=head1 DESCRIPTION
-This document describes differences between the 5.6.0 release and the
-5.8.0 release.
+This document describes differences between the 5.6.0 release
+and the 5.8.0 release.
-=head1 Security Vulnerability Closed
+Many of the bug fixes in 5.8.0 were already seen in the 5.6.1
+maintenance release since the two releases were kept closely
+coordinated.
-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.
+If you are upgrading from Perl 5.005_03, you might also want
+to read L<perl56delta>.
-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.
+=head1 Highlights In 5.8.0
-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/).
+=over 4
-=head1 Incompatible Changes
+=item *
-=over 4
+Better Unicode support
=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>.
+New Thread Implementation
=item *
-The semantics of bless(REF, REF) were unclear and until someone proves
-it to make some sense, it is forbidden.
+Many New Modules
+
+=item *
+
+Better Numeric Accuracy
=item *
-A reference to a reference now stringify as "REF(0x81485ec)" instead
+Safe Signals
+
+=item *
+
+More Extensive Regression Testing
+
+=back
+
+=head1 Incompatible Changes
+
+=head2 64-bit platforms and malloc
+
+If your pointers are 64 bits wide, the Perl malloc is no longer being
+used because it does not work well with 8-byte pointers. Also,
+usually the system mallocs on such platforms are much better optimized
+for such large memory models than the Perl malloc. Some memory-hungry
+Perl applications like the PDL don't work well with Perl's malloc.
+Finally, other applications than Perl (like modperl) tend to prefer
+the system malloc. Such platforms include Alpha and 64-bit HPPA,
+MIPS, PPC, and Sparc.
+
+=head2 AIX Dynaloading
+
+The AIX dynaloading now uses in AIX releases 4.3 and newer the native
+dlopen interface of AIX instead of the old emulated interface. This
+change will probably break backward compatibility with compiled
+modules. The change was made to make Perl more compliant with other
+applications like modperl which are using the AIX native interface.
+
+=head2 Attributes for C<my> variables now handled at run-time.
+
+The C<my EXPR : ATTRS> syntax now applies variable attributes at
+run-time. (Subroutine and C<our> variables still get attributes applied
+at compile-time.) See L<attributes> for additional details. In particular,
+however, this allows variable attributes to be useful for C<tie> interfaces,
+which was a deficiency of earlier releases. Note that the new semantics
+doesn't work with the Attribute::Handlers module (as of version 0.76).
+
+=head2 Socket Extension Dynamic in VMS
+
+The Socket extension is now dynamically loaded instead of being
+statically built in. This may or may not be a problem with ancient
+TCP/IP stacks of VMS: we do not know since we weren't able to test
+Perl in such configurations.
+
+=head2 IEEE-format Floating Point Default on OpenVMS Alpha
+
+Perl now uses IEEE format (T_FLOAT) as the default internal floating
+point format on OpenVMS Alpha, potentially breaking binary compatibility
+with external libraries or existing data. G_FLOAT is still available as
+a configuration option. The default on VAX (D_FLOAT) has not changed.
+
+=head2 New Unicode Properties
+
+Unicode I<scripts> are now supported. Scripts are similar to (and superior
+to) Unicode I<blocks>. The difference between scripts and blocks is that
+scripts are the glyphs used by a language or a group of languages, while
+the blocks are more artificial groupings of (mostly) 256 characters based
+on the Unicode numbering.
+
+In general, scripts are more inclusive, but not universally so. For
+example, while the script C<Latin> includes all the Latin characters and
+their various diacritic-adorned versions, it does not include the various
+punctuation or digits (since they are not solely C<Latin>).
+
+A number of other properties are now supported, including C<\p{L&}>,
+C<\p{Any}> C<\p{Assigned}>, C<\p{Unassigned}>, C<\p{Blank}> and
+C<\p{SpacePerl}> (along with their C<\P{...}> versions, of course).
+See L<perlunicode> for details, and more additions.
+
+The C<In> or C<Is> prefix to names used with the C<\p{...}> and C<\P{...}>
+are now almost always optional. The only exception is that a C<In> prefix
+is required to signify a Unicode block when a block name conflicts with a
+script name. For example, C<\p{Tibetan}> refers to the script, while
+C<\p{InTibetan}> refers to the block. When there is no name conflict, you
+can omit the C<In> from the block name (e.g. C<\p{BraillePatterns}>), but
+to be safe, it's probably best to always use the C<In>).
+
+=head2 REF(...) Instead Of SCALAR(...)
+
+A reference to a reference now stringifies as "REF(0x81485ec)" instead
of "SCALAR(0x81485ec)" in order to be more consistent with the return
value of ref().
+=head2 pack/unpack D/F recycled
+
+The undocumented pack/unpack template letters D/F have been recycled
+for better use: now they stand for long double (if supported by the
+platform) and NV (Perl internal floating point type). (They used
+to be aliases for d/f, but you never knew that.)
+
+=head2 Deprecations
+
+=over 4
+
=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.
+The semantics of bless(REF, REF) were unclear and until someone proves
+it to make some sense, it is forbidden.
=item *
=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.
+The builtin dump() function has probably outlived most of its
+usefulness. The core-dumping functionality will remain in future
+available as an explicit call to C<CORE::dump()>, but in future
+releases the behaviour of an unqualified C<dump()> call may change.
+
+=item *
+
+The very dusty examples in the eg/ directory have been removed.
+Suggestions for new shiny examples welcome but the main issue is that
+the examples need to be documented, tested and (most importantly)
+maintained.
=item *
=item *
-lstat(FILEHANDLE) now gives a warning because the operation makes no sense.
-In future releases this may become a fatal error.
+The list of filenames from glob() (or <...>) is now by default sorted
+alphabetically to be csh-compliant (which is what happened before
+in most UNIX platforms). (bsd_glob() does still sort platform
+natively, ASCII or EBCDIC, unless GLOB_ALPHASORT is specified.)
=item *
-The long deprecated uppercase aliases for the string comparison
-operators (EQ, NE, LT, LE, GE, GT) have now been removed.
+Spurious syntax errors generated in certain situations, when glob()
+caused File::Glob to be loaded for the first time, have been fixed.
=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.
+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 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
+lstat(FILEHANDLE) now gives a warning because the operation makes no sense.
+In future releases this may become a fatal error.
-=head1 Core Enhancements
+=item *
-=over 4
+The C<package;> syntax (C<package> without an argument) has been
+deprecated. Its semantics were never that clear and its
+implementation even less so. If you have used that feature to
+disallow all but fully qualified variables, C<use strict;> instead.
=item *
-C<perl -d:Module=arg,arg,arg> now works (previously one couldn't pass
-in multiple arguments.)
+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 *
-my __PACKAGE__ $obj now works.
+The current user-visible implementation of pseudo-hashes (the weird
+use of the first array element) is deprecated starting from Perl 5.8.0
+and will be removed in Perl 5.10.0, and the feature will be
+implemented differently. Not only is the current interface rather
+ugly, but the current implementation slows down normal array and hash
+use quite noticeably. The C<fields> pragma interface will remain
+available. The I<restricted hashes> interface is expected to
+be the replacement interface (see L<Hash::Util>).
=item *
-C<no Module;> now works even if there is no "sub unimport" in the Module.
+The syntaxes C<< @a->[...] >> and C<< %h->{...} >> have now been deprecated.
=item *
-The numerical comparison operators return C<undef> if either operand
-is a NaN. Previously the behaviour was unspecified.
+After years of trying the suidperl is considered to be too complex to
+ever be considered truly secure. The suidperl functionality is likely
+to be removed in a future release.
=item *
-C<pack('U0a*', ...)> can now be used to force a string to UTF8.
+The long deprecated uppercase aliases for the string comparison
+operators (EQ, NE, LT, LE, GE, GT) have now been removed.
=item *
-prototype(\&) is now available.
+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', ...).
=item *
-There is now an UNTIE method.
+Earlier Perls treated "sub foo (@bar)" as equivalent to "sub foo (@)".
+The prototypes are now checked at compile-time for invalid characters.
+An optional warning is generated ("Illegal character in prototype...")
+but this may be upgraded to a fatal error in a future release.
=back
-=head1 Modules and Pragmata
+=head1 Core Enhancements
-=head2 New Modules
+=head2 PerlIO is Now The Default
=over 4
=item *
-File::Temp allows one to create temporary files and directories in an
-easy, portable, and secure way.
-
-=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:
-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.
+ open($fh,'>:crlf :utf8', $path) || ...
-=back
+or on already opened handles via extended C<binmode>:
-=head2 Updated And Improved Modules and Pragmata
+ binmode($fh,':encoding(iso-8859-7)');
-=over 4
+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).
-=item *
+Layers to be applied by default may be specified via the 'open' pragma.
-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.
+See L</"Installation and Configuration Improvements"> for the effects
+of PerlIO on your architecture name.
=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.
+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" :
-=item *
+ open($fh,">:utf8","Uni.txt");
-The attributes::reftype() now works on tied arguments.
+Note for EBCDIC users: the pseudo layer ":utf8" is erroneously named
+for you since it's not UTF-8 what you will be getting but instead
+UTF-EBCDIC. See L<perlunicode>, L<utf8>, and
+http://www.unicode.org/unicode/reports/tr16/ for more information.
+In future releases this naming may change.
=item *
-AutoLoader can now be disabled with C<no AutoLoader;>,
+File handles can translate character encodings from/to Perl's internal
+Unicode form on read/write via the ":encoding()" layer.
=item *
-The English module can now be used without the infamous performance
-hit by saying
-
- use English '-no_performance_hit';
-
-(Assuming, of course, that one doesn't need the troublesome variables
-C<$`>, C<$&>, or C<$'>.) Also, introduced C<@LAST_MATCH_START> and
-C<@LAST_MATCH_END> English aliases for C<@-> and C<@+>.
-
-=item *
+File handles can be opened to "in memory" files held in Perl scalars via:
-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.
+ open($fh,'>', \$variable) || ...
=item *
-File::Glob::glob() renamed to File::Glob::bsd_glob() to avoid
-prototype mismatch with CORE::glob().
+Anonymous temporary files are available without need to
+'use FileHandle' or other module via
-=item *
+ open($fh,"+>", undef) || ...
-IPC::Open3 now allows the use of numeric file descriptors.
+That is a literal undef, not an undefined value.
=item *
-use lib now works identically to @INC. Removing directories
-with 'no lib' now works.
+The list form of C<open> is now implemented for pipes (at least on UNIX):
-=item *
+ open($fh,"-|", 'cat', '/etc/motd')
-C<%INC> now localised in a Safe compartment so that use/require work.
+creates a pipe, and runs the equivalent of exec('cat', '/etc/motd') in
+the child process.
=item *
-The Shell module now has an OO interface.
+If your locale environment variables (LANGUAGE, LC_ALL, LC_CTYPE, LANG)
+contain the strings 'UTF-8' or 'UTF8' (case-insensitive matching),
+the default encoding of your STDIN, STDOUT, and STDERR, and of
+B<any subsequent file open>, is UTF-8.
=back
-=head1 Utility Changes
+=head2 Safe Signals
+
+Perl used to be fragile in that signals arriving at inopportune moments
+could corrupt Perl's internal state. Now Perl postpones handling of
+signals until it's safe (between opcodes).
+
+This change may have surprising side effects because signals no longer
+interrupt Perl instantly. Perl will now first finish whatever it was
+doing, like finishing an internal operation (like sort()) or an
+external operation (like an I/O operation), and only then look at any
+arrived signals (and before starting the next operation). No more corrupt
+internal state since the current operation is always finished first,
+but the signal may take more time to get heard. Note that breaking
+out from potentially blocking operations should still work, though.
+
+=head2 Unicode Overhaul
+
+Unicode in general should be now much more usable than in Perl 5.6.0
+(or even in 5.6.1). Unicode can be used in hash keys, Unicode in
+regular expressions should work now, Unicode in tr/// should work now,
+Unicode in I/O should work now. See L<perluniintro> for introduction
+and L<perlunicode> for details.
=over 4
=item *
-The Emacs perl mode (emacs/cperl-mode.el) has been updated to version
-4.31.
+The Unicode Character Database coming with Perl has been upgraded
+to Unicode 3.2.0. For more information, see http://www.unicode.org/ .
=item *
-Perlbug is now much more robust. It also sends the bug report to
-perl.org, not perl.com.
+For developers interested in enhancing Perl's Unicode capabilities:
+almost all the UCD files are included with the Perl distribution in
+the F<lib/unicore subdirectory>. The most notable omission, for space
+considerations, is the Unihan database.
=item *
-The 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 properties \p{Blank} and \p{SpacePerl} have been added. "Blank" is like
+C isblank(), that is, it contains only "horizontal whitespace" (the space
+character is, the newline isn't), and the "SpacePerl" is the Unicode
+equivalent of C<\s> (\p{Space} isn't, since that includes the vertical
+tabulator character, whereas C<\s> doesn't.)
-The xsubpp utility for extension writers now understands POD
-documentation embedded in the *.xs files.
+See "New Unicode Properties" earlier in this document for additional
+information on changes with Unicode properties.
=back
-=head1 New Documentation
+=head2 Understanding of Numbers
+
+In general a lot of fixing has happened in the area of Perl's
+understanding of numbers, both integer and floating point. Since in
+many systems the standard number parsing functions like C<strtoul()>
+and C<atof()> seem to have bugs, Perl tries to work around their
+deficiencies. This results hopefully in more accurate numbers.
+
+Perl now tries internally to use integer values in numeric conversions
+and basic arithmetics (+ - * /) if the arguments are integers, and
+tries also to keep the results stored internally as integers.
+This change leads to often slightly faster and always less lossy
+arithmetics. (Previously Perl always preferred floating point numbers
+in its math.)
+
+=head2 Miscellaneous Changes
=over 4
=item *
-perl56delta details the changes between the 5.005 release and the
-5.6.0 release.
+AUTOLOAD is now lvaluable, meaning that you can add the :lvalue attribute
+to AUTOLOAD subroutines and you can assign to the AUTOLOAD return value.
=item *
-perldebtut is a Perl debugging tutorial.
+C<perl -d:Module=arg,arg,arg> now works (previously one couldn't pass
+in multiple arguments.)
=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.
+The builtin dump() now gives an optional warning
+C<dump() better written as CORE::dump()>,
+meaning that by default C<dump(...)> is resolved as the builtin
+dump() which dumps core and aborts, not as (possibly) user-defined
+C<sub dump>. To call the latter, qualify the call as C<&dump(...)>.
+(The whole dump() feature is to considered deprecated, and possibly
+removed/changed in future releases.)
=item *
-perlnewmod tells about writing and submitting a new module.
+chomp() and chop() are now overridable. Note, however, that their
+prototype (as given by C<prototype("CORE::chomp")> is undefined,
+because it cannot be expressed and therefore one cannot really write
+replacements to override these builtins.
=item *
-perlposix-bc explains using Perl on the POSIX-BC platform
-(an EBCDIC mainframe platform).
+END blocks are now run even if you exit/die in a BEGIN block.
+Internally, the execution of END blocks is now controlled by
+PL_exit_flags & PERL_EXIT_DESTRUCT_END. This enables the new
+behaviour for Perl embedders. This will default in 5.10. See
+L<perlembed>.
=item *
-perlretut is a regular expression tutorial.
+Formats now support zero-padded decimal fields.
=item *
-perlrequick is a regular expressions quick-start guide.
-Yes, much quicker than perlretut.
+Lvalue subroutines can now return C<undef> in list context.
+However, the lvalue subroutine feature still remains experimental.
=item *
-perlutil explains the command line utilities packaged with the Perl
-distribution.
-
-=back
+A lost warning "Can't declare ... dereference in my" has been
+restored (Perl had it earlier but it became lost in later releases.)
-=head1 Performance Enhancements
+=item *
-=over 4
+A new special regular expression variable has been introduced:
+C<$^N>, which contains the most-recently closed group (submatch).
=item *
-map() that changes the size of the list should now work faster.
+C<no Module;> now works even if there is no "sub unimport" in the Module.
=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).
+The numerical comparison operators return C<undef> if either operand
+is a NaN. Previously the behaviour was unspecified.
-=back
+=item *
-=head1 Installation and Configuration Improvements
+The following builtin functions are now overridable: each(), keys(),
+pop(), push(), shift(), splice(), unshift().
-=head2 Generic Improvements
+=item *
-=over 4
+C<pack() / unpack()> now can group template letters with C<()> and then
+apply repetition/count modifiers on the groups.
=item *
-INSTALL now explains how you can configure Perl to use 64-bit
-integers even on non-64-bit platforms.
+C<pack() / unpack()> can now process the Perl internal numeric types:
+IVs, UVs, NVs-- and also long doubles, if supported by the platform.
+The template letters are C<j>, C<J>, C<F>, and C<D>.
=item *
-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.
+C<pack('U0a*', ...)> can now be used to force a string to UTF8.
=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.
+my __PACKAGE__ $obj now works.
=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.
+The printf() and sprintf() now support parameter reordering using the
+C<%\d+\$> and C<*\d+\$> syntaxes. For example
-=item *
+ print "%2\$s %1\$s\n", "foo", "bar";
-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.
+will print "bar foo\n". This feature helps in writing
+internationalised software, and in general when the order
+of the parameters can vary.
=item *
-If binary compatibility with the 5.005 release is not wanted, Configure
-no longer suggests including the 5.005 modules in @INC.
+prototype(\&) is now available.
=item *
-Configure C<-S> can now run non-interactively.
+prototype(\[$@%&]) is now available to implicitly create references
+(useful for example if you want to emulate the tie() interface).
=item *
-configure.gnu now works with options with whitespace in them.
+A new command-line option, C<-t> is available. It is the
+little brother of C<-T>: instead of dying on taint violations,
+lexical warnings are given. B<This is only meant as a temporary
+debugging aid while securing the code of old legacy applications.
+This is not a substitute for -T.>
=item *
-installperl now outputs everything to STDERR.
+In other taint news, the C<exec LIST> and C<system LIST> have now been
+considered too risky (think C<exec @ARGV>: it can start any program
+with any arguments), and now the said forms cause a warning.
+You should carefully launder the arguments to guarantee their
+validity. In future releases of Perl the forms will become fatal
+errors so consider starting laundering now.
=item *
-$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
+If tr/// is just counting characters, it doesn't attempt to
+modify its target.
=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.
+untie() will now call an UNTIE() hook if it exists. See L<perltie>
+for details.
=item *
-C<*foo{FORMAT}> now works.
+L<utime> now supports C<utime undef, undef, @files> to change the
+file timestamps to the current time.
=item *
-Lexical warnings now propagating correctly between scopes.
+The rules for allowing underscores (underbars) in numeric constants
+have been relaxed and simplified: now you can have an underscore
+simply B<between digits>.
=item *
-Line renumbering with eval and C<#line> now works.
+Rather than relying on C's argv[0] (which may not contain a full pathname)
+where possible $^X is now set by asking the operating system.
+(eg by reading F</proc/self/exe> on Linux, F</proc/curproc/file> on FreeBSD)
=item *
-Fixed numerous memory leaks, especially in eval "".
+A new variable, C<${^TAINT}>, indicates whether taint mode is enabled.
=item *
-Modulus of unsigned numbers now works (4063328477 % 65535 used to
-return 27406, instead of 27047).
+You can now override the readline() builtin, and this overrides also
+the <FILEHANDLE> angle bracket operator.
=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.
+The command-line options -s and -F are now recognized on the shebang
+(#!) line.
=item *
-our() variables will not cause "will not stay shared" warnings.
+Use of the C</c> match modifier without an accompanying C</g> modifier
+elicits a new warning: C<Use of /c modifier is meaningless without /g>.
-=item *
+Use of C</c> in substitutions, even with C</g>, elicits
+C<Use of /c modifier is meaningless in s///>.
-pack "Z" now correctly terminates the string with "\0".
+Use of C</g> with C<split> elicits <Use of /g modifier is meaningless
+in split>.
-=item *
+=back
-Fix password routines which in some shadow password platforms
-(e.g. HP-UX) caused getpwent() to return every other entry.
+=head1 Modules and Pragmata
-=item *
+=head2 New Modules and Pragmata
-printf() no longer resets the numeric locale to "C".
+=over 4
=item *
-C<q(a\\b)> now parses correctly as C<'a\\b'>.
+C<Attribute::Handlers> allows a class to define attribute handlers.
-=item *
+ package MyPack;
+ use Attribute::Handlers;
+ sub Wolf :ATTR(SCALAR) { print "howl!\n" }
-Printing quads (64-bit integers) with printf/sprintf now works
-without the q L ll prefixes (assuming you are on a quad-capable platform).
+ # later, in some package using or inheriting from MyPack...
-=item *
+ my MyPack $Fluffy : Wolf; # the attribute handler Wolf will be called
-Regular expressions on references and overloaded scalars now work.
+Both variables and routines can have attribute handlers. Handlers can
+be specific to type (SCALAR, ARRAY, HASH, or CODE), or specific to the
+exact compilation phase (BEGIN, CHECK, INIT, or END).
=item *
-scalar() now forces scalar context even when used in void context.
+B<B::Concise> is a new compiler backend for walking the Perl syntax
+tree, printing concise info about ops, from Stephen McCamant. The
+output is highly customisable. See L<B::Concise>.
=item *
-sort() arguments are now compiled in the right wantarray context
-(they were accidentally using the context of the sort() itself).
+The new bignum, bigint, and bigrat pragmas implement transparent
+bignum support (using the Math::BigInt, Math::BigFloat, and
+Math::BigRat backends), by Tels.
=item *
-Changed the POSIX character class C<[[:space:]]> to include the (very
-rare) vertical tab character. Added a new POSIX-ish character class
-C<[[:blank:]]> which stands for horizontal whitespace (currently,
-the space and the tab).
+C<Class::ISA> for reporting the search path for a class's ISA tree,
+by Sean Burke, has been added. See L<Class::ISA>.
=item *
-$AUTOLOAD, sort(), lock(), and spawning subprocesses
-in multiple threads simultaneously are now thread-safe.
+C<Cwd> has now a split personality: if possible, an XS extension is
+used, (this will hopefully be faster, more secure, and more robust)
+but if not possible, the familiar Perl implementation is used.
=item *
-Allow read-only string on left hand side of non-modifying tr///.
+C<Devel::PPPort>, originally from Kenneth Albanowski and now
+maintained by Paul Marquess, has been added. It is primarily used
+by C<h2xs> to enhance portability of XS modules between different
+versions of Perl.
=item *
-Several Unicode fixes (but still not perfect).
-
-=over 8
+C<Digest>, frontend module for calculating digests (checksums), from
+Gisle Aas, has been added. See L<Digest>.
=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.
+C<Digest::MD5> for calculating MD5 digests (checksums) as defined in
+RFC 1321, from Gisle Aas, has been added. See L<Digest::MD5>.
-=item *
+ use Digest::MD5 'md5_hex';
-The character tables have been updated to Unicode 3.0.1.
+ $digest = md5_hex("Thirsty Camel");
-=item *
+ print $digest, "\n"; # 01d19d9d2045e005c3f1b80e8b164de1
-chr() for values greater than 127 now create utf8 when under use
-utf8.
+NOTE: the C<MD5> backward compatibility module is deliberately not
+included since its further use is discouraged.
=item *
-Comparing with utf8 data does not magically upgrade non-utf8 data into
-utf8.
+C<Encode>, by Nick Ing-Simmons and Dan Kogai, provides a mechanism to
+translate between different character encodings. Support for Unicode,
+ISO-8859-1, and ASCII are compiled in to the module. Several other
+encodings (like the rest of the ISO-8859, CP*/Win*, Mac, KOI8-R, three
+variants EBCDIC, Chinese, Japanese, and Korean encodings) are included
+and can be loaded at runtime. (For space considerations, the largest
+Chinese encodings have been separated into their own CPAN module,
+Encode::HanExtra, which Encode will use if available). See L<Encode>.
+
+Any encoding supported by Encode module is also available to the
+":encoding()" layer if PerlIO is used.
=item *
-C<IsAlnum>, C<IsAlpha>, and C<IsWord> now match titlecase.
+C<Hash::Util> is the interface to the new I<restricted hashes>
+feature. A restricted hash is restricted to a certain set of keys,
+no keys outside the set can be added. Also individual keys can be
+restricted so that the key cannot be deleted and the value cannot be
+changed. (Implemented by Jeffrey Friedl, Nick Ing-Simmons, and
+Michael Schwern.)
=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.
+C<I18N::Langinfo> can be use to query locale information.
+See L<I18N::Langinfo>.
=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', ...)).
+C<I18N::LangTags> has functions for dealing with RFC3066-style
+language tags, by Sean Burke. See L<I18N::LangTags>.
=item *
-vec() now refuses to deal with characters >255.
+C<ExtUtils::Constant> is a new tool for extension writers for
+generating XS code to import C header constants, by Nicholas Clark.
+See L<ExtUtils::Constant>.
=item *
-Zero entries were missing from the Unicode classes like C<IsDigit>.
+C<Filter::Simple> is an easy-to-use frontend to Filter::Util::Call,
+from Damian Conway. See L<Filter::Simple>.
-=back
+ # in MyFilter.pm:
-=item *
+ package MyFilter;
-UNIVERSAL::isa no longer caches methods incorrectly. (This broke
-the Tk extension with 5.6.0.)
+ use Filter::Simple sub {
+ while (my ($from, $to) = splice @_, 0, 2) {
+ s/$from/$to/g;
+ }
+ };
-=back
+ 1;
-=head2 Platform Specific Changes and Fixes
+ # in user's code:
-=over 4
+ use MyFilter qr/red/ => 'green';
-=item *
+ print "red\n"; # this code is filtered, will print "green\n"
+ print "bored\n"; # this code is filtered, will print "bogreen\n"
-BSDI 4.*
+ no MyFilter;
-Perl now works on post-4.0 BSD/OSes.
+ print "red\n"; # this code is not filtered, will print "red\n"
=item *
-All BSDs
-
-Setting C<$0> now works (as much as possible; see perlvar for details).
+C<File::Temp> allows one to create temporary files and directories in
+an easy, portable, and secure way, by Tim Jenness. See L<File::Temp>.
=item *
-Cygwin
-
-Numerous updates; currently synchronised with Cygwin 1.1.4.
+C<Filter::Util::Call> provides you with the framework to write
+I<Source Filters> in Perl, from Paul Marquess. For most uses the
+frontend Filter::Simple is to be preferred. See L<Filter::Util::Call>.
=item *
-EPOC
-
-EPOC update after Perl 5.6.0. See README.epoc.
+C<if> is a new pragma for conditional inclusion of modules, from
+Ilya Zakharevich.
=item *
-FreeBSD 3.*
+L<libnet> is a collection of perl5 modules related to network
+programming, from Graham Barr. See L<Net::FTP>, L<Net::NNTP>,
+L<Net::Ping>, L<Net::POP3>, L<Net::SMTP>, and L<Net::Time>.
-Perl now works on post-3.0 FreeBSDs.
+Perl installation leaves libnet unconfigured, use F<libnetcfg> to configure.
=item *
-HP-UX
-
-README.hpux updated; C<Configure -Duse64bitall> now almost works.
+C<List::Util> is a selection of general-utility list subroutines, like
+sum(), min(), first(), and shuffle(), by Graham Barr. See L<List::Util>.
=item *
-IRIX
-
-Numerous compilation flag and hint enhancements; accidental mixing
-of 32-bit and 64-bit libraries (a doomed attempt) made much harder.
+C<Locale::Constants>, C<Locale::Country>, C<Locale::Currency>, and
+C<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.
-=item *
+ use Locale::Country;
-Linux
+ $country = code2country('jp'); # $country gets 'Japan'
+ $code = country2code('Norway'); # $code gets 'no'
-Long doubles should now work (see INSTALL).
+See L<Locale::Constants>, L<Locale::Country>, L<Locale::Currency>,
+and L<Locale::Language>.
=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.
+C<Locale::Maketext> is localization framework from Sean Burke. See
+L<Locale::Maketext>, and L<Locale::Maketext::TPJ13>. The latter is an
+article about software localization, originally published in The Perl
+Journal #13, republished here with kind permission.
=item *
-MPE/iX
-
-MPE/iX update after Perl 5.6.0. See README.mpeix.
+Math::BigRat for big rational numbers, to accompany Math::BigInt and
+Math::BigFloat, from Tels.
=item *
-NetBSD/sparc
-
-Perl now works on NetBSD/sparc.
+C<Memoize> can make your functions faster by trading space for time,
+from Mark-Jason Dominus. See L<Memoize>.
=item *
-OS/2
+C<MIME::Base64> allows you to encode data in base64, from Gisle Aas,
+as defined in RFC 2045 - I<MIME (Multipurpose Internet Mail
+Extensions)>.
-Now works with usethreads (see INSTALL).
+ use MIME::Base64;
-=item *
+ $encoded = encode_base64('Aladdin:open sesame');
+ $decoded = decode_base64($encoded);
-Solaris
+ print $encoded, "\n"; # "QWxhZGRpbjpvcGVuIHNlc2FtZQ=="
-64-bitness using the Sun Workshop compiler now works.
+See L<MIME::Base64>.
=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.
+C<MIME::QuotedPrint> allows you to encode data in quoted-printable
+encoding, as defined in RFC 2045 - I<MIME (Multipurpose Internet Mail
+Extensions)>, from Gisle Aas.
-=item *
+ use MIME::QuotedPrint;
-Unicos
+ $encoded = encode_qp("Smiley in Unicode: \x{263a}");
+ $decoded = decode_qp($encoded);
-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.
+ print $encoded, "\n"; # "Smiley in Unicode: =263A"
-=item *
+MIME::QuotedPrint has been enhanced to provide the basic methods
+necessary to use it with PerlIO::Via as in :
-VMS
+ use MIME::QuotedPrint;
+ open($fh,">Via(MIME::QuotedPrint)",$path);
-chdir() now works better despite a CRT bug; now works with MULTIPLICITY
-(see INSTALL); now works with Perl's malloc.
+See L<MIME::QuotedPrint>.
=item *
-Windows
-
-=over 8
+C<NEXT> is pseudo-class for method redispatch, from Damian Conway.
+See L<NEXT>.
=item *
-accept() no longer leaks memory.
+C<open> is a new pragma for setting the default I/O disciplines
+for open().
=item *
-Better chdir() return value for a non-existent directory.
+C<PerlIO::Scalar> provides the implementation of IO to "in memory"
+Perl scalars as discussed above, from Nick Ing-Simmons. It also
+serves as an example of a loadable PerlIO layer. Other future
+possibilities include PerlIO::Array and PerlIO::Code.
+See L<PerlIO::Scalar>.
=item *
-New %ENV entries now propagate to subprocesses.
+C<PerlIO::Via> acts as a PerlIO layer and wraps PerlIO layer
+functionality provided by a class (typically implemented in perl
+code), from Nick Ing-Simmons.
-=item *
+ use MIME::QuotedPrint;
+ open($fh,">Via(MIME::QuotedPrint)",$path);
-$ENV{LIB} now used to search for libs under Visual C.
+This will automatically convert everything output to C<$fh>
+to Quoted-Printable. See L<PerlIO::Via>.
=item *
-A failed (pseudo)fork now returns undef and sets errno to EAGAIN.
+C<Pod::ParseLink>, by Russ Allbery, has been added,
+to parse LZ<><> links in pods as described in the new
+perlpodspec.
=item *
-Allow REG_EXPAND_SZ keys in the registry.
+C<Pod::Text::Overstrike>, by Joe Smith, has been added.
+It converts POD data to formatted overstrike text.
+See L<Pod::Text::Overstrike>.
=item *
-Can now send() from all threads, not just the first one.
+C<Scalar::Util> is a selection of general-utility scalar subroutines,
+like blessed(), reftype(), and tainted(). See L<Scalar::Util>.
=item *
-Fake signal handling reenabled, bugs and all.
+C<sort> is a new pragma for controlling the behaviour of sort().
=item *
-Less stack reserved per thread so that more threads can run
-concurrently. (Still 16M per thread.)
+C<Storable> gives persistence to Perl data structures by allowing the
+storage and retrieval of Perl data to and from files in a fast and
+compact binary format, from Raphael Manfredi. See L<Storable>.
=item *
-C<File::Spec->tmpdir()> now prefers C:/temp over /tmp
-(works better when perl is running as service).
+C<Switch>, from Damian Conway, has been added. Just by saying
+
+ use Switch;
+
+you have C<switch> and C<case> available in Perl.
+
+ use Switch;
+
+ switch ($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>.
=item *
-Better UNC path handling under ithreads.
+C<Test::More> is yet another framework for writing test scripts,
+more extensive than Test::Simple, by Michael Schwern. See L<Test::More>.
=item *
-wait() and waitpid() now work much better.
+C<Test::Simple> has basic utilities for writing tests, by Michael
+Schwern. See L<Test::Simple>.
=item *
-winsock handle leak fixed.
+C<Text::Balanced> has been added, for extracting delimited text
+sequences from strings, from Damian Conway.
-=back
+ use Text::Balanced 'extract_delimited';
-=back
+ ($a, $b) = extract_delimited("'never say never', he never said", "'", '');
-=head1 New or Changed Diagnostics
+$a will be "'never say never'", $b will be ', he never said'.
-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.
+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>.
-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>.
+=item *
-The "Unrecognized escape" warning has been extended to include C<\8>,
-C<\9>, and C<\_>. There is no need to escape any of the C<\w> characters.
+C<threads> is an interface to interpreter threads, by Arthur Bergman.
+Interpreter threads (ithreads) is the new thread model introduced in
+Perl 5.6 but only available as an internal interface for extension
+writers (and for Win32 Perl for C<fork()> emulation). See L<threads>.
-=head1 Changed Internals
+=item *
-=over 4
+C<threads::shared> allows data sharing for interpreter threads, from
+Arthur Bergman. In the ithreads model any data sharing between
+threads must be explicit, as opposed to the old 5.005 thread model
+where data sharing was implicit. See L<threads::shared>.
=item *
-perlapi.pod (a companion to perlguts) now attempts to document the
-internal API.
+C<Tie::File>, by Mark-Jason Dominus, associates a Perl array with the
+lines of a file.
=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.
+C<Tie::Memoize>, by Ilya Zakharevich, provides on-demand loaded hashes.
=item *
-Added rsignal(), whichsig(), do_join() to the publicised API.
+C<Tie::RefHash::Nestable>, by Edward Avis, allows storing hash
+references (unlike the standard Tie::RefHash) The module is contained
+within Tie::RefHash, see L<Tie::RefHash>.
=item *
-Made possible to propagate customised exceptions via croak()ing.
+C<Time::HiRes> provides high resolution timing (ualarm, usleep,
+and gettimeofday), from Douglas E. Wegscheid. See L<Time::HiRes>.
=item *
-Added is_utf8_char(), is_utf8_string(), bytes_to_utf8(), and utf8_to_bytes().
+C<Unicode::UCD> offers a querying interface to the Unicode Character
+Database. See L<Unicode::UCD>.
=item *
-Now xsubs can have attributes just like subs.
+C<Unicode::Collate> implements the UCA (Unicode Collation Algorithm)
+for sorting Unicode strings, by SADAHIRO Tomoyuki. See L<Unicode::Collate>.
-=back
+=item *
-=head1 Known Problems
+C<Unicode::Normalize> implements the various Unicode normalization
+forms, by SADAHIRO Tomoyuki. See L<Unicode::Normalize>.
-=head2 Unicode Support Still Far From Perfect
+=item *
-We're working on it. Stay tuned.
+C<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.
-=head2 EBCDIC Still A Lost Platform
+=back
-The plan is to bring them back.
+=head2 Updated And Improved Modules and Pragmata
-=head2 Building Extensions Can Fail Because Of Largefiles
+=over 4
-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.
+=item *
-=head2 ftmp-security tests warn 'system possibly insecure'
+The following independently supported modules have been updated to the
+newest versions from CPAN: CGI, CPAN, DB_File, File::Spec, File::Temp,
+Getopt::Long, Math::BigFloat, Math::BigInt, the podlators bundle
+(Pod::Man, Pod::Text), Pod::LaTeX, Pod::Parser, Storable,
+Term::ANSIColor, Test, Text-Tabs+Wrap.
-Don't panic. Read INSTALL 'make test' section instead.
+=item *
-=head2 Test lib/posix Subtest 9 Fails In LP64-Configured HP-UX
+The attributes::reftype() now works on tied arguments.
-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.
+=item *
-=head2 Long Doubles Still Don't Work In Solaris
+AutoLoader can now be disabled with C<no AutoLoader;>.
-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.)
+=item *
-=head2 Linux With Sfio Fails op/misc Test 48
+B::Deparse 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.
-No known fix.
+=item *
-=head2 Storable tests fail in some platforms
+Class::Struct can now define the classes in compile time.
-If any Storable tests fail the use of Storable is not advisable.
+=item *
-=over 4
+Class::Struct now assigns the array/hash element if the accessor
+is called with an array/hash element as the B<sole> argument.
=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.
+Data::Dumper has now an option to sort hashes.
=item *
-DOS DJGPP may hang when testing Storable.
+Data::Dumper has now an option to dump code references
+using B::Deparse.
=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.
+DB_File now supports newer Berkeley DB versions, among
+other improvements.
=item *
-st-store.t and st-retrieve may fail with Compaq C 6.2 on OpenVMS Alpha 7.2.
-
-=back
+The English module can now be used without the infamous performance
+hit by saying
-=head2 Threads Are Still Experimental
+ use English '-no_match_vars';
-Multithreading is still an experimental feature. Some platforms
-emit the following message for lib/thr5005
+(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<@+>.
- #
- # 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. ;-)
- #
+=item *
-and another known thread-related warning is
+Fcntl, Socket, and Sys::Syslog have been rewritten to use the
+new-style constant dispatch section (see L<ExtUtils::Constant>).
+This means that they will be more robust and hopefully faster.
- 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
+=item *
-=head2 The Compiler Suite Is Still Experimental
+File::Find now chdir()s correctly when chasing symbolic links.
-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.
+=item *
-=head1 Security Vulnerability Closed
+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.
-(This change was already made in 5.7.0 but bears repeating here.)
+=item *
-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.
+File::Find is now (again) reentrant. It also has been made
+more portable.
-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.
+=item *
-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/).
+The warnings issued by File::Find now belong to their own category.
+You can enable/disable them with C<use/no warnings 'File::Find';>.
-=head1 Incompatible Changes
+=item *
-=over 4
+File::Glob::glob() renamed to File::Glob::bsd_glob() to avoid
+prototype mismatch with CORE::glob().
=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">.
+File::Glob now supports C<GLOB_LIMIT> constant to limit the size of
+the returned list of filenames.
=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.)
+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).
-=back
+=item *
-=head1 Core Enhancements
+IPC::Open3 now allows the use of numeric file descriptors.
-=head2 AUTOLOAD Is Now Lvaluable
+=item *
-AUTOLOAD is now lvaluable, meaning that you can add the :lvalue attribute
-to AUTOLOAD subroutines and you can assign to the AUTOLOAD return value.
+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.
-=head2 PerlIO is Now The Default
+=item *
-=over 4
+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 *
-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:
+IO::Socket::INET now supports C<LocalPort> of zero (usually meaning
+that the operating system will make one up.)
- open($fh,'>:crlf :utf8', $path) || ...
+=item *
-or on already opened handles via extended C<binmode>:
+use lib now works identically to @INC. Removing directories
+with 'no lib' now works.
- binmode($fh,':encoding(iso-8859-7)');
+=item *
-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).
+ExtUtils::MakeMaker now uses File::Spec internally, which hopefully
+leads into better portability.
-Layers to be applied by default may be specified via the 'open' pragma.
+=item *
-See L</"Installation and Configuration Improvements"> for the effects
-of PerlIO on your architecture name.
+Math::BigFloat and Math::BigInt have undergone a full rewrite.
+They are now magnitudes faster, and they support various
+bignum libraries such as GMP and PARI as their backends.
=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" :
+Math::Complex handles inf, NaN etc., better.
- open($fh,">:utf8","Uni.txt");
+=item *
-Note for EBCDIC users: the pseudo layer ":utf8" is erroneously named
-for you since it's not UTF-8 what you will be getting but instead
-UTF-EBCDIC. See L<perlunicode>, L<utf8>, and
-http://www.unicode.org/unicode/reports/tr16/ for more information.
-In future releases this naming may change.
+Net::Ping has been muchly enhanced. Multihoming is now supported.
+There is now "external" protocol which uses Net::Ping::External module
+which runs external ping(1) and parses the output. A version of
+Net::Ping::External is available in CPAN.
=item *
-File handles can translate character encodings from/to Perl's internal
-Unicode form on read/write via the ":encoding()" layer.
+POSIX::sigaction() is now much more flexible and robust.
+You can now install coderef handlers, 'DEFAULT', and 'IGNORE'
+handlers, installing new handlers was not atomic.
=item *
-File handles can be opened to "in memory" files held in Perl scalars via:
-
- open($fh,'>', \$variable) || ...
+In Safe the C<%INC> now localised in a Safe compartment so that
+use/require work.
=item *
-Anonymous temporary files are available without need to
-'use FileHandle' or other module via
+In SDBM_File on dosish platforms, some keys went missing because of
+lack of support for files with "holes". A workaround for the problem
+has been added.
- open($fh,"+>", undef) || ...
+=item *
-That is a literal undef, not an undefined value.
+In Search::Dict one can now have a pre-processing hook for the
+lines being searched.
=item *
-The list form of C<open> is now implemented for pipes (at least on UNIX):
+The Shell module now has an OO interface.
- open($fh,"-|", 'cat', '/etc/motd')
+=item *
-creates a pipe, and runs the equivalent of exec('cat', '/etc/motd') in
-the child process.
+In Sys::Syslog there is now a failover mechanism that will go
+through alternative connection mechanisms until the message
+is successfully logged.
=item *
-The following builtin functions are now overridable: chop(), chomp(),
-each(), keys(), pop(), push(), shift(), splice(), unshift().
+The Test module has been significantly enhanced.
=item *
-Formats now support zero-padded decimal fields.
+Time::Local::timelocal() does not handle fractional seconds anymore.
+The rationale is that neither does localtime(), and timelocal() and
+localtime() are supposed to be inverses of each other.
=item *
-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.)
+The vars pragma now supports declaring fully qualified variables.
+(Something that C<our()> does not and will not support.)
=item *
-The printf() and sprintf() now support parameter reordering using the
-C<%\d+\$> and C<*\d+\$> syntaxes. For example
+The C<utf8::> name space (as in the pragma) provides various
+Perl-callable functions to provide low level access to Perl's
+internal Unicode representation. At the moment only length()
+has been implemented.
- print "%2\$s %1\$s\n", "foo", "bar";
+=back
-will print "bar foo\n"; This feature helps in writing
-internationalised software.
+=head1 Utility Changes
+
+=over 4
=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)
+Emacs perl mode (emacs/cperl-mode.el) has been updated to version
+4.31.
=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.
+F<emacs/e2ctags.pl> is now much faster.
=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.)
+C<enc2xs> is a tool for people adding their own encodings to the
+Encode module.
-=back
+=item *
-=head2 Signals Are Now Safe
+C<h2ph> now supports C trigraphs.
-Perl used to be fragile in that signals arriving at inopportune moments
-could corrupt Perl's internal state.
+=item *
-=head1 Modules and Pragmata
+C<h2xs> now produces a template README.
-=head2 New Modules
+=item *
-=over 4
+C<h2xs> now uses C<Devel::PPort> for better portability between
+different versions of Perl.
=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.
+C<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 *
-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.
+C<libnetcfg> has been added to configure the libnet.
=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.
+C<perlbug> is now much more robust. It also sends the bug report to
+perl.org, not perl.com.
=item *
-Digest, a frontend module for calculating digests (checksums),
-from Gisle Aas, has been added.
-
-See L<Digest> for more information.
+C<perlcc> has been rewritten and its user interface (that is,
+command line) is much more like that of the UNIX C compiler, cc.
+(The perlbc tools has been removed. Use C<perlcc -B> instead.)
=item *
-Digest::MD5 for calculating MD5 digests (checksums), by Gisle Aas,
-has been added.
-
- use Digest::MD5 'md5_hex';
+C<perlivp> is a new Installation Verification Procedure utility
+for running any time after installing Perl.
- $digest = md5_hex("Thirsty Camel");
+=item *
- print $digest, "\n"; # 01d19d9d2045e005c3f1b80e8b164de1
+C<piconv> is an implementation of the character conversion utility
+C<iconv>, demonstrating the new Encode module.
-NOTE: the MD5 backward compatibility module is deliberately not
-included since its use is discouraged.
+=item *
-See L<Digest::MD5> for more information.
+C<pod2html> now allows specifying a cache directory.
=item *
-Encode, by Nick Ing-Simmons, provides a mechanism to translate
-between different character encodings. Support for Unicode,
-ISO-8859-*, ASCII, CP*, KOI8-R, and three variants of EBCDIC are
-compiled in to the module. Several other encodings (like Japanese,
-Chinese, and MacIntosh encodings) are included and will be loaded at
-runtime.
+C<s2p> has been completely rewritten in Perl. (It is in fact a full
+implementation of sed in Perl: you can use the sed functionality by
+using the C<psed> utility.)
-Any encoding supported by Encode module is also available to the
-":encoding()" layer if PerlIO is used.
+=item *
-See L<Encode> for more information.
+C<xsubpp> now understands POD documentation embedded in the *.xs files.
=item *
-Filter::Simple is an easy-to-use frontend to Filter::Util::Call,
-from Damian Conway.
-
- # in MyFilter.pm:
+C<xsubpp> now supports OUT keyword.
- package MyFilter;
+=back
- use Filter::Simple sub {
- while (my ($from, $to) = splice @_, 0, 2) {
- s/$from/$to/g;
- }
- };
+=head1 New Documentation
- 1;
+=over 4
- # in user's code:
+=item *
- use MyFilter qr/red/ => 'green';
+perl56delta details the changes between the 5.005 release and the
+5.6.0 release.
- print "red\n"; # this code is filtered, will print "green\n"
- print "bored\n"; # this code is filtered, will print "bogreen\n"
+=item *
- no MyFilter;
+perlclib documents the internal replacements for standard C library
+functions. (Interesting only for extension writers and Perl core
+hackers.)
- print "red\n"; # this code is not filtered, will print "red\n"
+=item *
-See L<Filter::Simple> for more information.
+perldebtut is a Perl debugging tutorial.
=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.
+perlebcdic contains considerations for running Perl on EBCDIC platforms.
=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.
+perlintro is a gentle introduction to Perl.
- use Locale::Country;
-
- $country = code2country('jp'); # $country gets 'Japan'
- $code = country2code('Norway'); # $code gets 'no'
+=item *
-See L<Locale::Constants>, L<Locale::Country>, L<Locale::Currency>,
-and L<Locale::Language> for more information.
+perliol documents the internals of PerlIO with layers.
=item *
-MIME::Base64, by Gisle Aas, allows you to encode data in base64.
+perlmodstyle is a style guide for writing modules.
- use MIME::Base64;
+=item *
- $encoded = encode_base64('Aladdin:open sesame');
- $decoded = decode_base64($encoded);
+perlnewmod tells about writing and submitting a new module.
- print $encoded, "\n"; # "QWxhZGRpbjpvcGVuIHNlc2FtZQ=="
+=item *
-See L<MIME::Base64> for more information.
+perlpacktut is a pack() tutorial.
=item *
-MIME::QuotedPrint, by Gisle Aas, allows you to encode data in
-quoted-printable encoding.
+perlpod has been rewritten to be clearer and to record the best
+practices gathered over the years.
- use MIME::QuotedPrint;
+=item *
- $encoded = encode_qp("Smiley in Unicode: \x{263a}");
- $decoded = decode_qp($encoded);
+perlpodspec is a more formal specification of the pod format,
+mainly of interest for writers of pod applications, not to
+people writing in pod.
- print $encoded, "\n"; # "Smiley in Unicode: =263A"
+=item *
-MIME::QuotedPrint has been enhanced to provide the basic methods
-necessary to use it with PerlIO::Via as in :
+perlretut is a regular expression tutorial.
- use MIME::QuotedPrint;
- open($fh,">Via(MIME::QuotedPrint)",$path)
+=item *
-See L<MIME::QuotedPrint> for more information.
+perlrequick is a regular expressions quick-start guide.
+Yes, much quicker than perlretut.
=item *
-PerlIO::Scalar, by Nick Ing-Simmons, provides the implementation of
-IO to "in memory" Perl scalars as discussed above. It also serves as
-an example of a loadable layer. Other future possibilities include
-PerlIO::Array and PerlIO::Code. See L<PerlIO::Scalar> for more
-information.
+perltodo has been updated.
=item *
-PerlIO::Via, by Nick Ing-Simmons, acts as a PerlIO layer and wraps
-PerlIO layer functionality provided by a class (typically implemented
-in perl code).
+perltootc has been renamed as perltooc (to not to conflict
+with perltoot in filesystems restricted to "8.3" names)
- use MIME::QuotedPrint;
- open($fh,">Via(MIME::QuotedPrint)",$path)
+=item *
-This will automatically convert everything output to C<$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.
+perluniintro is an introduction to using Unicode in Perl.
+(perlunicode is more of a detailed reference and background
+information)
=item *
-Switch from Damian Conway has been added. Just by saying
+perlutil explains the command line utilities packaged with the Perl
+distribution.
- use Switch;
+=back
-you have C<switch> and C<case> available in Perl.
+The following platform-specific documents are available before
+the installation as README.I<platform>, and after the installation
+as perlI<platform>:
- use Switch;
+ perlaix perlamiga perlapollo perlbeos perlbs2000
+ perlce perlcygwin perldgux perldos perlepoc perlhpux
+ perlhurd perlmachten perlmacos perlmint perlmpeix
+ perlnetware perlos2 perlos390 perlplan9 perlqnx perlsolaris
+ perltru64 perluts perlvmesa perlvms perlvos perlwin32
- switch ($val) {
+=over 4
- case 1 { print "number 1" }
- case "a" { print "string a" }
- case [1..10,42] { print "number in list" }
- case (@array) { print "number in list" }
- case /\w+/ { print "pattern" }
- case qr/\w+/ { print "pattern" }
- case (%hash) { print "entry in hash" }
- case (\%hash) { print "entry in hash" }
- case (\&sub) { print "arg to subroutine" }
- else { print "previous case not true" }
- }
+=item *
-See L<Switch> for more information.
+The documentation for the POSIX-BC platform is called "BS2000", to avoid
+confusion with the Perl POSIX module.
=item *
-Text::Balanced from Damian Conway has been added, for
-extracting delimited text sequences from strings.
+The documentation for the WinCE platform is called perlce (README.ce
+in the source code kit), to avoid confusion with the perlwin32
+documentation on 8.3-restricted filesystems.
- use Text::Balanced 'extract_delimited';
+=back
- ($a, $b) = extract_delimited("'never say never', he never said", "'", '');
+=head1 Performance Enhancements
-$a will be "'never say never'", $b will be ', he never said'.
+=over 4
-In addition to extract_delimited() there are also extract_bracketed(),
-extract_quotelike(), extract_codeblock(), extract_variable(),
-extract_tagged(), extract_multiple(), gen_delimited_pat(), and
-gen_extract_tagged(). With these you can implement rather advanced
-parsing algorithms. See L<Text::Balanced> for more information.
+=item *
+
+map() could get pathologically slow when the result list it generates
+is larger than the source list. The performance has been improved for
+common scenarios.
+
+=item *
+
+sort() has been changed to use primarily mergesort internally as
+opposed to the earlier quicksort. For very small lists this may
+result in slightly slower sorting times, but in general the speedup
+should be at least 20%. Additional bonuses are that the worst case
+behaviour of sort() is now better (in computer science terms it now
+runs in time O(N log N), as opposed to quicksort's Theta(N**2)
+worst-case run time behaviour), and that sort() is now stable
+(meaning that elements with identical keys will stay ordered as they
+were before the sort). See the C<sort> pragma for information.
+
+The story in more detail: suppose you want to serve yourself a little
+slice of Pi.
+
+ @digits = ( 3,1,4,1,5,9 );
+
+A numerical sort of the digits will yield (1,1,3,4,5,9), as expected.
+Which C<1> comes first is hard to know, since one C<1> looks pretty
+much like any other. You can regard this as totally trivial,
+or somewhat profound. However, if you just want to sort the even
+digits ahead of the odd ones, then what will
+
+ sort { ($a % 2) <=> ($b % 2) } @digits;
+
+yield? The only even digit, C<4>, will come first. But how about
+the odd numbers, which all compare equal? With the quicksort algorithm
+used to implement Perl 5.6 and earlier, the order of ties is left up
+to the sort. So, as you add more and more digits of Pi, the order
+in which the sorted even and odd digits appear will change.
+and, for sufficiently large slices of Pi, the quicksort algorithm
+in Perl 5.8 won't return the same results even if reinvoked with the
+same input. The justification for this rests with quicksort's
+worst case behavior. If you run
+
+ sort { $a <=> $b } ( 1 .. $N , 1 .. $N );
+
+(something you might approximate if you wanted to merge two sorted
+arrays using sort), doubling $N doesn't just double the quicksort time,
+it I<quadruples> it. Quicksort has a worst case run time that can
+grow like N**2, so-called I<quadratic> behaviour, and it can happen
+on patterns that may well arise in normal use. You won't notice this
+for small arrays, but you I<will> notice it with larger arrays,
+and you may not live long enough for the sort to complete on arrays
+of a million elements. So the 5.8 quicksort scrambles large arrays
+before sorting them, as a statistical defence against quadratic behaviour.
+But that means if you sort the same large array twice, ties may be
+broken in different ways.
+
+Because of the unpredictability of tie-breaking order, and the quadratic
+worst-case behaviour, quicksort was I<almost> replaced completely with
+a stable mergesort. I<Stable> means that ties are broken to preserve
+the original order of appearance in the input array. So
+
+ sort { ($a % 2) <=> ($b % 2) } (3,1,4,1,5,9);
+
+will yield (4,3,1,1,5,9), guaranteed. The even and odd numbers
+appear in the output in the same order they appeared in the input.
+Mergesort has worst case O(NlogN) behaviour, the best value
+attainable. And, ironically, this mergesort does particularly
+well where quicksort goes quadratic: mergesort sorts (1..$N, 1..$N)
+in O(N) time. But quicksort was rescued at the last moment because
+it is faster than mergesort on certain inputs and platforms.
+For example, if you really I<don't> care about the order of even
+and odd digits, quicksort will run in O(N) time; it's very good
+at sorting many repetitions of a small number of distinct elements.
+The quicksort divide and conquer strategy works well on platforms
+with relatively small, very fast, caches. Eventually, the problem gets
+whittled down to one that fits in the cache, from which point it
+benefits from the increased memory speed.
+
+Quicksort was rescued by implementing a sort pragma to control aspects
+of the sort. The B<stable> subpragma forces stable behaviour,
+regardless of algorithm. The B<_quicksort> and B<_mergesort>
+subpragmas are heavy-handed ways to select the underlying implementation.
+The leading C<_> is a reminder that these subpragmas may not survive
+beyond 5.8. More appropriate mechanisms for selecting the implementation
+exist, but they wouldn't have arrived in time to save quicksort.
=item *
-Tie::RefHash::Nestable, by Edward Avis, allows storing hash references
-(unlike the standard Tie::RefHash) The module is contained within
-Tie::RefHash.
+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 *
-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.
+unshift() should now be noticeably faster.
=back
-=head2 Updated And Improved Modules and Pragmata
+=head1 Installation and Configuration Improvements
+
+=head2 Generic Improvements
=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.
+INSTALL now explains how you can configure Perl to use 64-bit
+integers even on non-64-bit platforms.
=item *
-Class::Struct can now define the classes in compile time.
+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 *
-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/)
+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 *
-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).
+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 *
-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.
+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 *
-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.
+If binary compatibility with the 5.005 release is not wanted, Configure
+no longer suggests including the 5.005 modules in @INC.
=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.
+Configure C<-S> can now run non-interactively.
=item *
-The C<open> pragma allows layers other than ":raw" and ":crlf" when
-using PerlIO.
+Configure support for pdp11-style memory models has been removed due
+to obsolescence.
=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.
+configure.gnu now works with options with whitespace in them.
=item *
-The Test module has been significantly enhanced. Its use is
-greatly recommended for module writers.
+installperl now outputs everything to STDERR.
=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.
+$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
+=item *
-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.
+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.
-=head1 Performance Enhancements
+=item *
-=over 4
+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 *
-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.
+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 *
-unshift() should now be noticeably faster.
-
-=back
+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.
-=head1 Utility Changes
+=item *
-=over 4
+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 *
-h2xs now produces template README.
+Building Berkeley DB3 for compatibility modes for DB, NDBM, and ODBM
+has been documented in INSTALL.
=item *
-s2p has been completely rewritten in Perl. (It is in fact a full
-implementation of sed in Perl.)
+If you have CPAN access (either network or a local copy such as a
+CD-ROM) you can during specify extra modules to Configure to build and
+install with Perl using the -Dextras=... option. See INSTALL for
+more details.
=item *
-xsubpp now supports OUT keyword.
+In addition to config.over a new override file, config.arch, is
+available. That is supposed to be used by hints file writers for
+architecture-wide changes (as opposed to config.over which is for
+site-wide changes).
-=back
+=item *
-=head1 New Documentation
+If your file system supports symbolic links you can build Perl outside
+of the source directory by
-=head2 perlclib
+ mkdir /tmp/perl/build/directory
+ cd /tmp/perl/build/directory
+ sh /path/to/perl/source/Configure -Dmksymlinks ...
-Internal replacements for standard C library functions.
-(Interesting only for extension writers and Perl core hackers.)
+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
-=head2 perliol
+ make all test
-Internals of PerlIO with layers.
+and Perl will be built and tested, all in /tmp/perl/build/directory.
-=head2 README.aix
+=item *
-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>.
+For Perl developers several new make targets for profiling
+and debugging have been added, see L<perlhack>.
-=head2 README.bs2000
+=over 8
-Documentation on compiling Perl on the POSIX-BC platform (an EBCDIC
-mainframe environment) has been added.
+=item *
-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>.
+Use of the F<gprof> tool to profile Perl has been documented in
+L<perlhack>. There is a make target called "perl.gprof" for
+generating a gprofiled Perl executable.
-=head2 README.macos
+=item *
-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>.
+If you have GCC 3, there is a make target called "perl.gcov" for
+creating a gcoved Perl executable for coverage analysis. See
+L<perlhack>.
-=head2 README.mpeix
+=item *
-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>.
+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.
-=head2 README.solaris
+=back
-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>.
+=item *
-=head2 README.vos
+Guidelines of how to construct minimal Perl installations have
+been added to INSTALL.
-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>.
+=item *
-=head2 Porting/repository.pod
+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>).
-Documentation on how to use the Perl source repository has been added.
+But note that the Thread.pm interface is now shared by both
+thread models.
-=head1 Installation and Configuration Improvements
+=item *
-=over 4
+The Gconvert macro ($Config{d_Gconvert}) used by perl for stringifying
+floating-point numbers is now more picky about using sprintf %.*g
+rules for the conversion. Some platforms that used to use gcvt may
+now resort to the slower sprintf.
-=item *
+=back
-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.
+=head2 New Or Improved Platforms
-=item *
+For the list of platforms known to support Perl,
+see L<perlport/"Supported Platforms">.
-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.)
+=over 4
=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.
+AIX dynamic loading should be now better supported.
=item *
-Building Berkeley DB3 for compatibility modes for DB, NDBM, and ODBM
-has been documented in INSTALL.
+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 *
-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.
+After a long pause, AmigaOS has been verified to be happy with Perl.
-=back
+=item *
-=head2 New Or Improved Platforms
+AtheOS ( http://www.atheos.cx/ ) is a new platform.
-For the list of platforms known to support Perl,
-see L<perlport/"Supported Platforms">.
+=item *
-=over 4
+BeOS has been reclaimed.
=item *
-AIX dynamic loading should be now better supported.
+DG/UX platform now supports the 5.005-style threads. See L<perldgux>.
=item *
-After a long pause, AmigaOS has been verified to be happy with Perl.
+DYNIX/ptx platform (a.k.a. dynixptx) is supported at or near osvers 4.5.2.
=item *
=item *
-NCR MP-RAS is now supported.
+MacOS X (or Darwin) should now be able to build Perl even on HFS+
+filesystems. (The case-insensitivity confused the Perl build process.)
=item *
-NonStop-UX is now supported.
+NCR MP-RAS is now supported.
=item *
-Amdahl UTS is now supported.
+All the NetBSD specific patches (except for the installation
+specific ones) have been merged back to the main distribution.
=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
+NetWare from Novell is now supported. See L<perlnetware>.
-=head2 Generic Improvements
+=item *
-=over 4
+NonStop-UX is now supported.
=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.
+NEC SUPER-UX is now supported.
=item *
-Some new Configure symbols, useful for extension writers:
+All the OpenBSD specific patches (except for the installation
+specific ones) have been merged back to the main distribution.
-=over 8
+=item *
+
+Perl has been tested with the GNU pth userlevel thread package
+( http://www.gnu.org/software/pth/pth.html ) . All but one thread
+test worked, and that one failure was because of test results arriving
+in unexpected order.
-=item d_cmsghdr
+=item *
-For struct cmsghdr.
+Amdahl UTS UNIX mainframe platform is now supported.
-=item d_fcntl_can_lock
+=item *
-Whether fcntl() can be used for file locking.
+WinCE is now supported. See L<perlce>.
-=item d_fsync
+=item *
-=item d_getitimer
+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.
-=item d_getpagsz
+=back
-For getpagesize(), though you should prefer POSIX::sysconf(_SC_PAGE_SIZE))
+=head1 Selected Bug Fixes
-=item d_msghdr_s
+Numerous memory leaks and uninitialized memory accesses have been
+hunted down. Most importantly anonymous subs used to leak quite
+a bit.
-For struct msghdr.
+=over 4
-=item need_va_copy
+=item *
-Whether one needs to use Perl_va_copy() to copy varargs.
+The autouse pragma didn't work for Multi::Part::Function::Names.
-=item d_readv
+=item *
-=item d_recvmsg
+caller() could cause core dumps in certain situations. Carp was sometimes
+affected by this problem.
-=item d_sendmsg
+=item *
-=item sig_size
+chop(@list) in list context returned the characters chopped in
+reverse order. This has been reversed to be in the right order.
-The number of elements in an array needed to hold all the available signals.
+=item *
-=item d_sockatmark
+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 d_strtoq
+=item *
-=item d_u32align
+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.
-Whether one needs to access character data aligned by U32 sized pointers.
+=item *
-=item d_ualarm
+The order of DESTROYs has been made more predictable.
-=item d_usleep
+=item *
-=back
+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 *
-Removed Configure symbols: the PDP-11 memory model settings: huge,
-large, medium, models.
+Perl 5.6.0 could emit spurious warnings about redefinition of dl_error()
+when statically building extensions into perl. This has been corrected.
=item *
-SOCKS support is now much more robust.
+L<dprofpp> -R didn't work.
=item *
-If your file system supports symbolic links you can build Perl outside
-of the source directory by
+C<*foo{FORMAT}> now works.
+=item *
- mkdir /tmp/perl/build/directory
- cd /tmp/perl/build/directory
- sh /path/to/perl/source/Configure -Dmksymlinks ...
+Infinity is now recognized as a number.
-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
+=item *
-and Perl will be built and tested, all in /tmp/perl/build/directory.
+UNIVERSAL::isa no longer caches methods incorrectly. (This broke
+the Tk extension with 5.6.0.)
-=back
+=item *
-=head1 Selected Bug Fixes
+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.
-Numerous memory leaks and uninitialized memory accesses have been hunted down.
-Most importantly anonymous subs used to leak quite a bit.
+=item *
-=over 4
+Lexicals II: lexicals leaked at file scope into subroutines that
+were declared before the lexicals.
=item *
-chop(@list) in list context returned the characters chopped in
-reverse order. This has been reversed to be in the right order.
+Lexical warnings now propagating correctly between scopes
+and into C<eval "...">.
=item *
-The order of DESTROYs has been made more predictable.
+C<use warnings qw(FATAL all)> did not work as intended. This has been
+corrected.
=item *
-mkdir() now ignores trailing slashes in the directory name,
-as mandated by POSIX.
+warnings::enabled() now reports the state of $^W correctly if the caller
+isn't using lexical warnings.
=item *
-Attributes (like :shared) didn't work with our().
+Line renumbering with eval and C<#line> now works.
=item *
-The PERL5OPT environment variable (for passing command line arguments
-to Perl) didn't work for more than a single group of options.
+Fixed numerous memory leaks, especially in eval "".
=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.
+mkdir() now ignores trailing slashes in the directory name,
+as mandated by POSIX.
=item *
-All but the first argument of the IO syswrite() method are now optional.
+Some versions of glibc have a broken modfl(). This affects builds
+with C<-Duselongdouble>. This version of Perl detects this brokenness
+and has a workaround for it. The glibc release 2.2.2 is known to have
+fixed the modfl() bug.
=item *
-Tie::ARRAY SPLICE method was broken.
+Modulus of unsigned numbers now works (4063328477 % 65535 used to
+return 27406, instead of 27047).
=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
+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.
-=head2 Platform Specific Changes and Fixes
+=item *
-=over 4
+Numeric conversions did not recognize changes in the string value
+properly in certain circumstances.
=item *
-Linux previously had problems related to sockaddrlen when using
-accept(), revcfrom() (in Perl: recv()), getpeername(), and getsockname().
+Attributes (like :shared) didn't work with our().
=item *
-Previously DYNIX/ptx had problems in its Configure probe for non-blocking I/O.
+our() variables will not cause "will not stay shared" warnings.
=item *
-Windows
-
-=over 8
+"our" variables of the same name declared in two sibling blocks
+resulted in bogus warnings about "redeclaration" of the variables.
+The problem has been corrected.
=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++).
+pack "Z" now correctly terminates the string with "\0".
=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.
+Fix password routines which in some shadow password platforms
+(e.g. HP-UX) caused getpwent() to return every other entry.
=item *
-Duping socket handles with open(F, ">&MYSOCK") now works under Windows 9x.
+The PERL5OPT environment variable (for passing command line arguments
+to Perl) didn't work for more than a single group of options.
=item *
-HTML files will be installed in c:\perl\html instead of c:\perl\lib\pod\html
+PERL5OPT with embedded spaces didn't work.
=item *
-The makefiles now provide a single switch to bulk-enable all the features
-enabled in ActiveState ActivePerl (a popular binary distribution).
-
-=back
+printf() no longer resets the numeric locale to "C".
-=back
+=item *
-=head1 New or Changed Diagnostics
+C<qw(a\\b)> now parses correctly as C<'a\\b'>.
-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.
+=item *
-=over 4
+pos() did not return the correct value within s///ge in earlier
+versions. This is now handled correctly.
=item *
-If an attempt to use a (non-blessed) reference as an array index
-is made, a warning is given.
+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 *
-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
+Regular expressions on references and overloaded scalars now work.
-=head1 Changed Internals
+=item *
-=over 4
+Right-hand side magic (GMAGIC) could in many cases such as string
+concatenation be invoked too many times.
=item *
-Some new APIs: ptr_table_clear(), ptr_table_free(), sv_setref_uv().
-For the full list of the available APIs see L<perlapi>.
+scalar() now forces scalar context even when used in void context.
=item *
-dTHR and djSP have been obsoleted; the former removed (because it's
-a no-op) and the latter replaced with dSP.
+SOCKS support is now much more robust.
=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).
+sort() arguments are now compiled in the right wantarray context
+(they were accidentally using the context of the sort() itself).
+The comparison block is now run in scalar context, and the arguments
+to be sorted are always provided list context.
-=back
+=item *
-=head1 New Tests
+Changed the POSIX character class C<[[:space:]]> to include the (very
+rarely used) vertical tab character. Added a new POSIX-ish character
+class C<[[:blank:]]> which stands for horizontal whitespace
+(currently, the space and the tab).
-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.
+=item *
-=head1 Known Problems
+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.
-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.
+=item *
-=head2 AIX vac 5.0.0.0 May Produce Buggy Code For Perl
+Some cases of inconsistent taint propagation (such as within hash
+values) have been fixed.
-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.
+=item *
-=head2 lib/ftmp-security tests warn 'system possibly insecure'
+The RE engine found in Perl 5.6.0 accidentally pessimised certain kinds
+of simple pattern matches. These are now handled better.
-Don't panic. Read INSTALL 'make test' section instead.
+=item *
-=head2 lib/io_multihomed Fails In LP64-Configured HP-UX
+Regular expression debug output (whether through C<use re 'debug'>
+or via C<-Dr>) now looks better.
-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).
+=item *
-=head2 Test lib/posix Subtest 9 Fails In LP64-Configured HP-UX
+Multi-line matches like C<"a\nxb\n" =~ /(?!\A)x/m> were flawed. The
+bug has been fixed.
-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.
+=item *
-=head2 lib/b test 19
+Use of $& could trigger a core dump under some situations. This
+is now avoided.
-The test fails on various platforms (PA64 and IA64 are known), but the
-exact cause is still being investigated.
+=item *
-=head2 Linux With Sfio Fails op/misc Test 48
+The regular expression captured submatches ($1, $2, ...) are now
+more consistently unset if the match fails, instead of leaving false
+data lying around in them.
-No known fix.
+=item *
-=head2 sigaction test 13 in VMS
+readline() on files opened in "slurp" mode could return an extra "" at
+the end in certain situations. This has been corrected.
-The test is known to fail; whether it's because of VMS of because
-of faulty test is not known.
+=item *
-=head2 sprintf tests 129 and 130
+Autovivification of symbolic references of special variables described
+in L<perlvar> (as in C<${$num}>) was accidentally disabled. This works
+again now.
-The op/sprintf tests 129 and 130 are known to fail on some platforms.
-Examples include any platform using sfio, and Compaq/Tandem's NonStop-UX.
-The failing platforms do not comply with the ANSI C Standard, line
-19ff on page 134 of ANSI X3.159 1989 to be exact. (They produce
-something else than "1" and "-1" when formatting 0.6 and -0.6 using
-the printf format "%.0f", most often they produce "0" and "-0".)
+=item *
-=head2 Failure of Thread tests
+Sys::Syslog ignored the C<LOG_AUTH> constant.
-The subtests 19 and 20 of lib/thr5005.t test are known to fail due to
-fundamental problems in the 5.005 threading implementation. These are
-not new failures--Perl 5.005_0x has the same bugs, but didn't have
-these tests. (Note that support for 5.005-style threading remains
-experimental.)
+=item *
-=head2 Localising a Tied Variable Leaks Memory
+All but the first argument of the IO syswrite() method are now optional.
- use Tie::Hash;
- tie my %tie_hash => 'Tie::StdHash';
+=item *
- ...
+$AUTOLOAD, sort(), lock(), and spawning subprocesses
+in multiple threads simultaneously are now thread-safe.
- local($tie_hash{Foo}) = 1; # leaks
+=item *
-Code like the above is known to leak memory every time the local()
-is executed.
+Tie::ARRAY SPLICE method was broken.
-=head2 Self-tying of Arrays and Hashes Is Forbidden
+=item *
-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).
+Allow read-only string on left hand side of non-modifying tr///.
-=head2 Building Extensions Can Fail Because Of Largefiles
+=item *
-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.
+If C<STDERR> is tied, warnings caused by C<warn> and C<die> now
+correctly pass to it.
-=head2 The Compiler Suite Is Still Experimental
+=item *
-The compiler suite is slowly getting better but is nowhere near
-working order yet.
+Several Unicode fixes.
-=head1 Security Vulnerability Closed
+=over 8
-(This change was already made in 5.7.0 but bears repeating here.)
+=item *
-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.
+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.
-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.
+=item *
-See http://www.cpan.org/src/5.0/sperl-2000-08-05/sperl-2000-08-05.txt
-for more information.
+The character tables have been updated to Unicode 3.1.1.
-=head1 Incompatible Changes
+=item *
-=head2 64-bit platforms and malloc
+Comparing with utf8 data does not magically upgrade non-utf8 data
+into utf8. (This was a problem for example if you were mixing data
+from I/O and Unicode data: your output might have got magically encoded
+as UTF-8.)
-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.
+=item *
-=head2 AIX Dynaloading
+Generating illegal Unicode code points like U+FFFE, or the UTF-16
+surrogates, now also generates an optional warning.
-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.
+=item *
-=head2 Socket Extension Dynamic in VMS
+C<IsAlnum>, C<IsAlpha>, and C<IsWord> now match titlecase.
-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.
+=item *
-=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>.
+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.
-=head2 Deprecations
+=item *
-The current user-visible implementation of pseudo-hashes (the weird
-use of the first array element) is deprecated starting from Perl 5.8.0
-and will be removed in Perl 5.10.0, and the feature will be
-implemented differently. Not only is the current interface rather
-ugly, but the current implementation slows down normal array and hash
-use quite noticeably. The C<fields> pragma interface will remain
-available.
+The C<tr///> operator now works. Note that the C<tr///CU>
+functionality has been removed (but see pack('U0', ...)).
-The syntaxes C<@a->[...]> and C<@h->{...}> have now been deprecated.
+=item *
-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.
+C<eval "v200"> now works.
-The C<package;> syntax (C<package> without an argument has been
-deprecated. Its semantics were never that clear and its
-implementation even less so. If you have used that feature to
-disallow all but fully qualified variables, C<use strict;> instead.
+=item *
-The chdir(undef) and chdir('') behaviors to match chdir() has been
-deprecated. In future versions, chdir(undef) and chdir('') will
-simply fail.
+Perl 5.6.0 parsed m/\x{ab}/ incorrectly, leading to spurious warnings.
+This has been corrected.
-=head1 Core Enhancements
+=item *
-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.
+Zero entries were missing from the Unicode classes like C<IsDigit>.
-=over 4
+=back
=item *
-The rules for allowing underscores (underbars) in numeric constants
-have been relaxed and simplified: now you can have an underscore
-B<between digits>.
+Large unsigned numbers (those above 2**31) could sometimes lose their
+unsignedness, causing bogus results in arithmetic operations.
-=item *
-
-GMAGIC (right-hand side magic) could in many cases such as string
-concatenation be invoked too many times.
+=back
-=item *
+=head2 Platform Specific Changes and Fixes
-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.
+=over 4
=item *
-Lexicals II: lexicals leaked at file scope into subroutines that
-were declared before the lexicals.
-
-=item *
+BSDI 4.*
-Lvalue subroutines can now return C<undef> in list context.
+Perl now works on post-4.0 BSD/OSes.
=item *
-The C<op_clear> and C<op_null> are now exported.
+All BSDs
+
+Setting C<$0> now works (as much as possible; see L<perlvar> for details).
=item *
-A new special regular expression variable has been introduced:
-C<$^N>, which contains the most-recently closed group (submatch).
+Cygwin
+
+Numerous updates; currently synchronised with Cygwin 1.3.10.
=item *
-L<utime> now supports C<utime undef, undef, @files> to change the
-file timestamps to the current time.
+Previously DYNIX/ptx had problems in its Configure probe for non-blocking I/O.
=item *
-The Perl parser has been stress tested using both random input and
-Markov chain input.
+EPOC
+
+EPOC update after Perl 5.6.0. See README.epoc.
=item *
-C<eval "v200"> now works.
+FreeBSD 3.*
+
+Perl now works on post-3.0 FreeBSDs.
=item *
-VMS now works under PerlIO.
+HP-UX
+
+README.hpux updated; C<Configure -Duse64bitall> now works.
=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>.
+IRIX
-=back
+Numerous compilation flag and hint enhancements; accidental mixing
+of 32-bit and 64-bit libraries (a doomed attempt) made much harder.
-=head1 Modules and Pragmata
+=item *
-=head2 New Modules and Distributions
+Linux
-=over 4
+=over 8
=item *
-L<Attribute::Handlers> - Simpler definition of attribute handlers
+Long doubles should now work (see INSTALL).
=item *
-L<ExtUtils::Constant> - generate XS code to import C header constants
+Linux previously had problems related to sockaddrlen when using
+accept(), revcfrom() (in Perl: recv()), getpeername(), and getsockname().
+
+=back
=item *
-L<I18N::Langinfo> - query locale information
+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 *
-L<I18N::LangTags> - functions for dealing with RFC3066-style language tags
+MPE/iX
+
+MPE/iX update after Perl 5.6.0. See README.mpeix.
=item *
-L<libnet> - a collection of perl5 modules related to network programming
+NetBSD/sparc
-Perl installation leaves libnet unconfigured, use F<libnetcfg> to configure.
+Perl now works on NetBSD/sparc.
=item *
-L<List::Util> - selection of general-utility list subroutines
+OS/2
+
+Now works with usethreads (see INSTALL).
=item *
-L<Locale::Maketext> - framework for localization
+Solaris
+
+64-bitness using the Sun Workshop compiler now works.
=item *
-L<Memoize> - Make your functions faster by trading space for time
+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 *
-L<NEXT> - pseudo-class for method redispatch
+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 *
-L<Scalar::Util> - selection of general-utility scalar subroutines
+VMS
-=item *
+chdir() now works better despite a CRT bug; now works with MULTIPLICITY
+(see INSTALL); now works with Perl's malloc.
-L<Test::More> - yet another framework for writing test scripts
+The tainting of C<%ENV> elements via C<keys> or C<values> was previously
+unimplemented. It now works as documented.
-=item *
+The C<waitpid> emulation has been improved. The worst bug (now fixed)
+was that a pid of -1 would cause a wildcard search of all processes on
+the system. The most significant enhancement is that we can now
+usually get the completion status of a terminated process.
-L<Test::Simple> - Basic utilities for writing tests
+POSIX-style signals are now emulated much better on VMS versions prior
+to 7.0.
-=item *
+The C<system> function and backticks operator have improved
+functionality and better error handling.
-L<Time::HiRes> - high resolution ualarm, usleep, and gettimeofday
+File access tests now use current process privileges rather than the
+user's default privileges, which could sometimes result in a mismatch
+between reported access and actual access.
=item *
-L<Time::Piece> - Object Oriented time objects
+Windows
-(Previously known as L<Time::Object>.)
+=over 8
=item *
-L<Time::Seconds> - a simple API to convert seconds to other date values
+accept() no longer leaks memory.
=item *
-L<UnicodeCD> - Unicode Character Database
-
-=back
-
-=head2 Updated And Improved Modules and Pragmata
-
-=over 4
+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 *
-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.
+Better chdir() return value for a non-existent directory.
=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.
+Duping socket handles with open(F, ">&MYSOCK") now works under Windows 9x.
=item *
-L<Cwd> extension is now (even) faster.
+New %ENV entries now propagate to subprocesses.
=item *
-L<DB_File> extension has been updated to version 1.77.
+Current directory entries in %ENV are now correctly propagated to child
+processes.
=item *
-L<Fcntl>, L<Socket>, and L<Sys::Syslog> have been rewritten to use the
-new-style constant dispatch section (see L<ExtUtils::Constant>).
+$ENV{LIB} now used to search for libs under Visual C.
=item *
-L<File::Find> is now (again) reentrant. It also has been made
-more portable.
+fork() emulation has been improved in various ways, but still continues
+to be experimental. See L<perlfork> for known bugs and caveats.
=item *
-L<File::Glob> now supports C<GLOB_LIMIT> constant to limit the
-size of the returned list of filenames.
+A failed (pseudo)fork now returns undef and sets errno to EAGAIN.
=item *
-L<IO::Socket::INET> now supports C<LocalPort> of zero (usually meaning
-that the operating system will make one up.)
+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 *
-The L<vars> pragma now supports declaring fully qualified variables.
-(Something that C<our()> does not and will not support.)
-
-=back
+HTML files will be installed in c:\perl\html instead of c:\perl\lib\pod\html
-=head1 Utility Changes
+=item *
-=over 4
+The makefiles now provide a single switch to bulk-enable all the features
+enabled in ActiveState ActivePerl (a popular Win32 binary distribution).
=item *
-The F<emacs/e2ctags.pl> is now much faster.
+Allow REG_EXPAND_SZ keys in the registry.
=item *
-L<h2ph> now supports C trigraphs.
+Can now send() from all threads, not just the first one.
=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.
+Fake signal handling reenabled, bugs and all.
=item *
-L<libnetcfg> has been added to configure the libnet.
+%SIG has been enabled under USE_ITHREADS, but its use is completely
+unsupported under all configurations.
=item *
-The F<Pod::Html> (and thusly L<pod2html>) now allows specifying
-a cache directory.
-
-=back
+Less stack reserved per thread so that more threads can run
+concurrently. (Still 16M per thread.)
-=head1 New Documentation
+=item *
-=over 4
+C<File::Spec->tmpdir()> now prefers C:/temp over /tmp
+(works better when perl is running as service).
=item *
-L<Locale::Maketext::TPJ13> is an article about software localization,
-originally published in The Perl Journal #13, republished here with
-kind permission.
+Better UNC path handling under ithreads.
=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>.
+wait(), waitpid() and backticks now return the correct exit status under
+Windows 9x.
=item *
-The F<Todo> and F<Todo-5.6> files have been merged into L<perltodo>.
+winsock handle leak fixed.
=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.
+The Perl parser has been stress tested using both random input and
+Markov chain input and the few found crashes and lockups have been
+fixed.
=back
-=head1 Installation and Configuration Improvements
+=back
-=head2 New Or Improved Platforms
+=head1 New or Changed Diagnostics
=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>.
+The lexical warnings category "deprecated" is no longer a sub-category
+of the "syntax" category. It is now a top-level category in its own
+right.
=item *
-AtheOS (http://www.atheos.cx/) is a new platform.
+All regular expression compilation error messages are now hopefully
+easier to understand both because the error message now comes before
+the failed regex and because the point of failure is now clearly
+marked by a C<E<lt>-- HERE> marker.
=item *
-DG/UX platform now supports the 5.005-style threads. See L<perldgux>.
+The various "opened only for", "on closed", "never opened" warnings
+drop the C<main::> prefix for filehandles in the C<main> package,
+for example C<STDIN> instead of C<main::STDIN>.
=item *
-DYNIX/ptx platform (a.k.a. dynixptx) is supported at or near osvers 4.5.2.
+The "Unrecognized escape" warning has been extended to include C<\8>,
+C<\9>, and C<\_>. There is no need to escape any of the C<\w> characters.
=item *
-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>.
+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.
=item *
-MacOS X (or Darwin) should now be able to build Perl even on HFS+
-filesystems. (The case-insensitivity confused the Perl build process.)
+The debugger (perl5db.pl) has been modified to present a more
+consistent commands interface, via (CommandSet=580). perl5db.t was
+also added to test the changes, and as a placeholder for further tests.
+
+See L<perldebug>.
=item *
-NetWare from Novell is now supported. See L<perlnetware>.
+The debugger has a new C<dumpDepth> option to control the maximum
+depth to which nested structures are dumped. The C<x> command has
+been extended so that C<x N EXPR> dumps out the value of I<EXPR> to a
+depth of at most I<N> levels.
=item *
-The Amdahl UTS UNIX mainframe platform is now supported.
+The debugger can now show lexical variables if you have the CPAN
+module PadWalker installed.
-=back
+=item *
-=head2 Generic Improvements
+If an attempt to use a (non-blessed) reference as an array index
+is made, a warning is given.
-=over 4
+=item *
+
+C<push @a;> and C<unshift @a;> (with no values to push or unshift)
+now give a warning. This may be a problem for generated and evaled
+code.
=item *
-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>.
+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 *
-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.
+Certain regex modifiers such as C<(?o)> make sense only if applied to
+the entire regex. You will get an optional warning if you try to do
+otherwise.
=item *
-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>).
+Using arrays or hashes as references (e.g. C<< %foo->{bar} >>
+has been deprecated for a while. Now you will get an optional warning.
=item *
-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>.
+Using C<sort> in scalar context now issues an optional warning.
+This didn't do anything useful, as the sort was not performed.
=back
-=head1 Selected Bug Fixes
+=head1 Changed Internals
-=over 5
+=over 4
=item *
-The autouse pragma didn't work for Multi::Part::Function::Names.
+perlapi.pod (a companion to perlguts) now attempts to document the
+internal API.
=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.
+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 *
-L<dprofpp> -R didn't work.
+Added rsignal(), whichsig(), do_join(), op_clear, op_null,
+ptr_table_clear(), ptr_table_free(), sv_setref_uv(), and several UTF-8
+interfaces to the publicised API. For the full list of the available
+APIs see L<perlapi>.
=item *
-PERL5OPT with embedded spaces didn't work.
+Made possible to propagate customised exceptions via croak()ing.
=item *
-L<Sys::Syslog> ignored the C<LOG_AUTH> constant.
-
-=back
-
-=head2 Platform Specific Changes and Fixes
-
-=over 4
+Now xsubs can have attributes just like subs. (Well, at least the
+built-in attributes.)
=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
+dTHR and djSP have been obsoleted; the former removed (because it's
+a no-op) and the latter replaced with dSP.
-=head1 New or Changed Diagnostics
+=item *
-=over 4
+PERL_OBJECT has been completely removed.
=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.
+The MAGIC constants (e.g. C<'P'>) have been macrofied
+(e.g. C<PERL_MAGIC_TIED>) for better source code readability
+and maintainability.
=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.
+The regex compiler now maintains a structure that identifies nodes in
+the compiled bytecode with the corresponding syntactic features of the
+original regex expression. The information is attached to the new
+C<offsets> member of the C<struct regexp>. See L<perldebguts> for more
+complete information.
=item *
-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.
+The C code has been made much more C<gcc -Wall> clean. Some warning
+messages still remain in some platforms, so if you are compiling with
+gcc you may see some warnings about dubious practices. The warnings
+are being worked on.
=item *
-Using arrays or hashes as references (e.g. C<%foo->{bar}> has been
-deprecated for a while. Now you will get an optional warning.
+F<perly.c>, F<sv.c>, and F<sv.h> have now been extensively commented.
-=back
+=item *
-=head1 Source Code Enhancements
+Documentation on how to use the Perl source repository has been added
+to F<Porting/repository.pod>.
-=head2 MAGIC constants
+=item *
-The MAGIC constants (e.g. C<'P'>) have been macrofied
-(e.g. C<PERL_MAGIC_TIED>) for better source code readability
-and maintainability.
+There are now several profiling make targets.
-=head2 Better commented code
+=back
-F<perly.c>, F<sv.c>, and F<sv.h> have now been extensively commented.
+=head1 Security Vulnerability Closed
-=head2 Regex pre-/post-compilation items matched up
+(This change was already made in 5.7.0 but bears repeating here.)
-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.
+A potential security vulnerability in the optional suidperl component
+of Perl was identified in August 2000. suidperl is neither built nor
+installed by default. As of November 2001 the only known vulnerable
+platform is Linux, most likely all Linux distributions. CERT and
+various vendors and distributors have been alerted about the vulnerability.
+See http://www.cpan.org/src/5.0/sperl-2000-08-05/sperl-2000-08-05.txt
+for more information.
-=head2 gcc -Wall
+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 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.
+The exploit attempt reporting feature has been completely removed from
+Perl 5.8.0 (and the maintenance release 5.6.1, and it was removed also
+from all the Perl 5.7 releases), so that particular vulnerability
+isn't there anymore. However, further security vulnerabilities are,
+unfortunately, always possible. The suidperl functionality is most
+probably going to be removed in Perl 5.10. In any case, suidperl
+should only be used by security experts who know exactly what they are
+doing and why they are using suidperl instead of some other solution
+such as sudo ( see http://www.courtesan.com/sudo/ ).
=head1 New Tests
-Several new tests have been added, especially for the F<lib> subsection.
+Several new tests have been added, especially for the F<lib>
+subsection. There are now about 56 000 individual tests (spread over
+about 620 test scripts), in the regression suite (5.6.1 has about
+11700 tests, in 258 test scripts) Many of the new tests are introduced
+by the new modules, but still in general Perl is now more thoroughly
+tested.
+
+Because of the large number of tests, running the regression suite
+will take considerably longer time than it used to: expect the suite
+to take up to 4-5 times longer to run than in perl 5.6. In a really
+fast machine you can hope to finish the suite in about 6-8 minutes
+(wallclock time).
The tests are now reported in a different order than in earlier Perls.
(This happens because the test scripts from under t/lib have been moved
=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
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.
+"lslpp -L|grep vac.C" will tell you the vac version. See README.aix.
+
+=item *
+
+If building threaded Perl, you may get compilation warning from pp_sys.c:
+
+ "pp_sys.c", line 4651.39: 1506-280 (W) Function argument assignment between types "unsigned char*" and "const void*" is not allowed.
+
+This is harmless; it is caused by the getnetbyaddr() and getnetbyaddr_r()
+having slightly different types for their first argument.
=back
=head2 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
+works, but for example C<bin:perl -v> doesn't. The exact reason isn't
known but the current suspect is the F<ixemul> library.
-=head2 lib/ftmp-security tests warn 'system possibly insecure'
+=head2 FreeBSD Failing locale Test 117 For ISO8859-15 Locales
-Don't panic. Read INSTALL 'make test' section instead.
+The ISO8859-15 locales may fail the locale test 117 in FreeBSD.
+This is caused by the characters \xFF (y with diaeresis) and \xBE
+(Y with diaeresis) not behaving correctly when being matched
+case-insensitively.
-=head2 Cygwin intermittent failures of lib/Memoize/t/expire_file 11 and 12
+=head2 mod_perl 1.26 Doesn't Build With Threaded Perl
-The subtests 11 and 12 sometimes fail and sometimes work.
+Use mod_perl 1.27 or higher.
-=head2 HP-UX lib/io_multihomed Fails When LP64-Configured
+=head2 lib/ftmp-security tests warn 'system possibly insecure'
-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).
+Don't panic. Read INSTALL 'make test' section instead.
=head2 HP-UX lib/posix Subtest 9 Fails When LP64-Configured
No known fix.
-=head2 OS/390
+=head2 Mac OS X
-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.
+Please remember to set your environment variable LC_ALL to "C"
+(setenv LC_ALL C) before running "make test" to avoid a lot of
+warnings about the broken locales of Mac OS X.
+
+The following tests are known to fail:
+
+ Failed Test Stat Wstat Total Fail Failed List of Failed
+ -------------------------------------------------------------------------
+ ../ext/DB_File/t/db-btree.t 0 11 ?? ?? % ??
+ ../ext/DB_File/t/db-recno.t 149 3 2.01% 61 63 65
+ ../ext/POSIX/t/posix.t 31 1 3.23% 10
+
+If you are building on a UFS partition, you will also probably see
+t/op/stat.t subtest #9 fail. This is caused by Darwin's UFS not
+supporting inode change time.
+
+=head2 op/sprintf tests 91, 129, and 130
- 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.
+The op/sprintf tests 91, 129, and 130 are known to fail on some platforms.
Examples include any platform using sfio, and Compaq/Tandem's NonStop-UX.
-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
+The test 91 is known to fail at QNX6 (nto), because C<sprintf '%e',0>
+incorrectly produces C<0.000000e+0> instead of C<0.000000e+00>.
-B<Note that support for 5.005-style threading remains experimental.>
+For the tests 129 and 130 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 (5.005-style) tests
+
+B<Note that support for 5.005-style threading remains experimental
+and practically unsupported.>
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
+ ../ext/List/Util/t/first.t 255 65280 7 4 57.14% 2 5-7
+ ../lib/English.t 2 512 54 2 3.70% 2-3
+ ../lib/Filter/Simple/t/data.t 6 3 50.00% 1-3
+ ../lib/Filter/Simple/t/filter_onl 9 3 33.33% 1-2 5
+ ../lib/autouse.t 10 1 10.00% 4
+ op/flip.t 15 1 6.67% 15
+
+These failures are unlikely to get fixed as the 5.005-style
+threads are considered fundamentally broken.
=head2 UNICOS
+ Failed Test Stat Wstat Total Fail Failed List of Failed
+ -------------------------------------------------------------------------
+ ../ext/Socket/socketpair.t 1 256 45 1 2.22% 12
+ ../lib/Math/Trig.t 26 1 3.85% 25
+ ../lib/warnings.t 460 1 0.22% 425
+ io/fs.t 36 1 2.78% 31
+ op/numconvert.t 1440 13 0.90% 208 509-510
+ 657-658 665-666 829-830 989-990 1149-1150
+
+=head2 UNICOS and UNICOS/mk
+
+The io/fs test #31 is failing because in UNICOS and UNICOS/mk the Perl
+truncate() cannot be used to grow the size of filehandles, only to
+reduce the size. The workaround is to truncate files instead of
+filehandles.
+
+=head2 UNICOS/mk
+
=over 4
=item *
-ext/POSIX/sigaction subtests 6 and 13 may fail.
+During Configure the test
-=item *
+ Guessing which symbols your C compiler and preprocessor define...
-lib/ExtUtils may spuriously claim that subtest 28 failed,
-which is interesting since the test only has 27 tests.
+will probably fail with error messages like
-=item *
+ CC-20 cc: ERROR File = try.c, Line = 3
+ The identifier "bad" is undefined.
+
+ bad switch yylook 79bad switch yylook 79bad switch yylook 79bad switch yylook 79#ifdef A29K
+ ^
-Numerous numerical test failures
+ CC-65 cc: ERROR File = try.c, Line = 3
+ A semicolon is expected at this point.
- op/numconvert 209,210,217,218
- op/override 7
- ext/Time/HiRes/HiRes 9
- lib/Math/BigInt/t/bigintpm 1145
- lib/Math/Trig 25
+This is caused by a bug in awk utility of UNICOS/mk. You can ignore
+the error, but it does cause a slight problem: you cannot fully
+benefit from the h2ph utility (see L<h2ph>) that can be used to
+convert C headers to Perl libraries, mainly used to be able to access
+from Perl the constants defined using C preprocessor, cpp. Because of
+the above error parts of the converted headers will be invisible.
+Luckily, these days the need for h2ph is rare.
+
+=item *
-These tests fail because of yet unresolved floating point inaccuracies.
+If building Perl with the interpreter threads (ithreads), the
+getgrent(), getgrnam(), and getgrgid() functions cannot return the
+list of the group members due to a bug in the multithreaded support of
+UNICOS/mk. What this means that in list context the functions will
+return only three values, not four.
=back
=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.
+There should be no reported test failures with a default configuration,
+though there are a number of tests marked TODO that point to areas
+needing further debugging and/or porting work.
=head2 Win32
In multi-CPU boxes there are some problems with the I/O buffering:
-some output may appear twice.
+some output may appear twice. The following Win32 failures are known
+as of 5.7.3:
+
+ Failed Test Stat Wstat Total Fail Failed List of Failed
+ -------------------------------------------------------------------------
+ ..\ext/threads/t/end.t 6 4 66.67% 3-6
=head2 Localising a Tied Variable Leaks Memory
Code like the above is known to leak memory every time the local()
is executed.
+=head2 z/OS (OS/390)
+
+z/OS 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/Data/Dumper/t/dumper.t 321 2 0.62% 311 314
+ ../ext/IO/lib/IO/t/io_unix.t 5 4 80.00% 2-5
+ ../lib/utf8.t 94 13 13.83% 27 30-31 43 46 73
+ 76 79 82 85 88 91
+ 94
+ ../lib/Benchmark.t 1 256 159 1 0.63% 75
+ ../lib/ExtUtils/t/Constant.t 27 19 70.37% 5-23
+ ../lib/ExtUtils/t/Embed.t 9 9 100.00% 1-9
+ op/pat.t 864 9 1.04% 242-243 665 776
+ 785 832-834 845
+ op/sprintf.t 224 3 1.34% 98 100 136
+ op/tr.t 97 5 5.15% 63 71-74
+ uni/fold.t 767 8 1.04% 25-26 62 169 196
+ 648 697-698
+ 60 tests and 384 subtests skipped.
+
+=head2 Localising Tied Arrays and Hashes Is Broken
+
+ local %tied_array;
+
+doesn't work as one would expect: the old value is restored
+incorrectly.
+
=head2 Self-tying of Arrays and Hashes Is Forbidden
Self-tying of arrays and hashes is broken in rather deep and
frustrated at the mysterious results (core dumps, most often) it is
for now forbidden (you will get a fatal error even from an attempt).
-=head2 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
all binaries with different ideas about file offsets, all this is
platform-dependent.
+=head2 Unicode Support on EBCDIC Still Spotty
+
+Though mostly working, Unicode support still has problem spots on
+EBCDIC platforms. One such known spot are the C<\p{}> and C<\P{}>
+regular expression constructs for code points less than 256: the
+pP are testing for Unicode code points, not knowing about EBCDIC.
+
=head2 The Compiler Suite Is Still Experimental
-The compiler suite is slowly getting better but is nowhere near
-working order yet.
+The compiler suite is slowly getting better but it continues to be
+highly experimental. Use in production environments is discouraged.
-=head2 The Long Double Support is Still Experimental
+=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
operations are more likely to be executed by less optimised
libraries).
+=head2 Seen In Perl 5.7 But Gone Now
+
+C<Time::Piece> (previously known as C<Time::Object>) was removed
+because it was felt that it didn't have enough value in it to be a
+core module. It is still a useful module, though, and is available
+from the CPAN.
+
=head1 Reporting Bugs
If you find what you think is a bug, you might check the articles
recently posted to the comp.lang.perl.misc newsgroup and the perl
-bug database at http://bugs.perl.org. There may also be
-information at http://www.perl.com/perl/, the Perl Home Page.
+bug database at http://bugs.perl.org/ There may also be
+information at http://www.perl.com/ , the Perl Home Page.
If you believe you have an unreported bug, please run the B<perlbug>
program included with your release. Be sure to trim your bug down
projects / p5sagit/p5-mst-13.2.git / blobdiff