| =head1 NAME |
| |
| perl571delta - what's new for perl v5.7.1 |
| |
| =head1 DESCRIPTION |
| |
| 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<perl570delta>.) |
| |
| =head1 Security Vulnerability Closed |
| |
| (This change was already made in 5.7.0 but bears repeating here.) |
| |
| A potential security vulnerability in the optional suidperl component |
| of Perl was identified in August 2000. suidperl is neither built nor |
| installed by default. As of April 2001 the only known vulnerable |
| platform is Linux, most likely all Linux distributions. CERT and |
| various vendors and distributors have been alerted about the vulnerability. |
| See http://www.cpan.org/src/5.0/sperl-2000-08-05/sperl-2000-08-05.txt |
| for more information. |
| |
| The problem was caused by Perl trying to report a suspected security |
| exploit attempt using an external program, /bin/mail. On Linux |
| platforms the /bin/mail program had an undocumented feature which |
| when combined with suidperl gave access to a root shell, resulting in |
| a serious compromise instead of reporting the exploit attempt. If you |
| don't have /bin/mail, or if you have 'safe setuid scripts', or if |
| suidperl is not installed, you are safe. |
| |
| The exploit attempt reporting feature has been completely removed from |
| all the Perl 5.7 releases (and will be gone also from the maintenance |
| release 5.6.1), so that particular vulnerability isn't there anymore. |
| However, further security vulnerabilities are, unfortunately, always |
| possible. The suidperl code is being reviewed and if deemed too risky |
| to continue to be supported, it may be completely removed from future |
| releases. In any case, suidperl should only be used by security |
| experts who know exactly what they are doing and why they are using |
| suidperl instead of some other solution such as sudo |
| ( see http://www.courtesan.com/sudo/ ). |
| |
| =head1 Incompatible Changes |
| |
| =over 4 |
| |
| =item * |
| |
| Although "you shouldn't do that", it was possible to write code that |
| depends on Perl's hashed key order (Data::Dumper does this). The new |
| algorithm "One-at-a-Time" produces a different hashed key order. |
| More details are in L</"Performance Enhancements">. |
| |
| =item * |
| |
| The list of filenames from glob() (or <...>) is now by default sorted |
| alphabetically to be csh-compliant. (bsd_glob() does still sort platform |
| natively, ASCII or EBCDIC, unless GLOB_ALPHASORT is specified.) |
| |
| =back |
| |
| =head1 Core Enhancements |
| |
| =head2 AUTOLOAD Is Now Lvaluable |
| |
| AUTOLOAD is now lvaluable, meaning that you can add the :lvalue attribute |
| to AUTOLOAD subroutines and you can assign to the AUTOLOAD return value. |
| |
| =head2 PerlIO is Now The Default |
| |
| =over 4 |
| |
| =item * |
| |
| IO is now by default done via PerlIO rather than system's "stdio". |
| PerlIO allows "layers" to be "pushed" onto a file handle to alter the |
| handle's behaviour. Layers can be specified at open time via 3-arg |
| form of open: |
| |
| open($fh,'>:crlf :utf8', $path) || ... |
| |
| or on already opened handles via extended C<binmode>: |
| |
| binmode($fh,':encoding(iso-8859-7)'); |
| |
| The built-in layers are: unix (low level read/write), stdio (as in |
| previous Perls), perlio (re-implementation of stdio buffering in a |
| portable manner), crlf (does CRLF <=> "\n" translation as on Win32, |
| but available on any platform). A mmap layer may be available if |
| platform supports it (mostly UNIXes). |
| |
| Layers to be applied by default may be specified via the 'open' pragma. |
| |
| See L</"Installation and Configuration Improvements"> for the effects |
| of PerlIO on your architecture name. |
| |
| =item * |
| |
| File handles can be marked as accepting Perl's internal encoding of Unicode |
| (UTF-8 or UTF-EBCDIC depending on platform) by a pseudo layer ":utf8" : |
| |
| open($fh,">:utf8","Uni.txt"); |
| |
| Note for EBCDIC users: the pseudo layer ":utf8" is erroneously named |
| for you since it's not UTF-8 what you will be getting but instead |
| UTF-EBCDIC. See L<perlunicode>, L<utf8>, and |
| http://www.unicode.org/unicode/reports/tr16/ for more information. |
| In future releases this naming may change. |
| |
| =item * |
| |
| File handles can translate character encodings from/to Perl's internal |
| Unicode form on read/write via the ":encoding()" layer. |
| |
| =item * |
| |
| File handles can be opened to "in memory" files held in Perl scalars via: |
| |
| open($fh,'>', \$variable) || ... |
| |
| =item * |
| |
| Anonymous temporary files are available without need to |
| 'use FileHandle' or other module via |
| |
| open($fh,"+>", undef) || ... |
| |
| That is a literal undef, not an undefined value. |
| |
| =item * |
| |
| The list form of C<open> is now implemented for pipes (at least on UNIX): |
| |
| open($fh,"-|", 'cat', '/etc/motd') |
| |
| creates a pipe, and runs the equivalent of exec('cat', '/etc/motd') in |
| the child process. |
| |
| =item * |
| |
| The following builtin functions are now overridable: chop(), chomp(), |
| each(), keys(), pop(), push(), shift(), splice(), unshift(). |
| |
| =item * |
| |
| Formats now support zero-padded decimal fields. |
| |
| =item * |
| |
| Perl now tries internally to use integer values in numeric conversions |
| and basic arithmetics (+ - * /) if the arguments are integers, and |
| tries also to keep the results stored internally as integers. |
| This change leads into often slightly faster and always less lossy |
| arithmetics. (Previously Perl always preferred floating point numbers |
| in its math.) |
| |
| =item * |
| |
| The printf() and sprintf() now support parameter reordering using the |
| C<%\d+\$> and C<*\d+\$> syntaxes. For example |
| |
| print "%2\$s %1\$s\n", "foo", "bar"; |
| |
| will print "bar foo\n"; This feature helps in writing |
| internationalised software. |
| |
| =item * |
| |
| Unicode in general should be now much more usable. Unicode can be |
| used in hash keys, Unicode in regular expressions should work now, |
| Unicode in tr/// should work now (though tr/// seems to be a |
| particularly tricky to get right, so you have been warned) |
| |
| =item * |
| |
| The Unicode Character Database coming with Perl has been upgraded |
| to Unicode 3.1. For more information, see http://www.unicode.org/ , |
| and http://www.unicode.org/unicode/reports/tr27/ |
| |
| For developers interested in enhancing Perl's Unicode capabilities: |
| almost all the UCD files are included with the Perl distribution in |
| the lib/unicode subdirectory. The most notable omission, for space |
| considerations, is the Unihan database. |
| |
| =item * |
| |
| The Unicode character classes \p{Blank} and \p{SpacePerl} have been |
| added. "Blank" is like C isblank(), that is, it contains only |
| "horizontal whitespace" (the space character is, the newline isn't), |
| and the "SpacePerl" is the Unicode equivalent of C<\s> (\p{Space} |
| isn't, since that includes the vertical tabulator character, whereas |
| C<\s> doesn't.) |
| |
| =back |
| |
| =head2 Signals Are Now Safe |
| |
| Perl used to be fragile in that signals arriving at inopportune moments |
| could corrupt Perl's internal state. |
| |
| =head1 Modules and Pragmata |
| |
| =head2 New Modules |
| |
| =over 4 |
| |
| =item * |
| |
| B::Concise, by Stephen McCamant, is a new compiler backend for |
| walking the Perl syntax tree, printing concise info about ops. |
| The output is highly customisable. |
| |
| See L<B::Concise> for more information. |
| |
| =item * |
| |
| Class::ISA, by Sean Burke, for reporting the search path for a |
| class's ISA tree, has been added. |
| |
| See L<Class::ISA> for more information. |
| |
| =item * |
| |
| Cwd has now a split personality: if possible, an extension is used, |
| (this will hopefully be both faster and more secure and robust) but |
| if not possible, the familiar Perl library implementation is used. |
| |
| =item * |
| |
| Digest, a frontend module for calculating digests (checksums), |
| from Gisle Aas, has been added. |
| |
| See L<Digest> for more information. |
| |
| =item * |
| |
| Digest::MD5 for calculating MD5 digests (checksums), by Gisle Aas, |
| has been added. |
| |
| use Digest::MD5 'md5_hex'; |
| |
| $digest = md5_hex("Thirsty Camel"); |
| |
| print $digest, "\n"; # 01d19d9d2045e005c3f1b80e8b164de1 |
| |
| NOTE: the MD5 backward compatibility module is deliberately not |
| included since its use is discouraged. |
| |
| See L<Digest::MD5> for more information. |
| |
| =item * |
| |
| Encode, by Nick Ing-Simmons, provides a mechanism to translate |
| between different character encodings. Support for Unicode, |
| ISO-8859-*, ASCII, CP*, KOI8-R, and three variants of EBCDIC are |
| compiled in to the module. Several other encodings (like Japanese, |
| Chinese, and MacIntosh encodings) are included and will be loaded at |
| runtime. |
| |
| Any encoding supported by Encode module is also available to the |
| ":encoding()" layer if PerlIO is used. |
| |
| See L<Encode> for more information. |
| |
| =item * |
| |
| Filter::Simple is an easy-to-use frontend to Filter::Util::Call, |
| from Damian Conway. |
| |
| # in MyFilter.pm: |
| |
| package MyFilter; |
| |
| use Filter::Simple sub { |
| while (my ($from, $to) = splice @_, 0, 2) { |
| s/$from/$to/g; |
| } |
| }; |
| |
| 1; |
| |
| # in user's code: |
| |
| use MyFilter qr/red/ => 'green'; |
| |
| print "red\n"; # this code is filtered, will print "green\n" |
| print "bored\n"; # this code is filtered, will print "bogreen\n" |
| |
| no MyFilter; |
| |
| print "red\n"; # this code is not filtered, will print "red\n" |
| |
| See L<Filter::Simple> for more information. |
| |
| =item * |
| |
| Filter::Util::Call, by Paul Marquess, provides you with the |
| framework to write I<Source Filters> in Perl. For most uses |
| the frontend Filter::Simple is to be preferred. |
| See L<Filter::Util::Call> for more information. |
| |
| =item * |
| |
| Locale::Constants, Locale::Country, Locale::Currency, and Locale::Language, |
| from Neil Bowers, have been added. They provide the codes for various |
| locale standards, such as "fr" for France, "usd" for US Dollar, and |
| "jp" for Japanese. |
| |
| use Locale::Country; |
| |
| $country = code2country('jp'); # $country gets 'Japan' |
| $code = country2code('Norway'); # $code gets 'no' |
| |
| See L<Locale::Constants>, L<Locale::Country>, L<Locale::Currency>, |
| and L<Locale::Language> for more information. |
| |
| =item * |
| |
| MIME::Base64, by Gisle Aas, allows you to encode data in base64. |
| |
| use MIME::Base64; |
| |
| $encoded = encode_base64('Aladdin:open sesame'); |
| $decoded = decode_base64($encoded); |
| |
| print $encoded, "\n"; # "QWxhZGRpbjpvcGVuIHNlc2FtZQ==" |
| |
| See L<MIME::Base64> for more information. |
| |
| =item * |
| |
| MIME::QuotedPrint, by Gisle Aas, allows you to encode data in |
| quoted-printable encoding. |
| |
| use MIME::QuotedPrint; |
| |
| $encoded = encode_qp("Smiley in Unicode: \x{263a}"); |
| $decoded = decode_qp($encoded); |
| |
| print $encoded, "\n"; # "Smiley in Unicode: =263A" |
| |
| MIME::QuotedPrint has been enhanced to provide the basic methods |
| necessary to use it with PerlIO::Via as in : |
| |
| use MIME::QuotedPrint; |
| open($fh,">Via(MIME::QuotedPrint)",$path) |
| |
| See L<MIME::QuotedPrint> for more information. |
| |
| =item * |
| |
| PerlIO::Scalar, by Nick Ing-Simmons, provides the implementation of |
| IO to "in memory" Perl scalars as discussed above. It also serves as |
| an example of a loadable layer. Other future possibilities include |
| PerlIO::Array and PerlIO::Code. See L<PerlIO::Scalar> for more |
| information. |
| |
| =item * |
| |
| PerlIO::Via, by Nick Ing-Simmons, acts as a PerlIO layer and wraps |
| PerlIO layer functionality provided by a class (typically implemented |
| in perl code). |
| |
| use MIME::QuotedPrint; |
| open($fh,">Via(MIME::QuotedPrint)",$path) |
| |
| This will automatically convert everything output to C<$fh> |
| to Quoted-Printable. See L<PerlIO::Via> for more information. |
| |
| =item * |
| |
| Pod::Text::Overstrike, by Joe Smith, has been added. |
| It converts POD data to formatted overstrike text. |
| See L<Pod::Text::Overstrike> for more information. |
| |
| =item * |
| |
| Switch from Damian Conway has been added. Just by saying |
| |
| use Switch; |
| |
| you have C<switch> and C<case> available in Perl. |
| |
| use Switch; |
| |
| switch ($val) { |
| |
| case 1 { print "number 1" } |
| case "a" { print "string a" } |
| case [1..10,42] { print "number in list" } |
| case (@array) { print "number in list" } |
| case /\w+/ { print "pattern" } |
| case qr/\w+/ { print "pattern" } |
| case (%hash) { print "entry in hash" } |
| case (\%hash) { print "entry in hash" } |
| case (\&sub) { print "arg to subroutine" } |
| else { print "previous case not true" } |
| } |
| |
| See L<Switch> for more information. |
| |
| =item * |
| |
| Text::Balanced from Damian Conway has been added, for |
| extracting delimited text sequences from strings. |
| |
| use Text::Balanced 'extract_delimited'; |
| |
| ($a, $b) = extract_delimited("'never say never', he never said", "'", ''); |
| |
| $a will be "'never say never'", $b will be ', he never said'. |
| |
| In addition to extract_delimited() there are also extract_bracketed(), |
| extract_quotelike(), extract_codeblock(), extract_variable(), |
| extract_tagged(), extract_multiple(), gen_delimited_pat(), and |
| gen_extract_tagged(). With these you can implement rather advanced |
| parsing algorithms. See L<Text::Balanced> for more information. |
| |
| =item * |
| |
| Tie::RefHash::Nestable, by Edward Avis, allows storing hash references |
| (unlike the standard Tie::RefHash) The module is contained within |
| Tie::RefHash. |
| |
| =item * |
| |
| XS::Typemap, by Tim Jenness, is a test extension that exercises XS |
| typemaps. Nothing gets installed but for extension writers the code |
| is worth studying. |
| |
| =back |
| |
| =head2 Updated And Improved Modules and Pragmata |
| |
| =over 4 |
| |
| =item * |
| |
| B::Deparse should be now more robust. It still far from providing a full |
| round trip for any random piece of Perl code, though, and is under active |
| development: expect more robustness in 5.7.2. |
| |
| =item * |
| |
| Class::Struct can now define the classes in compile time. |
| |
| =item * |
| |
| Math::BigFloat has undergone much fixing, and in addition the fmod() |
| function now supports modulus operations. |
| |
| ( The fixed Math::BigFloat module is also available in CPAN for those |
| who can't upgrade their Perl: http://www.cpan.org/authors/id/J/JP/JPEACOCK/ ) |
| |
| =item * |
| |
| Devel::Peek now has an interface for the Perl memory statistics |
| (this works only if you are using perl's malloc, and if you have |
| compiled with debugging). |
| |
| =item * |
| |
| IO::Socket has now atmark() method, which returns true if the socket |
| is positioned at the out-of-band mark. The method is also exportable |
| as a sockatmark() function. |
| |
| =item * |
| |
| IO::Socket::INET has support for ReusePort option (if your platform |
| supports it). The Reuse option now has an alias, ReuseAddr. For clarity |
| you may want to prefer ReuseAddr. |
| |
| =item * |
| |
| Net::Ping has been enhanced. There is now "external" protocol which |
| uses Net::Ping::External module which runs external ping(1) and parses |
| the output. An alpha version of Net::Ping::External is available in |
| CPAN and in 5.7.2 the Net::Ping::External may be integrated to Perl. |
| |
| =item * |
| |
| The C<open> pragma allows layers other than ":raw" and ":crlf" when |
| using PerlIO. |
| |
| =item * |
| |
| POSIX::sigaction() is now much more flexible and robust. |
| You can now install coderef handlers, 'DEFAULT', and 'IGNORE' |
| handlers, installing new handlers was not atomic. |
| |
| =item * |
| |
| The Test module has been significantly enhanced. Its use is |
| greatly recommended for module writers. |
| |
| =item * |
| |
| The utf8:: name space (as in the pragma) provides various |
| Perl-callable functions to provide low level access to Perl's |
| internal Unicode representation. At the moment only length() |
| has been implemented. |
| |
| =back |
| |
| The following modules have been upgraded from the versions at CPAN: |
| CPAN, CGI, DB_File, File::Temp, Getopt::Long, Pod::Man, Pod::Text, |
| Storable, Text-Tabs+Wrap. |
| |
| =head1 Performance Enhancements |
| |
| =over 4 |
| |
| =item * |
| |
| Hashes now use Bob Jenkins "One-at-a-Time" hashing key algorithm |
| ( http://burtleburtle.net/bob/hash/doobs.html ). This algorithm is |
| reasonably fast while producing a much better spread of values than |
| the old hashing algorithm (originally by Chris Torek, later tweaked by |
| Ilya Zakharevich). Hash values output from the algorithm on a hash of |
| all 3-char printable ASCII keys comes much closer to passing the |
| DIEHARD random number generation tests. According to perlbench, this |
| change has not affected the overall speed of Perl. |
| |
| =item * |
| |
| unshift() should now be noticeably faster. |
| |
| =back |
| |
| =head1 Utility Changes |
| |
| =over 4 |
| |
| =item * |
| |
| h2xs now produces template README. |
| |
| =item * |
| |
| s2p has been completely rewritten in Perl. (It is in fact a full |
| implementation of sed in Perl.) |
| |
| =item * |
| |
| xsubpp now supports OUT keyword. |
| |
| =back |
| |
| =head1 New Documentation |
| |
| =head2 perlclib |
| |
| Internal replacements for standard C library functions. |
| (Interesting only for extension writers and Perl core hackers.) |
| |
| =head2 perliol |
| |
| Internals of PerlIO with layers. |
| |
| =head2 README.aix |
| |
| Documentation on compiling Perl on AIX has been added. AIX has |
| several different C compilers and getting the right patch level |
| is essential. On install README.aix will be installed as L<perlaix>. |
| |
| =head2 README.bs2000 |
| |
| Documentation on compiling Perl on the POSIX-BC platform (an EBCDIC |
| mainframe environment) has been added. |
| |
| This was formerly known as README.posix-bc but the name was considered |
| to be too confusing (it has nothing to do with the POSIX module or the |
| POSIX standard). On install README.bs2000 will be installed as L<perlbs2000>. |
| |
| =head2 README.macos |
| |
| In perl 5.7.1 (and in the 5.6.1) the MacPerl sources have been |
| synchronised with the standard Perl sources. To compile MacPerl |
| some additional steps are required, and this file documents those |
| steps. On install README.macos will be installed as L<perlmacos>. |
| |
| =head2 README.mpeix |
| |
| The README.mpeix has been podified, which means that this information |
| about compiling and using Perl on the MPE/iX miniframe platform will |
| be installed as L<perlmpeix>. |
| |
| =head2 README.solaris |
| |
| README.solaris has been created and Solaris wisdom from elsewhere |
| in the Perl documentation has been collected there. On install |
| README.solaris will be installed as L<perlsolaris>. |
| |
| =head2 README.vos |
| |
| The README.vos has been podified, which means that this information |
| about compiling and using Perl on the Stratus VOS miniframe platform |
| will be installed as L<perlvos>. |
| |
| =head2 Porting/repository.pod |
| |
| Documentation on how to use the Perl source repository has been added. |
| |
| =head1 Installation and Configuration Improvements |
| |
| =over 4 |
| |
| =item * |
| |
| Because PerlIO is now the default on most platforms, "-perlio" doesn't |
| get appended to the $Config{archname} (also known as $^O) anymore. |
| Instead, if you explicitly choose not to use perlio (Configure command |
| line option -Uuseperlio), you will get "-stdio" appended. |
| |
| =item * |
| |
| Another change related to the architecture name is that "-64all" |
| (-Duse64bitall, or "maximally 64-bit") is appended only if your |
| pointers are 64 bits wide. (To be exact, the use64bitall is ignored.) |
| |
| =item * |
| |
| APPLLIB_EXP, a less-know configuration-time definition, has been |
| documented. It can be used to prepend site-specific directories |
| to Perl's default search path (@INC), see INSTALL for information. |
| |
| =item * |
| |
| Building Berkeley DB3 for compatibility modes for DB, NDBM, and ODBM |
| has been documented in INSTALL. |
| |
| =item * |
| |
| If you are on IRIX or Tru64 platforms, new profiling/debugging options |
| have been added, see L<perlhack> for more information about pixie and |
| Third Degree. |
| |
| =back |
| |
| =head2 New Or Improved Platforms |
| |
| For the list of platforms known to support Perl, |
| see L<perlport/"Supported Platforms">. |
| |
| =over 4 |
| |
| =item * |
| |
| AIX dynamic loading should be now better supported. |
| |
| =item * |
| |
| After a long pause, AmigaOS has been verified to be happy with Perl. |
| |
| =item * |
| |
| EBCDIC platforms (z/OS, also known as OS/390, POSIX-BC, and VM/ESA) |
| have been regained. Many test suite tests still fail and the |
| co-existence of Unicode and EBCDIC isn't quite settled, but the |
| situation is much better than with Perl 5.6. See L<perlos390>, |
| L<perlbs2000> (for POSIX-BC), and L<perlvmesa> for more information. |
| |
| =item * |
| |
| Building perl with -Duseithreads or -Duse5005threads now works under |
| HP-UX 10.20 (previously it only worked under 10.30 or later). You will |
| need a thread library package installed. See README.hpux. |
| |
| =item * |
| |
| 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, |
| 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<push @a;> and C<unshift @a;> (with no values to push or unshift) |
| now give a warning. This may be a problem for generated and 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<perlapi>. |
| |
| =item * |
| |
| dTHR and djSP have been obsoleted; the former removed (because it's |
| a no-op) and the latter replaced with dSP. |
| |
| =item * |
| |
| Perl now uses system malloc instead of Perl malloc on all 64-bit |
| platforms, and even in some not-always-64-bit platforms like AIX, |
| IRIX, and Solaris. This change breaks backward compatibility but |
| Perl's malloc has problems with large address spaces and also the |
| speed of vendors' malloc is generally better in large address space |
| machines (Perl's malloc is mostly tuned for space). |
| |
| =back |
| |
| =head1 New Tests |
| |
| Many new tests have been added. The most notable is probably the |
| lib/1_compile: it is very notable because running it takes quite a |
| long time -- it test compiles all the Perl modules in the distribution. |
| Please be patient. |
| |
| =head1 Known Problems |
| |
| Note that unlike other sections in this document (which describe |
| changes since 5.7.0) this section is cumulative containing known |
| problems for all the 5.7 releases. |
| |
| =head2 AIX vac 5.0.0.0 May Produce Buggy Code For Perl |
| |
| The AIX C compiler vac version 5.0.0.0 may produce buggy code, |
| resulting in few random tests failing, but when the failing tests |
| are run by hand, they succeed. We suggest upgrading to at least |
| vac version 5.0.1.0, that has been known to compile Perl correctly. |
| "lslpp -L|grep vac.C" will tell you the vac version. |
| |
| =head2 lib/ftmp-security tests warn 'system possibly insecure' |
| |
| Don't panic. Read INSTALL 'make test' section instead. |
| |
| =head2 lib/io_multihomed Fails In LP64-Configured HP-UX |
| |
| The lib/io_multihomed test may hang in HP-UX if Perl has been |
| configured to be 64-bit. Because other 64-bit platforms do not hang in |
| this test, HP-UX is suspect. All other tests pass in 64-bit HP-UX. The |
| test attempts to create and connect to "multihomed" sockets (sockets |
| which have multiple IP addresses). |
| |
| =head2 Test lib/posix Subtest 9 Fails In LP64-Configured HP-UX |
| |
| If perl is configured with -Duse64bitall, the successful result of the |
| subtest 10 of lib/posix may arrive before the successful result of the |
| subtest 9, which confuses the test harness so much that it thinks the |
| subtest 9 failed. |
| |
| =head2 lib/b test 19 |
| |
| The test fails on various platforms (PA64 and IA64 are known), but the |
| exact cause is still being investigated. |
| |
| =head2 Linux With Sfio Fails op/misc Test 48 |
| |
| No known fix. |
| |
| =head2 sigaction test 13 in VMS |
| |
| The test is known to fail; whether it's because of VMS of because |
| of faulty test is not known. |
| |
| =head2 sprintf tests 129 and 130 |
| |
| The op/sprintf tests 129 and 130 are known to fail on some platforms. |
| Examples include any platform using sfio, and Compaq/Tandem's NonStop-UX. |
| The failing platforms do not comply with the ANSI C Standard, line |
| 19ff on page 134 of ANSI X3.159 1989 to be exact. (They produce |
| something else than "1" and "-1" when formatting 0.6 and -0.6 using |
| the printf format "%.0f", most often they produce "0" and "-0".) |
| |
| =head2 Failure of Thread tests |
| |
| The subtests 19 and 20 of lib/thr5005.t test are known to fail due to |
| fundamental problems in the 5.005 threading implementation. These are |
| not new failures--Perl 5.005_0x has the same bugs, but didn't have |
| these tests. (Note that support for 5.005-style threading remains |
| experimental.) |
| |
| =head2 Localising a Tied Variable Leaks Memory |
| |
| use Tie::Hash; |
| tie my %tie_hash => 'Tie::StdHash'; |
| |
| ... |
| |
| local($tie_hash{Foo}) = 1; # leaks |
| |
| Code like the above is known to leak memory every time the local() |
| is executed. |
| |
| =head2 Self-tying of Arrays and Hashes Is Forbidden |
| |
| Self-tying of arrays and hashes is broken in rather deep and |
| hard-to-fix ways. As a stop-gap measure to avoid people from getting |
| frustrated at the mysterious results (core dumps, most often) it is |
| for now forbidden (you will get a fatal error even from an attempt). |
| |
| =head2 Building Extensions Can Fail Because Of Largefiles |
| |
| Some extensions like mod_perl are known to have issues with |
| `largefiles', a change brought by Perl 5.6.0 in which file offsets |
| default to 64 bits wide, where supported. Modules may fail to compile |
| at all or compile and work incorrectly. Currently there is no good |
| solution for the problem, but Configure now provides appropriate |
| non-largefile ccflags, ldflags, libswanted, and libs in the %Config |
| hash (e.g., $Config{ccflags_nolargefiles}) so the extensions that are |
| having problems can try configuring themselves without the |
| largefileness. This is admittedly not a clean solution, and the |
| solution may not even work at all. One potential failure is whether |
| one can (or, if one can, whether it's a good idea) link together at |
| all binaries with different ideas about file offsets, all this is |
| platform-dependent. |
| |
| =head2 The Compiler Suite Is Still Experimental |
| |
| The compiler suite is slowly getting better but is nowhere near |
| working order yet. |
| |
| =head1 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. |
| |
| If you believe you have an unreported bug, please run the B<perlbug> |
| program included with your release. Be sure to trim your bug down |
| 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.org to be |
| analysed by the Perl porting team. |
| |
| =head1 SEE ALSO |
| |
| The F<Changes> file for exhaustive details on what changed. |
| |
| The F<INSTALL> file for how to build Perl. |
| |
| The F<README> file for general stuff. |
| |
| The F<Artistic> and F<Copying> files for copyright information. |
| |
| =head1 HISTORY |
| |
| 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.org>>. |
| |
| =cut |