X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=pod%2Fperldelta.pod;h=7d15597e19675f4a60b3a6c4be5c0025be449bc9;hb=5e12dbfa1fc5fab9ffcdf3a398fa9f5c92327e0d;hp=ba940817dff34ea48aa9dfd0b8c9032267d2ae88;hpb=14638679dafeb8e4998a4e631fea795c5b015a16;p=p5sagit%2Fp5-mst-13.2.git diff --git a/pod/perldelta.pod b/pod/perldelta.pod index ba94081..7d15597 100644 --- a/pod/perldelta.pod +++ b/pod/perldelta.pod @@ -1,878 +1,13 @@ =head1 NAME -perldelta - what's new for perl v5.7.0 +perldelta - what will be new for perl v5.8.0 =head1 DESCRIPTION -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 - -=over 4 - -=item * - -Arrays now always interpolate into double-quoted strings: -constructs like "foo@bar" now always assume C<@bar> is an array, -whether or not the compiler has seen use of C<@bar>. - -=item * - -The semantics of bless(REF, REF) were unclear and until someone proves -it to make some sense, it is forbidden. - -=item * - -A reference to a reference now stringify as "REF(0x81485ec)" instead -of "SCALAR(0x81485ec)" in order to be more consistent with the return -value of ref(). - -=item * - -The very dusty examples in the eg/ directory have been removed. -Suggestions for new shiny examples welcome but the main issue is that -the examples need to be documented, tested and (most importantly) -maintained. - -=item * - -The obsolete chat2 library that should never have been allowed -to escape the laboratory has been decommissioned. - -=item * - -The unimplemented POSIX regex features [[.cc.]] and [[=c=]] are still -recognised but now cause fatal errors. The previous behaviour of -ignoring them by default and warning if requested was unacceptable -since it, in a way, falsely promised that the features could be used. - -=item * - -The (bogus) escape sequences \8 and \9 now give an optional warning -("Unrecognized escape passed through"). There is no need to \-escape -any C<\w> character. - -=item * - -lstat(FILEHANDLE) now gives a warning because the operation makes no sense. -In future releases this may become a fatal error. - -=item * - -The long deprecated uppercase aliases for the string comparison -operators (EQ, NE, LT, LE, GE, GT) have now been removed. - -=item * - -The regular expression captured submatches ($1, $2, ...) are now -more consistently unset if the match fails, instead of leaving false -data lying around in them. - -=item * - -The tr///C and tr///U features have been removed and will not return; -the interface was a mistake. Sorry about that. For similar -functionality, see pack('U0', ...) and pack('C0', ...). - -=back - -=head1 Core Enhancements - -=over 4 - -=item * - -C now works (previously one couldn't pass -in multiple arguments.) - -=item * - -my __PACKAGE__ now works. - -=item * - -C now works even if there is no "sub unimport" in the Module. - -=item * - -The numerical comparison operators return C if either operand -is a NaN. Previously the behaviour was unspecified. - -=item * - -C can now be used to force a string to UTF8. - -=item * - -prototype(\&) is now available. - -=item * - -There is now an UNTIE method. - -=back - -=head1 Modules and Pragmata - -=head2 New Modules - -=over 4 - -=item * - -File::Temp allows one to create temporary files and directories in an -easy, portable, and secure way. - -=item * - -Storable gives persistence to Perl data structures by allowing the -storage and retrieval of Perl data to and from files in a fast and -compact binary format. - -=back - -=head2 Updated And Improved Modules and Pragmata - -=over 4 - -=item * - -The following independently supported modules have been updated to -newer versions from CPAN: CGI, CPAN, DB_File, File::Spec, Getopt::Long, -the podlators bundle, Pod::LaTeX, Pod::Parser, Term::ANSIColor, Test. - -=item * - -Bug fixes and minor enhancements have been applied to B::Deparse, -Data::Dumper, IO::Poll, IO::Socket::INET, Math::BigFloat, -Math::Complex, Math::Trig, Net::protoent, the re pragma, SelfLoader, -Sys::SysLog, Test::Harness, Text::Wrap, UNIVERSAL, and the warnings -pragma. - -=item * - -The attributes::reftype() now works on tied arguments. - -=item * - -AutoLoader can now be disabled with C, - -=item * - -The English module can now be used without the infamous performance -hit by saying - - use English '-no_performance_hit'; - -(Assuming, of course, that one doesn't need the troublesome variables -C<$`>, C<$&>, or C<$'>.) Also, introduced C<@LAST_MATCH_START> and -C<@LAST_MATCH_END> English aliases for C<@-> and C<@+>. - -=item * - -File::Find now has pre- and post-processing callbacks. It also -correctly changes directories when chasing symbolic links. Callbacks -(naughtily) exiting with "next;" instead of "return;" now work. - -=item * - -File::Glob::glob() renamed to File::Glob::bsd_glob() to avoid -prototype mismatch with CORE::glob(). - -=item * - -IPC::Open3 now allows the use of numeric file descriptors. - -=item * - -use lib now works identically to @INC. Removing directories -with 'no lib' now works. - -=item * - -C<%INC> now localised in a Safe compartment so that use/require work. - -=item * - -The Shell module now has an OO interface. - -=item * - -=back - -=head1 Utility Changes - -=over 4 - -=item * - -The Emacs perl mode (emacs/cperl-mode.el) has been updated to version -4.31. - -=item * - -Perlbug is now much more robust. It also sends the bug report to -perl.org, not perl.com. - -=item * - -The perlcc utility has been rewritten and its user interface (that is, -command line) is much more like that of the UNIX C compiler, cc. - -=item * - -The xsubpp utility for extension writers now understands POD -documentation embedded in the *.xs files. - -=back - -=head1 New Documentation - -=over 4 - -=item * - -perl56delta details the changes between the 5.005 release and the -5.6.0 release. - -=item * - -perldebtut is a Perl debugging tutorial. - -=item * - -perlebcdic contains considerations for running Perl on EBCDIC platforms. -Note that unfortunately EBCDIC platforms that used to supported back in -Perl 5.005 are still unsupported by Perl 5.7.0; the plan, however, is to -bring them back to the fold. - -=item * - -perlnewmod tells about writing and submitting a new module. - -=item * - -perlposix-bc explains using Perl on the POSIX-BC platform -(an EBCDIC mainframe platform). - -=item * - -perlretut is a regular expression tutorial. - -=item * - -perlrequick is a regular expressions quick-start guide. -Yes, much quicker than perlretut. - -=item * - -perlutil explains the command line utilities packaged with the Perl -distribution. - -=back - -=head1 Performance Enhancements - -=over 4 - -=item * - -map() that changes the size of the list should now work faster. - -=item * - -sort() has been changed to use mergesort internally as opposed to the -earlier quicksort. For very small lists this may result in slightly -slower sorting times, but in general the speedup should be at least -20%. Additional bonuses are that the worst case behaviour of sort() -is now better (in computer science terms it now runs in time O(N log N), -as opposed to quicksort's Theta(N**2) worst-case run time behaviour), -and that sort() is now stable (meaning that elements with identical -keys will stay ordered as they were before the sort). - -=back - -=head1 Installation and Configuration Improvements - -=head2 Generic Improvements - -=over 4 - -=item * - -INSTALL now explains how you can configure Perl to use 64-bit -integers even on non-64-bit platforms. - -=item * - -Policy.sh policy change: if you are reusing a Policy.sh file -(see INSTALL) and you use Configure -Dprefix=/foo/bar and in the old -Policy $prefix eq $siteprefix and $prefix eq $vendorprefix, all of -them will now be changed to the new prefix, /foo/bar. (Previously -only $prefix changed.) If you do not like this new behaviour, -specify prefix, siteprefix, and vendorprefix explicitly. - -=item * - -A new optional location for Perl libraries, otherlibdirs, is available. -It can be used for example for vendor add-ons without disturbing Perl's -own library directories. - -=item * - -In many platforms the vendor-supplied 'cc' is too stripped-down to -build Perl (basically, 'cc' doesn't do ANSI C). If this seems -to be the case and 'cc' does not seem to be the GNU C compiler -'gcc', an automatic attempt is made to find and use 'gcc' instead. - -=item * - -gcc needs to closely track the operating system release to avoid -build problems. If Configure finds that gcc was built for a different -operating system release than is running, it now gives a clearly visible -warning that there may be trouble ahead. - -=item * - -If binary compatibility with the 5.005 release is not wanted, Configure -no longer suggests including the 5.005 modules in @INC. - -=item * - -Configure C<-S> can now run non-interactively. - -=item * - -configure.gnu now works with options with whitespace in them. - -=item * - -installperl now outputs everything to STDERR. - -=item * - -$Config{byteorder} is now computed dynamically (this is more robust -with "fat binaries" where an executable image contains binaries for -more than one binary platform.) - -=item * - -Configure no longer included the DBM libraries (dbm, gdbm, db, ndbm) -when building the Perl binary. The only exception to this is SunOS 4.x, -which needs them. - -=back - -=head1 Selected Bug Fixes - -=over 4 - -=item * - -Several debugger fixes: exit code now reflects the script exit code, -condition C<"0"> now treated correctly, the C command now checks -line number, the C<$.> no longer gets corrupted, all debugger output now -goes correctly to the socket if RemotePort is set. - -=item * - -C<*foo{FORMAT}> now works. - -=item * - -Lexical warnings now propagating correctly between scopes. - -=item * - -Line renumbering with eval and C<#line> now works. - -=item * - -Fixed numerous memory leaks, especially in eval "". - -=item * - -Modulus of unsigned numbers now works (4063328477 % 65535 used to -return 27406, instead of 27047). - -=item * - -Some "not a number" warnings introduced in 5.6.0 eliminated to be -more compatible with 5.005. Infinity is now recognised as a number. - -=item * - -our() variables will not cause "will not stay shared" warnings. - -=item * - -pack "Z" now correctly terminates the string with "\0". - -=item * - -Fix password routines which in some shadow password platforms -(e.g. HP-UX) caused getpwent() to return every other entry. - -=item * - -printf() no longer resets the numeric locale to "C". - -=item * - -C now parses correctly as C<'a\\b'>. - -=item * - -Printing quads (64-bit integers) with printf/sprintf now works -without the q L ll prefixes (assuming you are on a quad-capable platform). - -=item * - -Regular expressions on references and overloaded scalars now work. - -=item * - -scalar() now forces scalar context even when used in void context. - -=item * - -sort() arguments are now compiled in the right wantarray context -(they were accidentally using the context of the sort() itself). - -=item * - -Changed the POSIX character class C<[[:space:]]> to include the (very -rare) vertical tab character. Added a new POSIX-ish character class -C<[[:blank:]]> which stands for horizontal whitespace (currently, -the space and the tab). - -=item * - -$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, C, and C now match titlecase. - -=item * - -Concatenation with the C<.> operator or via variable interpolation, -C, C, C, C, the C operator, -substitution with C, single-quoted UTF8, should now work--in -theory. - -=item * - -The C operator now works I better but is still rather -broken. Note that the C 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. - -=back - -=item * - -UNIVERSAL::isa no longer caches methods incorrectly. (This broke -the Tk extension with 5.6.0.) - -=back - -=head2 Platform Specific Changes and Fixes - -=over 4 - -=item * - -BSDI 4.* - -Perl now works on post-4.0 BSD/OSes. - -=item * - -All BSDs - -Setting C<$0> now works (as much as possible; see perlvar for details). - -=item * - -Cygwin - -Numerous updates; currently synchronised with Cygwin 1.1.4. - -=item * - -EPOC - -EPOC update after Perl 5.6.0. See README.epoc. - -=item * - -FreeBSD 3.* - -Perl now works on post-3.0 FreeBSDs. - -=item * - -HP-UX - -README.hpux updated; C now almost works. - -=item * - -IRIX - -Numerous compilation flag and hint enhancements; accidental mixing -of 32-bit and 64-bit libraries (a doomed attempt) made much harder. - -=item * - -Linux - -Long doubles should now work (see INSTALL). - -=item * - -MacOS Classic - -Compilation of the standard Perl distribution in MacOS Classic should -now work if you have the Metrowerks development environment and -the missing Mac-specific toolkit bits. Contact the macperl mailing -list for details. - -=item * - -MPE/iX - -MPE/iX update after Perl 5.6.0. See README.mpeix. - -=item * - -NetBSD/sparc - -Perl now works on NetBSD/sparc. - -=item * - -OS/2 - -Now works with usethreads (see INSTALL). - -=item * - -Solaris - -64-bitness using the Sun Workshop compiler now works. - -=item * - -Tru64 (aka Digital UNIX, aka DEC OSF/1) - -The operating system version letter now recorded in $Config{osvers}. -Allow compiling with gcc (previously explicitly forbidden). Compiling -with gcc still not recommended because buggy code results, even with -gcc 2.95.2. - -=item * - -Unicos - -Fixed various alignment problems that lead into core dumps either -during build or later; no longer dies on math errors at runtime; -now using full quad integers (64 bits), previously was using -only 46 bit integers for speed. - -=item * - -VMS - -chdir() now works better despite a CRT bug; now works with MULTIPLICITY -(see INSTALL); now works with Perl's malloc. - -=item * - -Windows - -=over 8 - -=item * - -accept() no longer leaks memory. - -=item * - -Better chdir() return value for a non-existent directory. - -=item * - -New %ENV entries now propagate to subprocesses. - -=item * - -$ENV{LIB} now used to search for libs under Visual C. - -=item * - -A failed (pseudo)fork now returns undef and sets errno to EAGAIN. - -=item * - -Allow REG_EXPAND_SZ keys in the registry. - -=item * - -Can now send() from all threads, not just the first one. - -=item * - -Fake signal handling reenabled, bugs and all. - -=item * - -Less stack reserved per thread so that more threads can run -concurrently. (Still 16M per thread.) - -=item * - -Ctmpdir()> 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 prefix for filehandles in the C
package, -for example C instead of . - -The "Unrecognized escape" warning has been extended to include C<\8>, -C<\9>, and C<\_>. There is no need to escape any of the C<\w> characters. - -=head1 Changed Internals - -=over 4 - -=item * - -perlapi.pod (a companion to perlguts) now attempts to document the -internal API. - -=item * - -You can now build a really minimal perl called microperl. -Building microperl does not require even running Configure; -C should be enough. Beware: microperl makes -many assumptions, some of which may be too bold; the resulting -executable may crash or otherwise misbehave in wondrous ways. -For careful hackers only. - -=item * - -Added rsignal(), whichsig(), do_join() to the publicised API. - -=item * - -Made possible to propagate customised exceptions via croak()ing. - -=item * - -Added is_utf8_char(), is_utf8_string(), bytes_to_utf8(), and utf8_to_bytes(). - -=item * - -Now xsubs can have attributes just like subs. - -=back - -=head1 Known Problems - -=head2 Unicode Support Still Far From Perfect - -We're working on it. Stay tuned. - -=head2 EBCDIC Still A Lost Platform - -The plan is to bring them back. - -=head2 Building Extensions Can Fail Because Of Largefiles - -Certain extensions like mod_perl and BSD::Resource are known to have -issues with `largefiles', a change brought by Perl 5.6.0 in which file -offsets default to 64 bits wide, where supported. Modules may fail to -compile at all or compile and work incorrectly. Currently there is no -good solution for the problem, but Configure now provides appropriate -non-largefile ccflags, ldflags, libswanted, and libs in the %Config -hash (e.g., $Config{ccflags_nolargefiles}) so the extensions that are -having problems can try configuring themselves without the -largefileness. This is admittedly not a clean solution, and the -solution may not even work at all. One potential failure is whether -one can (or, if one can, whether it's a good idea) link together at -all binaries with different ideas about file offsets, all this is -platform-dependent. - -=head2 ftmp-security tests warn 'system possibly insecure' - -Don't panic. Read INSTALL 'make test' section instead. - -=head2 Test lib/posix Subtest 9 Fails In LP64-Configured HP-UX - -If perl is configured with -Duse64bitall, the successful result of the -subtest 10 of lib/posix may arrive before the successful result of the -subtest 9, which confuses the test harness so much that it thinks the -subtest 9 failed. - -=head2 Long Doubles Still Don't Work In Solaris - -The experimental long double support is still very much so in Solaris. -(Other platforms like Linux and Tru64 are beginning to solidify in -this area.) - -=head2 Linux With Sfio Fails op/misc Test 48 - -No known fix. - -=head2 Storable tests fail in some platforms - -If any Storable tests fail the use of Storable is not advisable. - -=over 4 - -=item * - -Many Storable tests fail on AIX configured with 64 bit integers. - -So far unidentified problems break Storable in AIX if Perl is -configured to use 64 bit integers. AIX in 32-bit mode works and -other 64-bit platforms work with Storable. - -=item * - -DOS DJGPP may hang when testing Storable. - -=item * - -st-06compat fails in UNICOS and UNICOS/mk. - -This means that you cannot read old (pre-Storable-0.7) Storable images -made in other platforms. - -=item * - -st-store.t and st-retrieve may fail with Compaq C 6.2 on OpenVMS Alpha 7.2. - -=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 +This document does not exist yet. When the Perl 5.8.0 is released +this document will describe the changes since Perl 5.6.0, the previous +major release. In the meanwhile, see L and +L. =head1 Reporting Bugs @@ -899,9 +34,6 @@ The F and F files for copyright information. =head1 HISTORY -Written by Jarkko Hietaniemi >, with many contributions -from The Perl Porters and Perl Users submitting feedback and patches. - -Send omissions or corrections to >. +Written by Jarkko Hietaniemi >. =cut