perl571delta
PERL571DELTA(1) Perl Programmers Reference Guide PERL571DELTA(1)
NAME
perl571delta - what's new for perl v5.7.1
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 perl570delta.)
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 plat-
form 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 plat-
forms the /bin/mail program had an undocumented feature which when com-
bined 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/ ).
Incompatible Changes
o 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 "Performance Enhancements".
o 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.)
Core Enhancements
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.
PerlIO is Now The Default
o 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', $path) || ...
or on already opened handles via extended "binmode":
binmode($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 "Installation and Configuration Improvements" for the effects
of PerlIO on your architecture name.
o 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($fh,">:utf8","Uni.txt");
Note for EBCDIC users: the pseudo layer ":utf8" is erroneously
named for you since it's not UTF-8 what you will be getting but
instead UTF-EBCDIC. See perlunicode, utf8, and http://www.uni-
code.org/unicode/reports/tr16/ for more information. In future
releases this naming may change.
o File handles can translate character encodings from/to Perl's
internal Unicode form on read/write via the ":encoding()" layer.
o File handles can be opened to "in memory" files held in Perl
scalars via:
open($fh,'>', \$variable) || ...
o Anonymous temporary files are available without need to 'use File-
Handle' or other module via
open($fh,"+>", undef) || ...
That is a literal undef, not an undefined value.
o The list form of "open" is now implemented for pipes (at least on
UNIX):
open($fh,"-|", 'cat', '/etc/motd')
creates a pipe, and runs the equivalent of exec('cat', '/etc/motd')
in the child process.
o The following builtin functions are now overridable: chop(),
chomp(), each(), keys(), pop(), push(), shift(), splice(),
unshift().
o Formats now support zero-padded decimal fields.
o Perl now tries internally to use integer values in numeric conver-
sions and basic arithmetics (+ - * /) if the arguments are inte-
gers, and tries also to keep the results stored internally as inte-
gers. This change leads into often slightly faster and always less
lossy arithmetics. (Previously Perl always preferred floating point
numbers in its math.)
o The printf() and sprintf() now support parameter reordering using
the "%\d+\$" and "*\d+\$" syntaxes. For example
print "%2\$s %1\$s\n", "foo", "bar";
will print "bar foo\n"; This feature helps in writing internation-
alised software.
o 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 par-
ticularly tricky to get right, so you have been warned)
o 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.
o 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 "\s"
(\p{Space} isn't, since that includes the vertical tabulator char-
acter, whereas "\s" doesn't.)
Signals Are Now Safe
Perl used to be fragile in that signals arriving at inopportune moments
could corrupt Perl's internal state.
Modules and Pragmata
New Modules
o 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 B::Concise for more information.
o Class::ISA, by Sean Burke, for reporting the search path for a
class's ISA tree, has been added.
See Class::ISA for more information.
o 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.
o Digest, a frontend module for calculating digests (checksums), from
Gisle Aas, has been added.
See Digest for more information.
o Digest::MD5 for calculating MD5 digests (checksums), by Gisle Aas,
has been added.
use Digest::MD5 'md5_hex';
$digest = md5_hex("Thirsty Camel");
print $digest, "\n"; # 01d19d9d2045e005c3f1b80e8b164de1
NOTE: the MD5 backward compatibility module is deliberately not
included since its use is discouraged.
See Digest::MD5 for more information.
o Encode, by Nick Ing-Simmons, provides a mechanism to translate
between different character encodings. Support for Unicode,
ISO-8859-*, ASCII, CP*, KOI8-R, and three variants of EBCDIC are
compiled in to the module. Several other encodings (like Japanese,
Chinese, and MacIntosh encodings) are included and will be loaded
at runtime.
Any encoding supported by Encode module is also available to the
":encoding()" layer if PerlIO is used.
See Encode for more information.
o Filter::Simple is an easy-to-use frontend to Filter::Util::Call,
from Damian Conway.
# in MyFilter.pm:
package MyFilter;
use Filter::Simple sub {
while (my ($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 Filter::Simple for more information.
o Filter::Util::Call, by Paul Marquess, provides you with the frame-
work to write Source Filters in Perl. For most uses the frontend
Filter::Simple is to be preferred. See Filter::Util::Call for more
information.
o 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 Locale::Constants, Locale::Country, Locale::Currency, and
Locale::Language for more information.
o 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 MIME::Base64 for more information.
o 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)",$path)
See MIME::QuotedPrint for more information.
o PerlIO::Scalar, by Nick Ing-Simmons, provides the implementation of
IO to "in memory" Perl scalars as discussed above. It also serves
as an example of a loadable layer. Other future possibilities
include PerlIO::Array and PerlIO::Code. See PerlIO::Scalar for
more information.
o PerlIO::Via, by Nick Ing-Simmons, acts as a PerlIO layer and wraps
PerlIO layer functionality provided by a class (typically imple-
mented in perl code).
use MIME::QuotedPrint;
open($fh,">Via(MIME::QuotedPrint)",$path)
This will automatically convert everything output to $fh to
Quoted-Printable. See PerlIO::Via for more information.
o Pod::Text::Overstrike, by Joe Smith, has been added. It converts
POD data to formatted overstrike text. See Pod::Text::Overstrike
for more information.
o Switch from Damian Conway has been added. Just by saying
use Switch;
you have "switch" and "case" available in Perl.
use Switch;
switch ($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 Switch for more information.
o 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_brack-
eted(), extract_quotelike(), extract_codeblock(), extract_vari-
able(), extract_tagged(), extract_multiple(), gen_delimited_pat(),
and gen_extract_tagged(). With these you can implement rather
advanced parsing algorithms. See Text::Balanced for more informa-
tion.
o Tie::RefHash::Nestable, by Edward Avis, allows storing hash refer-
ences (unlike the standard Tie::RefHash) The module is contained
within Tie::RefHash.
o 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.
Updated And Improved Modules and Pragmata
o 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.
o Class::Struct can now define the classes in compile time.
o 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/ )
o 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).
o 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.
o 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.
o 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 inte-
grated to Perl.
o The "open" pragma allows layers other than ":raw" and ":crlf" when
using PerlIO.
o 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.
o The Test module has been significantly enhanced. Its use is
greatly recommended for module writers.
o 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.
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.
Performance Enhancements
o 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 pass-
ing the DIEHARD random number generation tests. According to perl-
bench, this change has not affected the overall speed of Perl.
o unshift() should now be noticeably faster.
Utility Changes
o h2xs now produces template README.
o s2p has been completely rewritten in Perl. (It is in fact a full
implementation of sed in Perl.)
o xsubpp now supports OUT keyword.
New Documentation
perlclib
Internal replacements for standard C library functions. (Interesting
only for extension writers and Perl core hackers.)
perliol
Internals of PerlIO with layers.
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 perlaix.
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
perlbs2000.
README.macos
In perl 5.7.1 (and in the 5.6.1) the MacPerl sources have been synchro-
nised with the standard Perl sources. To compile MacPerl some addi-
tional steps are required, and this file documents those steps. On
install README.macos will be installed as perlmacos.
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 perlmpeix.
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 perlsolaris.
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 perlvos.
Porting/repository.pod
Documentation on how to use the Perl source repository has been added.
Installation and Configuration Improvements
o 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 (Con-
figure command line option -Uuseperlio), you will get "-stdio"
appended.
o 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.)
o 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.
o Building Berkeley DB3 for compatibility modes for DB, NDBM, and
ODBM has been documented in INSTALL.
o If you are on IRIX or Tru64 platforms, new profiling/debugging
options have been added, see perlhack for more information about
pixie and Third Degree.
New Or Improved Platforms
For the list of platforms known to support Perl, see "Supported Plat-
forms" in perlport.
o AIX dynamic loading should be now better supported.
o After a long pause, AmigaOS has been verified to be happy with
Perl.
o 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 situa-
tion is much better than with Perl 5.6. See perlos390, perlbs2000
(for POSIX-BC), and perlvmesa for more information.
o 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.
o 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)
o NCR MP-RAS is now supported.
o NonStop-UX is now supported.
o Amdahl UTS is now supported.
o z/OS (formerly known as OS/390, formerly known as MVS OE) has now
support for dynamic loading. This is not selected by default, how-
ever, you must specify -Dusedl in the arguments of Configure.
Generic Improvements
o 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.
o Some new Configure symbols, useful for extension writers:
d_cmsghdr
For struct cmsghdr.
d_fcntl_can_lock
Whether fcntl() can be used for file locking.
d_fsync
d_getitimer
d_getpagsz
For getpagesize(), though you should prefer
POSIX::sysconf(_SC_PAGE_SIZE))
d_msghdr_s
For struct msghdr.
need_va_copy
Whether one needs to use Perl_va_copy() to copy varargs.
d_readv
d_recvmsg
d_sendmsg
sig_size
The number of elements in an array needed to hold all the
available signals.
d_sockatmark
d_strtoq
d_u32align
Whether one needs to access character data aligned by U32
sized pointers.
d_ualarm
d_usleep
o Removed Configure symbols: the PDP-11 memory model settings: huge,
large, medium, models.
o SOCKS support is now much more robust.
o If your file system supports symbolic links you can build Perl out-
side 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.
Selected Bug Fixes
Numerous memory leaks and uninitialized memory accesses have been
hunted down. Most importantly anonymous subs used to leak quite a bit.
o chop(@list) in list context returned the characters chopped in
reverse order. This has been reversed to be in the right order.
o The order of DESTROYs has been made more predictable.
o mkdir() now ignores trailing slashes in the directory name, as man-
dated by POSIX.
o Attributes (like :shared) didn't work with our().
o The PERL5OPT environment variable (for passing command line argu-
ments to Perl) didn't work for more than a single group of options.
o 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.
o All but the first argument of the IO syswrite() method are now
optional.
o Tie::ARRAY SPLICE method was broken.
o 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.
Platform Specific Changes and Fixes
o Linux previously had problems related to sockaddrlen when using
accept(), revcfrom() (in Perl: recv()), getpeername(), and getsock-
name().
o Previously DYNIX/ptx had problems in its Configure probe for non-
blocking I/O.
o Windows
o 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++).
o Win32::GetCwd() correctly returns C:\ instead of C: when at
the drive root. Other bugs in chdir() and Cwd::cwd() have
also been fixed.
o Duping socket handles with open(F, ">&MYSOCK") now works
under Windows 9x.
o HTML files will be installed in c:\perl\html instead of
c:\perl\lib\pod\html
o The makefiles now provide a single switch to bulk-enable
all the features enabled in ActiveState ActivePerl (a
popular binary distribution).
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, respec-
tively.
o If an attempt to use a (non-blessed) reference as an array index is
made, a warning is given.
o "push @a;" and "unshift @a;" (with no values to push or unshift)
now give a warning. This may be a problem for generated and evaled
code.
Changed Internals
o Some new APIs: ptr_table_clear(), ptr_table_free(), sv_setref_uv().
For the full list of the available APIs see perlapi.
o dTHR and djSP have been obsoleted; the former removed (because it's
a no-op) and the latter replaced with dSP.
o 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).
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.
Known Problems
Note that unlike other sections in this document (which describe
changes since 5.7.0) this section is cumulative containing known prob-
lems for all the 5.7 releases.
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, result-
ing 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.
lib/ftmp-security tests warn 'system possibly insecure'
Don't panic. Read INSTALL 'make test' section instead.
lib/io_multihomed Fails In LP64-Configured HP-UX
The lib/io_multihomed test may hang in HP-UX if Perl has been config-
ured 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).
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.
lib/b test 19
The test fails on various platforms (PA64 and IA64 are known), but the
exact cause is still being investigated.
Linux With Sfio Fails op/misc Test 48
No known fix.
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.
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 Non-
Stop-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".)
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.)
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.
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 frus-
trated at the mysterious results (core dumps, most often) it is for now
forbidden (you will get a fatal error even from an attempt).
Building Extensions Can Fail Because Of Largefiles
Some extensions like mod_perl are known to have issues with `large-
files', 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., $Con-
fig{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.
The Compiler Suite Is Still Experimental
The compiler suite is slowly getting better but is nowhere near working
order yet.
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 perlbug pro-
gram 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 "perl -V", will be sent off to perlbug@perl.org to be analysed by
the Perl porting team.
SEE ALSO
The Changes file for exhaustive details on what changed.
The INSTALL file for how to build Perl.
The README file for general stuff.
The Artistic and Copying files for copyright information.
HISTORY
Written by Jarkko Hietaniemi <jhi@iki.fi>, with many contributions from
The Perl Porters and Perl Users submitting feedback and patches.
Send omissions or corrections to <perlbug@perl.org>.
perl v5.8.6 2004-11-05 PERL571DELTA(1)
