In case you are wondering about 5.6.1, it was bug-fix-wise ratheridentical to the development release 5.7.1. Confused? This timelinehopefully helps a bit: it lists the new major releases, their maintenancereleases, and the development releases.

  New Maintenance  Development
 
   5.6.0 2000-Mar-22
    5.7.0 2000-Sep-02
   5.6.1 2001-Apr-08
    5.7.1 2001-Apr-09
    5.7.2 2001-Jul-13
    5.7.3 2002-Mar-05
   5.8.0 2002-Jul-18
   5.8.1 2003-Sep-25

Incompatible Changes

Hash Randomisation

Mainly due to security reasons, the "random ordering" of hasheshas been made even more random. Previously while the order of hashelements from keys(), values(), and each() was essentially random,it was still repeatable. Now, however, the order varies betweendifferent runs of Perl.

Perl has never guaranteed any ordering of the hash keys, and theordering has already changed several times during the lifetime ofPerl 5. Also, the ordering of hash keys has always been, andcontinues to be, affected by the insertion order.

The added randomness may affect applications.

One possible scenario is when output of an application has includedhash data. For example, if you have used the Data::Dumper module todump data into different files, and then compared the files to seewhether the data has changed, now you will have false positives sincethe order in which hashes are dumped will vary. In general the cureis to sort the keys (or the values); in particular for Data::Dumper touse the Sortkeys option. If some particular order is reallyimportant, use tied hashes: for example the Tie::IxHash modulewhich by default preserves the order in which the hash elementswere added.

More subtle problem is reliance on the order of "global destruction".That is what happens at the end of execution: Perl destroys all datastructures, including user data. If your destructors (the DESTROYsubroutines) have assumed any particular ordering to the globaldestruction, there might be problems ahead. For example, in adestructor of one object you cannot assume that objects of any otherclass are still available, unless you hold a reference to them.If the environment variable PERL_DESTRUCT_LEVEL is set to a non-zerovalue, or if Perl is exiting a spawned thread, it will also destructthe ordinary references and the symbol tables that are no longer in use.You can't call a class method or an ordinary function on a class thathas been collected that way.

The hash randomisation is certain to reveal hidden assumptions aboutsome particular ordering of hash elements, and outright bugs: itrevealed a few bugs in the Perl core and core modules.

To disable the hash randomisation in runtime, set the environmentvariable PERL_HASH_SEED to 0 (zero) before running Perl (for moreinformation see PERL_HASH_SEED in perlrun), or to disable the featurecompletely in compile time, compile with -DNO_HASH_SEED (see INSTALL).

See Algorithmic Complexity Attacks in perlsec for the originalrationale behind this change.

UTF-8 On Filehandles No Longer Activated By Locale

In Perl 5.8.0 all filehandles, including the standard filehandles,were implicitly set to be in Unicode UTF-8 if the locale settingsindicated the use of UTF-8. This feature caused too many problems,so the feature was turned off and redesigned: see Core Enhancements.

Single-number v-strings are no longer v-strings before "=>"

The version strings or v-strings (see Version Strings in perldata)feature introduced in Perl 5.6.0 has been a source of some confusion--especially when the user did not want to use it, but Perl thought itknew better. Especially troublesome has been the feature that beforea "=>" a version string (a "v" followed by digits) has been interpretedas a v-string instead of a string literal. In other words:

%h = ( v65 => 42 );

has meant since Perl 5.6.0

%h = ( 'A' => 42 );

(at least in platforms of ASCII progeny) Perl 5.8.1 restores themore natural interpretation

%h = ( 'v65' => 42 );

The multi-number v-strings like v65.66 and 65.66.67 still continue tobe v-strings in Perl 5.8.

(Win32) The -C Switch Has Been Repurposed

The -C switch has changed in an incompatible way. The old semanticsof this switch only made sense in Win32 and only in the "use utf8"universe in 5.6.x releases, and do not make sense for the Unicodeimplementation in 5.8.0. Since this switch could not have been usedby anyone, it has been repurposed. The behavior that this switchenabled in 5.6.x releases may be supported in a transparent,data-dependent fashion in a future release.

For the new life of this switch, see UTF-8 no longer default under UTF-8 locales, and -C in perlrun.

(Win32) The /d Switch Of cmd.exe

Perl 5.8.1 uses the /d switch when running the cmd.exe shellinternally for system(), backticks, and when opening pipes to externalprograms. The extra switch disables the execution of AutoRun commandsfrom the registry, which is generally considered undesirable whenrunning external programs. If you wish to retain compatibility withthe older behavior, set PERL5SHELL in your environment to cmd /x/c.

Core Enhancements

UTF-8 no longer default under UTF-8 locales

In Perl 5.8.0 many Unicode features were introduced. One of themwas found to be of more nuisance than benefit: the automagic(and silent) "UTF-8-ification" of filehandles, including thestandard filehandles, if the user's locale settings indicateduse of UTF-8.

For example, if you had en_US.UTF-8 as your locale, your STDIN andSTDOUT were automatically "UTF-8", in other words an implicitbinmode(..., ":utf8") was made. This meant that trying to print, say,chr(0xff), ended up printing the bytes 0xc3 0xbf. Hardly whatyou had in mind unless you were aware of this feature of Perl 5.8.0.The problem is that the vast majority of people weren't: for examplein RedHat releases 8 and 9 the default locale setting is UTF-8, soall RedHat users got UTF-8 filehandles, whether they wanted it or not.The pain was intensified by the Unicode implementation of Perl 5.8.0(still) having nasty bugs, especially related to the use of s/// andtr///. (Bugs that have been fixed in 5.8.1)

Therefore a decision was made to backtrack the feature and change itfrom implicit silent default to explicit conscious option. The newPerl command line option -C and its counterpart environmentvariable PERL_UNICODE can now be used to control how Perl and Unicodeinteract at interfaces like I/O and for example the command linearguments. See -C in perlrun and PERL_UNICODE in perlrun for moreinformation.

Unsafe signals again available

In Perl 5.8.0 the so-called "safe signals" were introduced. Thismeans that Perl no longer handles signals immediately but instead"between opcodes", when it is safe to do so. The earlier immediatehandling easily could corrupt the internal state of Perl, resultingin mysterious crashes.

However, the new safer model has its problems too. Because now anopcode, a basic unit of Perl execution, is never interrupted butinstead let to run to completion, certain operations that can take along time now really do take a long time. For example, certainnetwork operations have their own blocking and timeout mechanisms, andbeing able to interrupt them immediately would be nice.

Therefore perl 5.8.1 introduces a "backdoor" to restore the pre-5.8.0(pre-5.7.3, really) signal behaviour. Just set the environment variablePERL_SIGNALS to unsafe, and the old immediate (and unsafe)signal handling behaviour returns. See PERL_SIGNALS in perlrunand Deferred Signals (Safe Signals) in perlipc.

In completely unrelated news, you can now use safe signals withPOSIX::SigAction. See POSIX::SigAction in POSIX.

Tied Arrays with Negative Array Indices

Formerly, the indices passed to FETCH, STORE, EXISTS, andDELETE methods in tied array class were always non-negative. Ifthe actual argument was negative, Perl would call FETCHSIZE implicitlyand add the result to the index before passing the result to the tiedarray method. This behaviour is now optional. If the tied array classcontains a package variable named $NEGATIVE_INDICES which is set toa true value, negative values will be passed to FETCH, STORE,EXISTS, and DELETE unchanged.

local ${$x}

The syntaxes

local ${$x}
 local @{$x}
 local %{$x}

now do localise variables, given that the $x is a valid variable name.

Unicode Character Database 4.0.0

The copy of the Unicode Character Database included in Perl 5.8 hasbeen updated to 4.0.0 from 3.2.0. This means for example that theUnicode character properties are as in Unicode 4.0.0.

Deprecation Warnings

There is one new feature deprecation. Perl 5.8.0 forgot to addsome deprecation warnings, these warnings have now been added.Finally, a reminder of an impending feature removal.

(Reminder) Pseudo-hashes are deprecated (really)

Pseudo-hashes were deprecated in Perl 5.8.0 and will be removed inPerl 5.10.0, see perl58delta for details. Each attempt to accesspseudo-hashes will trigger the warning Pseudo-hashes are deprecated.If you really want to continue using pseudo-hashes but not to see thedeprecation warnings, use:

 no warnings 'deprecated';

Or you can continue to use the fields pragma, but please don'texpect the data structures to be pseudohashes any more.

(Reminder) 5.005-style threads are deprecated (really)

5.005-style threads (activated by use Thread;) were deprecated inPerl 5.8.0 and will be removed after Perl 5.8, see perl58delta fordetails. Each 5.005-style thread creation will trigger the warning5.005 threads are deprecated. If you really want to continueusing the 5.005 threads but not to see the deprecation warnings, use:

 no warnings 'deprecated';

(Reminder) The $* variable is deprecated (really)

The $* variable controlling multi-line matching has been deprecatedand will be removed after 5.8. The variable has been deprecated for along time, and a deprecation warning Use of $* is deprecated is given,now the variable will just finally be removed. The functionality hasbeen supplanted by the /s and /m modifiers on pattern matching.If you really want to continue using the $*-variable but not to seethe deprecation warnings, use:

 no warnings 'deprecated';

Miscellaneous Enhancements

map in void context is no longer expensive. map is now contextaware, and will not construct a list if called in void context.

If a socket gets closed by the server while printing to it, the clientnow gets a SIGPIPE. While this new feature was not planned, it fellnaturally out of PerlIO changes, and is to be considered an accidentalfeature.

PerlIO::get_layers(FH) returns the names of the PerlIO layersactive on a filehandle.

PerlIO::via layers can now have an optional UTF8 method toindicate whether the layer wants to "auto-:utf8" the stream.

utf8::is_utf8() has been added as a quick way to test whethera scalar is encoded internally in UTF-8 (Unicode).

Modules and Pragmata

Updated Modules And Pragmata

The following modules and pragmata have been updated since Perl 5.8.0:

base
B::Bytecode
In much better shape than it used to be. Still far from perfect, butmaybe worth a try.
B::Concise
B::Deparse
Benchmark
An optional feature, :hireswallclock, now allows for highresolution wall clock times (uses Time::HiRes).
ByteLoader
See B::Bytecode.
bytes
Now has bytes::substr.
CGI
charnames
One can now have custom character name aliases.
CPAN
There is now a simple command line frontend to the CPAN.pmmodule called cpan.
Data::Dumper
A new option, Pair, allows choosing the separator between hash keysand values.
DB_File
Devel::PPPort
Digest::MD5
Encode
Significant updates on the encoding pragma functionality(tr/// and the DATA filehandle, formats).
If a filehandle has been marked as to have an encoding, unmappablecharacters are detected already during input, not later (when thecorrupted data is being used).
The ISO 8859-6 conversion table has been corrected (the 0x30..0x39erroneously mapped to U+0660..U+0669, instead of U+0030..U+0039). TheGSM 03.38 conversion did not handle escape sequences correctly. TheUTF-7 encoding has been added (making Encode feature-complete withUnicode::String).
fields
libnet
Math::BigInt
A lot of bugs have been fixed since v1.60, the version included in Perlv5.8.0. Especially noteworthy are the bug in Calc that caused div and mod tofail for some large values, and the fixes to the handling of bad inputs.
Some new features were added, e.g. the broot() method, you can now passparameters to config() to change some settings at runtime, and it is nowpossible to trap the creation of NaN and infinity.
As usual, some optimizations took place and made the math overall a tadfaster. In some cases, quite a lot faster, actually. Especially alternativelibraries like Math::BigInt::GMP benefit from this. In addition, a lot of thequite clunky routines like fsqrt() and flog() are now much much faster.
MIME::Base64
NEXT
Diamond inheritance now works.
Net::Ping
PerlIO::scalar
Reading from non-string scalars (like the special variables, seeperlvar) now works.
podlators
Pod::LaTeX
PodParsers
Pod::Perldoc
Complete rewrite. As a side-effect, no longer refuses to startup whenrun by root.
Scalar::Util
New utilities: refaddr, isvstring, looks_like_number, set_prototype.
Storable
Can now store code references (via B::Deparse, so not foolproof).
strict
Earlier versions of the strict pragma did not check the parametersimplicitly passed to its "import" (use) and "unimport" (no) routine.This caused the false idiom such as:
```
 use strict qw(@ISA);
  @ISA = qw(Foo);
 
```
This however (probably) raised the false expectation that the strictrefs, vars and subs were being enforced (and that @ISA was somehow"declared"). But the strict refs, vars, and subs are not enforcedwhen using this false idiom.
Starting from Perl 5.8.1, the above will cause an error to beraised. This may cause programs which used to execute seeminglycorrectly without warnings and errors to fail when run under 5.8.1.This happens because
```
 use strict qw(@ISA);
 
```
will now fail with the error:
```
 Unknown 'strict' tag(s) '@ISA'
 
```
The remedy to this problem is to replace this code with the correct idiom:
```
 use strict;
  use vars qw(@ISA);
  @ISA = qw(Foo);
 
```
Term::ANSIcolor
Test::Harness
Now much more picky about extra or missing output from test scripts.
Test::More
Test::Simple
Text::Balanced
Time::HiRes
Use of nanosleep(), if available, allows mixing subsecond sleeps withalarms.
threads
Several fixes, for example for join() problems and memoryleaks. In some platforms (like Linux) that use glibc the minimum memoryfootprint of one ithread has been reduced by several hundred kilobytes.
threads::shared
Many memory leaks have been fixed.
Unicode::Collate
Unicode::Normalize
Win32::GetFolderPath
Win32::GetOSVersion
Now returns extra information.

Utility Changes

The h2xs utility now produces a more modern layout:Foo-Bar/lib/Foo/Bar.pm instead of Foo/Bar/Bar.pm.Also, the boilerplate test is now called t/Foo-Bar.tinstead of t/1.t.

The Perl debugger (lib/perl5db.pl) has now been extensivelydocumented and bugs found while documenting have been fixed.

perldoc has been rewritten from scratch to be more robust andfeature rich.

perlcc -B works now at least somewhat better, while perlcc -cis rather more broken. (The Perl compiler suite as a whole continuesto be experimental.)

New Documentation

perl573delta has been added to list the differences between the(now quite obsolete) development releases 5.7.2 and 5.7.3.

perl58delta has been added: it is the perldelta of 5.8.0, detailingthe differences between 5.6.0 and 5.8.0.

perlartistic has been added: it is the Artistic License in pod format,making it easier for modules to refer to it.

perlcheat has been added: it is a Perl cheat sheet.

perlgpl has been added: it is the GNU General Public License in podformat, making it easier for modules to refer to it.

perlmacosx has been added to tell about the installation and useof Perl in Mac OS X.

perlos400 has been added to tell about the installation and useof Perl in OS/400 PASE.

perlreref has been added: it is a regular expressions quick reference.

Installation and Configuration Improvements

The Unix standard Perl location, /usr/bin/perl, is no longeroverwritten by default if it exists. This change was very prudentbecause so many Unix vendors already provide a /usr/bin/perl,but simultaneously many system utilities may depend on thatexact version of Perl, so better not to overwrite it.

One can now specify installation directories for site and vendor manand HTML pages, and site and vendor scripts. See INSTALL.

One can now specify a destination directory for Perl installationby specifying the DESTDIR variable for make install. (This featureis slightly different from the previous Configure -Dinstallprefix=....)See INSTALL.

gcc versions 3.x introduced a new warning that caused a lot of noiseduring Perl compilation: gcc -Ialreadyknowndirectory (warning:changing search order). This warning has now been avoided byConfigure weeding out such directories before the compilation.

One can now build subsets of Perl core modules by using theConfigure flags -Dnoextensions=... and -Donlyextensions=...,see INSTALL.

Platform-specific enhancements

In Cygwin Perl can now be built with threads (Configure -Duseithreads).This works with both Cygwin 1.3.22 and Cygwin 1.5.3.

In newer FreeBSD releases Perl 5.8.0 compilation failed because oftrying to use malloc.h, which in FreeBSD is just a dummy file, anda fatal error to even try to use. Now malloc.h is not used.

Perl is now known to build also in Hitachi HI-UXMPP.

Perl is now known to build again in LynxOS.

Mac OS X now installs with Perl version number embedded ininstallation directory names for easier upgrading of user-compiledPerl, and the installation directories in general are more standard.In other words, the default installation no longer breaks theApple-provided Perl. On the other hand, with Configure -Dprefix=/usryou can now really replace the Apple-supplied Perl (please be careful).

Mac OS X now builds Perl statically by default. This change was donemainly for faster startup times. The Apple-provided Perl is stilldynamically linked and shared, and you can enable the sharedness foryour own Perl builds by Configure -Duseshrplib.

Perl has been ported to IBM's OS/400 PASE environment. The best wayto build a Perl for PASE is to use an AIX host as a cross-compilationenvironment. See README.os400.

Yet another cross-compilation option has been added: now Perl buildson OpenZaurus, an Linux distribution based on Mandrake + Embedix forthe Sharp Zaurus PDA. See the Cross/README file.

Tru64 when using gcc 3 drops the optimisation for toke.c to -O2because of gigantic memory use with the default -O3.

Tru64 can now build Perl with the newer Berkeley DBs.

Building Perl on WinCE has been much enhanced, see README.ceand README.perlce.

Selected Bug Fixes

Closures, eval and lexicals

There have been many fixes in the area of anonymous subs, lexicals andclosures. Although this means that Perl is now more "correct", it ispossible that some existing code will break that happens to rely onthe faulty behaviour. In practice this is unlikely unless your codecontains a very complex nesting of anonymous subs, evals and lexicals.

Generic fixes

If an input filehandle is marked :utf8 and Perl sees illegal UTF-8coming in when doing <FH>, if warnings are enabled a warning isimmediately given - instead of being silent about it and Perl beingunhappy about the broken data later. (The :encoding(utf8) layeralso works the same way.)

binmode(SOCKET, ":utf8") only worked on the input side, not on theoutput side of the socket. Now it works both ways.

For threaded Perls certain system database functions like getpwent()and getgrent() now grow their result buffer dynamically, instead offailing. This means that at sites with lots of users and groups thefunctions no longer fail by returning only partial results.

Perl 5.8.0 had accidentally broken the capability for usersto define their own uppercase<->lowercase Unicode mappings(as advertised by the Camel). This feature has been fixed andis also documented better.

In 5.8.0 this

$some_unicode .= <FH>;

didn't work correctly but instead corrupted the data. This has nowbeen fixed.

Tied methods like FETCH etc. may now safely access tied values, i.e.resulting in a recursive call to FETCH etc. Remember to break therecursion, though.

At startup Perl blocks the SIGFPE signal away since there isn't muchPerl can do about it. Previously this blocking was in effect also forprograms executed from within Perl. Now Perl restores the originalSIGFPE handling routine, whatever it was, before running externalprograms.

Linenumbers in Perl scripts may now be greater than 65536, or 2**16.(Perl scripts have always been able to be larger than that, it's justthat the linenumber for reported errors and warnings have "wrappedaround".) While scripts that large usually indicate a need to rethinkyour code a bit, such Perl scripts do exist, for example as resultsfrom generated code. Now linenumbers can go all the way to4294967296, or 2**32.

Platform-specific fixes

Linux

Setting $0 works again (with certain limitations thatPerl cannot do much about: see $0 in perlvar)

HP-UX

Setting $0 now works.

VMS

Configuration now tests for the presence of poll(), and IO::Pollnow uses the vendor-supplied function if detected.
A rare access violation at Perl start-up could occur if the Perl image wasinstalled with privileges or if there was an identifier with thesubsystem attribute set in the process's rightslist. Either of thesecircumstances triggered tainting code that contained a pointer bug. The faulty pointer arithmetic has been fixed.
The length limit on values (not keys) in the %ENV hash has been raisedfrom 255 bytes to 32640 bytes (except when the PERL_ENV_TABLES settingoverrides the default use of logical names for %ENV). If it isnecessary to access these long values from outside Perl, be aware thatthey are implemented using search list logical names that store thevalue in pieces, each 255-byte piece (up to 128 of them) being anelement in the search list. When doing a lookup in %ENV from withinPerl, the elements are combined into a single value. The existingVMS-specific ability to access individual elements of a search listlogical name via the $ENV{'foo;N'} syntax (where N is the search listindex) is unimpaired.
The piping implementation now uses local rather than global DCLsymbols for inter-process communication.
File::Find could become confused when navigating to a relativedirectory whose name collided with a logical name. This problem hasbeen corrected by adding directory syntax to relative path names, thuspreventing logical name translation.

Win32

A memory leak in the fork() emulation has been fixed.
The return value of the ioctl() built-in function was accidentallybroken in 5.8.0. This has been corrected.
The internal message loop executed by perl during blocking operationssometimes interfered with messages that were external to Perl.This often resulted in blocking operations terminating prematurely orreturning incorrect results, when Perl was executing under environmentsthat could generate Windows messages. This has been corrected.
Pipes and sockets are now automatically in binary mode.
The four-argument form of select() did not preserve $! (errno) properlywhen there were errors in the underlying call. This is now fixed.
The "CR CR LF" problem of has been fixed, binmode(FH, ":crlf")is now effectively a no-op.

New or Changed Diagnostics

All the warnings related to pack() and unpack() were made moreinformative and consistent.

Changed "A thread exited while %d threads were running"

The old version

 A thread exited while %d other threads were still running

was misleading because the "other" included also the thread givingthe warning.

Removed "Attempt to clear a restricted hash"

It is not illegal to clear a restricted hash, so the warningwas removed.

New "Illegal declaration of anonymous subroutine"

You must specify the block of code for sub.

Changed "Invalid range "%s" in transliteration operator"

The old version

 Invalid [] range "%s" in transliteration operator

was simply wrong because there are no "[] ranges" in tr///.

New "Missing control char name in \c"

Self-explanatory.

New "Newline in left-justified string for %s"

The padding spaces would appear after the newline, which isprobably not what you had in mind.

New "Possible precedence problem on bitwise %c operator"

If you think this

 $x & $y == 0

tests whether the bitwise AND of $x and $y is zero,you will like this warning.

New "Pseudo-hashes are deprecated"

This warning should have been already in 5.8.0, since they are.

New "read() on %s filehandle %s"

You cannot read() (or sysread()) from a closed or unopened filehandle.

New "5.005 threads are deprecated"

This warning should have been already in 5.8.0, since they are.

New "Tied variable freed while still in use"

Something pulled the plug on a live tied variable, Perl playssafe by bailing out.

New "To%s: illegal mapping '%s'"

An illegal user-defined Unicode casemapping was specified.

New "Use of freed value in iteration"

Something modified the values being iterated over. This is not good.

Changed Internals

These news matter to you only if you either write XS code or like toknow about or hack Perl internals (using Devel::Peek or any of theB:: modules counts), or like to run Perl with the -D option.

The embedding examples of perlembed have been reviewed to beup to date and consistent: for example, the correct use ofPERL_SYS_INIT3() and PERL_SYS_TERM().

Extensive reworking of the pad code (the code responsiblefor lexical variables) has been conducted by Dave Mitchell.

Extensive work on the v-strings by John Peacock.

UTF-8 length and position cache: to speed up the handling of Unicode(UTF-8) scalars, a cache was introduced. Potential problems exist ifan extension bypasses the official APIs and directly modifies the PVof an SV: the UTF-8 cache does not get cleared as it should.

APIs obsoleted in Perl 5.8.0, like sv_2pv, sv_catpvn, sv_catsv,sv_setsv, are again available.

Certain Perl core C APIs like cxinc and regatom are no longeravailable at all to code outside the Perl core of the Perl coreextensions. This is intentional. They never should have beenavailable with the shorter names, and if you application depends onthem, you should (be ashamed and) contact perl5-porters to discusswhat are the proper APIs.

Certain Perl core C APIs like Perl_list are no longer availablewithout their Perl_ prefix. If your XS module stops workingbecause some functions cannot be found, in many cases a simple fix isto add the Perl_ prefix to the function and the thread contextaTHX_ as the first argument of the function call. This is also howit should always have been done: letting the Perl_-less forms to leakfrom the core was an accident. For cleaner embedding you can alsoforce this for all APIs by defining at compile time the cpp definePERL_NO_SHORT_NAMES.

Perl_save_bool() has been added.

Regexp objects (those created with qr) now have S-magic rather thanR-magic. This fixed regexps of the form /...(??{...;$x})/ to nolonger ignore changes made to $x. The S-magic avoids droppingthe caching optimization and making (??{...}) constructs obscenelyslow (and consequently useless). See also Magic Variables in perlguts.Regexp::Copy was affected by this change.

The Perl internal debugging macros DEBUG() and DEB() have been renamedto PERL_DEBUG() and PERL_DEB() to avoid namespace conflicts.

-DL removed (the leaktest had been broken and unsupported for years,use alternative debugging mallocs or tools like valgrind and Purify).

Verbose modifier v added for -DXv and -Dsv, see perlrun.

New Tests

In Perl 5.8.0 there were about 69000 separate tests in about 700 test files,in Perl 5.8.1 there are about 77000 separate tests in about 780 test files.The exact numbers depend on the Perl configuration and on the operatingsystem platform.

Known Problems

The hash randomisation mentioned in Incompatible Changes is definitelyproblematic: it will wake dormant bugs and shake out bad assumptions.

If you want to use mod_perl 2.x with Perl 5.8.1, you will needmod_perl-1.99_10 or higher. Earlier versions of mod_perl 2.xdo not work with the randomised hashes. (mod_perl 1.x works fine.)You will also need Apache::Test 1.04 or higher.

Many of the rarer platforms that worked 100% or pretty close to itwith perl 5.8.0 have been left a little bit untended since theirmaintainers have been otherwise busy lately, and therefore there willbe more failures on those platforms. Such platforms include Mac OSClassic, IBM z/OS (and other EBCDIC platforms), and NetWare. The mostcommon Perl platforms (Unix and Unix-like, Microsoft platforms, andVMS) have large enough testing and expert population that they aredoing well.

Tied hashes in scalar context

Tied hashes do not currently return anything useful in scalar context,for example when used as boolean tests:

if (%tied_hash) { ... }

The current nonsensical behaviour is always to return false,regardless of whether the hash is empty or has elements.

The root cause is that there is no interface for the implementors oftied hashes to implement the behaviour of a hash in scalar context.

Net::Ping 450_service and 510_ping_udp failures

The subtests 9 and 18 of lib/Net/Ping/t/450_service.t, and thesubtest 2 of lib/Net/Ping/t/510_ping_udp.t might fail if you havean unusual networking setup. For example in the latter case thetest is trying to send a UDP ping to the IP address 127.0.0.1.

B::C

The C-generating compiler backend B::C (the frontend beingperlcc -c) is even more broken than it used to be because ofthe extensive lexical variable changes. (The good news is thatB::Bytecode and ByteLoader are better than they used to be.)

Platform Specific Problems

EBCDIC Platforms

IBM z/OS and other EBCDIC platforms continue to be problematicregarding Unicode support. Many Unicode tests are skipped whenthey really should be fixed.

Cygwin 1.5 problems

In Cygwin 1.5 the io/tell and op/sysio tests have failures forsome yet unknown reason. In 1.5.5 the threads tests stress_cv,stress_re, and stress_string are failing unless the environmentvariable PERLIO is set to "perlio" (which makes also the io/tellfailure go away).

Perl 5.8.1 does build and work well with Cygwin 1.3: with (uname -a)CYGWIN_NT-5.0 ... 1.3.22(0.78/3/2) 2003-03-18 09:20 i686 ...a 100% "make test" was achieved with Configure -des -Duseithreads.

HP-UX: HP cc warnings about sendfile and sendpath

With certain HP C compiler releases (e.g. B.11.11.02) you willget many warnings like this (lines wrapped for easier reading):

  cc: "/usr/include/sys/socket.h", line 504: warning 562:
  Redeclaration of "sendfile" with a different storage class specifier:
   "sendfile" will have internal linkage.
   cc: "/usr/include/sys/socket.h", line 505: warning 562:
  Redeclaration of "sendpath" with a different storage class specifier:
   "sendpath" will have internal linkage.

The warnings show up both during the build of Perl and during certainlib/ExtUtils tests that invoke the C compiler. The warning, however,is not serious and can be ignored.

IRIX: t/uni/tr_7jis.t falsely failing

The test t/uni/tr_7jis.t is known to report failure under 'make test'or the test harness with certain releases of IRIX (at least IRIX 6.5and MIPSpro Compilers Version 7.3.1.1m), but if run manually the testfully passes.

Mac OS X: no usemymalloc

The Perl malloc (-Dusemymalloc) does not work at all in Mac OS X.This is not that serious, though, since the native malloc works justfine.

Tru64: No threaded builds with GNU cc (gcc)

In the latest Tru64 releases (e.g. v5.1B or later) gcc cannot be usedto compile a threaded Perl (-Duseithreads) because the system<pthread.h> file doesn't know about gcc.

Win32: sysopen, sysread, syswrite

As of the 5.8.0 release, sysopen()/sysread()/syswrite() do not behavelike they used to in 5.6.1 and earlier with respect to "text" mode.These built-ins now always operate in "binary" mode (even if sysopen()was passed the O_TEXT flag, or if binmode() was used on the filehandle). Note that this issue should only make a difference for diskfiles, as sockets and pipes have always been in "binary" mode in theWindows port. As this behavior is currently considered a bug,compatible behavior may be re-introduced in a future release. Untilthen, the use of sysopen(), sysread() and syswrite() is not supportedfor "text" mode operations.

Future Directions

The following things might happen in future. The first publiclyavailable releases having these characteristics will be the developerreleases Perl 5.9.x, culminating in the Perl 5.10.0 release. Theseare our best guesses at the moment: we reserve the right to rethink.

PerlIO will become The Default. Currently (in Perl 5.8.x) the stdiolibrary is still used if Perl thinks it can use certain tricks tomake stdio go really fast. For future releases our goal is tomake PerlIO go even faster.
A new feature called assertions will be available. This means thatone can have code called assertions sprinkled in the code: usuallythey are optimised away, but they can be enabled with the -A option.
A new operator // (defined-or) will be available. This means thatone will be able to say
```
 $a // $b
 
```
instead of
```
   defined $a ? $a : $b
 
```
and
```
   $c //= $d;
 
```
instead of
```
   $c = $d unless defined $c;
 
```
The operator will have the same precedence and associativity as ||.A source code patch against the Perl 5.8.1 sources will be availablein CPAN as authors/id/H/HM/HMBRAND/dor-5.8.1.diff.
unpack() will default to unpacking the $_.
Various Copy-On-Write techniques will be investigated in hopesof speeding up Perl.
CPANPLUS, Inline, and Module::Build will become core modules.
The ability to write true lexically scoped pragmas will be introduced.
Work will continue on the bytecompiler and byteloader.
v-strings as they currently exist are scheduled to be deprecated. Thev-less form (1.2.3) will become a "version object" when used with use,require, and $VERSION. $^V will also be a "version object" so theprintf("%vd",...) construct will no longer be needed. The v-ful version(v1.2.3) will become obsolete. The equivalence of strings and v-strings (e.g.that currently 5.8.0 is equal to "\5\8\0") will go away. There may be nodeprecation warning for v-strings, though: it is quite hard to detect whenv-strings are being used safely, and when they are not.
5.005 Threads Will Be Removed
The $* Variable Will Be Removed(it was deprecated a long time ago)
Pseudohashes Will Be Removed

Reporting Bugs

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

If you believe you have an unreported bug, please run the perlbugprogram included with your release. Be sure to trim your bug downto a tiny but sufficient test case. Your bug report, along with theoutput of perl -V, will be sent off to [email protected] to beanalysed by the Perl porting team. You can browse and searchthe Perl 5 bugs at http://bugs.perl.org/

What is new for perl v5.8.1

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