-
-=item *
-
-In Sys::Syslog there is now a failover mechanism that will go
-through alternative connection mechanisms until the message
-is successfully logged.
-
-=item *
-
-The Test module has been significantly enhanced.
-
-=item *
-
-Time::Local::timelocal() does not handle fractional seconds anymore.
-The rationale is that neither does localtime(), and timelocal() and
-localtime() are supposed to be inverses of each other.
-
-=item *
-
-The vars pragma now supports declaring fully qualified variables.
-(Something that C<our()> does not and will not support.)
-
-=item *
-
-The C<utf8::> name space (as in the pragma) provides various
-Perl-callable functions to provide low level access to Perl's
-internal Unicode representation. At the moment only length()
-has been implemented.
-
-=back
-
-=head1 Utility Changes
-
-=over 4
-
-=item *
-
-Emacs perl mode (emacs/cperl-mode.el) has been updated to version
-4.31.
-
-=item *
-
-F<emacs/e2ctags.pl> is now much faster.
-
-=item *
-
-C<enc2xs> is a tool for people adding their own encodings to the
-Encode module.
-
-=item *
-
-C<h2ph> now supports C trigraphs.
-
-=item *
-
-C<h2xs> now produces a template README.
-
-=item *
-
-C<h2xs> now uses C<Devel::PPPort> for better portability between
-different versions of Perl.
-
-=item *
-
-C<h2xs> uses the new L<ExtUtils::Constant|ExtUtils::Constant> module
-which will affect newly created extensions that define constants.
-Since the new code is more correct (if you have two constants where the
-first one is a prefix of the second one, the first constant B<never>
-got defined), less lossy (it uses integers for integer constant,
-as opposed to the old code that used floating point numbers even for
-integer constants), and slightly faster, you might want to consider
-regenerating your extension code (the new scheme makes regenerating
-easy). L<h2xs> now also supports C trigraphs.
-
-=item *
-
-C<libnetcfg> has been added to configure libnet.
-
-=item *
-
-C<perlbug> is now much more robust. It also sends the bug report to
-perl.org, not perl.com.
-
-=item *
-
-C<perlcc> has been rewritten and its user interface (that is,
-command line) is much more like that of the UNIX C compiler, cc.
-(The perlbc tools has been removed. Use C<perlcc -B> instead.)
-B<Note that perlcc is still considered very experimental and
-unsupported.> [561]
-
-=item *
-
-C<perlivp> is a new Installation Verification Procedure utility
-for running any time after installing Perl.
-
-=item *
-
-C<piconv> is an implementation of the character conversion utility
-C<iconv>, demonstrating the new Encode module.
-
-=item *
-
-C<pod2html> now allows specifying a cache directory.
-
-=item *
-
-C<pod2html> now produces XHTML 1.0.
-
-=item *
-
-C<pod2html> now understands POD written using different line endings
-(PC-like CRLF versus UNIX-like LF versus MacClassic-like CR).
-
-=item *
-
-C<s2p> has been completely rewritten in Perl. (It is in fact a full
-implementation of sed in Perl: you can use the sed functionality by
-using the C<psed> utility.)
-
-=item *
-
-C<xsubpp> now understands POD documentation embedded in the *.xs
-files. [561]
-
-=item *
-
-C<xsubpp> now supports the OUT keyword.
-
-=back
-
-=head1 New Documentation
-
-=over 4
-
-=item *
-
-perl56delta details the changes between the 5.005 release and the
-5.6.0 release.
-
-=item *
-
-perlclib documents the internal replacements for standard C library
-functions. (Interesting only for extension writers and Perl core
-hackers.) [561+]
-
-=item *
-
-perldebtut is a Perl debugging tutorial. [561+]
-
-=item *
-
-perlebcdic contains considerations for running Perl on EBCDIC
-platforms. [561+]
-
-=item *
-
-perlintro is a gentle introduction to Perl.
-
-=item *
-
-perliol documents the internals of PerlIO with layers.
-
-=item *
-
-perlmodstyle is a style guide for writing modules.
-
-=item *
-
-perlnewmod tells about writing and submitting a new module. [561+]
-
-=item *
-
-perlpacktut is a pack() tutorial.
-
-=item *
-
-perlpod has been rewritten to be clearer and to record the best
-practices gathered over the years.
-
-=item *
-
-perlpodspec is a more formal specification of the pod format,
-mainly of interest for writers of pod applications, not to
-people writing in pod.
-
-=item *
-
-perlretut is a regular expression tutorial. [561+]
-
-=item *
-
-perlrequick is a regular expressions quick-start guide.
-Yes, much quicker than perlretut. [561]
-
-=item *
-
-perltodo has been updated.
-
-=item *
-
-perltootc has been renamed as perltooc (to not to conflict
-with perltoot in filesystems restricted to "8.3" names).
-
-=item *
-
-perluniintro is an introduction to using Unicode in Perl.
-(perlunicode is more of a detailed reference and background
-information)
-
-=item *
-
-perlutil explains the command line utilities packaged with the Perl
-distribution. [561+]
-
-=back
-
-The following platform-specific documents are available before
-the installation as README.I<platform>, and after the installation
-as perlI<platform>:
-
- perlaix perlamiga perlapollo perlbeos perlbs2000
- perlce perlcygwin perldgux perldos perlepoc perlfreebsd perlhpux
- perlhurd perlirix perlmachten perlmacos perlmint perlmpeix
- perlnetware perlos2 perlos390 perlplan9 perlqnx perlsolaris
- perltru64 perluts perlvmesa perlvms perlvos perlwin32
-
-These documents usually detail one or more of the following subjects:
-configuring, building, testing, installing, and sometimes also using
-Perl on the said platform.
-
-Eastern Asian Perl users are now welcomed in their own languages:
-README.jp (Japanese), README.ko (Korean), README.cn (simplified
-Chinese) and README.tw (traditional Chinese), which are written in
-normal pod but encoded in EUC-JP, EUC-KR, EUC-CN and Big5. These
-will get installed as
-
- perljp perlko perlcn perltw
-
-=over 4
-
-=item *
-
-The documentation for the POSIX-BC platform is called "BS2000", to avoid
-confusion with the Perl POSIX module.
-
-=item *
-
-The documentation for the WinCE platform is called perlce (README.ce
-in the source code kit), to avoid confusion with the perlwin32
-documentation on 8.3-restricted filesystems.
-
-=back
-
-=head1 Performance Enhancements
-
-=over 4
-
-=item *
-
-map() could get pathologically slow when the result list it generates
-is larger than the source list. The performance has been improved for
-common scenarios. [561]
-
-=item *
-
-sort() is also fully reentrant, in the sense that the sort function
-can itself call sort(). This did not work reliably in previous
-releases. [561]
-
-=item *
-
-sort() has been changed to use primarily mergesort internally as
-opposed to the earlier quicksort. For very small lists this may
-result in slightly slower sorting times, but in general the speedup
-should be at least 20%. Additional bonuses are that the worst case
-behaviour of sort() is now better (in computer science terms it now
-runs in time O(N log N), as opposed to quicksort's Theta(N**2)
-worst-case run time behaviour), and that sort() is now stable
-(meaning that elements with identical keys will stay ordered as they
-were before the sort). See the C<sort> pragma for information.
-
-The story in more detail: suppose you want to serve yourself a little
-slice of Pi.
-
- @digits = ( 3,1,4,1,5,9 );
-
-A numerical sort of the digits will yield (1,1,3,4,5,9), as expected.
-Which C<1> comes first is hard to know, since one C<1> looks pretty
-much like any other. You can regard this as totally trivial,
-or somewhat profound. However, if you just want to sort the even
-digits ahead of the odd ones, then what will
-
- sort { ($a % 2) <=> ($b % 2) } @digits;
-
-yield? The only even digit, C<4>, will come first. But how about
-the odd numbers, which all compare equal? With the quicksort algorithm
-used to implement Perl 5.6 and earlier, the order of ties is left up
-to the sort. So, as you add more and more digits of Pi, the order
-in which the sorted even and odd digits appear will change.
-and, for sufficiently large slices of Pi, the quicksort algorithm
-in Perl 5.8 won't return the same results even if reinvoked with the
-same input. The justification for this rests with quicksort's
-worst case behavior. If you run
-
- sort { $a <=> $b } ( 1 .. $N , 1 .. $N );
-
-(something you might approximate if you wanted to merge two sorted
-arrays using sort), doubling $N doesn't just double the quicksort time,
-it I<quadruples> it. Quicksort has a worst case run time that can
-grow like N**2, so-called I<quadratic> behaviour, and it can happen
-on patterns that may well arise in normal use. You won't notice this
-for small arrays, but you I<will> notice it with larger arrays,
-and you may not live long enough for the sort to complete on arrays
-of a million elements. So the 5.8 quicksort scrambles large arrays
-before sorting them, as a statistical defence against quadratic behaviour.
-But that means if you sort the same large array twice, ties may be
-broken in different ways.
-
-Because of the unpredictability of tie-breaking order, and the quadratic
-worst-case behaviour, quicksort was I<almost> replaced completely with
-a stable mergesort. I<Stable> means that ties are broken to preserve
-the original order of appearance in the input array. So
-
- sort { ($a % 2) <=> ($b % 2) } (3,1,4,1,5,9);
-
-will yield (4,3,1,1,5,9), guaranteed. The even and odd numbers
-appear in the output in the same order they appeared in the input.
-Mergesort has worst case O(N log N) behaviour, the best value
-attainable. And, ironically, this mergesort does particularly
-well where quicksort goes quadratic: mergesort sorts (1..$N, 1..$N)
-in O(N) time. But quicksort was rescued at the last moment because
-it is faster than mergesort on certain inputs and platforms.
-For example, if you really I<don't> care about the order of even
-and odd digits, quicksort will run in O(N) time; it's very good
-at sorting many repetitions of a small number of distinct elements.
-The quicksort divide and conquer strategy works well on platforms
-with relatively small, very fast, caches. Eventually, the problem gets
-whittled down to one that fits in the cache, from which point it
-benefits from the increased memory speed.
-
-Quicksort was rescued by implementing a sort pragma to control aspects
-of the sort. The B<stable> subpragma forces stable behaviour,
-regardless of algorithm. The B<_quicksort> and B<_mergesort>
-subpragmas are heavy-handed ways to select the underlying implementation.
-The leading C<_> is a reminder that these subpragmas may not survive
-beyond 5.8. More appropriate mechanisms for selecting the implementation
-exist, but they wouldn't have arrived in time to save quicksort.
-
-=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 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 *
-
-unshift() should now be noticeably faster.
-
-=back
-
-=head1 Installation and Configuration Improvements
-
-=head2 Generic Improvements
-
-=over 4
-
-=item *
-
-INSTALL now explains how you can configure Perl to use 64-bit
-integers even on non-64-bit platforms.
-
-=item *
-
-Policy.sh policy change: if you are reusing a Policy.sh file
-(see INSTALL) and you use Configure -Dprefix=/foo/bar and in the old
-Policy $prefix eq $siteprefix and $prefix eq $vendorprefix, all of
-them will now be changed to the new prefix, /foo/bar. (Previously
-only $prefix changed.) If you do not like this new behaviour,
-specify prefix, siteprefix, and vendorprefix explicitly.
-
-=item *
-
-A new optional location for Perl libraries, otherlibdirs, is available.
-It can be used for example for vendor add-ons without disturbing Perl's
-own library directories.
-
-=item *
-
-In many platforms, the vendor-supplied 'cc' is too stripped-down to
-build Perl (basically, 'cc' doesn't do ANSI C). If this seems
-to be the case and 'cc' does not seem to be the GNU C compiler
-'gcc', an automatic attempt is made to find and use 'gcc' instead.
-
-=item *
-
-gcc needs to closely track the operating system release to avoid
-build problems. If Configure finds that gcc was built for a different
-operating system release than is running, it now gives a clearly visible
-warning that there may be trouble ahead.
-
-=item *
-
-Since Perl 5.8 is not binary-compatible with previous releases
-of Perl, Configure no longer suggests including the 5.005
-modules in @INC.
-
-=item *
-
-Configure C<-S> can now run non-interactively. [561]
-
-=item *
-
-Configure support for pdp11-style memory models has been removed due
-to obsolescence. [561]
-
-=item *
-
-configure.gnu now works with options with whitespace in them.
-
-=item *
-
-installperl now outputs everything to STDERR.
-
-=item *
-
-Because PerlIO is now the default on most platforms, "-perlio" doesn't
-get appended to the $Config{archname} (also known as $^O) anymore.
-Instead, if you explicitly choose not to use perlio (Configure command
-line option -Uuseperlio), you will get "-stdio" appended.
-
-=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. (To be exact, the use64bitall is ignored.)
-
-=item *
-
-In AFS installations, one can configure the root of the AFS to be
-somewhere else than the default F</afs> by using the Configure
-parameter C<-Dafsroot=/some/where/else>.
-
-=item *
-
-APPLLIB_EXP, a lesser-known configuration-time definition, has been
-documented. It can be used to prepend site-specific directories
-to Perl's default search path (@INC); see INSTALL for information.
-
-=item *
-
-The version of Berkeley DB used when the Perl (and, presumably, the
-DB_File extension) was built is now available as
-C<@Config{qw(db_version_major db_version_minor db_version_patch)}>
-from Perl and as C<DB_VERSION_MAJOR_CFG DB_VERSION_MINOR_CFG
-DB_VERSION_PATCH_CFG> from C.
-
-=item *
-
-Building Berkeley DB3 for compatibility modes for DB, NDBM, and ODBM
-has been documented in INSTALL.
-
-=item *
-
-If you have CPAN access (either network or a local copy such as a
-CD-ROM) you can during specify extra modules to Configure to build and
-install with Perl using the -Dextras=... option. See INSTALL for
-more details.
-
-=item *
-
-In addition to config.over, a new override file, config.arch, is
-available. This file is supposed to be used by hints file writers
-for architecture-wide changes (as opposed to config.over which is
-for site-wide changes).
-
-=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 ...
-
-This will create in /tmp/perl/build/directory a tree of symbolic links
-pointing to files in /path/to/perl/source. The original files are left
-unaffected. After Configure has finished, you can just say
-
- make all test
-
-and Perl will be built and tested, all in /tmp/perl/build/directory.
-[561]
-
-=item *
-
-For Perl developers, several new make targets for profiling
-and debugging have been added; see L<perlhack>.
-
-=over 8
-
-=item *
-
-Use of the F<gprof> tool to profile Perl has been documented in
-L<perlhack>. There is a make target called "perl.gprof" for
-generating a gprofiled Perl executable.
-
-=item *
-
-If you have GCC 3, there is a make target called "perl.gcov" for
-creating a gcoved Perl executable for coverage analysis. See
-L<perlhack>.
-
-=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
-Third Degree.
-
-=back
-
-=item *
-
-Guidelines of how to construct minimal Perl installations have
-been added to INSTALL.
-
-=item *
-
-The Thread extension is now not built at all under ithreads
-(C<Configure -Duseithreads>) because it wouldn't work anyway (the
-Thread extension requires being Configured with C<-Duse5005threads>).
-
-B<Note that the 5.005 threads are unsupported and deprecated: if you
-have code written for the old threads you should migrate it to the
-new ithreads model.>
-
-=item *
-
-The Gconvert macro ($Config{d_Gconvert}) used by perl for stringifying
-floating-point numbers is now more picky about using sprintf %.*g
-rules for the conversion. Some platforms that used to use gcvt may
-now resort to the slower sprintf.
-
-=item *
-
-The obsolete method of making a special (e.g., debugging) flavor
-of perl by saying
-
- make LIBPERL=libperld.a
-
-has been removed. Use -DDEBUGGING instead.
-
-=back
-
-=head2 New Or Improved Platforms
-
-For the list of platforms known to support Perl,
-see L<perlport/"Supported Platforms">.
-
-=over 4
-
-=item *
-
-AIX dynamic loading should be now better supported.
-
-=item *
-
-AIX should now work better with gcc, threads, and 64-bitness. Also the
-long doubles support in AIX should be better now. See L<perlaix>.
-
-=item *
-
-AtheOS ( http://www.atheos.cx/ ) is a new platform.
-
-=item *
-
-BeOS has been reclaimed.
-
-=item *
-
-The DG/UX platform now supports 5.005-style threads.
-See L<perldgux>.
-
-=item *
-
-The DYNIX/ptx platform (also known as dynixptx) is supported at or
-near osvers 4.5.2.
-
-=item *
-
-EBCDIC platforms (z/OS (also known as OS/390), POSIX-BC, and VM/ESA)
-have been regained. Many test suite tests still fail and the
-co-existence of Unicode and EBCDIC isn't quite settled, but the
-situation is much better than with Perl 5.6. See L<perlos390>,
-L<perlbs2000> (for POSIX-BC), and L<perlvmesa> for more information.
-
-=item *
-
-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. [561]
-
-=item *
-
-Mac OS Classic is now supported in the mainstream source package
-(MacPerl has of course been available since perl 5.004 but now the
-source code bases of standard Perl and MacPerl have been synchronised)
-[561]
-
-=item *
-
-Mac OS X (or Darwin) should now be able to build Perl even on HFS+
-filesystems. (The case-insensitivity used to confuse the Perl build
-process.)
-
-=item *
-
-NCR MP-RAS is now supported. [561]
-
-=item *
-
-All the NetBSD specific patches (except for the installation
-specific ones) have been merged back to the main distribution.
-
-=item *
-
-NetWare from Novell is now supported. See L<perlnetware>.
-
-=item *
-
-NonStop-UX is now supported. [561]
-
-=item *
-
-NEC SUPER-UX is now supported.
-
-=item *
-
-All the OpenBSD specific patches (except for the installation
-specific ones) have been merged back to the main distribution.
-
-=item *
-
-Perl has been tested with the GNU pth userlevel thread package
-( http://www.gnu.org/software/pth/pth.html ). All thread tests
-of Perl now work, but not without adding some yield()s to the tests,
-so while pth (and other userlevel thread implementations) can be
-considered to be "working" with Perl ithreads, keep in mind the
-possible non-preemptability of the underlying thread implementation.
-
-=item *
-
-Stratus VOS is now supported using Perl's native build method
-(Configure). This is the recommended method to build Perl on
-VOS. The older methods, which build miniperl, are still
-available. See L<perlvos>. [561+]
-
-=item *
-
-The Amdahl UTS UNIX mainframe platform is now supported. [561]
-
-=item *
-
-WinCE is now supported. See L<perlce>.
-
-=item *
-
-z/OS (formerly known as OS/390, formerly known as MVS OE) now has
-support for dynamic loading. This is not selected by default,
-however, you must specify -Dusedl in the arguments of Configure. [561]
-
-=back
-
-=head1 Selected Bug Fixes
-
-Numerous memory leaks and uninitialized memory accesses have been
-hunted down. Most importantly, anonymous subs used to leak quite
-a bit. [561]
-
-=over 4
-
-=item *
-
-The autouse pragma didn't work for Multi::Part::Function::Names.
-
-=item *
-
-caller() could cause core dumps in certain situations. Carp was
-sometimes affected by this problem. In particular, caller() now
-returns a subroutine name of C<(unknown)> for subroutines that have
-been removed from the symbol table.
-
-=item *
-
-chop(@list) in list context returned the characters chopped in
-reverse order. This has been reversed to be in the right order. [561]
-
-=item *
-
-Configure no longer includes the DBM libraries (dbm, gdbm, db, ndbm)
-when building the Perl binary. The only exception to this is SunOS 4.x,
-which needs them. [561]
-
-=item *
-
-The behaviour of non-decimal but numeric string constants such as
-"0x23" was platform-dependent: in some platforms that was seen as 35,
-in some as 0, in some as a floating point number (don't ask). This
-was caused by Perl's using the operating system libraries in a situation
-where the result of the string to number conversion is undefined: now
-Perl consistently handles such strings as zero in numeric contexts.
-
-=item *
-
-Several debugger fixes: exit code now reflects the script exit code,
-condition C<"0"> now treated correctly, the C<d> command now checks
-line number, C<$.> no longer gets corrupted, and all debugger output
-now goes correctly to the socket if RemotePort is set. [561]
-
-=item *
-
-The debugger (perl5db.pl) has been modified to present a more
-consistent commands interface, via (CommandSet=580). perl5db.t was
-also added to test the changes, and as a placeholder for further tests.
-
-See L<perldebug>.
-
-=item *
-
-The debugger has a new C<dumpDepth> option to control the maximum
-depth to which nested structures are dumped. The C<x> command has
-been extended so that C<x N EXPR> dumps out the value of I<EXPR> to a
-depth of at most I<N> levels.
-
-=item *
-
-The debugger can now show lexical variables if you have the CPAN
-module PadWalker installed.
-
-=item *
-
-The order of DESTROYs has been made more predictable.
-
-=item *
-
-Perl 5.6.0 could emit spurious warnings about redefinition of
-dl_error() when statically building extensions into perl.
-This has been corrected. [561]
-
-=item *
-
-L<dprofpp> -R didn't work.
-
-=item *
-
-C<*foo{FORMAT}> now works.
-
-=item *
-
-Infinity is now recognized as a number.
-
-=item *
-
-UNIVERSAL::isa no longer caches methods incorrectly. (This broke
-the Tk extension with 5.6.0.) [561]
-
-=item *
-
-Lexicals I: lexicals outside an eval "" weren't resolved
-correctly inside a subroutine definition inside the eval "" if they
-were not already referenced in the top level of the eval""ed code.
-
-=item *
-
-Lexicals II: lexicals leaked at file scope into subroutines that
-were declared before the lexicals.
-
-=item *
-
-Lexical warnings now propagating correctly between scopes
-and into C<eval "...">.
-
-=item *
-
-C<use warnings qw(FATAL all)> did not work as intended. This has been
-corrected. [561]
-
-=item *
-
-warnings::enabled() now reports the state of $^W correctly if the caller
-isn't using lexical warnings. [561]
-
-=item *
-
-Line renumbering with eval and C<#line> now works. [561]
-
-=item *
-
-Fixed numerous memory leaks, especially in eval "".
-
-=item *
-
-Localised tied variables no longer leak memory
-
- use Tie::Hash;
- tie my %tied_hash => 'Tie::StdHash';
-
- ...
-
- # Used to leak memory every time local() was called;
- # in a loop, this added up.
- local($tied_hash{Foo}) = 1;
-
-=item *
-
-Localised hash elements (and %ENV) are correctly unlocalised to not
-exist, if they didn't before they were localised.
-
-
- use Tie::Hash;
- tie my %tied_hash => 'Tie::StdHash';
-
- ...
-
- # Nothing has set the FOO element so far
-
- { local $tied_hash{FOO} = 'Bar' }
-
- # This used to print, but not now.
- print "exists!\n" if exists $tied_hash{FOO};
-
-As a side effect of this fix, tied hash interfaces B<must> define
-the EXISTS and DELETE methods.
-
-=item *
-
-mkdir() now ignores trailing slashes in the directory name,
-as mandated by POSIX.
-
-=item *
-
-Some versions of glibc have a broken modfl(). This affects builds
-with C<-Duselongdouble>. This version of Perl detects this brokenness
-and has a workaround for it. The glibc release 2.2.2 is known to have
-fixed the modfl() bug.
-
-=item *
-
-Modulus of unsigned numbers now works (4063328477 % 65535 used to
-return 27406, instead of 27047). [561]
-
-=item *
-
-Some "not a number" warnings introduced in 5.6.0 eliminated to be
-more compatible with 5.005. Infinity is now recognised as a number. [561]
-
-=item *
-
-Numeric conversions did not recognize changes in the string value
-properly in certain circumstances. [561]
-
-=item *
-
-Attributes (such as :shared) didn't work with our().
-
-=item *
-
-our() variables will not cause bogus "Variable will not stay shared"
-warnings. [561]
-
-=item *
-
-"our" variables of the same name declared in two sibling blocks
-resulted in bogus warnings about "redeclaration" of the variables.
-The problem has been corrected. [561]
-
-=item *
-
-pack "Z" now correctly terminates the string with "\0".
-
-=item *
-
-Fix password routines which in some shadow password platforms
-(e.g. HP-UX) caused getpwent() to return every other entry.
-
-=item *
-
-The PERL5OPT environment variable (for passing command line arguments
-to Perl) didn't work for more than a single group of options. [561]
-
-=item *
-
-PERL5OPT with embedded spaces didn't work.
-
-=item *
-
-printf() no longer resets the numeric locale to "C".
-
-=item *
-
-C<qw(a\\b)> now parses correctly as C<'a\\b'>: that is, as three
-characters, not four. [561]
-
-=item *
-
-pos() did not return the correct value within s///ge in earlier
-versions. This is now handled correctly. [561]
-
-=item *
-
-Printing quads (64-bit integers) with printf/sprintf now works
-without the q L ll prefixes (assuming you are on a quad-capable platform).
-
-=item *
-
-Regular expressions on references and overloaded scalars now work. [561+]
-
-=item *
-
-Right-hand side magic (GMAGIC) could in many cases such as string
-concatenation be invoked too many times.
-
-=item *
-
-scalar() now forces scalar context even when used in void context.
-
-=item *
-
-SOCKS support is now much more robust.
-
-=item *
-
-sort() arguments are now compiled in the right wantarray context
-(they were accidentally using the context of the sort() itself).
-The comparison block is now run in scalar context, and the arguments
-to be sorted are always provided list context. [561]
-
-=item *
-
-Changed the POSIX character class C<[[:space:]]> to include the (very
-rarely used) vertical tab character. Added a new POSIX-ish character
-class C<[[:blank:]]> which stands for horizontal whitespace
-(currently, the space and the tab).
-
-=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. [561]
-
-=item *
-
-Some cases of inconsistent taint propagation (such as within hash
-values) have been fixed.
-
-=item *
-
-The RE engine found in Perl 5.6.0 accidentally pessimised certain kinds
-of simple pattern matches. These are now handled better. [561]
-
-=item *
-
-Regular expression debug output (whether through C<use re 'debug'>
-or via C<-Dr>) now looks better. [561]
-
-=item *
-
-Multi-line matches like C<"a\nxb\n" =~ /(?!\A)x/m> were flawed. The
-bug has been fixed. [561]
-
-=item *
-
-Use of $& could trigger a core dump under some situations. This
-is now avoided. [561]
-
-=item *
-
-The regular expression captured submatches ($1, $2, ...) are now
-more consistently unset if the match fails, instead of leaving false
-data lying around in them. [561]
-
-=item *
-
-readline() on files opened in "slurp" mode could return an extra
-"" (blank line) at the end in certain situations. This has been
-corrected. [561]
-
-=item *
-
-Autovivification of symbolic references of special variables described
-in L<perlvar> (as in C<${$num}>) was accidentally disabled. This works
-again now. [561]
-
-=item *
-
-Sys::Syslog ignored the C<LOG_AUTH> constant.
-
-=item *
-
-$AUTOLOAD, sort(), lock(), and spawning subprocesses
-in multiple threads simultaneously are now thread-safe.
-
-=item *
-
-Tie::Array's SPLICE method was broken.
-
-=item *
-
-Allow a read-only string on the left-hand side of a non-modifying tr///.
-
-=item *
-
-If C<STDERR> is tied, warnings caused by C<warn> and C<die> now
-correctly pass to it.
-
-=item *
-
-Several Unicode fixes.
-
-=over 8
-
-=item *
-
-BOMs (byte order marks) at the beginning of Perl files
-(scripts, modules) should now be transparently skipped.
-UTF-16 and UCS-2 encoded Perl files should now be read correctly.
-
-=item *
-
-The character tables have been updated to Unicode 3.2.0.
-
-=item *
-
-Comparing with utf8 data does not magically upgrade non-utf8 data
-into utf8. (This was a problem for example if you were mixing data
-from I/O and Unicode data: your output might have got magically encoded
-as UTF-8.)
-
-=item *
-
-Generating illegal Unicode code points such as U+FFFE, or the UTF-16
-surrogates, now also generates an optional warning.
-
-=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 UTF8, should now work.
-
-=item *
-
-The C<tr///> operator now works. Note that the C<tr///CU>
-functionality has been removed (but see pack('U0', ...)).
-
-=item *
-
-C<eval "v200"> now works.
-
-=item *
-
-Perl 5.6.0 parsed m/\x{ab}/ incorrectly, leading to spurious warnings.
-This has been corrected. [561]
-
-=item *
-
-Zero entries were missing from the Unicode classes such as C<IsDigit>.
-
-=back
-
-=item *
-
-Large unsigned numbers (those above 2**31) could sometimes lose their
-unsignedness, causing bogus results in arithmetic operations. [561]
-
-=item *
-
-The Perl parser has been stress tested using both random input and
-Markov chain input and the few found crashes and lockups have been
-fixed.
-
-=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 L<perlvar> for details).
-
-=item *
-
-Cygwin
-
-Numerous updates; currently synchronised with Cygwin 1.3.10.
-
-=item *
-
-Previously DYNIX/ptx had problems in its Configure probe for non-blocking I/O.
-
-=item *
-
-EPOC
-
-EPOC now better supported. See README.epoc. [561]
-
-=item *
-
-FreeBSD 3.*
-
-Perl now works on post-3.0 FreeBSDs.
-
-=item *
-
-HP-UX
-
-README.hpux updated; C<Configure -Duse64bitall> now works;
-now uses HP-UX malloc instead of Perl malloc.
-
-=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
-
-=over 8
-
-=item *
-
-Long doubles should now work (see INSTALL). [561]
-
-=item *
-
-Linux previously had problems related to sockaddrlen when using
-accept(), recvfrom() (in Perl: recv()), getpeername(), and
-getsockname().
-
-=back
-
-=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. [561]
-
-=item *
-
-NetBSD/threads: try installing the GNU pth (should be in the
-packages collection, or http://www.gnu.org/software/pth/),
-and Configure with -Duseithreads.
-
-=item *
-
-NetBSD/sparc
-
-Perl now works on NetBSD/sparc.
-
-=item *
-
-OS/2
-
-Now works with usethreads (see INSTALL). [561]
-
-=item *
-
-Solaris
-
-64-bitness using the Sun Workshop compiler now works.
-
-=item *
-
-Stratus VOS
-
-The native build method requires at least VOS Release 14.5.0
-and GNU C++/GNU Tools 2.0.1 or later. The Perl pack function
-now maps overflowed values to +infinity and underflowed values
-to -infinity.
-
-=item *
-
-Tru64 (aka Digital UNIX, aka DEC OSF/1)
-
-The operating system version letter now recorded in $Config{osvers}.
-Allow compiling with gcc (previously explicitly forbidden). Compiling
-with gcc still not recommended because buggy code results, even with
-gcc 2.95.2.
-
-=item *
-
-Unicos
-
-Fixed various alignment problems that lead into core dumps either
-during build or later; no longer dies on math errors at runtime;
-now using full quad integers (64 bits), previously was using
-only 46 bit integers for speed.
-
-=item *
-
-VMS
-
-See L</"Socket Extension Dynamic in VMS"> and L</"IEEE-format Floating Point
-Default on OpenVMS Alpha"> for important changes not otherwise listed here.
-
-chdir() now works better despite a CRT bug; now works with MULTIPLICITY
-(see INSTALL); now works with Perl's malloc.
-
-The tainting of C<%ENV> elements via C<keys> or C<values> was previously
-unimplemented. It now works as documented.
-
-The C<waitpid> emulation has been improved. The worst bug (now fixed)
-was that a pid of -1 would cause a wildcard search of all processes on
-the system.
-
-POSIX-style signals are now emulated much better on VMS versions prior
-to 7.0.
-
-The C<system> function and backticks operator have improved
-functionality and better error handling. [561]
-
-File access tests now use current process privileges rather than the
-user's default privileges, which could sometimes result in a mismatch
-between reported access and actual access. This improvement is only
-available on VMS v6.0 and later.
-
-There is a new C<kill> implementation based on C<sys$sigprc> that allows
-older VMS systems (pre-7.0) to use C<kill> to send signals rather than
-simply force exit. This implementation also allows later systems to
-call C<kill> from within a signal handler.
-
-Iterative logical name translations are now limited to 10 iterations in
-imitation of SHOW LOGICAL and other OpenVMS facilities.
-
-=item *
-
-Windows
-
-=over 8
-
-=item *
-
-Signal handling now works better than it used to. It is now implemented
-using a Windows message loop, and is therefore less prone to random
-crashes.
-
-=item *
-
-fork() emulation is now more robust, but still continues to have a few
-esoteric bugs and caveats. See L<perlfork> for details. [561+]
-
-=item *
-
-A failed (pseudo)fork now returns undef and sets errno to EAGAIN. [561]
-
-=item *
-
-The following modules now work on Windows:
-
- ExtUtils::Embed [561]
- IO::Pipe
- IO::Poll
- Net::Ping
-
-=item *
-
-IO::File::new_tmpfile() is no longer limited to 32767 invocations
-per-process.
-
-=item *
-
-Better chdir() return value for a non-existent directory.
-
-=item *
-
-Compiling perl using the 64-bit Platform SDK tools is now supported.
-
-=item *
-
-The Win32::SetChildShowWindow() builtin can be used to control the
-visibility of windows created by child processes. See L<Win32> for
-details.
-
-=item *
-
-Non-blocking waits for child processes (or pseudo-processes) are
-supported via C<waitpid($pid, &POSIX::WNOHANG)>.
-
-=item *
-
-The behavior of system() with multiple arguments has been rationalized.
-Each unquoted argument will be automatically quoted to protect whitespace,
-and any existing whitespace in the arguments will be preserved. This
-improves the portability of system(@args) by avoiding the need for
-Windows C<cmd> shell specific quoting in perl programs.
-
-Note that this means that some scripts that may have relied on earlier
-buggy behavior may no longer work correctly. For example,
-C<system("nmake /nologo", @args)> will now attempt to run the file
-C<nmake /nologo> and will fail when such a file isn't found.
-On the other hand, perl will now execute code such as
-C<system("c:/Program Files/MyApp/foo.exe", @args)> correctly.
-
-=item *
-
-The perl header files no longer suppress common warnings from the
-Microsoft Visual C++ compiler. This means that additional warnings may
-now show up when compiling XS code.
-
-=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++). [561]
-
-=item *
-
-Duping socket handles with open(F, ">&MYSOCK") now works under Windows 9x.
-[561]
-
-=item *
-
-Current directory entries in %ENV are now correctly propagated to child
-processes. [561]
-
-=item *
-
-New %ENV entries now propagate to subprocesses. [561]
-
-=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. [561]
-
-=item *
-
-The makefiles now default to the features enabled in ActiveState ActivePerl
-(a popular Win32 binary distribution). [561]
-
-=item *
-
-HTML files will now be installed in c:\perl\html instead of
-c:\perl\lib\pod\html
-
-=item *
-
-REG_EXPAND_SZ keys are now allowed in registry settings used by perl. [561]
-
-=item *
-
-Can now send() from all threads, not just the first one. [561]
-
-=item *
-
-ExtUtils::MakeMaker now uses $ENV{LIB} to search for libraries. [561]
-
-=item *
-
-Less stack reserved per thread so that more threads can run
-concurrently. (Still 16M per thread.) [561]
-
-=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. [561]
-
-=item *
-
-wait(), waitpid(), and backticks now return the correct exit status
-under Windows 9x. [561]
-
-=item *
-
-A socket handle leak in accept() has been fixed. [561]
-
-=back
-
-=back
-
-=head1 New or Changed Diagnostics
-
-Please see L<perldiag> for more details.
-
-=over 4
-
-=item *
-
-Ambiguous range in the transliteration operator (like a-z-9) now
-gives a warning.
-
-=item *
-
-chdir("") and chdir(undef) now give a deprecation warning because they
-cause a possible unintentional chdir to the home directory.
-Say chdir() if you really mean that.
-
-=item *
-
-Two new debugging options have been added: if you have compiled your
-Perl with debugging, you can use the -DT [561] and -DR options to trace
-tokenising and to add reference counts to displaying variables,
-respectively.
-
-=item *
-
-The lexical warnings category "deprecated" is no longer a sub-category
-of the "syntax" category. It is now a top-level category in its own
-right.
-
-=item *
-
-Unadorned dump() will now give a warning suggesting to
-use explicit CORE::dump() if that's what really is meant.
-
-=item *
-
-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.
-
-=item *
-
-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 by a C<E<lt>-- HERE> marker.
-
-=item *
-
-Various I/O (and socket) functions like binmode(), close(), and so
-forth now more consistently warn if they are used illogically either
-on a yet unopened or on an already closed filehandle (or socket).
-
-=item *
-
-Using lstat() on a filehandle now gives a warning. (It's a non-sensical
-thing to do.)
-
-=item *
-
-The C<-M> and C<-m> options now warn if you didn't supply the module name.
-
-=item *
-
-If you in C<use> specify a required minimum version, modules matching
-the name and but not defining a $VERSION will cause a fatal failure.
-
-=item *
-
-Using negative offset for vec() in lvalue context is now a warnable offense.
-
-=item *
-
-Odd number of arguments to oveload::constant now elicits a warning.
-
-=item *
-
-Odd number of elements to in anonymous hash now elicits a warning.
-
-=item *
-
-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 C<main::STDIN>.
-
-=item *
-
-Subroutine prototypes are now checked more carefully, you may
-get warnings for example if you have used non-prototype characters.
-
-=item *
-
-If an attempt to use a (non-blessed) reference as an array index
-is made, a warning is given.
-
-=item *
-
-C<push @a;> and C<unshift @a;> (with no values to push or unshift)
-now give a warning. This may be a problem for generated and evaled
-code.
-
-=item *
-
-If you try to L<perlfunc/pack> a number less than 0 or larger than 255
-using the C<"C"> format you will get an optional warning. Similarly
-for the C<"c"> format and a number less than -128 or more than 127.
-
-=item *
-
-pack C<P> format now demands an explicit size.
-
-=item *
-
-unpack C<w> now warns of unterminated compressed integers.
-
-=item *
-
-Warnings relating to the use of PerlIO have been added.
-
-=item *
-
-Certain regex modifiers such as C<(?o)> make sense only if applied to
-the entire regex. You will get an optional warning if you try to do
-otherwise.
-
-=item *
-
-Variable length lookbehind has not yet been implemented, trying to
-use it will tell that.
-
-=item *
-
-Using arrays or hashes as references (e.g. C<< %foo->{bar} >>
-has been deprecated for a while. Now you will get an optional warning.
-
-=item *
-
-Warnings relating to the use of the new restricted hashes feature
-have been added.
-
-=item *
-
-Self-ties of arrays and hashes are not supported and fatal errors
-will happen even at an attempt to do so.
-
-=item *
-
-Using C<sort> in scalar context now issues an optional warning.
-This didn't do anything useful, as the sort was not performed.
-
-=item *
-
-Using the /g modifier in split() is meaningless and will cause a warning.
-
-=item *
-
-Using splice() past the end of an array now causes a warning.
-
-=item *
+=head1 Incompatible Changes
-Malformed Unicode encodings (UTF-8 and UTF-16) cause a lot of warnings,
-ad doestrying to use UTF-16 surrogates (which are unimplemented).
+=head1 Core Enhancements
-=item *
+=head1 Modules and Pragmata
-Trying to use Unicode characters on an I/O stream without marking the
-stream's encoding (using open() or binmode()) will cause "Wide character"
-warnings.
+=head1 Utility Changes
-=item *
+=head1 New Documentation
-Use of v-strings in use/require causes a (backward) portability warning.
+=head1 Performance Enhancements
-=item *
+=head1 Installation and Configuration Improvements
-Warnings relating to the use interpreter threads and their shared data
-have been added.
+=head1 Selected Bug Fixes
-=back
+=head1 New or Changed Diagnostics
=head1 Changed Internals
-=over 4
-
-=item *
-
-PerlIO is now the default.
-
-=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(), op_clear, op_null,
-ptr_table_clear(), ptr_table_free(), sv_setref_uv(), and several UTF-8
-interfaces to the publicised API. For the full list of the available
-APIs see L<perlapi>.
-
-=item *
-
-Made possible to propagate customised exceptions via croak()ing.
-
-=item *
-
-Now xsubs can have attributes just like subs. (Well, at least the
-built-in attributes.)
-
-=item *
-
-dTHR and djSP have been obsoleted; the former removed (because it's
-a no-op) and the latter replaced with dSP.
-
-=item *
-
-PERL_OBJECT has been completely removed.
-
-=item *
-
-The MAGIC constants (e.g. C<'P'>) have been macrofied
-(e.g. C<PERL_MAGIC_TIED>) for better source code readability
-and maintainability.
-
-=item *
-
-The regex compiler now maintains a structure that identifies nodes in
-the compiled bytecode with the corresponding syntactic features of the
-original regex expression. The information is attached to the new
-C<offsets> member of the C<struct regexp>. See L<perldebguts> for more
-complete information.
-
-=item *
-
-The C code has been made much more C<gcc -Wall> clean. Some warning
-messages still remain in some platforms, so if you are compiling with
-gcc you may see some warnings about dubious practices. The warnings
-are being worked on.
-
-=item *
-
-F<perly.c>, F<sv.c>, and F<sv.h> have now been extensively commented.
-
-=item *
-
-Documentation on how to use the Perl source repository has been added
-to F<Porting/repository.pod>.
-
-=item *
-
-There are now several profiling make targets.
-
-=back
-
-=head1 Security Vulnerability Closed [561]
-
-(This change was already made in 5.7.0 but bears repeating here.)
-(5.7.0 came out before 5.6.1: the development branch 5.7 released
-earlier than the maintenance branch 5.6)
-
-A potential security vulnerability in the optional suidperl component
-of Perl was identified in August 2000. suidperl is neither built nor
-installed by default. As of November 2001 the only known vulnerable
-platform is Linux, most likely all Linux distributions. CERT and
-various vendors and distributors have been alerted about the vulnerability.
-See http://www.cpan.org/src/5.0/sperl-2000-08-05/sperl-2000-08-05.txt
-for more information.
-
-The problem was caused by Perl trying to report a suspected security
-exploit attempt using an external program, /bin/mail. On Linux
-platforms the /bin/mail program had an undocumented feature which
-when combined with suidperl gave access to a root shell, resulting in
-a serious compromise instead of reporting the exploit attempt. If you
-don't have /bin/mail, or if you have 'safe setuid scripts', or if
-suidperl is not installed, you are safe.
-
-The exploit attempt reporting feature has been completely removed from
-Perl 5.8.0 (and the maintenance release 5.6.1, and it was removed also
-from all the Perl 5.7 releases), so that particular vulnerability
-isn't there anymore. However, further security vulnerabilities are,
-unfortunately, always possible. The suidperl functionality is most
-probably going to be removed in Perl 5.10. In any case, suidperl
-should only be used by security experts who know exactly what they are
-doing and why they are using suidperl instead of some other solution
-such as sudo ( see http://www.courtesan.com/sudo/ ).
-
=head1 New Tests
-Several new tests have been added, especially for the F<lib> and
-F<ext> subsections. There are now about 69 000 individual tests
-(spread over about 700 test scripts), in the regression suite (5.6.1
-has about 11 700 tests, in 258 test scripts) The exact numbers depend
-on the platform and Perl configuration used. Many of the new tests
-are of course introduced by the new modules, but still in general Perl
-is now more thoroughly tested.
-
-Because of the large number of tests, running the regression suite
-will take considerably longer time than it used to: expect the suite
-to take up to 4-5 times longer to run than in perl 5.6. On a really
-fast machine you can hope to finish the suite in about 6-8 minutes
-(wallclock time).
-
-The tests are now reported in a different order than in earlier Perls.
-(This happens because the test scripts from under t/lib have been moved
-to be closer to the library/extension they are testing.)
-
=head1 Known Problems
-=head2 The Compiler Suite Is Still Very Experimental
-
-The compiler suite is slowly getting better but it continues to be
-highly experimental. Use in production environments is discouraged.
-
-=head2 Localising Tied Arrays and Hashes Is Broken
-
- local %tied_array;
-
-doesn't work as one would expect: the old value is restored
-incorrectly. This will be changed in a future release, but we don't
-know yet what the new semantics will exactly be. In any case, the
-change will break existing code that relies on the current
-(ill-defined) semantics, so just avoid doing this in general.
-
-=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 they may 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 to) link
-together at all binaries with different ideas about file offsets;
-all this is platform-dependent.
-
-=head2 Modifying $_ Inside for(..)
-
- for (1..5) { $_++ }
-
-works without complaint. It shouldn't. (You should be able to
-modify only lvalue elements inside the loops.) You can see the
-correct behaviour by replacing the 1..5 with 1, 2, 3, 4, 5.
-
-=head2 mod_perl 1.26 Doesn't Build With Threaded Perl
-
-Use mod_perl 1.27 or higher.
-
-=head2 lib/ftmp-security tests warn 'system possibly insecure'
-
-Don't panic. Read the 'make test' section of INSTALL instead.
-
-=head2 libwww-perl (LWP) fails base/date #51
-
-Use libwww-perl 5.65 or later.
-
-=head2 PDL failing some tests
-
-Use PDL 2.3.4 or later.
-
-=head2 Perl_get_sv
-
-You may get errors like 'Undefined symbol "Perl_get_sv"' or "can't
-resolve symbol 'Perl_get_sv'", or the symbol may be "Perl_sv_2pv".
-This probably means that you are trying to use an older shared Perl
-library (or extensions linked with such) with Perl 5.8.0 executable.
-Perl used to have such a subroutine, but that is no more the case.
-Check your shared library path, and any shared Perl libraries in those
-directories.
-
-Sometimes this problem may also indicate a partial Perl 5.8.0
-installation, see L</"Mac OS X dyld undefined symbols"> for an
-example and how to deal with it.
-
-=head2 Self-tying Problems
-
-Self-tying of arrays and hashes is broken in rather deep and
-hard-to-fix ways. As a stop-gap measure to avoid people from getting
-frustrated at the mysterious results (core dumps, most often), it is
-forbidden for now (you will get a fatal error even from an attempt).
-
-A change to self-tying of globs has caused them to be recursively
-referenced (see: L<perlobj/"Two-Phased Garbage Collection">). You
-will now need an explicit untie to destroy a self-tied glob. This
-behaviour may be fixed at a later date.
-
-Self-tying of scalars and IO thingies works.
-
-=head2 ext/threads/t/libc
-
-If this test fails, it indicates that your libc (C library) is not
-threadsafe. This particular test stress tests the localtime() call to
-find out whether it is threadsafe. See L<perlthrtut> for more information.
-
-=head2 Failure of Thread (5.005-style) tests
-
-B<Note that support for 5.005-style threading is deprecated,
-experimental and practically unsupported. In 5.10, it is expected
-to be removed. You should migrate your code to ithreads.>
-
-The following tests 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.
-
- ../ext/B/t/xref.t 255 65280 14 12 85.71% 3-14
- ../ext/List/Util/t/first.t 255 65280 7 4 57.14% 2 5-7
- ../lib/English.t 2 512 54 2 3.70% 2-3
- ../lib/FileCache.t 5 1 20.00% 5
- ../lib/Filter/Simple/t/data.t 6 3 50.00% 1-3
- ../lib/Filter/Simple/t/filter_only. 9 3 33.33% 1-2 5
- ../lib/Math/BigInt/t/bare_mbf.t 1627 4 0.25% 8 11 1626-1627
- ../lib/Math/BigInt/t/bigfltpm.t 1629 4 0.25% 10 13 1628-
- 1629
- ../lib/Math/BigInt/t/sub_mbf.t 1633 4 0.24% 8 11 1632-1633
- ../lib/Math/BigInt/t/with_sub.t 1628 4 0.25% 9 12 1627-1628
- ../lib/Tie/File/t/31_autodefer.t 255 65280 65 32 49.23% 34-65
- ../lib/autouse.t 10 1 10.00% 4
- op/flip.t 15 1 6.67% 15
-
-These failures are unlikely to get fixed as 5.005-style threads
-are considered fundamentally broken. (Basically what happens is that
-competing threads can corrupt shared global state, one good example
-being regular expression engine's state.)
-
-=head2 Timing problems
-
-The following tests may fail intermittently because of timing
-problems, for example if the system is heavily loaded.
-
- t/op/alarm.t
- ext/Time/HiRes/HiRes.t
- lib/Benchmark.t
- lib/Memoize/t/expmod_t.t
- lib/Memoize/t/speed.t
-
-In case of failure please try running them manually, for example
-
- ./perl -Ilib ext/Time/HiRes/HiRes.t
-
-=head2 Tied/Magical Array/Hash Elements Do Not Autovivify
-
-For normal arrays C<$foo = \$bar[1]> will assign C<undef> to
-C<$bar[1]> (assuming that it didn't exist before), but for
-tied/magical arrays and hashes such autovivification does not happen
-because there is currently no way to catch the reference creation.
-The same problem affects slicing over non-existent indices/keys of
-a tied/magical array/hash.
-
-=head2 Unicode in package/class and subroutine names does not work
-
-One can have Unicode in identifier names, but not in package/class or
-subroutine names. While some limited functionality towards this does
-exist as of Perl 5.8.0, that is more accidental than designed; use of
-Unicode for the said purposes is unsupported.
-
-One reason of this unfinishedness is its (currently) inherent
-unportability: since both package names and subroutine names may
-need to be mapped to file and directory names, the Unicode capability
-of the filesystem becomes important-- and there unfortunately aren't
-portable answers.
-
=head1 Platform Specific Problems
-=head2 AIX
-
-=over 4
-
-=item *
-
-If using the AIX native make command, instead of just "make" issue
-"make all". In some setups the former has been known to spuriously
-also try to run "make install". Alternatively, you may want to use
-GNU make.
-
-=item *
-
-In AIX 4.2, Perl extensions that use C++ functions that use statics
-may have problems in that the statics are not getting initialized.
-In newer AIX releases, this has been solved by linking Perl with
-the libC_r library, but unfortunately in AIX 4.2 the said library
-has an obscure bug where the various functions related to time
-(such as time() and gettimeofday()) return broken values, and
-therefore in AIX 4.2 Perl is not linked against libC_r.
-
-=item *
-
-vac 5.0.0.0 May Produce Buggy Code For Perl
-
-The AIX C compiler vac version 5.0.0.0 may produce buggy code,
-resulting in a few random tests failing when run as part of "make
-test", 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. See README.aix.
-
-=item *
-
-If building threaded Perl, you may get compilation warning from pp_sys.c:
-
- "pp_sys.c", line 4651.39: 1506-280 (W) Function argument assignment between types "unsigned char*" and "const void*" is not allowed.
-
-This is harmless; it is caused by the getnetbyaddr() and getnetbyaddr_r()
-having slightly different types for their first argument.
-
-=back
-
-=head2 Alpha systems with old gccs fail several tests
-
-If you see op/pack, op/pat, op/regexp, or ext/Storable tests failing
-in a Linux/alpha or *BSD/Alpha, it's probably time to upgrade your gcc.
-gccs prior to 2.95.3 are definitely not good enough, and gcc 3.1 may
-be even better. (RedHat Linux/alpha with gcc 3.1 reported no problems,
-as did Linux 2.4.18 with gcc 2.95.4.) (In Tru64, it is preferable to
-use the bundled C compiler.)
-
-=head2 AmigaOS
-
-Perl 5.8.0 doesn't build in AmigaOS. It broke at some point during
-the ithreads work and we could not find Amiga experts to unbreak the
-problems. Perl 5.6.1 still works for AmigaOS (as does the the 5.7.2
-development release).
-
-=head2 BeOS
-
-The following tests fail on 5.8.0 Perl in BeOS Personal 5.03:
-
- t/op/lfs............................FAILED at test 17
- t/op/magic..........................FAILED at test 24
- ext/Fcntl/t/syslfs..................FAILED at test 17
- ext/File/Glob/t/basic...............FAILED at test 3
- ext/POSIX/t/sigaction...............FAILED at test 13
- ext/POSIX/t/waitpid.................FAILED at test 1
-
-See L<perlbeos> (README.beos) for more details.
-
-=head2 Cygwin "unable to remap"
-
-For example when building the Tk extension for Cygwin,
-you may get an error message saying "unable to remap".
-This is known problem with Cygwin, and a workaround is
-detailed in here: http://sources.redhat.com/ml/cygwin/2001-12/msg00894.html
-
-=head2 Cygwin ndbm tests fail on FAT
-
-One can build but not install (or test the build of) the NDBM_File
-on FAT filesystems. Installation (or build) on NTFS works fine.
-If one attempts the test on a FAT install (or build) the following
-failures are expected:
-
- ../ext/NDBM_File/ndbm.t 13 3328 71 59 83.10% 1-2 4 16-71
- ../ext/ODBM_File/odbm.t 255 65280 ?? ?? % ??
- ../lib/AnyDBM_File.t 2 512 12 2 16.67% 1 4
- ../lib/Memoize/t/errors.t 0 139 11 5 45.45% 7-11
- ../lib/Memoize/t/tie_ndbm.t 13 3328 4 4 100.00% 1-4
- run/fresh_perl.t 97 1 1.03% 91
-
-NDBM_File fails and ODBM_File just coredumps.
-
-=head2 DJGPP Failures
-
- t/op/stat............................FAILED at test 29
- lib/File/Find/t/find.................FAILED at test 1
- lib/File/Find/t/taint................FAILED at test 1
- lib/h2xs.............................FAILED at test 15
- lib/Pod/t/eol........................FAILED at test 1
- lib/Test/Harness/t/strap-analyze.....FAILED at test 8
- lib/Test/Harness/t/test-harness......FAILED at test 23
- lib/Test/Simple/t/exit...............FAILED at test 1
-
-The above failures are known as of 5.8.0 with native builds with long
-filenames, but there are a few more if running under dosemu because of
-limitations (and maybe bugs) of dosemu:
-
- t/comp/cpp...........................FAILED at test 3
- t/op/inccode.........................(crash)
-
-and a few lib/ExtUtils tests, and several hundred Encode/t/Aliases.t
-failures that work fine with long filenames. So you really might
-prefer native builds and long filenames.
-
-=head2 FreeBSD built with ithreads coredumps reading large directories
-
-This is a known bug in FreeBSD 4.5's readdir_r(), it has been fixed in
-FreeBSD 4.6 (see L<perlfreebsd> (README.freebsd)).
-
-=head2 FreeBSD Failing locale Test 117 For ISO 8859-15 Locales
-
-The ISO 8859-15 locales may fail the locale test 117 in FreeBSD.
-This is caused by the characters \xFF (y with diaeresis) and \xBE
-(Y with diaeresis) not behaving correctly when being matched
-case-insensitively. Apparently this problem has been fixed in
-the latest FreeBSD releases.
-( http://www.freebsd.org/cgi/query-pr.cgi?pr=34308 )
-
-=head2 IRIX fails ext/List/Util/t/shuffle.t or Digest::MD5
-
-IRIX with MIPSpro 7.3.1.2m or 7.3.1.3m compiler may fail the List::Util
-test ext/List/Util/t/shuffle.t by dumping core. This seems to be
-a compiler error since if compiled with gcc no core dump ensues, and
-no failures have been seen on the said test on any other platform.
-
-Similarly, building the Digest::MD5 extension has been
-known to fail with "*** Termination code 139 (bu21)".
-
-The cure is to drop optimization level (Configure -Doptimize=-O2).
-
-=head2 HP-UX lib/posix Subtest 9 Fails When LP64-Configured
-
-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 Linux with glibc 2.2.5 fails t/op/int subtest #6 with -Duse64bitint
-
-This is a known bug in the glibc 2.2.5 with long long integers.
-( http://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=65612 )
-
-=head2 Linux With Sfio Fails op/misc Test 48
-
-No known fix.
-
-=head2 Mac OS X
-
-Please remember to set your environment variable LC_ALL to "C"
-(setenv LC_ALL C) before running "make test" to avoid a lot of
-warnings about the broken locales of Mac OS X.
-
-The following tests are known to fail in Mac OS X 10.1.5 because of
-buggy (old) implementations of Berkeley DB included in Mac OS X:
-
- Failed Test Stat Wstat Total Fail Failed List of Failed
- -------------------------------------------------------------------------
- ../ext/DB_File/t/db-btree.t 0 11 ?? ?? % ??
- ../ext/DB_File/t/db-recno.t 149 3 2.01% 61 63 65
-
-If you are building on a UFS partition, you will also probably see
-t/op/stat.t subtest #9 fail. This is caused by Darwin's UFS not
-supporting inode change time.
-
-Also the ext/POSIX/t/posix.t subtest #10 fails but it is skipped for
-now because the failure is Apple's fault, not Perl's (blocked signals
-are lost).
-
-If you Configure with ithreads, ext/threads/t/libc.t will fail. Again,
-this is not Perl's fault-- the libc of Mac OS X is not threadsafe
-(in this particular test, the localtime() call is found to be
-threadunsafe.)
-
-=head2 Mac OS X dyld undefined symbols
-
-If after installing Perl 5.8.0 you are getting warnings about missing
-symbols, for example
-
- dyld: perl Undefined symbols
- _perl_sv_2pv
- _perl_get_sv
-
-you probably have an old pre-Perl-5.8.0 installation (or parts of one)
-in /Library/Perl (the undefined symbols used to exist in pre-5.8.0 Perls).
-It seems that for some reason "make install" doesn't always completely
-overwrite the files in /Library/Perl. You can move the old Perl
-shared library out of the way like this:
-
- cd /Library/Perl/darwin/CORE
- mv libperl.dylib libperlold.dylib
-
-and then reissue "make install". Note that the above of course is
-extremely disruptive for anything using the /usr/local/bin/perl.
-If that doesn't help, you may have to try removing all the .bundle
-files from beneath /Library/Perl, and again "make install"-ing.
-
-=head2 OS/2 Test Failures
-
-The following tests are known to fail on OS/2 (for clarity
-only the failures are shown, not the full error messages):
-
- ../lib/ExtUtils/t/Mkbootstrap.t 1 256 18 1 5.56% 8
- ../lib/ExtUtils/t/Packlist.t 1 256 34 1 2.94% 17
- ../lib/ExtUtils/t/basic.t 1 256 17 1 5.88% 14
- lib/os2_process.t 2 512 227 2 0.88% 174 209
- lib/os2_process_kid.t 227 2 0.88% 174 209
- lib/rx_cmprt.t 255 65280 18 3 16.67% 16-18
-
-=head2 op/sprintf tests 91, 129, and 130
-
-The op/sprintf tests 91, 129, and 130 are known to fail on some platforms.
-Examples include any platform using sfio, and Compaq/Tandem's NonStop-UX.
-
-Test 91 is known to fail on QNX6 (nto), because C<sprintf '%e',0>
-incorrectly produces C<0.000000e+0> instead of C<0.000000e+00>.
-
-For tests 129 and 130, the failing platforms do not comply with
-the ANSI C Standard: lines 19ff on page 134 of ANSI X3.159 1989, to
-be exact. (They produce something other than "1" and "-1" when
-formatting 0.6 and -0.6 using the printf format "%.0f"; most often,
-they produce "0" and "-0".)
-
-=head2 Solaris 2.5
-
-In case you are still using Solaris 2.5 (aka SunOS 5.5), you may
-experience failures (the test core dumping) in lib/locale.t.
-The suggested cure is to upgrade your Solaris.
-
-=head2 Solaris x86 Fails Tests With -Duse64bitint
-
-The following tests are known to fail in Solaris x86 with Perl
-configured to use 64 bit integers:
-
- ext/Data/Dumper/t/dumper.............FAILED at test 268
- ext/Devel/Peek/Peek..................FAILED at test 7
-
-=head2 SUPER-UX (NEC SX)
-
-The following tests are known to fail on SUPER-UX:
-
- op/64bitint...........................FAILED tests 29-30, 32-33, 35-36
- op/arith..............................FAILED tests 128-130
- op/pack...............................FAILED tests 25-5625
- op/pow................................
- op/taint..............................# msgsnd failed
- ../ext/IO/lib/IO/t/io_poll............FAILED tests 3-4
- ../ext/IPC/SysV/ipcsysv...............FAILED tests 2, 5-6
- ../ext/IPC/SysV/t/msg.................FAILED tests 2, 4-6
- ../ext/Socket/socketpair..............FAILED tests 12
- ../lib/IPC/SysV.......................FAILED tests 2, 5-6
- ../lib/warnings.......................FAILED tests 115-116, 118-119
-
-The op/pack failure ("Cannot compress negative numbers at op/pack.t line 126")
-is serious but as of yet unsolved. It points at some problems with the
-signedness handling of the C compiler, as do the 64bitint, arith, and pow
-failures. Most of the rest point at problems with SysV IPC.
-
-=head2 Term::ReadKey not working on Win32
-
-Use Term::ReadKey 2.20 or later.
-
-=head2 UNICOS/mk
-
-=over 4
-
-=item *
-
-During Configure, the test
-
- Guessing which symbols your C compiler and preprocessor define...
-
-will probably fail with error messages like
-
- CC-20 cc: ERROR File = try.c, Line = 3
- The identifier "bad" is undefined.
-
- bad switch yylook 79bad switch yylook 79bad switch yylook 79bad switch yylook 79#ifdef A29K
- ^
-
- CC-65 cc: ERROR File = try.c, Line = 3
- A semicolon is expected at this point.
-
-This is caused by a bug in the awk utility of UNICOS/mk. You can ignore
-the error, but it does cause a slight problem: you cannot fully
-benefit from the h2ph utility (see L<h2ph>) that can be used to
-convert C headers to Perl libraries, mainly used to be able to access
-from Perl the constants defined using C preprocessor, cpp. Because of
-the above error, parts of the converted headers will be invisible.
-Luckily, these days the need for h2ph is rare.
-
-=item *
-
-If building Perl with interpreter threads (ithreads), the
-getgrent(), getgrnam(), and getgrgid() functions cannot return the
-list of the group members due to a bug in the multithreaded support of
-UNICOS/mk. What this means is that in list context the functions will
-return only three values, not four.
-
-=back
-
-=head2 UTS
-
-There are a few known test failures, see L<perluts> (README.uts).
-
-=head2 VOS (Stratus)
-
-When Perl is built using the native build process on VOS Release
-14.5.0 and GNU C++/GNU Tools 2.0.1, all attempted tests either
-pass or result in TODO (ignored) failures.
-
-=head2 VMS
-
-There should be no reported test failures with a default configuration,
-though there are a number of tests marked TODO that point to areas
-needing further debugging and/or porting work.
-
-=head2 Win32
-
-In multi-CPU boxes, there are some problems with the I/O buffering:
-some output may appear twice.
-
-=head2 XML::Parser not working
-
-Use XML::Parser 2.31 or later.
-
-=head2 z/OS (OS/390)
-
-z/OS has rather many test failures but the situation is actually much
-better than it was in 5.6.0; it's just that so many new modules and
-tests have been added.
-
- Failed Test Stat Wstat Total Fail Failed List of Failed
- ---------------------------------------------------------------------------
- ../ext/Data/Dumper/t/dumper.t 357 8 2.24% 311 314 325 327
- 331 333 337 339
- ../ext/IO/lib/IO/t/io_unix.t 5 4 80.00% 2-5
- ../ext/Storable/t/downgrade.t 12 3072 169 12 7.10% 14-15 46-47 78-79
- 110-111 150 161
- ../lib/ExtUtils/t/Constant.t 121 30976 48 48 100.00% 1-48
- ../lib/ExtUtils/t/Embed.t 9 9 100.00% 1-9
- op/pat.t 922 7 0.76% 665 776 785 832-
- 834 845
- op/sprintf.t 224 3 1.34% 98 100 136
- op/tr.t 97 5 5.15% 63 71-74
- uni/fold.t 780 6 0.77% 61 169 196 661
- 710-711
-
-The failures in dumper.t and downgrade.t are problems in the tests,
-those in io_unix and sprintf are problems in the USS (UDP sockets and
-printf formats). The pat, tr, and fold failures are genuine Perl
-problems caused by EBCDIC (and in the pat and fold cases, combining
-that with Unicode). The Constant and Embed are probably problems in
-the tests (since they test Perl's ability to build extensions, and
-that seems to be working reasonably well.)
-
-=head2 Unicode Support on EBCDIC Still Spotty
-
-Though mostly working, Unicode support still has problem spots on
-EBCDIC platforms. One such known spot are the C<\p{}> and C<\P{}>
-regular expression constructs for code points less than 256: the
-C<pP> are testing for Unicode code points, not knowing about EBCDIC.
-
-=head2 Seen In Perl 5.7 But Gone Now
-
-C<Time::Piece> (previously known as C<Time::Object>) was removed
-because it was felt that it didn't have enough value in it to be a
-core module. It is still a useful module, though, and is available
-from the CPAN.
-
-Perl 5.8 unfortunately does not build anymore on AmigaOS; this broke
-accidentally at some point. Since there are not that many Amiga
-developers available, we could not get this fixed and tested in time
-for 5.8.0. Perl 5.6.1 still works for AmigaOS (as does the the 5.7.2
-development release).
-
-The C<PerlIO::Scalar> and C<PerlIO::Via> (capitalised) were renamed as
-C<PerlIO::scalar> and C<PerlIO::via> (all lowercase) just before 5.8.0.
-The main rationale was to have all core PerlIO layers to have all
-lowercase names. The "plugins" are named as usual, for example
-C<PerlIO::via::QuotedPrint>.
-
-The C<threads::shared::queue> and C<threads::shared::semaphore> were
-renamed as C<Thread::Queue> and C<Thread::Semaphore> just before 5.8.0.
-The main rationale was to have thread modules to obey normal naming,
-C<Thread::> (the C<threads> and C<threads::shared> themselves are
-more pragma-like, they affect compile-time, so they stay lowercase).
-
=head1 Reporting Bugs
If you find what you think is a bug, you might check the articles
The F<Artistic> and F<Copying> files for copyright information.
-=head1 HISTORY
-
-Written by Jarkko Hietaniemi <F<jhi@iki.fi>>.
-
=cut
projects / p5sagit/p5-mst-13.2.git / commitdiff