X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=pod%2Fperl571delta.pod;h=56eb74f4b58e7b72f16d8a1925d7f8235f6544e7;hb=3c295041e5d570578f09b8e99de0a179cc172164;hp=ae5dd7f69f185bf9512884f070fcf689f3655aa5;hpb=d468ca0452c17d0537a54afdfb4073bba9b1b292;p=p5sagit%2Fp5-mst-13.2.git diff --git a/pod/perl571delta.pod b/pod/perl571delta.pod index ae5dd7f..56eb74f 100644 --- a/pod/perl571delta.pod +++ b/pod/perl571delta.pod @@ -8,7 +8,38 @@ This document describes differences between the 5.7.0 release and the 5.7.1 release. (To view the differences between the 5.6.0 release and the 5.7.0 -release, see L). +release, see L.) + +=head1 Security Vulnerability Closed + +(This change was already made in 5.7.0 but bears repeating here.) + +A potential security vulnerability in the optional suidperl component +of Perl was identified in August 2000. suidperl is neither built nor +installed by default. As of April 2001 the only known vulnerable +platform is Linux, most likely all Linux distributions. CERT and +various vendors and distributors have been alerted about the vulnerability. +See http://www.cpan.org/src/5.0/sperl-2000-08-05/sperl-2000-08-05.txt +for more information. + +The problem was caused by Perl trying to report a suspected security +exploit attempt using an external program, /bin/mail. On Linux +platforms the /bin/mail program had an undocumented feature which +when combined with suidperl gave access to a root shell, resulting in +a serious compromise instead of reporting the exploit attempt. If you +don't have /bin/mail, or if you have 'safe setuid scripts', or if +suidperl is not installed, you are safe. + +The exploit attempt reporting feature has been completely removed from +all the Perl 5.7 releases (and will be gone also from the maintenance +release 5.6.1), so that particular vulnerability isn't there anymore. +However, further security vulnerabilities are, unfortunately, always +possible. The suidperl code is being reviewed and if deemed too risky +to continue to be supported, it may be completely removed from future +releases. In any case, suidperl should only be used by security +experts who know exactly what they are doing and why they are using +suidperl instead of some other solution such as sudo +( see http://www.courtesan.com/sudo/ ). =head1 Incompatible Changes @@ -19,25 +50,463 @@ release, see L). 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. +More details are in L. + +=item * + +The list of filenames from glob() (or <...>) is now by default sorted +alphabetically to be csh-compliant. (bsd_glob() does still sort platform +natively, ASCII or EBCDIC, unless GLOB_ALPHASORT is specified.) =back =head1 Core Enhancements +=head2 AUTOLOAD Is Now Lvaluable + +AUTOLOAD is now lvaluable, meaning that you can add the :lvalue attribute +to AUTOLOAD subroutines and you can assign to the AUTOLOAD return value. + +=head2 PerlIO is Now The Default + =over 4 =item * +IO is now by default done via PerlIO rather than system's "stdio". +PerlIO allows "layers" to be "pushed" onto a file handle to alter the +handle's behaviour. Layers can be specified at open time via 3-arg +form of open: + + open($fh,'>:crlf :utf8', $path) || ... + +or on already opened handles via extended C: + + binmode($fh,':encoding(iso-8859-7)'); + +The built-in layers are: unix (low level read/write), stdio (as in +previous Perls), perlio (re-implementation of stdio buffering in a +portable manner), crlf (does CRLF <=> "\n" translation as on Win32, +but available on any platform). A mmap layer may be available if +platform supports it (mostly UNIXes). + +Layers to be applied by default may be specified via the 'open' pragma. + +See L for the effects +of PerlIO on your architecture name. + +=item * + +File handles can be marked as accepting Perl's internal encoding of Unicode +(UTF-8 or UTF-EBCDIC depending on platform) by a pseudo layer ":utf8" : + + open($fh,">:utf8","Uni.txt"); + +Note for EBCDIC users: the pseudo layer ":utf8" is erroneously named +for you since it's not UTF-8 what you will be getting but instead +UTF-EBCDIC. See L, L, and +http://www.unicode.org/unicode/reports/tr16/ for more information. +In future releases this naming may change. + +=item * + +File handles can translate character encodings from/to Perl's internal +Unicode form on read/write via the ":encoding()" layer. + +=item * + +File handles can be opened to "in memory" files held in Perl scalars via: + + open($fh,'>', \$variable) || ... + +=item * + +Anonymous temporary files are available without need to +'use FileHandle' or other module via + + open($fh,"+>", undef) || ... + +That is a literal undef, not an undefined value. + +=item * + +The list form of C is now implemented for pipes (at least on UNIX): + + open($fh,"-|", 'cat', '/etc/motd') + +creates a pipe, and runs the equivalent of exec('cat', '/etc/motd') in +the child process. + +=item * + +The following builtin functions are now overridable: chop(), chomp(), +each(), keys(), pop(), push(), shift(), splice(), unshift(). + +=item * + Formats now support zero-padded decimal fields. =item * - -The printf and sprintf now support parameter reordering using the -C<%\d+\$> and C<*\d+\$> syntaxes. + +Perl now tries internally to use integer values in numeric conversions +and basic arithmetics (+ - * /) if the arguments are integers, and +tries also to keep the results stored internally as integers. +This change leads into often slightly faster and always less lossy +arithmetics. (Previously Perl always preferred floating point numbers +in its math.) + +=item * + +The printf() and sprintf() now support parameter reordering using the +C<%\d+\$> and C<*\d+\$> syntaxes. For example + + print "%2\$s %1\$s\n", "foo", "bar"; + +will print "bar foo\n"; This feature helps in writing +internationalised software. + +=item * + +Unicode in general should be now much more usable. Unicode can be +used in hash keys, Unicode in regular expressions should work now, +Unicode in tr/// should work now (though tr/// seems to be a +particularly tricky to get right, so you have been warned) + +=item * + +The Unicode Character Database coming with Perl has been upgraded +to Unicode 3.1. For more information, see http://www.unicode.org/ , +and http://www.unicode.org/unicode/reports/tr27/ + +For developers interested in enhancing Perl's Unicode capabilities: +almost all the UCD files are included with the Perl distribution in +the lib/unicode subdirectory. The most notable omission, for space +considerations, is the Unihan database. + +=item * + +The Unicode character classes \p{Blank} and \p{SpacePerl} have been +added. "Blank" is like C isblank(), that is, it contains only +"horizontal whitespace" (the space character is, the newline isn't), +and the "SpacePerl" is the Unicode equivalent of C<\s> (\p{Space} +isn't, since that includes the vertical tabulator character, whereas +C<\s> doesn't.) =back +=head2 Signals Are Now Safe + +Perl used to be fragile in that signals arriving at inopportune moments +could corrupt Perl's internal state. + +=head1 Modules and Pragmata + +=head2 New Modules + +=over 4 + +=item * + +B::Concise, by Stephen McCamant, is a new compiler backend for +walking the Perl syntax tree, printing concise info about ops. +The output is highly customisable. + +See L for more information. + +=item * + +Class::ISA, by Sean Burke, for reporting the search path for a +class's ISA tree, has been added. + +See L for more information. + +=item * + +Cwd has now a split personality: if possible, an extension is used, +(this will hopefully be both faster and more secure and robust) but +if not possible, the familiar Perl library implementation is used. + +=item * + +Digest, a frontend module for calculating digests (checksums), +from Gisle Aas, has been added. + +See L for more information. + +=item * + +Digest::MD5 for calculating MD5 digests (checksums), by Gisle Aas, +has been added. + + use Digest::MD5 'md5_hex'; + + $digest = md5_hex("Thirsty Camel"); + + print $digest, "\n"; # 01d19d9d2045e005c3f1b80e8b164de1 + +NOTE: the MD5 backward compatibility module is deliberately not +included since its use is discouraged. + +See L for more information. + +=item * + +Encode, by Nick Ing-Simmons, provides a mechanism to translate +between different character encodings. Support for Unicode, +ISO-8859-*, ASCII, CP*, KOI8-R, and three variants of EBCDIC are +compiled in to the module. Several other encodings (like Japanese, +Chinese, and MacIntosh encodings) are included and will be loaded at +runtime. + +Any encoding supported by Encode module is also available to the +":encoding()" layer if PerlIO is used. + +See L for more information. + +=item * + +Filter::Simple is an easy-to-use frontend to Filter::Util::Call, +from Damian Conway. + + # in MyFilter.pm: + + package MyFilter; + + use Filter::Simple sub { + while (my ($from, $to) = splice @_, 0, 2) { + s/$from/$to/g; + } + }; + + 1; + + # in user's code: + + use MyFilter qr/red/ => 'green'; + + print "red\n"; # this code is filtered, will print "green\n" + print "bored\n"; # this code is filtered, will print "bogreen\n" + + no MyFilter; + + print "red\n"; # this code is not filtered, will print "red\n" + +See L for more information. + +=item * + +Filter::Util::Call, by Paul Marquess, provides you with the +framework to write I in Perl. For most uses +the frontend Filter::Simple is to be preferred. +See L for more information. + +=item * + +Locale::Constants, Locale::Country, Locale::Currency, and Locale::Language, +from Neil Bowers, have been added. They provide the codes for various +locale standards, such as "fr" for France, "usd" for US Dollar, and +"jp" for Japanese. + + use Locale::Country; + + $country = code2country('jp'); # $country gets 'Japan' + $code = country2code('Norway'); # $code gets 'no' + +See L, L, L, +and L for more information. + +=item * + +MIME::Base64, by Gisle Aas, allows you to encode data in base64. + + use MIME::Base64; + + $encoded = encode_base64('Aladdin:open sesame'); + $decoded = decode_base64($encoded); + + print $encoded, "\n"; # "QWxhZGRpbjpvcGVuIHNlc2FtZQ==" + +See L for more information. + +=item * + +MIME::QuotedPrint, by Gisle Aas, allows you to encode data in +quoted-printable encoding. + + use MIME::QuotedPrint; + + $encoded = encode_qp("Smiley in Unicode: \x{263a}"); + $decoded = decode_qp($encoded); + + print $encoded, "\n"; # "Smiley in Unicode: =263A" + +MIME::QuotedPrint has been enhanced to provide the basic methods +necessary to use it with PerlIO::Via as in : + + use MIME::QuotedPrint; + open($fh,">Via(MIME::QuotedPrint)",$path) + +See L for more information. + +=item * + +PerlIO::Scalar, by Nick Ing-Simmons, provides the implementation of +IO to "in memory" Perl scalars as discussed above. It also serves as +an example of a loadable layer. Other future possibilities include +PerlIO::Array and PerlIO::Code. See L for more +information. + +=item * + +PerlIO::Via, by Nick Ing-Simmons, acts as a PerlIO layer and wraps +PerlIO layer functionality provided by a class (typically implemented +in perl code). + + use MIME::QuotedPrint; + open($fh,">Via(MIME::QuotedPrint)",$path) + +This will automatically convert everything output to C<$fh> +to Quoted-Printable. See L for more information. + +=item * + +Pod::Text::Overstrike, by Joe Smith, has been added. +It converts POD data to formatted overstrike text. +See L for more information. + +=item * + +Switch from Damian Conway has been added. Just by saying + + use Switch; + +you have C and C available in Perl. + + use Switch; + + switch ($val) { + + case 1 { print "number 1" } + case "a" { print "string a" } + case [1..10,42] { print "number in list" } + case (@array) { print "number in list" } + case /\w+/ { print "pattern" } + case qr/\w+/ { print "pattern" } + case (%hash) { print "entry in hash" } + case (\%hash) { print "entry in hash" } + case (\&sub) { print "arg to subroutine" } + else { print "previous case not true" } + } + +See L for more information. + +=item * + +Text::Balanced from Damian Conway has been added, for +extracting delimited text sequences from strings. + + use Text::Balanced 'extract_delimited'; + + ($a, $b) = extract_delimited("'never say never', he never said", "'", ''); + +$a will be "'never say never'", $b will be ', he never said'. + +In addition to extract_delimited() there are also extract_bracketed(), +extract_quotelike(), extract_codeblock(), extract_variable(), +extract_tagged(), extract_multiple(), gen_delimited_pat(), and +gen_extract_tagged(). With these you can implement rather advanced +parsing algorithms. See L for more information. + +=item * + +Tie::RefHash::Nestable, by Edward Avis, allows storing hash references +(unlike the standard Tie::RefHash) The module is contained within +Tie::RefHash. + +=item * + +XS::Typemap, by Tim Jenness, is a test extension that exercises XS +typemaps. Nothing gets installed but for extension writers the code +is worth studying. + +=back + +=head2 Updated And Improved Modules and Pragmata + +=over 4 + +=item * + +B::Deparse should be now more robust. It still far from providing a full +round trip for any random piece of Perl code, though, and is under active +development: expect more robustness in 5.7.2. + +=item * + +Class::Struct can now define the classes in compile time. + +=item * + +Math::BigFloat has undergone much fixing, and in addition the fmod() +function now supports modulus operations. + +( The fixed Math::BigFloat module is also available in CPAN for those +who can't upgrade their Perl: http://www.cpan.org/authors/id/J/JP/JPEACOCK/ ) + +=item * + +Devel::Peek now has an interface for the Perl memory statistics +(this works only if you are using perl's malloc, and if you have +compiled with debugging). + +=item * + +IO::Socket has now atmark() method, which returns true if the socket +is positioned at the out-of-band mark. The method is also exportable +as a sockatmark() function. + +=item * + +IO::Socket::INET has support for ReusePort option (if your platform +supports it). The Reuse option now has an alias, ReuseAddr. For clarity +you may want to prefer ReuseAddr. + +=item * + +Net::Ping has been enhanced. There is now "external" protocol which +uses Net::Ping::External module which runs external ping(1) and parses +the output. An alpha version of Net::Ping::External is available in +CPAN and in 5.7.2 the Net::Ping::External may be integrated to Perl. + +=item * + +The C pragma allows layers other than ":raw" and ":crlf" when +using PerlIO. + +=item * + +POSIX::sigaction() is now much more flexible and robust. +You can now install coderef handlers, 'DEFAULT', and 'IGNORE' +handlers, installing new handlers was not atomic. + +=item * + +The Test module has been significantly enhanced. Its use is +greatly recommended for module writers. + +=item * + +The utf8:: name space (as in the pragma) provides various +Perl-callable functions to provide low level access to Perl's +internal Unicode representation. At the moment only length() +has been implemented. + +=back + +The following modules have been upgraded from the versions at CPAN: +CPAN, CGI, DB_File, File::Temp, Getopt::Long, Pod::Man, Pod::Text, +Storable, Text-Tabs+Wrap. + =head1 Performance Enhancements =over 4 @@ -45,56 +514,540 @@ C<%\d+\$> and C<*\d+\$> syntaxes. =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. 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. +( http://burtleburtle.net/bob/hash/doobs.html ). This algorithm is +reasonably fast while producing a much better spread of values than +the old hashing algorithm (originally by Chris Torek, later tweaked by +Ilya Zakharevich). Hash values output from the algorithm on a hash of +all 3-char printable ASCII keys comes much closer to passing the +DIEHARD random number generation tests. According to perlbench, this +change has not affected the overall speed of Perl. + +=item * + +unshift() should now be noticeably faster. + +=back + +=head1 Utility Changes + +=over 4 + +=item * + +h2xs now produces template README. + +=item * + +s2p has been completely rewritten in Perl. (It is in fact a full +implementation of sed in Perl.) + +=item * + +xsubpp now supports OUT keyword. =back +=head1 New Documentation + +=head2 perlclib + +Internal replacements for standard C library functions. +(Interesting only for extension writers and Perl core hackers.) + +=head2 perliol + +Internals of PerlIO with layers. + +=head2 README.aix + +Documentation on compiling Perl on AIX has been added. AIX has +several different C compilers and getting the right patch level +is essential. On install README.aix will be installed as L. + +=head2 README.bs2000 + +Documentation on compiling Perl on the POSIX-BC platform (an EBCDIC +mainframe environment) has been added. + +This was formerly known as README.posix-bc but the name was considered +to be too confusing (it has nothing to do with the POSIX module or the +POSIX standard). On install README.bs2000 will be installed as L. + +=head2 README.macos + +In perl 5.7.1 (and in the 5.6.1) the MacPerl sources have been +synchronised with the standard Perl sources. To compile MacPerl +some additional steps are required, and this file documents those +steps. On install README.macos will be installed as L. + +=head2 README.mpeix + +The README.mpeix has been podified, which means that this information +about compiling and using Perl on the MPE/iX miniframe platform will +be installed as L. + +=head2 README.solaris + +README.solaris has been created and Solaris wisdom from elsewhere +in the Perl documentation has been collected there. On install +README.solaris will be installed as L. + +=head2 README.vos + +The README.vos has been podified, which means that this information +about compiling and using Perl on the Stratus VOS miniframe platform +will be installed as L. + +=head2 Porting/repository.pod + +Documentation on how to use the Perl source repository has been added. + =head1 Installation and Configuration Improvements =over 4 =item * +Because PerlIO is now the default on most platforms, "-perlio" doesn't +get appended to the $Config{archname} (also known as $^O) anymore. +Instead, if you explicitly choose not to use perlio (Configure command +line option -Uuseperlio), you will get "-stdio" appended. + +=item * + +Another change related to the architecture name is that "-64all" +(-Duse64bitall, or "maximally 64-bit") is appended only if your +pointers are 64 bits wide. (To be exact, the use64bitall is ignored.) + +=item * + +APPLLIB_EXP, a less-know configuration-time definition, has been +documented. It can be used to prepend site-specific directories +to Perl's default search path (@INC), see INSTALL for information. + +=item * + +Building Berkeley DB3 for compatibility modes for DB, NDBM, and ODBM +has been documented in INSTALL. + +=item * + +If you are on IRIX or Tru64 platforms, new profiling/debugging options +have been added, see L for more information about pixie and +Third Degree. + +=back + +=head2 New Or Improved Platforms + +For the list of platforms known to support Perl, +see L. + +=over 4 + +=item * + +AIX dynamic loading should be now better supported. + +=item * + +After a long pause, AmigaOS has been verified to be happy with Perl. + +=item * + +EBCDIC platforms (z/OS, also known as OS/390, POSIX-BC, and VM/ESA) +have been regained. Many test suite tests still fail and the +co-existence of Unicode and EBCDIC isn't quite settled, but the +situation is much better than with Perl 5.6. See L, +L (for POSIX-BC), and L for more information. + +=item * + +Building perl with -Duseithreads or -Duse5005threads now works under +HP-UX 10.20 (previously it only worked under 10.30 or later). You will +need a thread library package installed. See README.hpux. + +=item * + +Mac OS Classic (MacPerl has of course been available since +perl 5.004 but now the source code bases of standard Perl +and MacPerl have been synchronised) + +=item * + +NCR MP-RAS is now supported. + +=item * + +NonStop-UX is now supported. + +=item * + +Amdahl UTS is now supported. + +=item * + +z/OS (formerly known as OS/390, formerly known as MVS OE) has now +support for dynamic loading. This is not selected by default, +however, you must specify -Dusedl in the arguments of Configure. + +=back + +=head2 Generic Improvements + +=over 4 + +=item * + Configure no longer includes the DBM libraries (dbm, gdbm, db, ndbm) -when building the Perl binary. The only exception to this is SunOS 4.x, +when building the Perl binary. The only exception to this is SunOS 4.x, which needs them. +=item * + +Some new Configure symbols, useful for extension writers: + +=over 8 + +=item d_cmsghdr + +For struct cmsghdr. + +=item d_fcntl_can_lock + +Whether fcntl() can be used for file locking. + +=item d_fsync + +=item d_getitimer + +=item d_getpagsz + +For getpagesize(), though you should prefer POSIX::sysconf(_SC_PAGE_SIZE)) + +=item d_msghdr_s + +For struct msghdr. + +=item need_va_copy + +Whether one needs to use Perl_va_copy() to copy varargs. + +=item d_readv + +=item d_recvmsg + +=item d_sendmsg + +=item sig_size + +The number of elements in an array needed to hold all the available signals. + +=item d_sockatmark + +=item d_strtoq + +=item d_u32align + +Whether one needs to access character data aligned by U32 sized pointers. + +=item d_ualarm + +=item d_usleep + +=back + +=item * + +Removed Configure symbols: the PDP-11 memory model settings: huge, +large, medium, models. + +=item * + +SOCKS support is now much more robust. + +=item * + +If your file system supports symbolic links you can build Perl outside +of the source directory by + + mkdir perl/build/directory + cd perl/build/directory + sh /path/to/perl/source/Configure -Dmksymlinks ... + +This will create in perl/build/directory a tree of symbolic links +pointing to files in /path/to/perl/source. The original files are left +unaffected. After Configure has finished you can just say + + make all test + +and Perl will be built and tested, all in perl/build/directory. + =back =head1 Selected Bug Fixes +Numerous memory leaks and uninitialized memory accesses have been hunted down. +Most importantly anonymous subs used to leak quite a bit. + =over 4 =item * +chop(@list) in list context returned the characters chopped in +reverse order. This has been reversed to be in the right order. + +=item * + +The order of DESTROYs has been made more predictable. + +=item * + +mkdir() now ignores trailing slashes in the directory name, +as mandated by POSIX. + +=item * + +Attributes (like :shared) didn't work with our(). + +=item * + +The PERL5OPT environment variable (for passing command line arguments +to Perl) didn't work for more than a single group of options. + +=item * + +The tainting behaviour of sprintf() has been rationalized. It does +not taint the result of floating point formats anymore, making the +behaviour consistent with that of string interpolation. + +=item * + +All but the first argument of the IO syswrite() method are now optional. + +=item * + +Tie::ARRAY SPLICE method was broken. + +=item * + vec() now tries to work with characters <= 255 when possible, but it leaves higher character values in place. In that case, if vec() was used to modify the string, it is no longer considered to be utf8-encoded. =back +=head2 Platform Specific Changes and Fixes + +=over 4 + +=item * + +Linux previously had problems related to sockaddrlen when using +accept(), revcfrom() (in Perl: recv()), getpeername(), and getsockname(). + +=item * + +Previously DYNIX/ptx had problems in its Configure probe for non-blocking I/O. + +=item * + +Windows + +=over 8 + +=item * + +Borland C++ v5.5 is now a supported compiler that can build Perl. +However, the generated binaries continue to be incompatible with those +generated by the other supported compilers (GCC and Visual C++). + +=item * + +Win32::GetCwd() correctly returns C:\ instead of C: when at the drive root. +Other bugs in chdir() and Cwd::cwd() have also been fixed. + +=item * + +Duping socket handles with open(F, ">&MYSOCK") now works under Windows 9x. + +=item * + +HTML files will be installed in c:\perl\html instead of c:\perl\lib\pod\html + +=item * + +The makefiles now provide a single switch to bulk-enable all the features +enabled in ActiveState ActivePerl (a popular binary distribution). + +=back + +=back + +=head1 New or Changed Diagnostics + +Two new debugging options have been added: if you have compiled your +Perl with debugging, you can use the -DT and -DR options to trace +tokenising and to add reference counts to displaying variables, +respectively. + +=over 4 + +=item * + +If an attempt to use a (non-blessed) reference as an array index +is made, a warning is given. + +=item * + +C and C (with no values to push or unshift) +now give a warning. This may be a problem for generated and eval'ed +code. + +=back + +=head1 Changed Internals + +=over 4 + +=item * + +Some new APIs: ptr_table_clear(), ptr_table_free(), sv_setref_uv(). +For the full list of the available APIs see L. + +=item * + +dTHR and djSP have been obsoleted; the former removed (because it's +a no-op) and the latter replaced with dSP. + +=item * + +Perl now uses system malloc instead of Perl malloc on all 64-bit +platforms, and even in some not-always-64-bit platforms like AIX, +IRIX, and Solaris. This change breaks backward compatibility but +Perl's malloc has problems with large address spaces and also the +speed of vendors' malloc is generally better in large address space +machines (Perl's malloc is mostly tuned for space). + +=back + +=head1 New Tests + +Many new tests have been added. The most notable is probably the +lib/1_compile: it is very notable because running it takes quite a +long time -- it test compiles all the Perl modules in the distribution. +Please be patient. + =head1 Known Problems +Note that unlike other sections in this document (which describe +changes since 5.7.0) this section is cumulative containing known +problems for all the 5.7 releases. + +=head2 AIX vac 5.0.0.0 May Produce Buggy Code For Perl + +The AIX C compiler vac version 5.0.0.0 may produce buggy code, +resulting in few random tests failing, but when the failing tests +are run by hand, they succeed. We suggest upgrading to at least +vac version 5.0.1.0, that has been known to compile Perl correctly. +"lslpp -L|grep vac.C" will tell you the vac version. + +=head2 lib/ftmp-security tests warn 'system possibly insecure' + +Don't panic. Read INSTALL 'make test' section instead. + +=head2 lib/io_multihomed Fails In LP64-Configured HP-UX + +The lib/io_multihomed test may hang in HP-UX if Perl has been +configured to be 64-bit. Because other 64-bit platforms do not hang in +this test, HP-UX is suspect. All other tests pass in 64-bit HP-UX. The +test attempts to create and connect to "multihomed" sockets (sockets +which have multiple IP addresses). + +=head2 Test lib/posix Subtest 9 Fails In LP64-Configured HP-UX + +If perl is configured with -Duse64bitall, the successful result of the +subtest 10 of lib/posix may arrive before the successful result of the +subtest 9, which confuses the test harness so much that it thinks the +subtest 9 failed. + +=head2 lib/b test 19 + +The test fails on various platforms (PA64 and IA64 are known), but the +exact cause is still being investigated. + +=head2 Linux With Sfio Fails op/misc Test 48 + +No known fix. + +=head2 sigaction test 13 in VMS + +The test is known to fail; whether it's because of VMS of because +of faulty test is not known. + =head2 sprintf tests 129 and 130 -The op/sprintf tests 129 and 130 are known to fail in some platforms. -Examples include any platform using sfio, and Tandem's NonStop-UX. +The op/sprintf tests 129 and 130 are known to fail on some platforms. +Examples include any platform using sfio, and Compaq/Tandem's NonStop-UX. The failing platforms do not comply with the ANSI C Standard, line 19ff on page 134 of ANSI X3.159 1989 to be exact. (They produce something else than "1" and "-1" when formatting 0.6 and -0.6 using the printf format "%.0f", most often they produce "0" and "-0".) +=head2 Failure of Thread tests + +The subtests 19 and 20 of lib/thr5005.t test are known to fail due to +fundamental problems in the 5.005 threading implementation. These are +not new failures--Perl 5.005_0x has the same bugs, but didn't have +these tests. (Note that support for 5.005-style threading remains +experimental.) + +=head2 Localising a Tied Variable Leaks Memory + + use Tie::Hash; + tie my %tie_hash => 'Tie::StdHash'; + + ... + + local($tie_hash{Foo}) = 1; # leaks + +Code like the above is known to leak memory every time the local() +is executed. + +=head2 Self-tying of Arrays and Hashes Is Forbidden + +Self-tying of arrays and hashes is broken in rather deep and +hard-to-fix ways. As a stop-gap measure to avoid people from getting +frustrated at the mysterious results (core dumps, most often) it is +for now forbidden (you will get a fatal error even from an attempt). + +=head2 Building Extensions Can Fail Because Of Largefiles + +Some extensions like mod_perl are known to have issues with +`largefiles', a change brought by Perl 5.6.0 in which file offsets +default to 64 bits wide, where supported. Modules may fail to compile +at all or compile and work incorrectly. Currently there is no good +solution for the problem, but Configure now provides appropriate +non-largefile ccflags, ldflags, libswanted, and libs in the %Config +hash (e.g., $Config{ccflags_nolargefiles}) so the extensions that are +having problems can try configuring themselves without the +largefileness. This is admittedly not a clean solution, and the +solution may not even work at all. One potential failure is whether +one can (or, if one can, whether it's a good idea) link together at +all binaries with different ideas about file offsets, all this is +platform-dependent. + +=head2 The Compiler Suite Is Still Experimental + +The compiler suite is slowly getting better but is nowhere near +working order yet. + =head1 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/perl/ , the Perl Home Page. If you believe you have an unreported bug, please run the B program included with your release. Be sure to trim your bug down