=head1 NAME
-perldelta - what's new for perl v5.6 (as of v5.005_58)
+perldelta - what's new for perl v5.7.0
=head1 DESCRIPTION
-This is an unsupported alpha release, meant for intrepid Perl developers
-only. The included sources may not even build correctly on some platforms.
-Subscribing to perl5-porters is the best way to monitor and contribute
-to the progress of development releases (see www.perl.org for info).
-
-This document describes differences between the 5.005 release and this one.
+This document describes differences between the 5.6.0 release and
+the 5.7.0 release.
+
+=head1 Security Vulnerability Closed
+
+A potential security vulnerability in the optional suidperl component
+of Perl has been identified. suidperl is neither built nor installed
+by default. As of September the 2nd, 2000, the only known vulnerable
+platform is Linux, most likely all Linux distributions. CERT and
+various vendors have been alerted about the vulnerability.
+
+The problem was caused by Perl trying to report a suspected security
+exploit attempt using an external program, /bin/mail. On Linux
+platforms the /bin/mail program had an undocumented feature which
+when combined with suidperl gave access to a root shell, resulting in
+a serious compromise instead of reporting the exploit attempt. If you
+don't have /bin/mail, or if you have 'safe setuid scripts', or if
+suidperl is not installed, you are safe.
+
+The exploit attempt reporting feature has been completely removed from
+the Perl 5.7.0 release, so that particular vulnerability isn't there
+anymore. However, further security vulnerabilities are,
+unfortunately, always possible. The suidperl code is being reviewed
+and if deemed too risky to continue to be supported, it may be
+completely removed from future releases. In any case, suidperl should
+only be used by security experts who know exactly what they are doing
+and why they are using suidperl instead of some other solution such as
+sudo (see http://www.courtesan.com/sudo/).
=head1 Incompatible Changes
-=head2 Perl Source Incompatibilities
+=over 4
-TODO
+=item *
-=head2 C Source Incompatibilities
+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>.
-=over 4
+=item *
-=item C<PERL_POLLUTE>
+The semantics of bless(REF, REF) were unclear and until someone proves
+it to make some sense, it is forbidden.
-Release 5.005 grandfathered old global symbol names by providing preprocessor
-macros for extension source compatibility. As of release 5.6, these
-preprocessor definitions are not available by default. You need to explicitly
-compile perl with C<-DPERL_POLLUTE> to get these definitions. For
-extensions still using the old symbols, this option can be
-specified via MakeMaker:
+=item *
- perl Makefile.PL POLLUTE=1
+A reference to a reference now stringify as "REF(0x81485ec)" instead
+of "SCALAR(0x81485ec)" in order to be more consistent with the return
+value of ref().
-=item C<PERL_IMPLICIT_CONTEXT>
+=item *
-This new build option provides a set of macros for all API functions
-such that an implicit interpreter/thread context argument is passed to
-every API function. As a result of this, something like C<sv_setsv(foo,bar)>
-amounts to a macro invocation that actually translates to something like
-C<Perl_sv_setsv(my_perl,foo,bar)>. While this is generally expected
-to not have any significant source compatibility issues, the difference
-between a macro and a real function call will need to be considered.
+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.
-This means that there B<is> a source compatibility issue as a result of
-this if your extensions attempt to use pointers to any of the Perl API
-functions.
+=item *
-Note that the above issue is not relevant to the default build of
-Perl, whose interfaces continue to match those of prior versions
-(but subject to the other options described here).
+The obsolete chat2 library that should never have been allowed
+to escape the laboratory has been decommissioned.
-For testing purposes, the 5.005_58 release automatically enables
-PERL_IMPLICIT_CONTEXT whenever Perl is built with -Dusethreads or
--Dusemultiplicity.
+=item *
-See L<perlguts/"The Perl API"> for detailed information on the
-ramifications of building Perl using this option.
+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 C<PERL_POLLUTE_MALLOC>
+=item *
+
+lstat(FILEHANDLE) now gives a warning because the operation makes no sense.
+In future releases this may become a fatal error.
-Enabling Perl's malloc in release 5.005 and earlier caused
-the namespace of system versions of the malloc family of functions to
-be usurped by the Perl versions, since by default they used the
-same names.
+=item *
-Besides causing problems on platforms that do not allow these functions to
-be cleanly replaced, this also meant that the system versions could not
-be called in programs that used Perl's malloc. Previous versions of Perl
-have allowed this behaviour to be suppressed with the HIDEMYMALLOC and
-EMBEDMYMALLOC preprocessor definitions.
+The long deprecated uppercase aliases for the string comparison
+operators (EQ, NE, LT, LE, GE, GT) have now been removed.
-As of release 5.6, Perl's malloc family of functions have default names
-distinct from the system versions. You need to explicitly compile perl with
-C<-DPERL_POLLUTE_MALLOC> to get the older behaviour. HIDEMYMALLOC
-and EMBEDMYMALLOC have no effect, since the behaviour they enabled is now
-the default.
+=item *
-Note that these functions do B<not> constitute Perl's memory allocation API.
-See L<perlguts/"Memory Allocation"> for further information about that.
+The regular expression captured submatches ($1, $2, ...) are now
+more consistently unset if the match fails, instead of leaving false
+data lying around in them.
-=item C<PL_na> and C<dTHR> Issues
+=item *
-The C<PL_na> global is now thread local, so a C<dTHR> declaration is needed
-in the scope in which the global appears. XSUBs should handle this automatically,
-but if you have used C<PL_na> in support functions, you either need to
-change the C<PL_na> to a local variable (which is recommended), or put in
-a C<dTHR>.
+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
-=head2 Compatible C Source API Changes
+=head1 Core Enhancements
+
+=over 4
+
+=item *
-=over
+C<perl -d:Module=arg,arg,arg> now works (previously one couldn't pass
+in multiple arguments.)
-=item C<PATCHLEVEL> is now C<PERL_VERSION>
+=item *
-The cpp macros C<PERL_REVISION>, C<PERL_VERSION>, and C<PERL_SUBVERSION>
-are now available by default from perl.h, and reflect the base revision,
-patchlevel, and subversion respectively. C<PERL_REVISION> had no
-prior equivalent, while C<PERL_VERSION> and C<PERL_SUBVERSION> were
-previously available as C<PATCHLEVEL> and C<SUBVERSION>.
+my __PACKAGE__ now works.
-The new names cause less pollution of the B<cpp> namespace and reflect what
-the numbers have come to stand for in common practice. For compatibility,
-the old names are still supported when F<patchlevel.h> is explicitly
-included (as required before), so there is no source incompatibility
-from the change.
+=item *
-=back
+C<no Module;> now works even if there is no "sub unimport" in the Module.
-=head2 Binary Incompatibilities
+=item *
-The default build of this release is binary compatible with the 5.005
-release or its maintenance versions.
+The numerical comparison operators return C<undef> if either operand
+is a NaN. Previously the behaviour was unspecified.
-The usethreads or usemultiplicity builds are B<not> binary compatible
-with the corresponding builds in 5.005.
+=item *
-=head1 Core Changes
+C<pack('U0a*', ...)> can now be used to force a string to UTF8.
-=head2 Unicode and UTF-8 support
+=item *
-Perl can optionally use UTF-8 as its internal representation for character
-strings. The C<use utf8> pragma enables this support in the current lexical
-scope. See L<utf8> for more information.
+prototype(\&) is now available.
-=head2 Lexically scoped warning categories
+=item *
-You can now control the granularity of warnings emitted by perl at a finer
-level using the C<use warning> pragma. See L<warning> and L<perllexwarn>
-for details.
+There is now an UNTIE method.
-=head2 Binary numbers supported
+=back
-Binary numbers are now supported as literals, in s?printf formats, and
-C<oct()>:
+=head1 Modules and Pragmata
+
+=head2 New Modules
+
+=over 4
- $answer = 0b101010;
- printf "The answer is: %b\n", oct("0b101010");
+=item *
+
+File::Temp allows one to create temporary files and directories in an
+easy, portable, and secure way.
-=head2 syswrite() ease-of-use
+=item *
-The length argument of C<syswrite()> is now optional.
+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.
-=head2 64-bit support
+=back
-All platforms that have 64-bit integers either (a) natively as longs
-or ints (b) via special compiler flags (c) using long long are able to
-use "quads" (64-integers) as follows:
+=head2 Updated And Improved Modules and Pragmata
=over 4
-=item constants in the code
+=item *
-=item arguments to oct() and hex()
+The following independently supported modules have been updated to
+newer versions from CPAN: CGI, CPAN, DB_File, File::Spec, Getopt::Long,
+the podlators bundle, Pod::LaTeX, Pod::Parser, Term::ANSIColor, Test.
-=item arguments to print(), printf() and sprintf()
+=item *
-=item pack() and unpack() "q" format
+Bug fixes and minor enhancements have been applied to B::Deparse,
+Data::Dumper, IO::Poll, IO::Socket::INET, Math::BigFloat,
+Math::Complex, Math::Trig, Net::protoent, the re pragma, SelfLoader,
+Sys::SysLog, Test::Harness, Text::Wrap, UNIVERSAL, and the warnings
+pragma.
-=item in basic arithmetics
+=item *
-=back
+The attributes::reftype() now works on tied arguments.
-Note that unless you have the case (a) you will have to configure
-and compile Perl using the -Duse64bits Configure flag.
+=item *
-Unfortunately, bit operations (&, <<, ...) and vec() do not work,
-they are limited to 32 bits.
+AutoLoader can now be disabled with C<no AutoLoader;>,
-Last but not least: note that due to Perl's habit of always using
-floating point numbers the quads are still not true integers. When
-quads overflow their limits (18446744073709551615 unsigned,
--9223372036854775808...9223372036854775807 signed), they are silently
-promoted to floating point numbers, after which they will
-start losing precision (their lower digits).
+=item *
-=head2 Large file support
+The English module can now be used without the infamous performance
+hit by saying
-If you have filesystems that support "large files" (files larger than
-2 gigabytes), you may now also be able to create and access them from Perl.
+ use English '-no_performance_hit';
-Note that in addition to requiring a proper file system to do this you
-may also need to adjust your per-process (or even your per-system)
-maximum filesize limits before running Perl scripts that try to handle
-large files, especially if you intend to write such files.
+(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<@+>.
-Adjusting your file system/system limits is outside the scope of Perl.
-For process limits, you may try to increase the limits using your
-shell's limit/ulimit command before running Perl. The BSD::Resource
-extension (not included with the standard Perl distribution) may also
-be of use.
-
-(Large file support is also related to 64-bit support, for obvious reasons)
-
-=head2 Better syntax checks on parenthesized unary operators
+=item *
-Expressions such as:
+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.
- print defined(&foo,&bar,&baz);
- print uc("foo","bar","baz");
- undef($foo,&bar);
+=item *
-used to be accidentally allowed in earlier versions, and produced
-unpredictable behaviour. Some produced ancillary warnings
-when used in this way; others silently did the wrong thing.
+File::Glob::glob() renamed to File::Glob::bsd_glob() to avoid
+prototype mismatch with CORE::glob().
-The parenthesized forms of most unary operators that expect a single
-argument now ensure that they are not called with more than one
-argument, making the cases shown above syntax errors. The usual
-behaviour of:
+=item *
- print defined &foo, &bar, &baz;
- print uc "foo", "bar", "baz";
- undef $foo, &bar;
+IPC::Open3 now allows the use of numeric file descriptors.
-remains unchanged. See L<perlop>.
+=item *
-=head2 POSIX character class syntax [: :] supported
+use lib now works identically to @INC. Removing directories
+with 'no lib' now works.
-For example to match alphabetic characters use /[[:alpha:]]/.
-See L<perlre> for details.
+=item *
-=head2 Improved C<qw//> operator
+C<%INC> now localised in a Safe compartment so that use/require work.
-The C<qw//> operator is now evaluated at compile time into a true list
-instead of being replaced with a run time call to C<split()>. This
-removes the confusing misbehaviour of C<qw//> in scalar context, which
-had inherited that behaviour from split().
+=item *
-Thus:
+The Shell module now has an OO interface.
- $foo = ($bar) = qw(a b c); print "$foo|$bar\n";
+=item *
-now correctly prints "3|a", instead of "2|a".
+=back
-=head2 pack() format 'Z' supported
+=head1 Utility Changes
-The new format type 'Z' is useful for packing and unpacking null-terminated
-strings. See L<perlfunc/"pack">.
+=over 4
+
+=item *
+
+The Emacs perl mode (emacs/cperl-mode.el) has been updated to version
+4.31.
+
+=item *
+
+Perlbug is now much more robust. It also sends the bug report to
+perl.org, not perl.com.
+
+=item *
+
+The perlcc utility has been rewritten and its user interface (that is,
+command line) is much more like that of the UNIX C compiler, cc.
+
+=item *
-=head2 pack() format modifier '!' supported
+The xsubpp utility for extension writers now understands POD
+documentation embedded in the *.xs files.
-The new format type modifier '!' is useful for packing and unpacking
-native shorts, ints, and longs. See L<perlfunc/"pack">.
+=back
+
+=head1 New Documentation
+
+=over 4
-=head2 pack() and unpack() support counted strings
+=item *
-The template character '#' can be used to specify a counted string
-type to be packed or unpacked. See L<perlfunc/"pack">.
+perl56delta details the changes between the 5.005 release and the
+5.6.0 release.
-=head2 $^X variables may now have names longer than one character
+=item *
-Formerly, $^X was synonymous with ${"\cX"}, but $^XY was a syntax
-error. Now variable names that begin with a control character may be
-arbitrarily long. However, for compatibility reasons, these variables
-I<must> be written with explicit braces, as C<${^XY}> for example.
-C<${^XYZ}> is synonymous with ${"\cXYZ"}. Variable names with more
-than one control character, such as C<${^XY^Z}>, are illegal.
+perldebtut is a Perl debugging tutorial.
-The old syntax has not changed. As before, `^X' may be either a
-literal control-X character or the two-character sequence `caret' plus
-`X'. When braces are omitted, the variable name stops after the
-control character. Thus C<"$^XYZ"> continues to be synonymous with
-C<$^X . "YZ"> as before.
+=item *
-As before, lexical variables may not have names beginning with control
-characters. As before, variables whose names begin with a control
-character are always forced to be in package `main'. All such variables
-are reserved for future extensions, except those that begin with
-C<^_>, which may be used by user programs and is guaranteed not to
-acquire special meaning in any future version of Perl.
+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.
-=head1 Significant bug fixes
+=item *
-=head2 E<lt>HANDLEE<gt> on empty files
+perlnewmod tells about writing and submitting a new module.
-With C<$/> set to C<undef>, slurping an empty file returns a string of
-zero length (instead of C<undef>, as it used to) the first time the
-HANDLE is read. Further reads yield C<undef>.
+=item *
-This means that the following will append "foo" to an empty file (it used
-to do nothing):
+perlposix-bc explains using Perl on the POSIX-BC platform
+(an EBCDIC mainframe platform).
- perl -0777 -pi -e 's/^/foo/' empty_file
+=item *
-The behaviour of:
+perlretut is a regular expression tutorial.
- perl -pi -e 's/^/foo/' empty_file
+=item *
-is unchanged (it continues to leave the file empty).
+perlrequick is a regular expressions quick-start guide.
+Yes, much quicker than perlretut.
-=head2 C<eval '...'> improvements
+=item *
-Line numbers (as reflected by caller() and most diagnostics) within
-C<eval '...'> were often incorrect when here documents were involved.
-This has been corrected.
+perlutil explains the command line utilities packaged with the Perl
+distribution.
-Lexical lookups for variables appearing in C<eval '...'> within
-functions that were themselves called within an C<eval '...'> were
-searching the wrong place for lexicals. The lexical search now
-correctly ends at the subroutine's block boundary.
+=back
-Parsing of here documents used to be flawed when they appeared as
-the replacement expression in C<eval 's/.../.../e'>. This has
-been fixed.
+=head1 Performance Enhancements
-=head2 Automatic flushing of output buffers
+=over 4
-fork(), exec(), system(), qx//, and pipe open()s now flush buffers
-of all files opened for output when the operation
-was attempted. This mostly eliminates confusing
-buffering mishaps suffered by users unaware of how Perl internally
-handles I/O.
+=item *
-=head2 Better diagnostics on meaningless filehandle operations
+map() that changes the size of the list should now work faster.
-Constructs such as C<open(E<lt>FHE<gt>)> and C<close(E<lt>FHE<gt>)>
-are compile time errors. Attempting to read from filehandles that
-were opened only for writing will now produce warnings (just as
-writing to read-only filehandles does).
+=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).
-=head2 Buffered data discarded from input filehandle when dup'ed.
+=back
-C<open(NEW, "E<lt>&OLD")> now discards any data that was previously
-read and buffered in C<OLD>. The next read operation on C<NEW> will
-return the same data as the corresponding operation on C<OLD>.
-Formerly, it would have returned the data from the start of the
-following disk block instead.
+=head1 Installation and Configuration Improvements
-=head1 Supported Platforms
+=head2 Generic Improvements
=over 4
=item *
-VM/ESA is now supported.
+INSTALL now explains how you can configure Perl to use 64-bit
+integers even on non-64-bit platforms.
+
+=item *
+
+Policy.sh policy change: if you are reusing a Policy.sh file
+(see INSTALL) and you use Configure -Dprefix=/foo/bar and in the old
+Policy $prefix eq $siteprefix and $prefix eq $vendorprefix, all of
+them will now be changed to the new prefix, /foo/bar. (Previously
+only $prefix changed.) If you do not like this new behaviour,
+specify prefix, siteprefix, and vendorprefix explicitly.
=item *
-Siemens BS2000 is now supported under the POSIX Shell.
+A new optional location for Perl libraries, otherlibdirs, is available.
+It can be used for example for vendor add-ons without disturbing Perl's
+own library directories.
=item *
-The Mach CThreads (NEXTSTEP, OPENSTEP) are now supported by the Thread
-extension.
+In many platforms the vendor-supplied 'cc' is too stripped-down to
+build Perl (basically, 'cc' doesn't do ANSI C). If this seems
+to be the case and 'cc' does not seem to be the GNU C compiler
+'gcc', an automatic attempt is made to find and use 'gcc' instead.
=item *
-GNU/Hurd is now supported.
+gcc needs to closely track the operating system release to avoid
+build problems. If Configure finds that gcc was built for a different
+operating system release than is running, it now gives a clearly visible
+warning that there may be trouble ahead.
=item *
-Rhapsody is now supported.
+If binary compatibility with the 5.005 release is not wanted, Configure
+no longer suggests including the 5.005 modules in @INC.
=item *
-EPOC is is now supported (on Psion 5).
+Configure C<-S> can now run non-interactively.
+
+=item *
+
+configure.gnu now works with options with whitespace in them.
+
+=item *
+
+installperl now outputs everything to STDERR.
+
+=item *
+
+$Config{byteorder} is now computed dynamically (this is more robust
+with "fat binaries" where an executable image contains binaries for
+more than one binary platform.)
=back
-=head1 New tests
+=head1 Selected Bug Fixes
=over 4
-=item op/io_const
+=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.
-IO constants (SEEK_*, _IO*).
+=item *
-=item op/io_dir
+C<*foo{FORMAT}> now works.
-Directory-related IO methods (new, read, close, rewind, tied delete).
+=item *
-=item op/io_multihomed
+Lexical warnings now propagating correctly between scopes.
-INET sockets with multi-homed hosts.
+=item *
-=item op/io_poll
+Line renumbering with eval and C<#line> now works.
-IO poll().
+=item *
-=item op/io_unix
+Fixed numerous memory leaks, especially in eval "".
-UNIX sockets.
+=item *
-=item op/filetest
+Modulus of unsigned numbers now works (4063328477 % 65535 used to
+return 27406, instead of 27047).
-File test operators.
+=item *
-=item op/lex_assign
+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.
-Verify operations that access pad objects (lexicals and temporaries).
+=item *
+
+our() variables will not cause "will not stay shared" warnings.
+
+=item *
+
+pack "Z" now correctly terminates the string with "\0".
+
+=item *
+
+Fix password routines which in some shadow password platforms
+(e.g. HP-UX) caused getpwent() to return every other entry.
+
+=item *
+
+printf() no longer resets the numeric locale to "C".
+
+=item *
+
+C<q(a\\b)> now parses correctly as C<'a\\b'>.
+
+=item *
+
+Printing quads (64-bit integers) with printf/sprintf now works
+without the q L ll prefixes (assuming you are on a quad-capable platform).
+
+=item *
+
+Regular expressions on references and overloaded scalars now work.
+
+=item *
+
+scalar() now forces scalar context even when used in void context.
+
+=item *
+
+sort() arguments are now compiled in the right wantarray context
+(they were accidentally using the context of the sort() itself).
+
+=item *
+
+Changed the POSIX character class C<[[:space:]]> to include the (very
+rare) vertical tab character. Added a new POSIX-ish character class
+C<[[:blank:]]> which stands for horizontal whitespace (currently,
+the space and the tab).
+
+=item *
+
+$AUTOLOAD, sort(), lock(), and spawning subprocesses
+in multiple threads simultaneously are now thread-safe.
+
+=item *
+
+Allow read-only string on left hand side of non-modifying tr///.
+
+=item *
+
+Several Unicode fixes (but still not perfect).
+
+=over 8
+
+=item *
+
+BOMs (byte order marks) in the beginning of Perl files
+(scripts, modules) should now be transparently skipped.
+UTF-16 (UCS-2)encoded Perl files should now be read correctly.
+
+=item *
+
+The character tables have been updated to Unicode 3.0.1.
+
+=item *
+
+chr() for values greater than 127 now create utf8 when under use
+utf8.
+
+=item *
+
+Comparing with utf8 data does not magically upgrade non-utf8 data into
+utf8.
+
+=item *
+
+C<IsAlnum>, C<IsAlpha>, and C<IsWord> now match titlecase.
+
+=item *
+
+Concatenation with the C<.> operator or via variable interpolation,
+C<eq>, C<substr>, C<reverse>, C<quotemeta>, the C<x> operator,
+substitution with C<s///>, single-quoted UTF8, should now work--in
+theory.
+
+=item *
+
+The C<tr///> operator now works I<slightly> better but is still rather
+broken. Note that the C<tr///CU> functionality has been removed (but
+see pack('U0', ...)).
+
+=item *
+
+vec() now 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.
+
+=item *
+
+Zero entries were missing from the Unicode classes like C<IsDigit>.
=back
-=head1 Modules and Pragmata
+=item *
-=head2 Modules
+UNIVERSAL::isa no longer caches methods incorrectly. (This broke
+the Tk extension with 5.6.0.)
+
+=back
+
+=head2 Platform Specific Changes and Fixes
=over 4
-=item ByteLoader
+=item *
-The ByteLoader is a dedication extension to generate and run
-Perl bytecode. See L<ByteLoader>.
+BSDI 4.*
-=item B
+Perl now works on post-4.0 BSD/OSes.
-The Perl Compiler suite has been extensively reworked for this
-release.
+=item *
-=item Devel::DProf
+All BSDs
-Devel::DProf, a Perl source code profiler has been added.
+Setting C<$0> now works (as much as possible; see perlvar for details).
-=item Dumpvalue
+=item *
-Added Dumpvalue module provides screen dumps of Perl data.
+Cygwin
-=item Benchmark
+Numerous updates; currently synchronised with Cygwin 1.1.4.
-You can now run tests for I<n> seconds instead of guessing the right
-number of tests to run: e.g. timethese(-5, ...) will run each
-code for at least 5 CPU seconds. Zero as the "number of repetitions"
-means "for at least 3 CPU seconds". The output format has also
-changed. For example:
+=item *
-use Benchmark;$x=3;timethese(-5,{a=>sub{$x*$x},b=>sub{$x**2}})
+EPOC
-will now output something like this:
+EPOC update after Perl 5.6.0. See README.epoc.
-Benchmark: running a, b, each for at least 5 CPU seconds...
- a: 5 wallclock secs ( 5.77 usr + 0.00 sys = 5.77 CPU) @ 200551.91/s (n=1156516)
- b: 4 wallclock secs ( 5.00 usr + 0.02 sys = 5.02 CPU) @ 159605.18/s (n=800686)
+=item *
-New features: "each for at least N CPU seconds...", "wallclock secs",
-and the "@ operations/CPU second (n=operations)".
+FreeBSD 3.*
-=item Devel::Peek
+Perl now works on post-3.0 FreeBSDs.
-The Devel::Peek module provides access to the internal representation
-of Perl variables and data. It is a data debugging tool for the XS programmer.
+=item *
-=item Fcntl
+HP-UX
-More Fcntl constants added: F_SETLK64, F_SETLKW64, O_LARGEFILE for
-large (more than 4G) file access (64-bit support is not yet
-working, though, so no need to get overly excited), Free/Net/OpenBSD
-locking behaviour flags F_FLOCK, F_POSIX, Linux F_SHLCK, and
-O_ACCMODE: the mask of O_RDONLY, O_WRONLY, and O_RDWR.
+README.hpux updated; C<Configure -Duse64bitall> now almost works.
-=item File::Spec
+=item *
-New methods have been added to the File::Spec module: devnull() returns
-the name of the null device (/dev/null on Unix) and tmpdir() the name of
-the temp directory (normally /tmp on Unix). There are now also methods
-to convert between absolute and relative filenames: abs2rel() and
-rel2abs(). For compatibility with operating systems that specify volume
-names in file paths, the splitpath(), splitdir(), and catdir() methods
-have been added.
+IRIX
-=item File::Spec::Functions
+Numerous compilation flag and hint enhancements; accidental mixing
+of 32-bit and 64-bit libraries (a doomed attempt) made much harder.
-The new File::Spec::Functions modules provides a function interface
-to the File::Spec module. Allows shorthand
+=item *
- $fullname = catfile($dir1, $dir2, $file);
+Linux
-instead of
+Long doubles should now work (see INSTALL).
- $fullname = File::Spec->catfile($dir1, $dir2, $file);
+=item *
-=item Math::BigInt
+MacOS Classic
-The logical operations C<E<lt>E<lt>>, C<E<gt>E<gt>>, C<&>, C<|>,
-and C<~> are now supported on bigints.
+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 Math::Complex
+=item *
-The accessor methods Re, Im, arg, abs, rho, and theta can now also
-act as mutators (accessor $z->Re(), mutator $z->Re(3)).
+MPE/iX
-=item Math::Trig
+MPE/iX update after Perl 5.6.0. See README.mpeix.
-A little bit of radial trigonometry (cylindrical and spherical),
-radial coordinate conversions, and the great circle distance were added.
+=item *
-=item SDBM_File
+NetBSD/sparc
-An EXISTS method has been added to this module (and sdbm_exists() has
-been added to the underlying sdbm library), so one can now call exists
-on an SDBM_File tied hash and get the correct result, rather than a
-runtime error.
+Perl now works on NetBSD/sparc.
-=item Time::Local
+=item *
-The timelocal() and timegm() functions used to silently return bogus
-results when the date exceeded the machine's integer range. They
-now consistently croak() if the date falls in an unsupported range.
+OS/2
-=item Win32
+Now works with usethreads (see INSTALL).
-The error return value in list context has been changed for all functions
-that return a list of values. Previously these functions returned a list
-with a single element C<undef> if an error occurred. Now these functions
-return the empty list in these situations. This applies to the following
-functions:
+=item *
- Win32::FsType
- Win32::GetOSVersion
+Solaris
-The remaining functions are unchanged and continue to return C<undef> on
-error even in list context.
+64-bitness using the Sun Workshop compiler now works.
-The Win32::SetLastError(ERROR) function has been added as a complement
-to the Win32::GetLastError() function.
+=item *
-The new Win32::GetFullPathName(FILENAME) returns the full absolute
-pathname for FILENAME in scalar context. In list context it returns
-a two-element list containing the fully qualified directory name and
-the filename.
+Tru64 (aka Digital UNIX, aka DEC OSF/1)
-=item DBM Filters
+The operating system version letter now recorded in $Config{osvers}.
+Allow compiling with gcc (previously explicitly forbidden). Compiling
+with gcc still not recommended because buggy code results, even with
+gcc 2.95.2.
-A new feature called "DBM Filters" has been added to all the
-DBM modules--DB_File, GDBM_File, NDBM_File, ODBM_File, and SDBM_File.
-DBM Filters add four new methods to each DBM module:
+=item *
- filter_store_key
- filter_store_value
- filter_fetch_key
- filter_fetch_value
+Unicos
-These can be used to filter key-value pairs before the pairs are
-written to the database or just after they are read from the database.
-See L<perldbmfilter> for further information.
+Fixed various alignment problems that lead into core dumps either
+during build or later; no longer dies on math errors at runtime;
+now using full quad integers (64 bits), previously was using
+only 46 bit integers for speed.
-=back
+=item *
+
+VMS
-=head2 Pragmata
+chdir() now works better despite a CRT bug; now works with MULTIPLICITY
+(see INSTALL); now works with Perl's malloc.
-C<use utf8> to enable UTF-8 and Unicode support.
+=item *
+
+Windows
-C<use caller 'encoding'> allows modules to inherit pragmatic attributes
-from the caller's context. C<encoding> is currently the only supported
-attribute.
+=over 8
-Lexical warnings pragma, C<use warning;>, to control optional warnings.
+=item *
-C<use filetest> to control the behaviour of filetests (C<-r> C<-w> ...).
-Currently only one subpragma implemented, "use filetest 'access';",
-that enables the use of access(2) or equivalent to check
-permissions instead of using stat(2) as usual. This matters
-in filesystems where there are ACLs (access control lists): the
-stat(2) might lie, but access(2) knows better.
+accept() no longer leaks memory.
-=head1 Utility Changes
+=item *
+
+Better chdir() return value for a non-existent directory.
+
+=item *
-Todo.
+New %ENV entries now propagate to subprocesses.
-=head1 Documentation Changes
+=item *
+
+$ENV{LIB} now used to search for libs under Visual C.
+
+=item *
+
+A failed (pseudo)fork now returns undef and sets errno to EAGAIN.
+
+=item *
+
+Allow REG_EXPAND_SZ keys in the registry.
+
+=item *
+
+Can now send() from all threads, not just the first one.
+
+=item *
+
+Fake signal handling reenabled, bugs and all.
+
+=item *
+
+Less stack reserved per thread so that more threads can run
+concurrently. (Still 16M per thread.)
+
+=item *
+
+C<File::Spec->tmpdir()> now prefers C:/temp over /tmp
+(works better when perl is running as service).
+
+=item *
+
+Better UNC path handling under ithreads.
+
+=item *
+
+wait() and waitpid() now work much better.
+
+=item *
+
+winsock handle leak fixed.
+
+=back
+
+=head1 New or Changed Diagnostics
+
+All regular expression compilation error messages are now hopefully
+easier to understand both because the error message now comes before
+the failed regex and because the point of failure is now clearly
+marked.
+
+The various "opened only for", "on closed", "never opened" warnings
+drop the C<main::> prefix for filehandles in the C<main> package,
+for example C<STDIN> instead of <main::STDIN>.
+
+The "Unrecognized escape" warning has been extended to include C<\8>,
+C<\9>, and C<\_>. There is no need to escape any of the C<\w> characters.
+
+=head1 Changed Internals
=over 4
-=item perlopentut.pod
+=item *
+
+perlapi.pod (a companion to perlguts) now attempts to document the
+internal API.
-A tutorial on using open() effectively.
+=item *
-=item perlreftut.pod
+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.
-A tutorial that introduces the essentials of references.
+=item *
-=item perltootc.pod
+Added rsignal(), whichsig(), do_join() to the publicised API.
+
+=item *
-A tutorial on managing class data for object modules.
+Made possible to propagate customised exceptions via croak()ing.
+
+=item *
+
+Added is_utf8_char(), is_utf8_string(), bytes_to_utf8(), and utf8_to_bytes().
+
+=item *
+
+Now xsubs can have attributes just like subs.
=back
-=head1 New Diagnostics
+=head1 Known Problems
+
+=head2 Unicode Support Still Far From Perfect
+
+We're working on it. Stay tuned.
-=item /%s/: Unrecognized escape \\%c passed through
+=head2 EBCDIC Still A Lost Platform
-(W) You used a backslash-character combination which is not recognized
-by Perl. This combination appears in an interpolated variable or a
-C<'>-delimited regular expression.
+The plan is to bring them back.
-=item Filehandle %s opened only for output
+=head2 Building Extensions Can Fail Because Of Largefiles
-(W) You tried to read from a filehandle opened only for writing. If you
-intended it to be a read-write filehandle, you needed to open it with
-"+E<lt>" or "+E<gt>" or "+E<gt>E<gt>" instead of with "E<lt>" or nothing. If
-you intended only to read from the file, use "E<lt>". See
-L<perlfunc/open>.
+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 Missing command in piped open
+=head2 ftmp-security tests warn 'system possibly insecure'
-(W) You used the C<open(FH, "| command")> or C<open(FH, "command |")>
-construction, but the command was missing or blank.
+Don't panic. Read INSTALL 'make test' section instead.
-=item Unrecognized escape \\%c passed through
+=head2 Test lib/posix Subtest 9 Fails In LP64-Configured HP-UX
-(W) You used a backslash-character combination which is not recognized
-by Perl.
+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 defined(@array) is deprecated
+=head2 Long Doubles Still Don't Work In Solaris
-(D) defined() is not usually useful on arrays because it checks for an
-undefined I<scalar> value. If you want to see if the array is empty,
-just use C<if (@array) { # not empty }> for example.
+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 defined(%hash) is deprecated
+=head2 Linux With Sfio Fails op/misc Test 48
-(D) defined() is not usually useful on hashes because it checks for an
-undefined I<scalar> value. If you want to see if the hash is empty,
-just use C<if (%hash) { # not empty }> for example.
+No known fix.
-=head1 Obsolete Diagnostics
+=head2 Storable tests fail in some platforms
-Todo.
+If any Storable tests fail the use of Storable is not advisable.
-=head1 Configuration Changes
+=over 4
+
+=item *
-=head2 installusrbinperl
+Many Storable tests fail on AIX configured with 64 bit integers.
-You can use "Configure -Uinstallusrbinperl" which causes installperl
-to skip installing perl also as /usr/bin/perl. This is useful if you
-prefer not to modify /usr/bin for some reason or another but harmful
-because many scripts assume to find Perl in /usr/bin/perl.
+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.
-=head2 SOCKS support
+=item *
-You can use "Configure -Dusesocks" which causes Perl to probe
-for the SOCKS proxy protocol library, http://www.socks.nec.com/
+DOS DJGPP may hang when testing Storable.
+
+=item *
+
+st-06compat fails in UNICOS and UNICOS/mk.
+
+This means that you cannot read old (pre-Storable-0.7) Storable images
+made in other platforms.
+
+=item *
+
+st-store.t and st-retrieve may fail with Compaq C 6.2 on OpenVMS Alpha 7.2.
+
+=head2 Threads Are Still Experimental
+
+Multithreading is still an experimental feature. Some platforms
+emit the following message for lib/thr5005
+
+ #
+ # This is a KNOWN FAILURE, and one of the reasons why threading
+ # is still an experimental feature. It is here to stop people
+ # from deploying threads in production. ;-)
+ #
+
+and another known thread-related warning is
+
+ pragma/overload......Unbalanced saves: 3 more saves than restores
+ panic: magic_mutexfree during global destruction.
+ ok
+ lib/selfloader.......Unbalanced saves: 3 more saves than restores
+ panic: magic_mutexfree during global destruction.
+ ok
+ lib/st-dclone........Unbalanced saves: 3 more saves than restores
+ panic: magic_mutexfree during global destruction.
+ ok
+
+=head2 The Compiler Suite Is Still Experimental
+
+The compiler suite is slowly getting better but is nowhere near
+working order yet. The backend part that has seen perhaps the most
+progress is the bytecode compiler.
+
+=back
-=head1 BUGS
+=head1 Reporting Bugs
-If you find what you think is a bug, you might check the headers of
-articles recently posted to the comp.lang.perl.misc newsgroup.
-There may also be information at http://www.perl.com/perl/, the Perl
-Home Page.
+If you find what you think is a bug, you might check the articles
+recently posted to the comp.lang.perl.misc newsgroup and the perl
+bug database at http://bugs.perl.org. There may also be
+information at http://www.perl.com/perl/, the Perl Home Page.
If you believe you have an unreported bug, please run the B<perlbug>
-program included with your release. Make sure to trim your bug down
+program included with your release. Be sure to trim your bug down
to a tiny but sufficient test case. Your bug report, along with the
-output of C<perl -V>, will be sent off to perlbug@perl.com to be
+output of C<perl -V>, will be sent off to perlbug@perl.org to be
analysed by the Perl porting team.
=head1 SEE ALSO
=head1 HISTORY
-Written by Gurusamy Sarathy <F<gsar@umich.edu>>, with many contributions
-from The Perl Porters.
+Written by Jarkko Hietaniemi <F<jhi@iki.fi>>, with many contributions
+from The Perl Porters and Perl Users submitting feedback and patches.
-Send omissions or corrections to <F<perlbug@perl.com>>.
+Send omissions or corrections to <F<perlbug@perl.org>>.
=cut
projects / p5sagit/p5-mst-13.2.git / blobdiff