=head1 NAME
-perldelta - what will be new for perl v5.8.0
+perldelta - what is new for perl v5.8.0
=head1 DESCRIPTION
-This document does not exist yet. When the Perl 5.8.0 is released
-this document will describe the changes since Perl 5.6.0, the previous
-major release. In the meanwhile, see L<perl570delta> and
-L<perl571delta>.
+This document describes differences between the 5.6.0 release and the
+5.8.0 release.
+
+=head1 Security Vulnerability Closed
+
+A potential security vulnerability in the optional suidperl component
+of Perl has been identified. suidperl is neither built nor installed
+by default. As of September the 2nd, 2000, the only known vulnerable
+platform is Linux, most likely all Linux distributions. CERT and
+various vendors have been alerted about the vulnerability.
+
+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
+the Perl 5.7.0 release, 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/).
+
+=head1 Incompatible Changes
+
+=over 4
+
+=item *
+
+Arrays now always interpolate into double-quoted strings:
+constructs like "foo@bar" now always assume C<@bar> is an array,
+whether or not the compiler has seen use of C<@bar>.
+
+=item *
+
+The semantics of bless(REF, REF) were unclear and until someone proves
+it to make some sense, it is forbidden.
+
+=item *
+
+A reference to a reference now stringify as "REF(0x81485ec)" instead
+of "SCALAR(0x81485ec)" in order to be more consistent with the return
+value of ref().
+
+=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 obsolete chat2 library that should never have been allowed
+to escape the laboratory has been decommissioned.
+
+=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 *
+
+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 *
+
+lstat(FILEHANDLE) now gives a warning because the operation makes no sense.
+In future releases this may become a fatal error.
+
+=item *
+
+The long deprecated uppercase aliases for the string comparison
+operators (EQ, NE, LT, LE, GE, GT) have now been removed.
+
+=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.
+
+=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', ...).
+
+=back
+
+=head1 Core Enhancements
+
+=over 4
+
+=item *
+
+C<perl -d:Module=arg,arg,arg> now works (previously one couldn't pass
+in multiple arguments.)
+
+=item *
+
+my __PACKAGE__ $obj now works.
+
+=item *
+
+C<no Module;> now works even if there is no "sub unimport" in the Module.
+
+=item *
+
+The numerical comparison operators return C<undef> if either operand
+is a NaN. Previously the behaviour was unspecified.
+
+=item *
+
+C<pack('U0a*', ...)> can now be used to force a string to UTF8.
+
+=item *
+
+prototype(\&) is now available.
+
+=item *
+
+There is now an UNTIE method.
+
+=back
+
+=head1 Modules and Pragmata
+
+=head2 New Modules
+
+=over 4
+
+=item *
+
+File::Temp allows one to create temporary files and directories in an
+easy, portable, and secure way.
+
+=item *
+
+Storable gives persistence to Perl data structures by allowing the
+storage and retrieval of Perl data to and from files in a fast and
+compact binary format.
+
+=back
+
+=head2 Updated And Improved Modules and Pragmata
+
+=over 4
+
+=item *
+
+The following independently supported modules have been updated to
+newer versions from CPAN: CGI, CPAN, DB_File, File::Spec, Getopt::Long,
+the podlators bundle, Pod::LaTeX, Pod::Parser, Term::ANSIColor, Test.
+
+=item *
+
+Bug fixes and minor enhancements have been applied to B::Deparse,
+Data::Dumper, IO::Poll, IO::Socket::INET, Math::BigFloat,
+Math::Complex, Math::Trig, Net::protoent, the re pragma, SelfLoader,
+Sys::SysLog, Test::Harness, Text::Wrap, UNIVERSAL, and the warnings
+pragma.
+
+=item *
+
+The attributes::reftype() now works on tied arguments.
+
+=item *
+
+AutoLoader can now be disabled with C<no AutoLoader;>,
+
+=item *
+
+The English module can now be used without the infamous performance
+hit by saying
+
+ use English '-no_performance_hit';
+
+(Assuming, of course, that one doesn't need the troublesome variables
+C<$`>, C<$&>, or C<$'>.) Also, introduced C<@LAST_MATCH_START> and
+C<@LAST_MATCH_END> English aliases for C<@-> and C<@+>.
+
+=item *
+
+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::Glob::glob() renamed to File::Glob::bsd_glob() to avoid
+prototype mismatch with CORE::glob().
+
+=item *
+
+IPC::Open3 now allows the use of numeric file descriptors.
+
+=item *
+
+use lib now works identically to @INC. Removing directories
+with 'no lib' now works.
+
+=item *
+
+C<%INC> now localised in a Safe compartment so that use/require work.
+
+=item *
+
+The Shell module now has an OO interface.
+
+=back
+
+=head1 Utility Changes
+
+=over 4
+
+=item *
+
+The Emacs perl mode (emacs/cperl-mode.el) has been updated to version
+4.31.
+
+=item *
+
+Perlbug is now much more robust. It also sends the bug report to
+perl.org, not perl.com.
+
+=item *
+
+The perlcc utility has been rewritten and its user interface (that is,
+command line) is much more like that of the UNIX C compiler, cc.
+
+=item *
+
+The xsubpp utility for extension writers now understands POD
+documentation embedded in the *.xs files.
+
+=back
+
+=head1 New Documentation
+
+=over 4
+
+=item *
+
+perl56delta details the changes between the 5.005 release and the
+5.6.0 release.
+
+=item *
+
+perldebtut is a Perl debugging tutorial.
+
+=item *
+
+perlebcdic contains considerations for running Perl on EBCDIC platforms.
+Note that unfortunately EBCDIC platforms that used to supported back in
+Perl 5.005 are still unsupported by Perl 5.7.0; the plan, however, is to
+bring them back to the fold.
+
+=item *
+
+perlnewmod tells about writing and submitting a new module.
+
+=item *
+
+perlposix-bc explains using Perl on the POSIX-BC platform
+(an EBCDIC mainframe platform).
+
+=item *
+
+perlretut is a regular expression tutorial.
+
+=item *
+
+perlrequick is a regular expressions quick-start guide.
+Yes, much quicker than perlretut.
+
+=item *
+
+perlutil explains the command line utilities packaged with the Perl
+distribution.
+
+=back
+
+=head1 Performance Enhancements
+
+=over 4
+
+=item *
+
+map() that changes the size of the list should now work faster.
+
+=item *
+
+sort() has been changed to use 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).
+
+=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 $prefix changed.) If you do not like this new behaviour,
+specify prefix, siteprefix, and vendorprefix explicitly.
+
+=item *
+
+A new optional location for Perl libraries, otherlibdirs, is available.
+It can be used for example for vendor add-ons without disturbing Perl's
+own library directories.
+
+=item *
+
+In many platforms the vendor-supplied 'cc' is too stripped-down to
+build Perl (basically, 'cc' doesn't do ANSI C). If this seems
+to be the case and 'cc' does not seem to be the GNU C compiler
+'gcc', an automatic attempt is made to find and use 'gcc' instead.
+
+=item *
+
+gcc needs to closely track the operating system release to avoid
+build problems. If Configure finds that gcc was built for a different
+operating system release than is running, it now gives a clearly visible
+warning that there may be trouble ahead.
+
+=item *
+
+If binary compatibility with the 5.005 release is not wanted, Configure
+no longer suggests including the 5.005 modules in @INC.
+
+=item *
+
+Configure C<-S> can now run non-interactively.
+
+=item *
+
+configure.gnu now works with options with whitespace in them.
+
+=item *
+
+installperl now outputs everything to STDERR.
+
+=item *
+
+$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.)
+
+=back
+
+=head1 Selected Bug Fixes
+
+=over 4
+
+=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, the C<$.> no longer gets corrupted, all debugger output now
+goes correctly to the socket if RemotePort is set.
+
+=item *
+
+C<*foo{FORMAT}> now works.
+
+=item *
+
+Lexical warnings now propagating correctly between scopes.
+
+=item *
+
+Line renumbering with eval and C<#line> now works.
+
+=item *
+
+Fixed numerous memory leaks, especially in eval "".
+
+=item *
+
+Modulus of unsigned numbers now works (4063328477 % 65535 used to
+return 27406, instead of 27047).
+
+=item *
+
+Some "not a number" warnings introduced in 5.6.0 eliminated to be
+more compatible with 5.005. Infinity is now recognised as a number.
+
+=item *
+
+our() variables will not cause "will not stay shared" warnings.
+
+=item *
+
+pack "Z" now correctly terminates the string with "\0".
+
+=item *
+
+Fix password routines which in some shadow password platforms
+(e.g. HP-UX) caused getpwent() to return every other entry.
+
+=item *
+
+printf() no longer resets the numeric locale to "C".
+
+=item *
+
+C<q(a\\b)> now parses correctly as C<'a\\b'>.
+
+=item *
+
+Printing quads (64-bit integers) with printf/sprintf now works
+without the q L ll prefixes (assuming you are on a quad-capable platform).
+
+=item *
+
+Regular expressions on references and overloaded scalars now work.
+
+=item *
+
+scalar() now forces scalar context even when used in void context.
+
+=item *
+
+sort() arguments are now compiled in the right wantarray context
+(they were accidentally using the context of the sort() itself).
+
+=item *
+
+Changed the POSIX character class C<[[:space:]]> to include the (very
+rare) vertical tab character. Added a new POSIX-ish character class
+C<[[:blank:]]> which stands for horizontal whitespace (currently,
+the space and the tab).
+
+=item *
+
+$AUTOLOAD, sort(), lock(), and spawning subprocesses
+in multiple threads simultaneously are now thread-safe.
+
+=item *
+
+Allow read-only string on left hand side of non-modifying tr///.
+
+=item *
+
+Several Unicode fixes (but still not perfect).
+
+=over 8
+
+=item *
+
+BOMs (byte order marks) in the beginning of Perl files
+(scripts, modules) should now be transparently skipped.
+UTF-16 (UCS-2) encoded Perl files should now be read correctly.
+
+=item *
+
+The character tables have been updated to Unicode 3.0.1.
+
+=item *
+
+chr() for values greater than 127 now create utf8 when under use
+utf8.
+
+=item *
+
+Comparing with utf8 data does not magically upgrade non-utf8 data into
+utf8.
+
+=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--in
+theory.
+
+=item *
+
+The C<tr///> operator now works I<slightly> better but is still rather
+broken. Note that the C<tr///CU> functionality has been removed (but
+see pack('U0', ...)).
+
+=item *
+
+vec() now refuses to deal with characters >255.
+
+=item *
+
+Zero entries were missing from the Unicode classes like C<IsDigit>.
+
+=back
+
+=item *
+
+UNIVERSAL::isa no longer caches methods incorrectly. (This broke
+the Tk extension with 5.6.0.)
+
+=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 perlvar for details).
+
+=item *
+
+Cygwin
+
+Numerous updates; currently synchronised with Cygwin 1.1.4.
+
+=item *
+
+EPOC
+
+EPOC update after Perl 5.6.0. See README.epoc.
+
+=item *
+
+FreeBSD 3.*
+
+Perl now works on post-3.0 FreeBSDs.
+
+=item *
+
+HP-UX
+
+README.hpux updated; C<Configure -Duse64bitall> now almost works.
+
+=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
+
+Long doubles should now work (see INSTALL).
+
+=item *
+
+MacOS Classic
+
+Compilation of the standard Perl distribution in MacOS 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.
+
+=item *
+
+NetBSD/sparc
+
+Perl now works on NetBSD/sparc.
+
+=item *
+
+OS/2
+
+Now works with usethreads (see INSTALL).
+
+=item *
+
+Solaris
+
+64-bitness using the Sun Workshop compiler now works.
+
+=item *
+
+Tru64 (aka Digital UNIX, aka DEC OSF/1)
+
+The operating system version letter now recorded in $Config{osvers}.
+Allow compiling with gcc (previously explicitly forbidden). Compiling
+with gcc still not recommended because buggy code results, even with
+gcc 2.95.2.
+
+=item *
+
+Unicos
+
+Fixed various alignment problems that lead into core dumps either
+during build or later; no longer dies on math errors at runtime;
+now using full quad integers (64 bits), previously was using
+only 46 bit integers for speed.
+
+=item *
+
+VMS
+
+chdir() now works better despite a CRT bug; now works with MULTIPLICITY
+(see INSTALL); now works with Perl's malloc.
+
+=item *
+
+Windows
+
+=over 8
+
+=item *
+
+accept() no longer leaks memory.
+
+=item *
+
+Better chdir() return value for a non-existent directory.
+
+=item *
+
+New %ENV entries now propagate to subprocesses.
+
+=item *
+
+$ENV{LIB} now used to search for libs under Visual C.
+
+=item *
+
+A failed (pseudo)fork now returns undef and sets errno to EAGAIN.
+
+=item *
+
+Allow REG_EXPAND_SZ keys in the registry.
+
+=item *
+
+Can now send() from all threads, not just the first one.
+
+=item *
+
+Fake signal handling reenabled, bugs and all.
+
+=item *
+
+Less stack reserved per thread so that more threads can run
+concurrently. (Still 16M per thread.)
+
+=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.
+
+=item *
+
+wait() and waitpid() now work much better.
+
+=item *
+
+winsock handle leak fixed.
+
+=back
+
+=back
+
+=head1 New or Changed Diagnostics
+
+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.
+
+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 <main::STDIN>.
+
+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.
+
+=head1 Changed Internals
+
+=over 4
+
+=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() to the publicised API.
+
+=item *
+
+Made possible to propagate customised exceptions via croak()ing.
+
+=item *
+
+Added is_utf8_char(), is_utf8_string(), bytes_to_utf8(), and utf8_to_bytes().
+
+=item *
+
+Now xsubs can have attributes just like subs.
+
+=back
+
+=head1 Known Problems
+
+=head2 Unicode Support Still Far From Perfect
+
+We're working on it. Stay tuned.
+
+=head2 EBCDIC Still A Lost Platform
+
+The plan is to bring them back.
+
+=head2 Building Extensions Can Fail Because Of Largefiles
+
+Certain extensions like mod_perl and BSD::Resource are known to have
+issues with `largefiles', a change brought by Perl 5.6.0 in which file
+offsets default to 64 bits wide, where supported. Modules may fail to
+compile at all or compile and work incorrectly. Currently there is no
+good solution for the problem, but Configure now provides appropriate
+non-largefile ccflags, ldflags, libswanted, and libs in the %Config
+hash (e.g., $Config{ccflags_nolargefiles}) so the extensions that are
+having problems can try configuring themselves without the
+largefileness. This is admittedly not a clean solution, and the
+solution may not even work at all. One potential failure is whether
+one can (or, if one can, whether it's a good idea) link together at
+all binaries with different ideas about file offsets, all this is
+platform-dependent.
+
+=head2 ftmp-security tests warn 'system possibly insecure'
+
+Don't panic. Read INSTALL 'make test' section instead.
+
+=head2 Test lib/posix Subtest 9 Fails In LP64-Configured HP-UX
+
+If perl is configured with -Duse64bitall, the successful result of the
+subtest 10 of lib/posix may arrive before the successful result of the
+subtest 9, which confuses the test harness so much that it thinks the
+subtest 9 failed.
+
+=head2 Long Doubles Still Don't Work In Solaris
+
+The experimental long double support is still very much so in Solaris.
+(Other platforms like Linux and Tru64 are beginning to solidify in
+this area.)
+
+=head2 Linux With Sfio Fails op/misc Test 48
+
+No known fix.
+
+=head2 Storable tests fail in some platforms
+
+If any Storable tests fail the use of Storable is not advisable.
+
+=over 4
+
+=item *
+
+Many Storable tests fail on AIX configured with 64 bit integers.
+
+So far unidentified problems break Storable in AIX if Perl is
+configured to use 64 bit integers. AIX in 32-bit mode works and
+other 64-bit platforms work with Storable.
+
+=item *
+
+DOS DJGPP may hang when testing Storable.
+
+=item *
+
+st-06compat fails in UNICOS and UNICOS/mk.
+
+This means that you cannot read old (pre-Storable-0.7) Storable images
+made in other platforms.
+
+=item *
+
+st-store.t and st-retrieve may fail with Compaq C 6.2 on OpenVMS Alpha 7.2.
+
+=back
+
+=head2 Threads Are Still Experimental
+
+Multithreading is still an experimental feature. Some platforms
+emit the following message for lib/thr5005
+
+ #
+ # This is a KNOWN FAILURE, and one of the reasons why threading
+ # is still an experimental feature. It is here to stop people
+ # from deploying threads in production. ;-)
+ #
+
+and another known thread-related warning is
+
+ pragma/overload......Unbalanced saves: 3 more saves than restores
+ panic: magic_mutexfree during global destruction.
+ ok
+ lib/selfloader.......Unbalanced saves: 3 more saves than restores
+ panic: magic_mutexfree during global destruction.
+ ok
+ lib/st-dclone........Unbalanced saves: 3 more saves than restores
+ panic: magic_mutexfree during global destruction.
+ ok
+
+=head2 The Compiler Suite Is Still Experimental
+
+The compiler suite is slowly getting better but is nowhere near
+working order yet. The backend part that has seen perhaps the most
+progress is the bytecode compiler.
+
+=head1 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/).
+
+=head1 Incompatible Changes
+
+=over 4
+
+=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 *
+
+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.)
+
+=back
+
+=head1 Core Enhancements
+
+=head2 AUTOLOAD Is Now Lvaluable
+
+AUTOLOAD is now lvaluable, meaning that you can add the :lvalue attribute
+to AUTOLOAD subroutines and you can assign to the AUTOLOAD return value.
+
+=head2 PerlIO is Now The Default
+
+=over 4
+
+=item *
+
+IO is now by default done via PerlIO rather than system's "stdio".
+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 *
+
+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($fh,">:utf8","Uni.txt");
+
+Note for EBCDIC users: the pseudo layer ":utf8" is erroneously named
+for you since it's not UTF-8 what you will be getting but instead
+UTF-EBCDIC. See L<perlunicode>, L<utf8>, and
+http://www.unicode.org/unicode/reports/tr16/ for more information.
+In future releases this naming may change.
+
+=item *
+
+File handles can translate character encodings from/to Perl's internal
+Unicode form on read/write via the ":encoding()" layer.
+
+=item *
+
+File handles can be opened to "in memory" files held in Perl scalars via:
+
+ open($fh,'>', \$variable) || ...
+
+=item *
+
+Anonymous temporary files are available without need to
+'use FileHandle' or other module via
+
+ open($fh,"+>", undef) || ...
+
+That is a literal undef, not an undefined value.
+
+=item *
+
+The list form of C<open> is now implemented for pipes (at least on UNIX):
+
+ open($fh,"-|", 'cat', '/etc/motd')
+
+creates a pipe, and runs the equivalent of exec('cat', '/etc/motd') in
+the child process.
+
+=item *
+
+The following builtin functions are now overridable: chop(), chomp(),
+each(), keys(), pop(), push(), shift(), splice(), unshift().
+
+=item *
+
+Formats now support zero-padded decimal fields.
+
+=item *
+
+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.)
+
+=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.
+
+=item *
+
+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)
+
+=item *
+
+The Unicode Character Database coming with Perl has been upgraded
+to Unicode 3.1. For more information, see http://www.unicode.org/,
+and 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.
+
+=item *
+
+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 C<\s> (\p{Space}
+isn't, since that includes the vertical tabulator character, whereas
+C<\s> doesn't.)
+
+=back
+
+=head2 Signals Are Now Safe
+
+Perl used to be fragile in that signals arriving at inopportune moments
+could corrupt Perl's internal state.
+
+=head1 Modules and Pragmata
+
+=head2 New Modules
+
+=over 4
+
+=item *
+
+B::Concise, by Stephen McCamant, is a new compiler backend for
+walking the Perl syntax tree, printing concise info about ops.
+The output is highly customisable.
+
+See L<B::Concise> for more information.
+
+=item *
+
+Class::ISA, by Sean Burke, for reporting the search path for a
+class's ISA tree, has been added.
+
+See L<Class::ISA> for more information.
+
+=item *
+
+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.
+
+=item *
+
+Digest, a frontend module for calculating digests (checksums),
+from Gisle Aas, has been added.
+
+See L<Digest> for more information.
+
+=item *
+
+Digest::MD5 for calculating MD5 digests (checksums), by Gisle Aas,
+has been added.
+
+ use Digest::MD5 'md5_hex';
+
+ $digest = md5_hex("Thirsty Camel");
+
+ print $digest, "\n"; # 01d19d9d2045e005c3f1b80e8b164de1
+
+NOTE: the MD5 backward compatibility module is deliberately not
+included since its use is discouraged.
+
+See L<Digest::MD5> for more information.
+
+=item *
+
+Encode, by Nick Ing-Simmons, provides a mechanism to translate
+between different character encodings. Support for Unicode,
+ISO-8859-*, ASCII, CP*, KOI8-R, and three variants of EBCDIC are
+compiled in to the module. Several other encodings (like Japanese,
+Chinese, and MacIntosh encodings) are included and will be loaded at
+runtime.
+
+Any encoding supported by Encode module is also available to the
+":encoding()" layer if PerlIO is used.
+
+See L<Encode> for more information.
+
+=item *
+
+Filter::Simple is an easy-to-use frontend to Filter::Util::Call,
+from Damian Conway.
+
+ # in MyFilter.pm:
+
+ package MyFilter;
+
+ use Filter::Simple sub {
+ while (my ($from, $to) = splice @_, 0, 2) {
+ s/$from/$to/g;
+ }
+ };
+
+ 1;
+
+ # in user's code:
+
+ use MyFilter qr/red/ => 'green';
+
+ print "red\n"; # this code is filtered, will print "green\n"
+ print "bored\n"; # this code is filtered, will print "bogreen\n"
+
+ no MyFilter;
+
+ print "red\n"; # this code is not filtered, will print "red\n"
+
+See L<Filter::Simple> for more information.
+
+=item *
+
+Filter::Util::Call, by Paul Marquess, provides you with the
+framework to write I<Source Filters> in Perl. For most uses
+the frontend Filter::Simple is to be preferred.
+See L<Filter::Util::Call> for more information.
+
+=item *
+
+Locale::Constants, Locale::Country, Locale::Currency, 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 L<Locale::Constants>, L<Locale::Country>, L<Locale::Currency>,
+and L<Locale::Language> for more information.
+
+=item *
+
+MIME::Base64, by Gisle Aas, allows you to encode data in base64.
+
+ use MIME::Base64;
+
+ $encoded = encode_base64('Aladdin:open sesame');
+ $decoded = decode_base64($encoded);
+
+ print $encoded, "\n"; # "QWxhZGRpbjpvcGVuIHNlc2FtZQ=="
+
+See L<MIME::Base64> for more information.
+
+=item *
+
+MIME::QuotedPrint, 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)",$path)
+
+See L<MIME::QuotedPrint> for more information.
+
+=item *
+
+PerlIO::Scalar, by Nick Ing-Simmons, provides the implementation of
+IO to "in memory" Perl scalars as discussed above. It also serves as
+an example of a loadable layer. Other future possibilities include
+PerlIO::Array and PerlIO::Code. See L<PerlIO::Scalar> for more
+information.
+
+=item *
+
+PerlIO::Via, by Nick Ing-Simmons, acts as a PerlIO layer and wraps
+PerlIO layer functionality provided by a class (typically implemented
+in perl code).
+
+ use MIME::QuotedPrint;
+ open($fh,">Via(MIME::QuotedPrint)",$path)
+
+This will automatically convert everything output to C<$fh>
+to Quoted-Printable. See L<PerlIO::Via> for more information.
+
+=item *
+
+Pod::Text::Overstrike, by Joe Smith, has been added.
+It converts POD data to formatted overstrike text.
+See L<Pod::Text::Overstrike> for more information.
+
+=item *
+
+Switch from Damian Conway has been added. Just by saying
+
+ use Switch;
+
+you have C<switch> and C<case> available in Perl.
+
+ use Switch;
+
+ switch ($val) {
+
+ case 1 { print "number 1" }
+ case "a" { print "string a" }
+ case [1..10,42] { print "number in list" }
+ case (@array) { print "number in list" }
+ case /\w+/ { print "pattern" }
+ case qr/\w+/ { print "pattern" }
+ case (%hash) { print "entry in hash" }
+ case (\%hash) { print "entry in hash" }
+ case (\&sub) { print "arg to subroutine" }
+ else { print "previous case not true" }
+ }
+
+See L<Switch> for more information.
+
+=item *
+
+Text::Balanced from Damian Conway has been added, for
+extracting delimited text sequences from strings.
+
+ use Text::Balanced 'extract_delimited';
+
+ ($a, $b) = extract_delimited("'never say never', he never said", "'", '');
+
+$a will be "'never say never'", $b will be ', he never said'.
+
+In addition to extract_delimited() there are also extract_bracketed(),
+extract_quotelike(), extract_codeblock(), extract_variable(),
+extract_tagged(), extract_multiple(), gen_delimited_pat(), and
+gen_extract_tagged(). With these you can implement rather advanced
+parsing algorithms. See L<Text::Balanced> for more information.
+
+=item *
+
+Tie::RefHash::Nestable, by Edward Avis, allows storing hash references
+(unlike the standard Tie::RefHash) The module is contained within
+Tie::RefHash.
+
+=item *
+
+XS::Typemap, by Tim Jenness, is a test extension that exercises XS
+typemaps. Nothing gets installed but for extension writers the code
+is worth studying.
+
+=back
+
+=head2 Updated And Improved Modules and Pragmata
+
+=over 4
+
+=item *
+
+B::Deparse should be now more robust. It still far from providing a full
+round trip for any random piece of Perl code, though, and is under active
+development: expect more robustness in 5.7.2.
+
+=item *
+
+Class::Struct can now define the classes in compile time.
+
+=item *
+
+Math::BigFloat has undergone much fixing, and in addition the fmod()
+function now supports modulus operations.
+
+(The fixed Math::BigFloat module is also available in CPAN for those
+who can't upgrade their Perl: http://www.cpan.org/authors/id/J/JP/JPEACOCK/)
+
+=item *
+
+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 *
+
+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.
+
+=item *
+
+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.
+
+=item *
+
+Net::Ping has been enhanced. There is now "external" protocol which
+uses Net::Ping::External module which runs external ping(1) and parses
+the output. An alpha version of Net::Ping::External is available in
+CPAN and in 5.7.2 the Net::Ping::External may be integrated to Perl.
+
+=item *
+
+The C<open> pragma allows layers other than ":raw" and ":crlf" when
+using PerlIO.
+
+=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 *
+
+The Test module has been significantly enhanced. Its use is
+greatly recommended for module writers.
+
+=item *
+
+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.
+
+=back
+
+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.
+
+=head1 Performance Enhancements
+
+=over 4
+
+=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 Utility Changes
+
+=over 4
+
+=item *
+
+h2xs now produces template README.
+
+=item *
+
+s2p has been completely rewritten in Perl. (It is in fact a full
+implementation of sed in Perl.)
+
+=item *
+
+xsubpp now supports OUT keyword.
+
+=back
+
+=head1 New Documentation
+
+=head2 perlclib
+
+Internal replacements for standard C library functions.
+(Interesting only for extension writers and Perl core hackers.)
+
+=head2 perliol
+
+Internals of PerlIO with layers.
+
+=head2 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 L<perlaix>.
+
+=head2 README.bs2000
+
+Documentation on compiling Perl on the POSIX-BC platform (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 L<perlbs2000>.
+
+=head2 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 L<perlmacos>.
+
+=head2 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 L<perlmpeix>.
+
+=head2 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 L<perlsolaris>.
+
+=head2 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 L<perlvos>.
+
+=head2 Porting/repository.pod
+
+Documentation on how to use the Perl source repository has been added.
+
+=head1 Installation and Configuration Improvements
+
+=over 4
+
+=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 *
+
+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.
+
+=item *
+
+Building Berkeley DB3 for compatibility modes for DB, NDBM, and ODBM
+has been documented in INSTALL.
+
+=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
+
+=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 *
+
+After a long pause, AmigaOS has been verified to be happy with Perl.
+
+=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.
+
+=item *
+
+MacOS Classic (MacPerl has of course been available since
+perl 5.004 but now the source code bases of standard Perl
+and MacPerl have been synchronised)
+
+=item *
+
+NCR MP-RAS is now supported.
+
+=item *
+
+NonStop-UX is now supported.
+
+=item *
+
+Amdahl UTS is now supported.
+
+=item *
+
+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.
+
+=back
+
+=head2 Generic Improvements
+
+=over 4
+
+=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.
+
+=item *
+
+Some new Configure symbols, useful for extension writers:
+
+=over 8
+
+=item d_cmsghdr
+
+For struct cmsghdr.
+
+=item d_fcntl_can_lock
+
+Whether fcntl() can be used for file locking.
+
+=item d_fsync
+
+=item d_getitimer
+
+=item d_getpagsz
+
+For getpagesize(), though you should prefer POSIX::sysconf(_SC_PAGE_SIZE))
+
+=item d_msghdr_s
+
+For struct msghdr.
+
+=item need_va_copy
+
+Whether one needs to use Perl_va_copy() to copy varargs.
+
+=item d_readv
+
+=item d_recvmsg
+
+=item d_sendmsg
+
+=item sig_size
+
+The number of elements in an array needed to hold all the available signals.
+
+=item d_sockatmark
+
+=item d_strtoq
+
+=item d_u32align
+
+Whether one needs to access character data aligned by U32 sized pointers.
+
+=item d_ualarm
+
+=item d_usleep
+
+=back
+
+=item *
+
+Removed Configure symbols: the PDP-11 memory model settings: huge,
+large, medium, models.
+
+=item *
+
+SOCKS support is now much more robust.
+
+=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.
+
+=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.
+
+=over 4
+
+=item *
+
+chop(@list) in list context returned the characters chopped in
+reverse order. This has been reversed to be in the right order.
+
+=item *
+
+The order of DESTROYs has been made more predictable.
+
+=item *
+
+mkdir() now ignores trailing slashes in the directory name,
+as mandated by POSIX.
+
+=item *
+
+Attributes (like :shared) didn't work with our().
+
+=item *
+
+The PERL5OPT environment variable (for passing command line arguments
+to Perl) didn't work for more than a single group of options.
+
+=item *
+
+The tainting behaviour of sprintf() has been rationalized. It does
+not taint the result of floating point formats anymore, making the
+behaviour consistent with that of string interpolation.
+
+=item *
+
+All but the first argument of the IO syswrite() method are now optional.
+
+=item *
+
+Tie::ARRAY SPLICE method was broken.
+
+=item *
+
+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.
+
+=back
+
+=head2 Platform Specific Changes and Fixes
+
+=over 4
+
+=item *
+
+Linux previously had problems related to sockaddrlen when using
+accept(), revcfrom() (in Perl: recv()), getpeername(), and getsockname().
+
+=item *
+
+Previously DYNIX/ptx had problems in its Configure probe for non-blocking I/O.
+
+=item *
+
+Windows
+
+=over 8
+
+=item *
+
+Borland C++ v5.5 is now a supported compiler that can build Perl.
+However, the generated binaries continue to be incompatible with those
+generated by the other supported compilers (GCC and Visual C++).
+
+=item *
+
+Win32::GetCwd() correctly returns C:\ instead of C: when at the drive root.
+Other bugs in chdir() and Cwd::cwd() have also been fixed.
+
+=item *
+
+Duping socket handles with open(F, ">&MYSOCK") now works under Windows 9x.
+
+=item *
+
+HTML files will be installed in c:\perl\html instead of c:\perl\lib\pod\html
+
+=item *
+
+The makefiles now provide a single switch to bulk-enable all the features
+enabled in ActiveState ActivePerl (a popular binary distribution).
+
+=back
+
+=back
+
+=head1 New or Changed Diagnostics
+
+Two new debugging options have been added: if you have compiled your
+Perl with debugging, you can use the -DT and -DR options to trace
+tokenising and to add reference counts to displaying variables,
+respectively.
+
+=over 4
+
+=item *
+
+If an attempt to use a (non-blessed) reference as an array 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.
+
+=back
+
+=head1 Changed Internals
+
+=over 4
+
+=item *
+
+Some new APIs: ptr_table_clear(), ptr_table_free(), sv_setref_uv().
+For the full list of the available APIs see L<perlapi>.
+
+=item *
+
+dTHR and djSP have been obsoleted; the former removed (because it's
+a no-op) and the latter replaced with dSP.
+
+=item *
+
+Perl now uses system malloc instead of Perl malloc on all 64-bit
+platforms, and even in some not-always-64-bit platforms like AIX,
+IRIX, and Solaris. This change breaks backward compatibility but
+Perl's malloc has problems with large address spaces and also the
+speed of vendors' malloc is generally better in large address space
+machines (Perl's malloc is mostly tuned for space).
+
+=back
+
+=head1 New Tests
+
+Many new tests have been added. The most notable is probably the
+lib/1_compile: it is very notable because running it takes quite a
+long time -- it test compiles all the Perl modules in the distribution.
+Please be patient.
+
+=head1 Known Problems
+
+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.
+
+=head2 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 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.
+
+=head2 lib/ftmp-security tests warn 'system possibly insecure'
+
+Don't panic. Read INSTALL 'make test' section instead.
+
+=head2 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).
+
+=head2 Test lib/posix Subtest 9 Fails In LP64-Configured HP-UX
+
+If perl is configured with -Duse64bitall, the successful result of the
+subtest 10 of lib/posix may arrive before the successful result of the
+subtest 9, which confuses the test harness so much that it thinks the
+subtest 9 failed.
+
+=head2 lib/b test 19
+
+The test fails on various platforms (PA64 and IA64 are known), but the
+exact cause is still being investigated.
+
+=head2 Linux With Sfio Fails op/misc Test 48
+
+No known fix.
+
+=head2 sigaction test 13 in VMS
+
+The test is known to fail; whether it's because of VMS of because
+of faulty test is not known.
+
+=head2 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".)
+
+=head2 Failure of Thread tests
+
+The subtests 19 and 20 of lib/thr5005.t test are known to fail due to
+fundamental problems in the 5.005 threading implementation. These are
+not new failures--Perl 5.005_0x has the same bugs, but didn't have
+these tests. (Note that support for 5.005-style threading remains
+experimental.)
+
+=head2 Localising a Tied Variable Leaks Memory
+
+ use Tie::Hash;
+ tie my %tie_hash => 'Tie::StdHash';
+
+ ...
+
+ local($tie_hash{Foo}) = 1; # leaks
+
+Code like the above is known to leak memory every time the local()
+is executed.
+
+=head2 Self-tying of Arrays and Hashes Is Forbidden
+
+Self-tying of arrays and hashes is broken in rather deep and
+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).
+
+=head2 Building Extensions Can Fail Because Of Largefiles
+
+Some extensions like mod_perl are known to have issues with
+`largefiles', a change brought by Perl 5.6.0 in which file offsets
+default to 64 bits wide, where supported. Modules may fail to compile
+at all or compile and work incorrectly. Currently there is no good
+solution for the problem, but Configure now provides appropriate
+non-largefile ccflags, ldflags, libswanted, and libs in the %Config
+hash (e.g., $Config{ccflags_nolargefiles}) so the extensions that are
+having problems can try configuring themselves without the
+largefileness. This is admittedly not a clean solution, and the
+solution may not even work at all. One potential failure is whether
+one can (or, if one can, whether it's a good idea) link together at
+all binaries with different ideas about file offsets, all this is
+platform-dependent.
+
+=head2 The Compiler Suite Is Still Experimental
+
+The compiler suite is slowly getting better but is nowhere near
+working order yet.
+
+=head1 Security Vulnerability Closed
+
+(This change was already made in 5.7.0 but bears repeating here.)
+
+A security vulnerability affecting all Perl versions prior to 5.6.1
+was found in August 2000. The vulnerability does not affect default
+installations and as far as is known affects only the Linux platform.
+
+You should upgrade your Perl to 5.6.1 as soon as possible. Patches
+for earlier releases exist but using the patches require full
+recompilation from the source code anyway, so 5.6.1 is your best
+choice.
+
+See http://www.cpan.org/src/5.0/sperl-2000-08-05/sperl-2000-08-05.txt
+for more information.
+
+=head1 Incompatible Changes
+
+=head2 64-bit platforms and malloc
+
+If your pointers are 64 bits wide, the Perl malloc is no more being
+used because it simply does not work with 8-byte pointers. Also,
+usually the system malloc on such platforms are much better optimized
+for such large memory models than the Perl malloc.
+
+=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 modperl which are using the AIX native interface.
+
+=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 Different Definition of the Unicode Character Classes \p{In...}
+
+As suggested by the Unicode consortium, the Unicode character classes
+now prefer I<scripts> as opposed to I<blocks> (as defined by Unicode);
+in Perl, when the C<\p{In....}> and the C<\p{In....}> regular expression
+constructs are used. This has changed the definition of some of those
+character classes.
+
+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 256 characters based on the Unicode
+numbering.
+
+In general this change results in more inclusive Unicode character
+classes, but changes to the other direction also do take place:
+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>).
+
+Changes in the character class semantics may have happened if a script
+and a block happen to have the same name, for example C<Hebrew>.
+In such cases the script wins and C<\p{InHebrew}> now means the script
+definition of Hebrew. The block definition in still available,
+though, by appending C<Block> to the name: C<\p{InHebrewBlock}> means
+what C<\p{InHebrew}> meant in perl 5.6.0. For the full list
+of affected character classes, see L<perlunicode/Blocks>.
+
+=head2 Deprecations
+
+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 syntaxes C<@a->[...]> and C<@h->{...}> have now been deprecated.
+
+The suidperl is also considered to be too much a risk to continue
+maintaining and the suidperl code is likely to be removed in a future
+release.
+
+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.
+
+The chdir(undef) and chdir('') behaviors to match chdir() has been
+deprecated. In future versions, chdir(undef) and chdir('') will
+simply fail.
+
+=head1 Core Enhancements
+
+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.
+
+=over 4
+
+=item *
+
+The rules for allowing underscores (underbars) in numeric constants
+have been relaxed and simplified: now you can have an underscore
+B<between digits>.
+
+=item *
+
+GMAGIC (right-hand side magic) could in many cases such as string
+concatenation be invoked too many times.
+
+=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 *
+
+Lvalue subroutines can now return C<undef> in list context.
+
+=item *
+
+The C<op_clear> and C<op_null> are now exported.
+
+=item *
+
+A new special regular expression variable has been introduced:
+C<$^N>, which contains the most-recently closed group (submatch).
+
+=item *
+
+L<utime> now supports C<utime undef, undef, @files> to change the
+file timestamps to the current time.
+
+=item *
+
+The Perl parser has been stress tested using both random input and
+Markov chain input.
+
+=item *
+
+C<eval "v200"> now works.
+
+=item *
+
+VMS now works under PerlIO.
+
+=item *
+
+END blocks are now run even if you exit/die in a BEGIN block.
+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>.
+
+=back
+
+=head1 Modules and Pragmata
+
+=head2 New Modules and Distributions
+
+=over 4
+
+=item *
+
+L<Attribute::Handlers> - Simpler definition of attribute handlers
+
+=item *
+
+L<ExtUtils::Constant> - generate XS code to import C header constants
+
+=item *
+
+L<I18N::Langinfo> - query locale information
+
+=item *
+
+L<I18N::LangTags> - functions for dealing with RFC3066-style language tags
+
+=item *
+
+L<libnet> - a collection of perl5 modules related to network programming
+
+Perl installation leaves libnet unconfigured, use F<libnetcfg> to configure.
+
+=item *
+
+L<List::Util> - selection of general-utility list subroutines
+
+=item *
+
+L<Locale::Maketext> - framework for localization
+
+=item *
+
+L<Memoize> - Make your functions faster by trading space for time
+
+=item *
+
+L<NEXT> - pseudo-class for method redispatch
+
+=item *
+
+L<Scalar::Util> - selection of general-utility scalar subroutines
+
+=item *
+
+L<Test::More> - yet another framework for writing test scripts
+
+=item *
+
+L<Test::Simple> - Basic utilities for writing tests
+
+=item *
+
+L<Time::HiRes> - high resolution ualarm, usleep, and gettimeofday
+
+=item *
+
+L<Time::Piece> - Object Oriented time objects
+
+(Previously known as L<Time::Object>.)
+
+=item *
+
+L<Time::Seconds> - a simple API to convert seconds to other date values
+
+=item *
+
+L<UnicodeCD> - Unicode Character Database
+
+=back
+
+=head2 Updated And Improved Modules and Pragmata
+
+=over 4
+
+=item *
+
+L<B::Deparse> module has been significantly enhanced. It now
+can 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 *
+
+L<Class::Struct> now assigns the array/hash element if the accessor
+is called with an array/hash element as the B<sole> argument.
+
+=item *
+
+L<Cwd> extension is now (even) faster.
+
+=item *
+
+L<DB_File> extension has been updated to version 1.77.
+
+=item *
+
+L<Fcntl>, L<Socket>, and L<Sys::Syslog> have been rewritten to use the
+new-style constant dispatch section (see L<ExtUtils::Constant>).
+
+=item *
+
+L<File::Find> is now (again) reentrant. It also has been made
+more portable.
+
+=item *
+
+L<File::Glob> now supports C<GLOB_LIMIT> constant to limit the
+size of the returned list of filenames.
+
+=item *
+
+L<IO::Socket::INET> now supports C<LocalPort> of zero (usually meaning
+that the operating system will make one up.)
+
+=item *
+
+The L<vars> pragma now supports declaring fully qualified variables.
+(Something that C<our()> does not and will not support.)
+
+=back
+
+=head1 Utility Changes
+
+=over 4
+
+=item *
+
+The F<emacs/e2ctags.pl> is now much faster.
+
+=item *
+
+L<h2ph> now supports C trigraphs.
+
+=item *
+
+L<h2xs> uses the new L<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> gets 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 *
+
+L<libnetcfg> has been added to configure the libnet.
+
+=item *
+
+The F<Pod::Html> (and thusly L<pod2html>) now allows specifying
+a cache directory.
+
+=back
+
+=head1 New Documentation
+
+=over 4
+
+=item *
+
+L<Locale::Maketext::TPJ13> is an article about software localization,
+originally published in The Perl Journal #13, republished here with
+kind permission.
+
+=item *
+
+More README.$PLATFORM files have been converted into pod, which also
+means that they also be installed as perl$PLATFORM documentation
+files. The new files are L<perlapollo>, L<perlbeos>, L<perldgux>,
+L<perlhurd>, L<perlmint>, L<perlnetware>, L<perlplan9>, L<perlqnx>,
+and L<perltru64>.
+
+=item *
+
+The F<Todo> and F<Todo-5.6> files have been merged into L<perltodo>.
+
+=item *
+
+Use of the F<gprof> tool to profile Perl has been documented in
+L<perlhack>. There is a make target "perl.gprof" for generating a
+gprofiled Perl executable.
+
+=back
+
+=head1 Installation and Configuration Improvements
+
+=head2 New Or Improved Platforms
+
+=over 4
+
+=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 *
+
+DG/UX platform now supports the 5.005-style threads. See L<perldgux>.
+
+=item *
+
+DYNIX/ptx platform (a.k.a. dynixptx) is supported at or near osvers 4.5.2.
+
+=item *
+
+Several MacOS (Classic) portability patches have been applied. We
+hope to get a fully working port by 5.8.0. (The remaining problems
+relate to the changed IO model of Perl.) See L<perlmacos>.
+
+=item *
+
+MacOS X (or Darwin) should now be able to build Perl even on HFS+
+filesystems. (The case-insensitivity confused the Perl build process.)
+
+=item *
+
+NetWare from Novell is now supported. See L<perlnetware>.
+
+=item *
+
+The Amdahl UTS UNIX mainframe platform is now supported.
+
+=back
+
+=head2 Generic Improvements
+
+=over 4
+
+=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 *
+
+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 *
+
+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>).
+
+=item *
+
+The C<B::Deparse> compiler backend has been so significantly improved
+that almost the whole Perl test suite passes after being deparsed. A
+make target has been added to help in further testing: C<make test.deparse>.
+
+=back
+
+=head1 Selected Bug Fixes
+
+=over 5
+
+=item *
+
+The autouse pragma didn't work for Multi::Part::Function::Names.
+
+=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 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 *
+
+L<dprofpp> -R didn't work.
+
+=item *
+
+PERL5OPT with embedded spaces didn't work.
+
+=item *
+
+L<Sys::Syslog> ignored the C<LOG_AUTH> constant.
+
+=back
+
+=head2 Platform Specific Changes and Fixes
+
+=over 4
+
+=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.
+
+=back
+
+=head1 New or Changed Diagnostics
+
+=over 4
+
+=item *
+
+In the regular expression diagnostics the C<E<lt>E<lt> HERE> marker
+introduced in 5.7.0 has been changed to be C<E<lt>-- HERE> since too
+many people found the C<E<lt>E<lt>> to be too similar to here-document
+starters.
+
+=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 *
+
+Certain regex modifiers such as C<(?o)> make sense only if applied to
+the entire regex. You will an optional warning if you try to do otherwise.
+
+=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.
+
+=back
+
+=head1 Source Code Enhancements
+
+=head2 MAGIC constants
+
+The MAGIC constants (e.g. C<'P'>) have been macrofied
+(e.g. C<PERL_MAGIC_TIED>) for better source code readability
+and maintainability.
+
+=head2 Better commented code
+
+F<perly.c>, F<sv.c>, and F<sv.h> have now been extensively commented.
+
+=head2 Regex pre-/post-compilation items matched up
+
+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.
+
+=head2 gcc -Wall
+
+The C code has been made much more C<gcc -Wall> clean. Some warning
+messages still remain, though, so if you are compiling with gcc you
+will see some warnings about dubious practices. The warnings are
+being worked on.
+
+=head1 New Tests
+
+Several new tests have been added, especially for the F<lib> subsection.
+
+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
+
+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.
+
+=head2 AIX
+
+=over 4
+
+=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 the 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 few random tests failing, but when the failing tests
+are run by hand, they succeed. We suggest upgrading to at least
+vac version 5.0.1.0, that has been known to compile Perl correctly.
+"lslpp -L|grep vac.C" will tell you the vac version.
+
+=back
+
+=head2 Amiga Perl Invoking Mystery
+
+One cannot call Perl using the C<volume:> syntax, that is, C<perl -v>
+works, but for example C<bin:perl -v> doesn't. The exact reason is
+known but the current suspect is the F<ixemul> library.
+
+=head2 lib/ftmp-security tests warn 'system possibly insecure'
+
+Don't panic. Read INSTALL 'make test' section instead.
+
+=head2 Cygwin intermittent failures of lib/Memoize/t/expire_file 11 and 12
+
+The subtests 11 and 12 sometimes fail and sometimes work.
+
+=head2 HP-UX lib/io_multihomed Fails When LP64-Configured
+
+The lib/io_multihomed test may hang in HP-UX if Perl has been
+configured to be 64-bit. Because other 64-bit platforms do not hang in
+this test, HP-UX is suspect. All other tests pass in 64-bit HP-UX. The
+test attempts to create and connect to "multihomed" sockets (sockets
+which have multiple IP addresses).
+
+=head2 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 Sfio Fails op/misc Test 48
+
+No known fix.
+
+=head2 OS/390
+
+OS/390 has rather many test failures but the situation is actually
+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/B/Deparse.t 14 1 7.14% 14
+ ../ext/B/Showlex.t 1 1 100.00% 1
+ ../ext/Encode/Encode/Tcl.t 610 13 2.13% 592 594 596 598
+ 600 602 604-610
+ ../ext/IO/lib/IO/t/io_unix.t 113 28928 5 3 60.00% 3-5
+ ../ext/POSIX/POSIX.t 29 1 3.45% 14
+ ../ext/Storable/t/lock.t 255 65280 5 3 60.00% 3-5
+ ../lib/locale.t 129 33024 117 19 16.24% 99-117
+ ../lib/warnings.t 434 1 0.23% 75
+ ../lib/ExtUtils.t 27 1 3.70% 25
+ ../lib/Math/BigInt/t/bigintpm.t 1190 1 0.08% 1145
+ ../lib/Unicode/UCD.t 81 48 59.26% 1-16 49-64 66-81
+ ../lib/User/pwent.t 9 1 11.11% 4
+ op/pat.t 660 6 0.91% 242-243 424-425
+ 626-627
+ op/split.t 0 9 ?? ?? % ??
+ op/taint.t 174 3 1.72% 156 162 168
+ op/tr.t 70 3 4.29% 50 58-59
+ Failed 16/422 test scripts, 96.21% okay. 105/23251 subtests failed, 99.55% okay.
+
+=head2 op/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 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 Failure of Thread tests
+
+B<Note that support for 5.005-style threading remains experimental.>
+
+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.
+
+ lib/autouse.t 4
+ t/lib/thr5005.t 19-20
+
+=head2 UNICOS
+
+=over 4
+
+=item *
+
+ext/POSIX/sigaction subtests 6 and 13 may fail.
+
+=item *
+
+lib/ExtUtils may spuriously claim that subtest 28 failed,
+which is interesting since the test only has 27 tests.
+
+=item *
+
+Numerous numerical test failures
+
+ op/numconvert 209,210,217,218
+ op/override 7
+ ext/Time/HiRes/HiRes 9
+ lib/Math/BigInt/t/bigintpm 1145
+ lib/Math/Trig 25
+
+These tests fail because of yet unresolved floating point inaccuracies.
+
+=back
+
+=head2 UTS
+
+There are a few known test failures, see L<perluts>.
+
+=head2 VMS
+
+Rather many tests are failing in VMS but that actually more tests
+succeed in VMS than they used to, it's just that there are many,
+many more tests than there used to be.
+
+Here are the known failures from some compiler/platform combinations.
+
+DEC C V5.3-006 on OpenVMS VAX V6.2
+
+ [-.ext.list.util.t]tainted..............FAILED on test 3
+ [-.ext.posix]sigaction..................FAILED on test 7
+ [-.ext.time.hires]hires.................FAILED on test 14
+ [-.lib.file.find]taint..................FAILED on test 17
+ [-.lib.math.bigint.t]bigintpm...........FAILED on test 1183
+ [-.lib.test.simple.t]exit...............FAILED on test 1
+ [.lib]vmsish............................FAILED on test 13
+ [.op]sprintf............................FAILED on test 12
+ Failed 8/399 tests, 91.23% okay.
+
+DEC C V6.0-001 on OpenVMS Alpha V7.2-1 and
+Compaq C V6.2-008 on OpenVMS Alpha V7.1
+
+ [-.ext.list.util.t]tainted..............FAILED on test 3
+ [-.lib.file.find]taint..................FAILED on test 17
+ [-.lib.test.simple.t]exit...............FAILED on test 1
+ [.lib]vmsish............................FAILED on test 13
+ Failed 4/399 tests, 92.48% okay.
+
+Compaq C V6.4-005 on OpenVMS Alpha 7.2.1
+
+ [-.ext.b]showlex........................FAILED on test 1
+ [-.ext.list.util.t]tainted..............FAILED on test 3
+ [-.lib.file.find]taint..................FAILED on test 17
+ [-.lib.test.simple.t]exit...............FAILED on test 1
+ [.lib]vmsish............................FAILED on test 13
+ [.op]misc...............................FAILED on test 49
+ Failed 6/401 tests, 92.77% okay.
+
+=head2 Win32
+
+In multi-CPU boxes there are some problems with the I/O buffering:
+some output may appear twice.
+
+=head2 Localising a Tied Variable Leaks Memory
+
+ use Tie::Hash;
+ tie my %tie_hash => 'Tie::StdHash';
+
+ ...
+
+ local($tie_hash{Foo}) = 1; # leaks
+
+Code like the above is known to leak memory every time the local()
+is executed.
+
+=head2 Self-tying of Arrays and Hashes Is Forbidden
+
+Self-tying of arrays and hashes is broken in rather deep and
+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).
+
+=head2 Variable Attributes are not Currently Usable for Tieing
+
+This limitation will hopefully be fixed in future. (Subroutine
+attributes work fine for tieing, see L<Attribute::Handlers>).
+
+=head2 Building Extensions Can Fail Because Of Largefiles
+
+Some extensions like mod_perl are known to have issues with
+`largefiles', a change brought by Perl 5.6.0 in which file offsets
+default to 64 bits wide, where supported. Modules may fail to compile
+at all or compile and work incorrectly. Currently there is no good
+solution for the problem, but Configure now provides appropriate
+non-largefile ccflags, ldflags, libswanted, and libs in the %Config
+hash (e.g., $Config{ccflags_nolargefiles}) so the extensions that are
+having problems can try configuring themselves without the
+largefileness. This is admittedly not a clean solution, and the
+solution may not even work at all. One potential failure is whether
+one can (or, if one can, whether it's a good idea) link together at
+all binaries with different ideas about file offsets, all this is
+platform-dependent.
+
+=head2 The Compiler Suite Is Still Experimental
+
+The compiler suite is slowly getting better but is nowhere near
+working order yet.
+
+=head2 The Long Double Support is Still Experimental
+
+The ability to configure Perl's numbers to use "long doubles",
+floating point numbers of hopefully better accuracy, is still
+experimental. The implementations of long doubles are not yet
+widespread and the existing implementations are not quite mature
+or standardised, therefore trying to support them is a rare
+and moving target. The gain of more precision may also be offset
+by slowdown in computations (more bits to move around, and the
+operations are more likely to be executed by less optimised
+libraries).
=head1 Reporting Bugs
projects / p5sagit/p5-mst-13.2.git / commitdiff