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NAME
       perl571delta - what's new for perl v5.7.1

DESCRIPTION
       This document describes differences between the 5.7.0
       release and the 5.7.1 release.

       (To view the differences between the 5.6.0 release and the
       5.7.0 release, see perl570delta.)

Security Vulnerability Closed
       (This change was already made in 5.7.0 but bears repeating
       here.)

       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
       April 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 all the Perl 5.7 releases (and will be gone
       also from the maintenance release 5.6.1), so that
       particular vulnerability isn't there anymore.  However,
       further security vulnerabilities are, unfortunately,
       always possible.  The suidperl code is being reviewed and
       if deemed too risky to continue to be supported, it may be
       completely removed from future releases.  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/ ).

Incompatible Changes
       o   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 "Performance Enhancements".




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       o   The list of filenames from glob() (or <...>) is now by
           default sorted alphabetically to be csh-compliant.
           (bsd_glob() does still sort platform natively, ASCII
           or EBCDIC, unless GLOB_ALPHASORT is specified.)

Core Enhancements
   AUTOLOAD Is Now Lvaluable
       AUTOLOAD is now lvaluable, meaning that you can add the
       :lvalue attribute to AUTOLOAD subroutines and you can
       assign to the AUTOLOAD return value.

   PerlIO is Now The Default
       o   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 "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 "Installation and Configuration Improvements" for
           the effects of PerlIO on your architecture name.

       o   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
           perlunicode, utf8, and
           http://www.unicode.org/unicode/reports/tr16/ for more
           information.  In future releases this naming may
           change.

       o   File handles can translate character encodings from/to
           Perl's internal Unicode form on read/write via the



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           ":encoding()" layer.

       o   File handles can be opened to "in memory" files held
           in Perl scalars via:

              open($fh,'>', \$variable) || ...

       o   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.

       o   The list form of "open" is now implemented for pipes
           (at least on UNIX):

              open($fh,"-|", 'cat', '/etc/motd')

           creates a pipe, and runs the equivalent of exec('cat',
           '/etc/motd') in the child process.

       o   The following builtin functions are now overridable:
           chop(), chomp(), each(), keys(), pop(), push(),
           shift(), splice(), unshift().

       o   Formats now support zero-padded decimal fields.

       o   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 into often slightly faster and always less lossy
           arithmetics. (Previously Perl always preferred
           floating point numbers in its math.)

       o   The printf() and sprintf() now support parameter
           reordering using the "%\d+\$" and "*\d+\$" syntaxes.
           For example

               print "%2\$s %1\$s\n", "foo", "bar";

           will print "bar foo\n"; This feature helps in writing
           internationalised software.

       o   Unicode in general should be now much more usable.
           Unicode can be used in hash keys, Unicode in regular
           expressions should work now, Unicode in tr/// should
           work now (though tr/// seems to be a particularly
           tricky to get right, so you have been warned)

       o   The Unicode Character Database coming with Perl has
           been upgraded to Unicode 3.1.  For more information,
           see http://www.unicode.org/ , and



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           http://www.unicode.org/unicode/reports/tr27/

           For developers interested in enhancing Perl's Unicode
           capabilities: almost all the UCD files are included
           with the Perl distribution in the lib/unicode
           subdirectory.  The most notable omission, for space
           considerations, is the Unihan database.

       o   The Unicode character classes \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 "\s" (\p{Space} isn't, since that includes the
           vertical tabulator character, whereas "\s" doesn't.)

   Signals Are Now Safe
       Perl used to be fragile in that signals arriving at
       inopportune moments could corrupt Perl's internal state.

Modules and Pragmata
   New Modules
       o   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 B::Concise for more information.

       o   Class::ISA, by Sean Burke, for reporting the search
           path for a class's ISA tree, has been added.

           See Class::ISA for more information.

       o   Cwd has now a split personality: if possible, an
           extension is used, (this will hopefully be both faster
           and more secure and robust) but if not possible, the
           familiar Perl library implementation is used.

       o   Digest, a frontend module for calculating digests
           (checksums), from Gisle Aas, has been added.

           See Digest for more information.

       o   Digest::MD5 for calculating MD5 digests (checksums),
           by Gisle Aas, has been added.

               use Digest::MD5 'md5_hex';

               $digest = md5_hex("Thirsty Camel");

               print $digest, "\n"; # 01d19d9d2045e005c3f1b80e8b164de1

           NOTE: the MD5 backward compatibility module is



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           deliberately not included since its use is
           discouraged.

           See Digest::MD5 for more information.

       o   Encode, by Nick Ing-Simmons, provides a mechanism to
           translate between different character encodings.
           Support for Unicode, ISO-8859-*, ASCII, CP*, KOI8-R,
           and three variants of EBCDIC are compiled in to the
           module.  Several other encodings (like Japanese,
           Chinese, and MacIntosh encodings) are included and
           will be loaded at runtime.

           Any encoding supported by Encode module is also
           available to the ":encoding()" layer if PerlIO is
           used.

           See Encode for more information.

       o   Filter::Simple is an easy-to-use frontend to
           Filter::Util::Call, from Damian Conway.

               # in MyFilter.pm:

               package MyFilter;

               use Filter::Simple sub {
                   while (my ($from, $to) = splice @_, 0, 2) {
                           s/$from/$to/g;
                   }
               };

               1;

               # in user's code:

               use MyFilter qr/red/ => 'green';

               print "red\n";   # this code is filtered, will print "green\n"
               print "bored\n"; # this code is filtered, will print "bogreen\n"

               no MyFilter;

               print "red\n";   # this code is not filtered, will print "red\n"

           See Filter::Simple for more information.

       o   Filter::Util::Call, by Paul Marquess, provides you
           with the framework to write Source Filters in Perl.
           For most uses the frontend Filter::Simple is to be
           preferred.  See Filter::Util::Call for more
           information.

       o   Locale::Constants, Locale::Country, Locale::Currency,



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           and Locale::Language, from Neil Bowers, have been
           added.  They provide the codes for various locale
           standards, such as "fr" for France, "usd" for US
           Dollar, and "jp" for Japanese.

               use Locale::Country;

               $country = code2country('jp');               # $country gets 'Japan'
               $code    = country2code('Norway');           # $code gets 'no'

           See Locale::Constants, Locale::Country,
           Locale::Currency, and Locale::Language for more
           information.

       o   MIME::Base64, by Gisle Aas, allows you to encode data
           in base64.

               use MIME::Base64;

               $encoded = encode_base64('Aladdin:open sesame');
               $decoded = decode_base64($encoded);

               print $encoded, "\n"; # "QWxhZGRpbjpvcGVuIHNlc2FtZQ=="

           See MIME::Base64 for more information.

       o   MIME::QuotedPrint, by Gisle Aas, allows you to encode
           data in quoted-printable encoding.

               use MIME::QuotedPrint;

               $encoded = encode_qp("Smiley in Unicode: \x{263a}");
               $decoded = decode_qp($encoded);

               print $encoded, "\n"; # "Smiley in Unicode: =263A"

           MIME::QuotedPrint has been enhanced to provide the
           basic methods necessary to use it with PerlIO::Via as
           in :

               use MIME::QuotedPrint;
               open($fh,">Via(MIME::QuotedPrint)",$path)

           See MIME::QuotedPrint for more information.

       o   PerlIO::Scalar, by Nick Ing-Simmons, provides the
           implementation of IO to "in memory" Perl scalars as
           discussed above.  It also serves as an example of a
           loadable layer.  Other future possibilities include
           PerlIO::Array and PerlIO::Code.  See PerlIO::Scalar
           for more information.

       o   PerlIO::Via, by Nick Ing-Simmons, acts as a PerlIO
           layer and wraps PerlIO layer functionality provided by



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           a class (typically implemented in perl code).

               use MIME::QuotedPrint;
               open($fh,">Via(MIME::QuotedPrint)",$path)

           This will automatically convert everything output to
           $fh to Quoted-Printable.  See PerlIO::Via for more
           information.

       o   Pod::Text::Overstrike, by Joe Smith, has been added.
           It converts POD data to formatted overstrike text.
           See Pod::Text::Overstrike for more information.

       o   Switch from Damian Conway has been added.  Just by
           saying

               use Switch;

           you have "switch" and "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 Switch for more information.

       o   Text::Balanced from Damian Conway has been added, for
           extracting delimited text sequences from strings.

               use Text::Balanced 'extract_delimited';

               ($a, $b) = extract_delimited("'never say never', he never said", "'", '');

           $a will be "'never say never'", $b will be ', he never
           said'.

           In addition to extract_delimited() there are also
           extract_bracketed(), extract_quotelike(),
           extract_codeblock(), extract_variable(),
           extract_tagged(), extract_multiple(),
           gen_delimited_pat(), and gen_extract_tagged().  With
           these you can implement rather advanced parsing



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           algorithms.  See Text::Balanced for more information.

       o   Tie::RefHash::Nestable, by Edward Avis, allows storing
           hash references (unlike the standard Tie::RefHash)
           The module is contained within Tie::RefHash.

       o   XS::Typemap, by Tim Jenness, is a test extension that
           exercises XS typemaps.  Nothing gets installed but for
           extension writers the code is worth studying.

   Updated And Improved Modules and Pragmata
       o   B::Deparse should be now more robust.  It still far
           from providing a full round trip for any random piece
           of Perl code, though, and is under active development:
           expect more robustness in 5.7.2.

       o   Class::Struct can now define the classes in compile
           time.

       o   Math::BigFloat has undergone much fixing, and in
           addition the fmod() function now supports modulus
           operations.

           ( The fixed Math::BigFloat module is also available in
           CPAN for those who can't upgrade their Perl:
           http://www.cpan.org/authors/id/J/JP/JPEACOCK/ )

       o   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).

       o   IO::Socket has now 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.

       o   IO::Socket::INET has support for ReusePort option (if
           your platform supports it).  The Reuse option now has
           an alias, ReuseAddr.  For clarity you may want to
           prefer ReuseAddr.

       o   Net::Ping has been enhanced.  There is now "external"
           protocol which uses Net::Ping::External module which
           runs external ping(1) and parses the output.  An alpha
           version of Net::Ping::External is available in CPAN
           and in 5.7.2 the Net::Ping::External may be integrated
           to Perl.

       o   The "open" pragma allows layers other than ":raw" and
           ":crlf" when using PerlIO.

       o   POSIX::sigaction() is now much more flexible and
           robust.  You can now install coderef handlers,
           'DEFAULT', and 'IGNORE' handlers, installing new



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           handlers was not atomic.

       o   The Test module has been significantly enhanced.  Its
           use is greatly recommended for module writers.

       o   The 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.

       The following modules have been upgraded from the versions
       at CPAN: CPAN, CGI, DB_File, File::Temp, Getopt::Long,
       Pod::Man, Pod::Text, Storable, Text-Tabs+Wrap.

Performance Enhancements
       o   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.

       o   unshift() should now be noticeably faster.

Utility Changes
       o   h2xs now produces template README.

       o   s2p has been completely rewritten in Perl.  (It is in
           fact a full implementation of sed in Perl.)

       o   xsubpp now supports OUT keyword.

New Documentation
   perlclib
       Internal replacements for standard C library functions.
       (Interesting only for extension writers and Perl core
       hackers.)

   perliol
       Internals of PerlIO with layers.

   README.aix
       Documentation on compiling Perl on AIX has been added.
       AIX has several different C compilers and getting the
       right patch level is essential.  On install README.aix
       will be installed as perlaix.

   README.bs2000
       Documentation on compiling Perl on the POSIX-BC platform



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       (an EBCDIC mainframe environment) has been added.

       This was formerly known as README.posix-bc but the name
       was considered to be too confusing (it has nothing to do
       with the POSIX module or the POSIX standard).  On install
       README.bs2000 will be installed as perlbs2000.

   README.macos
       In perl 5.7.1 (and in the 5.6.1) the MacPerl sources have
       been synchronised with the standard Perl sources.  To
       compile MacPerl some additional steps are required, and
       this file documents those steps.  On install README.macos
       will be installed as perlmacos.

   README.mpeix
       The README.mpeix has been podified, which means that this
       information about compiling and using Perl on the MPE/iX
       miniframe platform will be installed as perlmpeix.

   README.solaris
       README.solaris has been created and Solaris wisdom from
       elsewhere in the Perl documentation has been collected
       there.  On install README.solaris will be installed as
       perlsolaris.

   README.vos
       The README.vos has been podified, which means that this
       information about compiling and using Perl on the Stratus
       VOS miniframe platform will be installed as perlvos.

   Porting/repository.pod
       Documentation on how to use the Perl source repository has
       been added.

Installation and Configuration Improvements
       o   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.

       o   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.)

       o   APPLLIB_EXP, a less-know 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.

       o   Building Berkeley DB3 for compatibility modes for DB,
           NDBM, and ODBM has been documented in INSTALL.



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       o   If you are on IRIX or Tru64 platforms, new
           profiling/debugging options have been added, see
           perlhack for more information about pixie and Third
           Degree.

   New Or Improved Platforms
       For the list of platforms known to support Perl, see
       "Supported Platforms" in perlport.

       o   AIX dynamic loading should be now better supported.

       o   After a long pause, AmigaOS has been verified to be
           happy with Perl.

       o   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 perlos390, perlbs2000
           (for POSIX-BC), and perlvmesa for more information.

       o   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.

       o   Mac OS Classic (MacPerl has of course been available
           since perl 5.004 but now the source code bases of
           standard Perl and MacPerl have been synchronised)

       o   NCR MP-RAS is now supported.

       o   NonStop-UX is now supported.

       o   Amdahl UTS is now supported.

       o   z/OS (formerly known as OS/390, formerly known as MVS
           OE) has now support for dynamic loading.  This is not
           selected by default, however, you must specify -Dusedl
           in the arguments of Configure.

   Generic Improvements
       o   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.

       o   Some new Configure symbols, useful for extension
           writers:

           d_cmsghdr
                   For struct cmsghdr.

           d_fcntl_can_lock
                   Whether fcntl() can be used for file locking.



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           d_fsync
           d_getitimer
           d_getpagsz
                   For getpagesize(), though you should prefer
                   POSIX::sysconf(_SC_PAGE_SIZE))

           d_msghdr_s
                   For struct msghdr.

           need_va_copy
                   Whether one needs to use Perl_va_copy() to
                   copy varargs.

           d_readv
           d_recvmsg
           d_sendmsg
           sig_size
                   The number of elements in an array needed to
                   hold all the available signals.

           d_sockatmark
           d_strtoq
           d_u32align
                   Whether one needs to access character data
                   aligned by U32 sized pointers.

           d_ualarm
           d_usleep
       o   Removed Configure symbols: the PDP-11 memory model
           settings: huge, large, medium, models.

       o   SOCKS support is now much more robust.

       o   If your file system supports symbolic links you can
           build Perl outside of the source directory by

                   mkdir perl/build/directory
                   cd perl/build/directory
                   sh /path/to/perl/source/Configure -Dmksymlinks ...

           This will create in 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
           perl/build/directory.

Selected Bug Fixes
       Numerous memory leaks and uninitialized memory accesses
       have been hunted down.  Most importantly anonymous subs



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       used to leak quite a bit.

       o   chop(@list) in list context returned the characters
           chopped in reverse order.  This has been reversed to
           be in the right order.

       o   The order of DESTROYs has been made more predictable.

       o   mkdir() now ignores trailing slashes in the directory
           name, as mandated by POSIX.

       o   Attributes (like :shared) didn't work with our().

       o   The PERL5OPT environment variable (for passing command
           line arguments to Perl) didn't work for more than a
           single group of options.

       o   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.

       o   All but the first argument of the IO syswrite() method
           are now optional.

       o   Tie::ARRAY SPLICE method was broken.

       o   vec() now tries to work with characters <= 255 when
           possible, but it leaves higher character values in
           place.  In that case, if vec() was used to modify the
           string, it is no longer considered to be utf8-encoded.

   Platform Specific Changes and Fixes
       o   Linux previously had problems related to sockaddrlen
           when using accept(), revcfrom() (in Perl: recv()),
           getpeername(), and getsockname().

       o   Previously DYNIX/ptx had problems in its Configure
           probe for non-blocking I/O.

       o   Windows

           o       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++).

           o       Win32::GetCwd() correctly returns C:\ instead
                   of C: when at the drive root.  Other bugs in
                   chdir() and Cwd::cwd() have also been fixed.

           o       Duping socket handles with open(F, ">&MYSOCK")
                   now works under Windows 9x.



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           o       HTML files will be installed in c:\perl\html
                   instead of c:\perl\lib\pod\html

           o       The makefiles now provide a single switch to
                   bulk-enable all the features enabled in
                   ActiveState ActivePerl (a popular binary
                   distribution).

New or Changed Diagnostics
       Two new debugging options have been added: if you have
       compiled your Perl with debugging, you can use the -DT and
       -DR options to trace tokenising and to add reference
       counts to displaying variables, respectively.

       o   If an attempt to use a (non-blessed) reference as an
           array index is made, a warning is given.

       o   "push @a;" and "unshift @a;" (with no values to push
           or unshift) now give a warning.  This may be a problem
           for generated and eval'ed code.

Changed Internals
       o   Some new APIs: ptr_table_clear(), ptr_table_free(),
           sv_setref_uv().  For the full list of the available
           APIs see perlapi.

       o   dTHR and djSP have been obsoleted; the former removed
           (because it's a no-op) and the latter replaced with
           dSP.

       o   Perl now uses system malloc instead of Perl malloc on
           all 64-bit platforms, and even in some
           not-always-64-bit platforms like AIX, IRIX, and
           Solaris.  This change breaks backward compatibility
           but Perl's malloc has problems with large address
           spaces and also the speed of vendors' malloc is
           generally better in large address space machines
           (Perl's malloc is mostly tuned for space).

New Tests
       Many new tests have been added.  The most notable is
       probably the lib/1_compile: it is very notable because
       running it takes quite a long time -- it test compiles all
       the Perl modules in the distribution.  Please be patient.

Known Problems
       Note that unlike other sections in this document (which
       describe changes since 5.7.0) this section is cumulative
       containing known problems for all the 5.7 releases.

   AIX 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 few random tests failing, but when the
       failing tests are run by hand, they succeed.  We suggest



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       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.

   lib/ftmp-security tests warn 'system possibly insecure'
       Don't panic.  Read INSTALL 'make test' section instead.

   lib/io_multihomed Fails In LP64-Configured HP-UX
       The lib/io_multihomed test may hang in HP-UX if Perl has
       been configured to be 64-bit. Because other 64-bit
       platforms do not hang in this test, HP-UX is suspect. All
       other tests pass in 64-bit HP-UX. The test attempts to
       create and connect to "multihomed" sockets (sockets which
       have multiple IP addresses).

   Test lib/posix Subtest 9 Fails In LP64-Configured HP-UX
       If perl is configured with -Duse64bitall, the successful
       result of the subtest 10 of lib/posix may arrive before
       the successful result of the subtest 9, which confuses the
       test harness so much that it thinks the subtest 9 failed.

   lib/b test 19
       The test fails on various platforms (PA64 and IA64 are
       known), but the exact cause is still being investigated.

   Linux With Sfio Fails op/misc Test 48
       No known fix.

   sigaction test 13 in VMS
       The test is known to fail; whether it's because of VMS of
       because of faulty test is not known.

   sprintf tests 129 and 130
       The op/sprintf tests 129 and 130 are known to fail on some
       platforms.  Examples include any platform using sfio, and
       Compaq/Tandem's NonStop-UX.  The failing platforms do not
       comply with the ANSI C Standard, line 19ff on page 134 of
       ANSI X3.159 1989 to be exact.  (They produce something
       else than "1" and "-1" when formatting 0.6 and -0.6 using
       the printf format "%.0f", most often they produce "0" and
       "-0".)

   Failure of Thread tests
       The subtests 19 and 20 of lib/thr5005.t test are known to
       fail due to fundamental problems in the 5.005 threading
       implementation. These are not new failures--Perl 5.005_0x
       has the same bugs, but didn't have these tests. (Note that
       support for 5.005-style threading remains experimental.)

   Localising a Tied Variable Leaks Memory
           use Tie::Hash;
           tie my %tie_hash => 'Tie::StdHash';

           ...



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           local($tie_hash{Foo}) = 1; # leaks

       Code like the above is known to leak memory every time the
       local() is executed.

   Self-tying of Arrays and Hashes Is Forbidden
       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 for now forbidden (you will
       get a fatal error even from an attempt).

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

   The Compiler Suite Is Still Experimental
       The compiler suite is slowly getting better but is nowhere
       near working order yet.

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

       If you believe you have an unreported bug, please run the
       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 "perl -V", will
       be sent off to perlbug@perl.org to be analysed by the Perl
       porting team.

SEE ALSO
       The Changes file for exhaustive details on what changed.

       The INSTALL file for how to build Perl.

       The README file for general stuff.



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       The Artistic and Copying files for copyright information.

HISTORY
       Written by Jarkko Hietaniemi <jhi@iki.fi>, with many
       contributions from The Perl Porters and Perl Users
       submitting feedback and patches.

       Send omissions or corrections to <perlbug@perl.org>.

















































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