PERL58DELTA(1) Perl Programmers Reference Guide PERL58DELTA(1) #
PERL58DELTA(1) Perl Programmers Reference Guide PERL58DELTA(1)
NNAAMMEE #
perl58delta - what is new for perl v5.8.0
DDEESSCCRRIIPPTTIIOONN #
This document describes differences between the 5.6.0 release and the
5.8.0 release.
Many of the bug fixes in 5.8.0 were already seen in the 5.6.1 maintenance
release since the two releases were kept closely coordinated (while 5.8.0
was still called 5.7.something).
Changes that were integrated into the 5.6.1 release are marked "[561]".
Many of these changes have been further developed since 5.6.1 was
released, those are marked "[561+]".
You can see the list of changes in the 5.6.1 release (both from the
5.005_03 release and the 5.6.0 release) by reading perl561delta.
HHiigghhlliigghhttss IInn 55..88..00 • Better Unicode support
• New IO Implementation
• New Thread Implementation
• Better Numeric Accuracy
• Safe Signals
• Many New Modules
• More Extensive Regression Testing
IInnccoommppaattiibbllee CChhaannggeess BBiinnaarryy IInnccoommppaattiibbiilliittyy PPeerrll 55..88 iiss nnoott bbiinnaarryy ccoommppaattiibbllee wwiitthh eeaarrlliieerr rreelleeaasseess ooff PPeerrll..
YYoouu hhaavvee ttoo rreeccoommppiillee yyoouurr XXSS mmoodduulleess..
(Pure Perl modules should continue to work.)
The major reason for the discontinuity is the new IO architecture called
PerlIO. PerlIO is the default configuration because without it many new
features of Perl 5.8 cannot be used. In other words: you just have to
recompile your modules containing XS code, sorry about that.
In future releases of Perl, non-PerlIO aware XS modules may become
completely unsupported. This shouldn't be too difficult for module
authors, however: PerlIO has been designed as a drop-in replacement (at
the source code level) for the stdio interface.
Depending on your platform, there are also other reasons why we decided
to break binary compatibility, please read on.
6644--bbiitt ppllaattffoorrmmss aanndd mmaalllloocc If your pointers are 64 bits wide, the Perl malloc is no longer being used because it does not work well with 8-byte pointers. Also, usually the system mallocs on such platforms are much better optimized for such large memory models than the Perl malloc. Some memory-hungry Perl applications like the PDL don’t work well with Perl’s malloc. Finally, other applications than Perl (such as mod_perl) tend to prefer the system malloc. Such platforms include Alpha and 64-bit HPPA, MIPS, PPC, and Sparc.
AAIIXX DDyynnaallooaaddiinngg The AIX dynaloading now uses in AIX releases 4.3 and newer the native dlopen interface of AIX instead of the old emulated interface. This change will probably break backward compatibility with compiled modules. The change was made to make Perl more compliant with other applications like mod_perl which are using the AIX native interface.
AAttttrriibbuutteess ffoorr “"mmyy"” vvaarriiaabblleess nnooww hhaannddlleedd aatt rruunn--ttiimmee The “my EXPR : ATTRS” syntax now applies variable attributes at run-time. (Subroutine and “our” variables still get attributes applied at compile- time.) See attributes for additional details. In particular, however, this allows variable attributes to be useful for “tie” interfaces, which was a deficiency of earlier releases. Note that the new semantics doesn’t work with the Attribute::Handlers module (as of version 0.76).
SSoocckkeett EExxtteennssiioonn DDyynnaammiicc iinn VVMMSS The Socket extension is now dynamically loaded instead of being statically built in. This may or may not be a problem with ancient TCP/IP stacks of VMS: we do not know since we weren’t able to test Perl in such configurations.
IIEEEEEE--ffoorrmmaatt FFllooaattiinngg PPooiinntt DDeeffaauulltt oonn OOppeennVVMMSS AAllpphhaa Perl now uses IEEE format (T_FLOAT) as the default internal floating point format on OpenVMS Alpha, potentially breaking binary compatibility with external libraries or existing data. G_FLOAT is still available as a configuration option. The default on VAX (D_FLOAT) has not changed.
NNeeww UUnniiccooddee SSeemmaannttiiccss ((nnoo mmoorree “"uussee uuttff88"”,, aallmmoosstt)) Previously in Perl 5.6 to use Unicode one would say “use utf8” and then the operations (like string concatenation) were Unicode-aware in that lexical scope.
This was found to be an inconvenient interface, and in Perl 5.8 the
Unicode model has completely changed: now the "Unicodeness" is bound to
the data itself, and for most of the time "use utf8" is not needed at
all. The only remaining use of "use utf8" is when the Perl script itself
has been written in the UTF-8 encoding of Unicode. (UTF-8 has not been
made the default since there are many Perl scripts out there that are
using various national eight-bit character sets, which would be illegal
in UTF-8.)
See perluniintro for the explanation of the current model, and utf8 for
the current use of the utf8 pragma.
NNeeww UUnniiccooddee PPrrooppeerrttiieess Unicode _s_c_r_i_p_t_s are now supported. Scripts are similar to (and superior to) Unicode _b_l_o_c_k_s. The difference between scripts and blocks is that scripts are the glyphs used by a language or a group of languages, while the blocks are more artificial groupings of (mostly) 256 characters based on the Unicode numbering.
In general, scripts are more inclusive, but not universally so. For
example, while the script "Latin" includes all the Latin characters and
their various diacritic-adorned versions, it does not include the various
punctuation or digits (since they are not solely "Latin").
A number of other properties are now supported, including "\p{L&}",
"\p{Any}" "\p{Assigned}", "\p{Unassigned}", "\p{Blank}" [561] and
"\p{SpacePerl}" [561] (along with their "\P{...}" versions, of course).
See perlunicode for details, and more additions.
The "In" or "Is" prefix to names used with the "\p{...}" and "\P{...}"
are now almost always optional. The only exception is that a "In" prefix
is required to signify a Unicode block when a block name conflicts with a
script name. For example, "\p{Tibetan}" refers to the script, while
"\p{InTibetan}" refers to the block. When there is no name conflict, you
can omit the "In" from the block name (e.g. "\p{BraillePatterns}"), but
to be safe, it's probably best to always use the "In").
RREEFF((......)) IInnsstteeaadd OOff SSCCAALLAARR((......)) A reference to a reference now stringifies as “REF(0x81485ec)” instead of “SCALAR(0x81485ec)” in order to be more consistent with the return value of rreeff(()).
ppaacckk//uunnppaacckk DD//FF rreeccyycclleedd The undocumented pack/unpack template letters D/F have been recycled for better use: now they stand for long double (if supported by the platform) and NV (Perl internal floating point type). (They used to be aliases for d/f, but you never knew that.)
gglloobb(()) nnooww rreettuurrnnss ffiilleennaammeess iinn aallpphhaabbeettiiccaall oorrddeerr The list of filenames from gglloobb(()) (or <…>) is now by default sorted alphabetically to be csh-compliant (which is what happened before in most Unix platforms). (bbssdd__gglloobb(()) does still sort platform natively, ASCII or EBCDIC, unless GLOB_ALPHASORT is specified.) [561]
DDeepprreeccaattiioonnss • The semantics of bless(REF, REF) were unclear and until someone proves it to make some sense, it is forbidden.
• The obsolete chat2 library that should never have been allowed to
escape the laboratory has been decommissioned.
• Using chdir("") or chdir(undef) instead of explicit cchhddiirr(()) is
doubtful. A failure (think chdir(ssoommee__ffuunnccttiioonn(())) can lead into
unintended cchhddiirr(()) to the home directory, therefore this behaviour is
deprecated.
• The builtin dduummpp(()) function has probably outlived most of its
usefulness. The core-dumping functionality will remain in future
available as an explicit call to "CORE::dump()", but in future
releases the behaviour of an unqualified "dump()" call may change.
• The very dusty examples in the eg/ directory have been removed.
Suggestions for new shiny examples welcome but the main issue is that
the examples need to be documented, tested and (most importantly)
maintained.
• The (bogus) escape sequences \8 and \9 now give an optional warning
("Unrecognized escape passed through"). There is no need to \-escape
any "\w" character.
• The *glob{FILEHANDLE} is deprecated, use *glob{IO} instead.
• The "package;" syntax ("package" without an argument) has been
deprecated. Its semantics were never that clear and its
implementation even less so. If you have used that feature to
disallow all but fully qualified variables, "use strict;" instead.
• The unimplemented POSIX regex features [[.cc.]] and [[=c=]] are still
recognised but now cause fatal errors. The previous behaviour of
ignoring them by default and warning if requested was unacceptable
since it, in a way, falsely promised that the features could be used.
• In future releases, non-PerlIO aware XS modules may become completely
unsupported. Since PerlIO is a drop-in replacement for stdio at the
source code level, this shouldn't be that drastic a change.
• Previous versions of perl and some readings of some sections of Camel
III implied that the ":raw" "discipline" was the inverse of ":crlf".
Turning off "clrfness" is no longer enough to make a stream truly
binary. So the PerlIO ":raw" layer (or "discipline", to use the Camel
book's older terminology) is now formally defined as being equivalent
to binmode(FH) - which is in turn defined as doing whatever is
necessary to pass each byte as-is without any translation. In
particular binmode(FH) - and hence ":raw" - will now turn off both
CRLF and UTF-8 translation and remove other layers (e.g. :eennccooddiinngg(()))
which would modify byte stream.
• The current user-visible implementation of pseudo-hashes (the weird
use of the first array element) is deprecated starting from Perl
5.8.0 and will be removed in Perl 5.10.0, and the feature will be
implemented differently. Not only is the current interface rather
ugly, but the current implementation slows down normal array and hash
use quite noticeably. The "fields" pragma interface will remain
available. The _r_e_s_t_r_i_c_t_e_d _h_a_s_h_e_s interface is expected to be the
replacement interface (see Hash::Util). If your existing programs
depends on the underlying implementation, consider using
Class::PseudoHash from CPAN.
• The syntaxes "@a->[...]" and "%h->{...}" have now been deprecated.
• After years of trying, suidperl is considered to be too complex to
ever be considered truly secure. The suidperl functionality is
likely to be removed in a future release.
• The 5.005 threads model (module "Thread") is deprecated and expected
to be removed in Perl 5.10. Multithreaded code should be migrated to
the new ithreads model (see threads, threads::shared and perlthrtut).
• The long deprecated uppercase aliases for the string comparison
operators (EQ, NE, LT, LE, GE, GT) have now been removed.
• The tr///C and tr///U features have been removed and will not return;
the interface was a mistake. Sorry about that. For similar
functionality, see pack('U0', ...) and pack('C0', ...). [561]
• Earlier Perls treated "sub foo (@bar)" as equivalent to "sub foo
(@)". The prototypes are now checked better at compile-time for
invalid syntax. An optional warning is generated ("Illegal character
in prototype...") but this may be upgraded to a fatal error in a
future release.
• The "exec LIST" and "system LIST" operations now produce warnings on
tainted data and in some future release they will produce fatal
errors.
• The existing behaviour when localising tied arrays and hashes is
wrong, and will be changed in a future release, so do not rely on the
existing behaviour. See "Localising Tied Arrays and Hashes Is
Broken".
CCoorree EEnnhhaanncceemmeennttss UUnniiccooddee OOvveerrhhaauull Unicode in general should be now much more usable than in Perl 5.6.0 (or even in 5.6.1). Unicode can be used in hash keys, Unicode in regular expressions should work now, Unicode in tr/// should work now, Unicode in I/O should work now. See perluniintro for introduction and perlunicode for details.
• The Unicode Character Database coming with Perl has been upgraded to
Unicode 3.2.0. For more information, see http://www.unicode.org/ .
[561+] (5.6.1 has UCD 3.0.1.)
• For developers interested in enhancing Perl's Unicode capabilities:
almost all the UCD files are included with the Perl distribution in
the _l_i_b_/_u_n_i_c_o_r_e subdirectory. The most notable omission, for space
considerations, is the Unihan database.
• The properties \p{Blank} and \p{SpacePerl} have been added. "Blank"
is like C iissbbllaannkk(()), 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 character, whereas "\s"
doesn't.)
See "New Unicode Properties" earlier in this document for additional
information on changes with Unicode properties.
PPeerrllIIOO iiss NNooww TThhee DDeeffaauulltt • 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.
• If your platform supports ffoorrkk(()), you can use the list form of "open"
for pipes. For example:
open KID_PS, "-|", "ps", "aux" or die $!;
forks the ppss(1) command (without spawning a shell, as there are more
than three arguments to ooppeenn(())), and reads its standard output via
the "KID_PS" filehandle. See perlipc.
• File handles can be marked as accepting Perl's internal encoding of
Unicode (UTF-8 or UTF-EBCDIC depending on platform) by a pseudo layer
":utf8" :
open($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.unicode.org/reports/tr16/ for more information. In future
releases this naming may change. See perluniintro for more
information about UTF-8.
• If your environment variables (LC_ALL, LC_CTYPE, LANG) look like you
want to use UTF-8 (any of the variables match "/utf-?8/i"), your
STDIN, STDOUT, STDERR handles and the default open layer (see open)
are marked as UTF-8. (This feature, like other new features that
combine Unicode and I/O, work only if you are using PerlIO, but
that's the default.)
Note that after this Perl really does assume that everything is
UTF-8: for example if some input handle is not, Perl will probably
very soon complain about the input data like this "Malformed UTF-8
..." since any old eight-bit data is not legal UTF-8.
Note for code authors: if you want to enable your users to use UTF-8
as their default encoding but in your code still have eight-bit I/O
streams (such as images or zip files), you need to explicitly ooppeenn(())
or bbiinnmmooddee(()) with ":bytes" (see "open" in perlfunc and "binmode" in
perlfunc), or you can just use "binmode(FH)" (nice for pre-5.8.0
backward compatibility).
• File handles can translate character encodings from/to Perl's
internal Unicode form on read/write via the ":eennccooddiinngg(())" layer.
• File handles can be opened to "in memory" files held in Perl scalars
via:
open($fh,'>', \$variable) || ...
• Anonymous temporary files are available without need to 'use
FileHandle' or other module via
open($fh,"+>", undef) || ...
That is a literal undef, not an undefined value.
iitthhrreeaaddss The new interpreter threads (“ithreads” for short) implementation of multithreading, by Arthur Bergman, replaces the old “5.005 threads” implementation. In the ithreads model any data sharing between threads must be explicit, as opposed to the model where data sharing was implicit. See threads and threads::shared, and perlthrtut.
As a part of the ithreads implementation Perl will also use any necessary
and detectable reentrant libc interfaces.
RReessttrriicctteedd HHaasshheess A restricted hash is restricted to a certain set of keys, no keys outside the set can be added. Also individual keys can be restricted so that the key cannot be deleted and the value cannot be changed. No new syntax is involved: the Hash::Util module is the interface.
SSaaffee SSiiggnnaallss Perl used to be fragile in that signals arriving at inopportune moments could corrupt Perl’s internal state. Now Perl postpones handling of signals until it’s safe (between opcodes).
This change may have surprising side effects because signals no longer
interrupt Perl instantly. Perl will now first finish whatever it was
doing, like finishing an internal operation (like ssoorrtt(())) or an external
operation (like an I/O operation), and only then look at any arrived
signals (and before starting the next operation). No more corrupt
internal state since the current operation is always finished first, but
the signal may take more time to get heard. Note that breaking out from
potentially blocking operations should still work, though.
UUnnddeerrssttaannddiinngg ooff NNuummbbeerrss In general a lot of fixing has happened in the area of Perl’s understanding of numbers, both integer and floating point. Since in many systems the standard number parsing functions like “strtoul()” and “atof()” seem to have bugs, Perl tries to work around their deficiencies. This results hopefully in more accurate numbers.
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 to often slightly faster and always less lossy arithmetics.
(Previously Perl always preferred floating point numbers in its math.)
AArrrraayyss nnooww aallwwaayyss iinntteerrppoollaattee iinnttoo ddoouubbllee--qquuootteedd ssttrriinnggss [[556611]] In double-quoted strings, arrays now interpolate, no matter what. The behavior in earlier versions of perl 5 was that arrays would interpolate into strings if the array had been mentioned before the string was compiled, and otherwise Perl would raise a fatal compile-time error. In versions 5.000 through 5.003, the error was
Literal @example now requires backslash
In versions 5.004_01 through 5.6.0, the error was
In string, @example now must be written as \@example
The idea here was to get people into the habit of writing
"fred\@example.com" when they wanted a literal "@" sign, just as they
have always written "Give me back my \$5" when they wanted a literal "$"
sign.
Starting with 5.6.1, when Perl now sees an "@" sign in a double-quoted
string, it _a_l_w_a_y_s attempts to interpolate an array, regardless of whether
or not the array has been used or declared already. The fatal error has
been downgraded to an optional warning:
Possible unintended interpolation of @example in string
This warns you that "fred@example.com" is going to turn into "fred.com"
if you don't backslash the "@". See http://perl.plover.com/at-error.html
for more details about the history here.
MMiisscceellllaanneeoouuss CChhaannggeess • AUTOLOAD is now lvaluable, meaning that you can add the :lvalue attribute to AUTOLOAD subroutines and you can assign to the AUTOLOAD return value.
• The $Config{byteorder} (and corresponding BYTEORDER in config.h) was
previously wrong in platforms if sizeof(long) was 4, but sizeof(IV)
was 8. The byteorder was only sizeof(long) bytes long (1234 or
4321), but now it is correctly sizeof(IV) bytes long, (12345678 or
87654321). (This problem didn't affect Windows platforms.)
Also, $Config{byteorder} is now computed dynamically--this is more
robust with "fat binaries" where an executable image contains
binaries for more than one binary platform, and when cross-compiling.
• "perl -d:Module=arg,arg,arg" now works (previously one couldn't pass
in multiple arguments.)
• "do" followed by a bareword now ensures that this bareword isn't a
keyword (to avoid a bug where "do q(foo.pl)" tried to call a
subroutine called "q"). This means that for example instead of "do
format()" you must write "do &format()".
• The builtin dduummpp(()) now gives an optional warning "dump() better
written as CORE::dump()", meaning that by default "dump(...)" is
resolved as the builtin dduummpp(()) which dumps core and aborts, not as
(possibly) user-defined "sub dump". To call the latter, qualify the
call as "&dump(...)". (The whole dduummpp(()) feature is to considered
deprecated, and possibly removed/changed in future releases.)
• cchhoommpp(()) and cchhoopp(()) are now overridable. Note, however, that their
prototype (as given by "prototype("CORE::chomp")" is undefined,
because it cannot be expressed and therefore one cannot really write
replacements to override these builtins.
• END blocks are now run even if you exit/die in a BEGIN block.
Internally, the execution of END blocks is now controlled by
PL_exit_flags & PERL_EXIT_DESTRUCT_END. This enables the new
behaviour for Perl embedders. This will default in 5.10. See
perlembed.
• Formats now support zero-padded decimal fields.
• 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".
• lstat(FILEHANDLE) now gives a warning because the operation makes no
sense. In future releases this may become a fatal error.
• Spurious syntax errors generated in certain situations, when gglloobb(())
caused File::Glob to be loaded for the first time, have been fixed.
[561]
• Lvalue subroutines can now return "undef" in list context. However,
the lvalue subroutine feature still remains experimental. [561+]
• A lost warning "Can't declare ... dereference in my" has been
restored (Perl had it earlier but it became lost in later releases.)
• A new special regular expression variable has been introduced: $^N,
which contains the most-recently closed group (submatch).
• "no Module;" does not produce an error even if Module does not have
an uunniimmppoorrtt(()) method. This parallels the behavior of "use" vis-a-vis
"import". [561]
• The numerical comparison operators return "undef" if either operand
is a NaN. Previously the behaviour was unspecified.
• "our" can now have an experimental optional attribute "unique" that
affects how global variables are shared among multiple interpreters,
see "our" in perlfunc.
• The following builtin functions are now overridable: eeaacchh(()), kkeeyyss(()),
ppoopp(()), ppuusshh(()), sshhiifftt(()), sspplliiccee(()), uunnsshhiifftt(()). [561]
• "pack() / unpack()" can now group template letters with "()" and then
apply repetition/count modifiers on the groups.
• "pack() / unpack()" can now process the Perl internal numeric types:
IVs, UVs, NVs-- and also long doubles, if supported by the platform.
The template letters are "j", "J", "F", and "D".
• "pack('U0a*', ...)" can now be used to force a string to UTF-8.
• my __PACKAGE__ $obj now works. [561]
• PPOOSSIIXX::::sslleeeepp(()) now returns the number of _u_n_s_l_e_p_t seconds (as the
POSIX standard says), as opposed to CCOORREE::::sslleeeepp(()) which returns the
number of slept seconds.
• pprriinnttff(()) and sspprriinnttff(()) now support parameter reordering using the
"%\d+\$" and "*\d+\$" syntaxes. For example
printf "%2\$s %1\$s\n", "foo", "bar";
will print "bar foo\n". This feature helps in writing
internationalised software, and in general when the order of the
parameters can vary.
• The (\&) prototype now works properly. [561]
• prototype(\[$@%&]) is now available to implicitly create references
(useful for example if you want to emulate the ttiiee(()) interface).
• A new command-line option, "-t" is available. It is the little
brother of "-T": instead of dying on taint violations, lexical
warnings are given. TThhiiss iiss oonnllyy mmeeaanntt aass aa tteemmppoorraarryy ddeebbuuggggiinngg aaiidd
wwhhiillee sseeccuurriinngg tthhee ccooddee ooff oolldd lleeggaaccyy aapppplliiccaattiioonnss.. TThhiiss iiss nnoott aa
ssuubbssttiittuuttee ffoorr --TT..
• In other taint news, the "exec LIST" and "system LIST" have now been
considered too risky (think "exec @ARGV": it can start any program
with any arguments), and now the said forms cause a warning under
lexical warnings. You should carefully launder the arguments to
guarantee their validity. In future releases of Perl the forms will
become fatal errors so consider starting laundering now.
• Tied hash interfaces are now required to have the EXISTS and DELETE
methods (either own or inherited).
• If tr/// is just counting characters, it doesn't attempt to modify
its target.
• uunnttiiee(()) will now call an UUNNTTIIEE(()) hook if it exists. See perltie for
details. [561]
• "utime" in perlfunc now supports "utime undef, undef, @files" to
change the file timestamps to the current time.
• The rules for allowing underscores (underbars) in numeric constants
have been relaxed and simplified: now you can have an underscore
simply bbeettwweeeenn ddiiggiittss.
• Rather than relying on C's argv[0] (which may not contain a full
pathname) where possible $^X is now set by asking the operating
system. (eg by reading _/_p_r_o_c_/_s_e_l_f_/_e_x_e on Linux, _/_p_r_o_c_/_c_u_r_p_r_o_c_/_f_i_l_e
on FreeBSD)
• A new variable, "${^TAINT}", indicates whether taint mode is enabled.
• You can now override the rreeaaddlliinnee(()) builtin, and this overrides also
the <FILEHANDLE> angle bracket operator.
• The command-line options -s and -F are now recognized on the shebang
(#!) line.
• Use of the "/c" match modifier without an accompanying "/g" modifier
elicits a new warning: "Use of /c modifier is meaningless without
/g".
Use of "/c" in substitutions, even with "/g", elicits "Use of /c
modifier is meaningless in s///".
Use of "/g" with "split" elicits "Use of /g modifier is meaningless
in split".
• Support for the "CLONE" special subroutine had been added. With
ithreads, when a new thread is created, all Perl data is cloned,
however non-Perl data cannot be cloned automatically. In "CLONE" you
can do whatever you need to do, like for example handle the cloning
of non-Perl data, if necessary. "CLONE" will be executed once for
every package that has it defined or inherited. It will be called in
the context of the new thread, so all modifications are made in the
new area.
See perlmod
MMoodduulleess aanndd PPrraaggmmaattaa NNeeww MMoodduulleess aanndd PPrraaggmmaattaa • “Attribute::Handlers”, originally by Damian Conway and now maintained by Arthur Bergman, allows a class to define attribute handlers.
package MyPack;
use Attribute::Handlers;
sub Wolf :ATTR(SCALAR) { print "howl!\n" }
# later, in some package using or inheriting from MyPack...
my MyPack $Fluffy : Wolf; # the attribute handler Wolf will be called
Both variables and routines can have attribute handlers. Handlers
can be specific to type (SCALAR, ARRAY, HASH, or CODE), or specific
to the exact compilation phase (BEGIN, CHECK, INIT, or END). See
Attribute::Handlers.
• "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. [561+]
• The new bignum, bigint, and bigrat pragmas, by Tels, implement
transparent bignum support (using the Math::BigInt, Math::BigFloat,
and Math::BigRat backends).
• "Class::ISA", by Sean Burke, is a module for reporting the search
path for a class's ISA tree. See Class::ISA.
• "Cwd" now has a split personality: if possible, an XS extension is
used, (this will hopefully be faster, more secure, and more robust)
but if not possible, the familiar Perl implementation is used.
• "Devel::PPPort", originally by Kenneth Albanowski and now maintained
by Paul Marquess, has been added. It is primarily used by "h2xs" to
enhance portability of XS modules between different versions of Perl.
See Devel::PPPort.
• "Digest", frontend module for calculating digests (checksums), from
Gisle Aas, has been added. See Digest.
• "Digest::MD5" for calculating MD5 digests (checksums) as defined in
RFC 1321, from Gisle Aas, has been added. See Digest::MD5.
use Digest::MD5 'md5_hex';
$digest = md5_hex("Thirsty Camel");
print $digest, "\n"; # 01d19d9d2045e005c3f1b80e8b164de1
NOTE: the "MD5" backward compatibility module is deliberately not
included since its further use is discouraged.
See also PerlIO::via::QuotedPrint.
• "Encode", originally by Nick Ing-Simmons and now maintained by Dan
Kogai, provides a mechanism to translate between different character
encodings. Support for Unicode, ISO-8859-1, and ASCII are compiled
in to the module. Several other encodings (like the rest of the
ISO-8859, CP*/Win*, Mac, KOI8-R, three variants EBCDIC, Chinese,
Japanese, and Korean encodings) are included and can be loaded at
runtime. (For space considerations, the largest Chinese encodings
have been separated into their own CPAN module, Encode::HanExtra,
which Encode will use if available). See Encode.
Any encoding supported by Encode module is also available to the
":eennccooddiinngg(())" layer if PerlIO is used.
• "Hash::Util" is the interface to the new _r_e_s_t_r_i_c_t_e_d _h_a_s_h_e_s feature.
(Implemented by Jeffrey Friedl, Nick Ing-Simmons, and Michael
Schwern.) See Hash::Util.
• "I18N::Langinfo" can be used to query locale information. See
I18N::Langinfo.
• "I18N::LangTags", by Sean Burke, has functions for dealing with
RFC3066-style language tags. See I18N::LangTags.
• "ExtUtils::Constant", by Nicholas Clark, is a new tool for extension
writers for generating XS code to import C header constants. See
ExtUtils::Constant.
• "Filter::Simple", by Damian Conway, is an easy-to-use frontend to
Filter::Util::Call. See Filter::Simple.
# in MyFilter.pm:
package MyFilter;
use Filter::Simple sub {
while (my ($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"
• "File::Temp", by Tim Jenness, allows one to create temporary files
and directories in an easy, portable, and secure way. See
File::Temp. [561+]
• "Filter::Util::Call", by Paul Marquess, provides you with the
framework to write _s_o_u_r_c_e _f_i_l_t_e_r_s in Perl. For most uses, the
frontend Filter::Simple is to be preferred. See Filter::Util::Call.
• "if", by Ilya Zakharevich, is a new pragma for conditional inclusion
of modules.
• libnet, by Graham Barr, is a collection of perl5 modules related to
network programming. See Net::FTP, Net::NNTP, Net::Ping (not part of
libnet, but related), Net::POP3, Net::SMTP, and Net::Time.
Perl installation leaves libnet unconfigured; use _l_i_b_n_e_t_c_f_g to
configure it.
• "List::Util", by Graham Barr, is a selection of general-utility list
subroutines, such as ssuumm(()), mmiinn(()), ffiirrsstt(()), and sshhuuffffllee(()). See
List::Util.
• "Locale::Constants", "Locale::Country", "Locale::Currency"
"Locale::Language", and Locale::Script, by Neil Bowers, have been
added. They provide the codes for various locale standards, such as
"fr" for France, "usd" for US Dollar, and "ja" 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.
• "Locale::Maketext", by Sean Burke, is a localization framework. See
Locale::Maketext, and Locale::Maketext::TPJ13. The latter is an
article about software localization, originally published in The Perl
Journal #13, and republished here with kind permission.
• "Math::BigRat" for big rational numbers, to accompany Math::BigInt
and Math::BigFloat, from Tels. See Math::BigRat.
• "Memoize" can make your functions faster by trading space for time,
from Mark-Jason Dominus. See Memoize.
• "MIME::Base64", by Gisle Aas, allows you to encode data in base64, as
defined in RFC 2045 - _M_I_M_E _(_M_u_l_t_i_p_u_r_p_o_s_e _I_n_t_e_r_n_e_t _M_a_i_l _E_x_t_e_n_s_i_o_n_s_).
use MIME::Base64;
$encoded = encode_base64('Aladdin:open sesame');
$decoded = decode_base64($encoded);
print $encoded, "\n"; # "QWxhZGRpbjpvcGVuIHNlc2FtZQ=="
See MIME::Base64.
• "MIME::QuotedPrint", by Gisle Aas, allows you to encode data in
quoted-printable encoding, as defined in RFC 2045 - _M_I_M_E
_(_M_u_l_t_i_p_u_r_p_o_s_e _I_n_t_e_r_n_e_t _M_a_i_l _E_x_t_e_n_s_i_o_n_s_).
use MIME::QuotedPrint;
$encoded = encode_qp("\xDE\xAD\xBE\xEF");
$decoded = decode_qp($encoded);
print $encoded, "\n"; # "=DE=AD=BE=EF\n"
print $decoded, "\n"; # "\xDE\xAD\xBE\xEF\n"
See also PerlIO::via::QuotedPrint.
• "NEXT", by Damian Conway, is a pseudo-class for method redispatch.
See NEXT.
• "open" is a new pragma for setting the default I/O layers for ooppeenn(()).
• "PerlIO::scalar", by Nick Ing-Simmons, provides the implementation of
IO to "in memory" Perl scalars as discussed above. It also serves as
an example of a loadable PerlIO layer. Other future possibilities
include PerlIO::Array and PerlIO::Code. See PerlIO::scalar.
• "PerlIO::via", by Nick Ing-Simmons, acts as a PerlIO layer and wraps
PerlIO layer functionality provided by a class (typically implemented
in Perl code).
• "PerlIO::via::QuotedPrint", by Elizabeth Mattijsen, is an example of
a "PerlIO::via" class:
use PerlIO::via::QuotedPrint;
open($fh,">:via(QuotedPrint)",$path);
This will automatically convert everything output to $fh to Quoted-
Printable. See PerlIO::via and PerlIO::via::QuotedPrint.
• "Pod::ParseLink", by Russ Allbery, has been added, to parse L<> links
in pods as described in the new perlpodspec.
• "Pod::Text::Overstrike", by Joe Smith, has been added. It converts
POD data to formatted overstrike text. See Pod::Text::Overstrike.
[561+]
• "Scalar::Util" is a selection of general-utility scalar subroutines,
such as bblleesssseedd(()), rreeffttyyppee(()), and ttaaiinntteedd(()). See Scalar::Util.
• "sort" is a new pragma for controlling the behaviour of ssoorrtt(()).
• "Storable" gives persistence to Perl data structures by allowing the
storage and retrieval of Perl data to and from files in a fast and
compact binary format. Because in effect Storable does serialisation
of Perl data structures, with it you can also clone deep,
hierarchical datastructures. Storable was originally created by
Raphael Manfredi, but it is now maintained by Abhijit Menon-Sen.
Storable has been enhanced to understand the two new hash features,
Unicode keys and restricted hashes. See Storable.
• "Switch", by Damian Conway, has been added. Just by saying
use Switch;
you have "switch" and "case" available in Perl.
use Switch;
switch ($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.
• "Test::More", by Michael Schwern, is yet another framework for
writing test scripts, more extensive than Test::Simple. See
Test::More.
• "Test::Simple", by Michael Schwern, has basic utilities for writing
tests. See Test::Simple.
• "Text::Balanced", by 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 eexxttrraacctt__ddeelliimmiitteedd(()), there are also
eexxttrraacctt__bbrraacckkeetteedd(()), eexxttrraacctt__qquuootteelliikkee(()), eexxttrraacctt__ccooddeebblloocckk(()),
eexxttrraacctt__vvaarriiaabbllee(()), eexxttrraacctt__ttaaggggeedd(()), eexxttrraacctt__mmuullttiippllee(()),
ggeenn__ddeelliimmiitteedd__ppaatt(()), and ggeenn__eexxttrraacctt__ttaaggggeedd(()). With these, you can
implement rather advanced parsing algorithms. See Text::Balanced.
• "threads", by Arthur Bergman, is an interface to interpreter threads.
Interpreter threads (ithreads) is the new thread model introduced in
Perl 5.6 but only available as an internal interface for extension
writers (and for Win32 Perl for "fork()" emulation). See threads,
threads::shared, and perlthrtut.
• "threads::shared", by Arthur Bergman, allows data sharing for
interpreter threads. See threads::shared.
• "Tie::File", by Mark-Jason Dominus, associates a Perl array with the
lines of a file. See Tie::File.
• "Tie::Memoize", by Ilya Zakharevich, provides on-demand loaded
hashes. See Tie::Memoize.
• "Tie::RefHash::Nestable", by Edward Avis, allows storing hash
references (unlike the standard Tie::RefHash) The module is
contained within Tie::RefHash. See Tie::RefHash.
• "Time::HiRes", by Douglas E. Wegscheid, provides high resolution
timing (ualarm, usleep, and gettimeofday). See Time::HiRes.
• "Unicode::UCD" offers a querying interface to the Unicode Character
Database. See Unicode::UCD.
• "Unicode::Collate", by SADAHIRO Tomoyuki, implements the UCA (Unicode
Collation Algorithm) for sorting Unicode strings. See
Unicode::Collate.
• "Unicode::Normalize", by SADAHIRO Tomoyuki, implements the various
Unicode normalization forms. See Unicode::Normalize.
• "XS::APItest", by Tim Jenness, is a test extension that exercises XS
APIs. Currently only "printf()" is tested: how to output various
basic data types from XS.
• "XS::Typemap", by Tim Jenness, is a test extension that exercises XS
typemaps. Nothing gets installed, but the code is worth studying for
extension writers.
UUppddaatteedd AAnndd IImmpprroovveedd MMoodduulleess aanndd PPrraaggmmaattaa • The following independently supported modules have been updated to the newest versions from CPAN: CGI, CPAN, DB_File, File::Spec, File::Temp, Getopt::Long, Math::BigFloat, Math::BigInt, the podlators bundle (Pod::Man, Pod::Text), Pod::LaTeX [561+], Pod::Parser, Storable, Term::ANSIColor, Test, Text-Tabs+Wrap.
• aattttrriibbuutteess::::rreeffttyyppee(()) now works on tied arguments.
• AutoLoader can now be disabled with "no AutoLoader;".
• B::Deparse has been significantly enhanced by Robin Houston. It can
now deparse almost all of the standard test suite (so that the tests
still succeed). There is a make target "test.deparse" for trying
this out.
• Carp now has better interface documentation, and the @CARP_NOT
interface has been added to get optional control over where errors
are reported independently of @ISA, by Ben Tilly.
• Class::Struct can now define the classes in compile time.
• Class::Struct now assigns the array/hash element if the accessor is
called with an array/hash element as the ssoollee argument.
• The return value of CCwwdd::::ffaassttccwwdd(()) is now tainted.
• Data::Dumper now has an option to sort hashes.
• Data::Dumper now has an option to dump code references using
B::Deparse.
• DB_File now supports newer Berkeley DB versions, among other
improvements.
• 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).
• The English module can now be used without the infamous performance
hit by saying
use English '-no_match_vars';
(Assuming, of course, that you don't need the troublesome variables
"$`", $&, or "$'".) Also, introduced @LAST_MATCH_START and
@LAST_MATCH_END English aliases for "@-" and "@+".
• ExtUtils::MakeMaker has been significantly cleaned up and fixed. The
enhanced version has also been backported to earlier releases of Perl
and submitted to CPAN so that the earlier releases can enjoy the
fixes.
• The arguments of WWrriitteeMMaakkeeffiillee(()) in Makefile.PL are now checked for
sanity much more carefully than before. This may cause new warnings
when modules are being installed. See ExtUtils::MakeMaker for more
details.
• ExtUtils::MakeMaker now uses File::Spec internally, which hopefully
leads to better portability.
• Fcntl, Socket, and Sys::Syslog have been rewritten by Nicholas Clark
to use the new-style constant dispatch section (see
ExtUtils::Constant). This means that they will be more robust and
hopefully faster.
• File::Find now cchhddiirr(())s correctly when chasing symbolic links. [561]
• File::Find now has pre- and post-processing callbacks. It also
correctly changes directories when chasing symbolic links. Callbacks
(naughtily) exiting with "next;" instead of "return;" now work.
• File::Find is now (again) reentrant. It also has been made more
portable.
• The warnings issued by File::Find now belong to their own category.
You can enable/disable them with "use/no warnings 'File::Find';".
• FFiillee::::GGlloobb::::gglloobb(()) has been renamed to FFiillee::::GGlloobb::::bbssdd__gglloobb(()) because
the name clashes with the builtin gglloobb(()). The older name is still
available for compatibility, but is deprecated. [561]
• File::Glob now supports "GLOB_LIMIT" constant to limit the size of
the returned list of filenames.
• IPC::Open3 now allows the use of numeric file descriptors.
• IO::Socket now has an aattmmaarrkk(()) method, which returns true if the
socket is positioned at the out-of-band mark. The method is also
exportable as a ssoocckkaattmmaarrkk(()) function.
• IO::Socket::INET failed to open the specified port if the service
name was not known. It now correctly uses the supplied port number
as is. [561]
• IO::Socket::INET has support for the ReusePort option (if your
platform supports it). The Reuse option now has an alias, ReuseAddr.
For clarity, you may want to prefer ReuseAddr.
• IO::Socket::INET now supports a value of zero for "LocalPort"
(usually meaning that the operating system will make one up.)
• 'use lib' now works identically to @INC. Removing directories with
'no lib' now works.
• Math::BigFloat and Math::BigInt have undergone a full rewrite by
Tels. They are now magnitudes faster, and they support various
bignum libraries such as GMP and PARI as their backends.
• Math::Complex handles inf, NaN etc., better.
• Net::Ping has been considerably enhanced by Rob Brown: multihoming is
now supported, Win32 functionality is better, there is now time
measuring functionality (optionally high-resolution using
Time::HiRes), and there is now "external" protocol which uses
Net::Ping::External module which runs your external ping utility and
parses the output. A version of Net::Ping::External is available in
CPAN. #
Note that some of the Net::Ping tests are disabled when running under
the Perl distribution since one cannot assume one or more of the
following: enabled echo port at localhost, full Internet
connectivity, or sympathetic firewalls. You can set the environment
variable PERL_TEST_Net_Ping to "1" (one) before running the Perl test
suite to enable all the Net::Ping tests.
• PPOOSSIIXX::::ssiiggaaccttiioonn(()) is now much more flexible and robust. You can now
install coderef handlers, 'DEFAULT', and 'IGNORE' handlers,
installing new handlers was not atomic.
• In Safe, %INC is now localised in a Safe compartment so that
use/require work.
• In SDBM_File on DOSish platforms, some keys went missing because of
lack of support for files with "holes". A workaround for the problem
has been added.
• In Search::Dict one can now have a pre-processing hook for the lines
being searched.
• The Shell module now has an OO interface.
• In Sys::Syslog there is now a failover mechanism that will go through
alternative connection mechanisms until the message is successfully
logged.
• The Test module has been significantly enhanced.
• TTiimmee::::LLooccaall::::ttiimmeellooccaall(()) does not handle fractional seconds anymore.
The rationale is that neither does llooccaallttiimmee(()), and ttiimmeellooccaall(()) and
llooccaallttiimmee(()) are supposed to be inverses of each other.
• The vars pragma now supports declaring fully qualified variables.
(Something that "our()" does not and will not support.)
• 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 lleennggtthh(()) has been
implemented.
UUttiilliittyy CChhaannggeess • Emacs perl mode (emacs/cperl-mode.el) has been updated to version 4.31.
• _e_m_a_c_s_/_e_2_c_t_a_g_s_._p_l is now much faster.
• "enc2xs" is a tool for people adding their own encodings to the
Encode module.
• "h2ph" now supports C trigraphs.
• "h2xs" now produces a template README.
• "h2xs" now uses "Devel::PPPort" for better portability between
different versions of Perl.
• "h2xs" uses the new ExtUtils::Constant module which will affect newly
created extensions that define constants. Since the new code is more
correct (if you have two constants where the first one is a prefix of
the second one, the first constant nneevveerr got defined), less lossy (it
uses integers for integer constant, as opposed to the old code that
used floating point numbers even for integer constants), and slightly
faster, you might want to consider regenerating your extension code
(the new scheme makes regenerating easy). h2xs now also supports C
trigraphs.
• "libnetcfg" has been added to configure libnet.
• "perlbug" is now much more robust. It also sends the bug report to
perl.org, not perl.com.
• "perlcc" has been rewritten and its user interface (that is, command
line) is much more like that of the Unix C compiler, cc. (The perlbc
tools has been removed. Use "perlcc -B" instead.) NNoottee tthhaatt ppeerrllcccc
iiss ssttiillll ccoonnssiiddeerreedd vveerryy eexxppeerriimmeennttaall aanndd uunnssuuppppoorrtteedd.. [561]
• "perlivp" is a new Installation Verification Procedure utility for
running any time after installing Perl.
• "piconv" is an implementation of the character conversion utility
"iconv", demonstrating the new Encode module.
• "pod2html" now allows specifying a cache directory.
• "pod2html" now produces XHTML 1.0.
• "pod2html" now understands POD written using different line endings
(PC-like CRLF versus Unix-like LF versus MacClassic-like CR).
• "s2p" has been completely rewritten in Perl. (It is in fact a full
implementation of sed in Perl: you can use the sed functionality by
using the "psed" utility.)
• "xsubpp" now understands POD documentation embedded in the *.xs
files. [561]
• "xsubpp" now supports the OUT keyword.
NNeeww DDooccuummeennttaattiioonn • perl56delta details the changes between the 5.005 release and the 5.6.0 release.
• perlclib documents the internal replacements for standard C library
functions. (Interesting only for extension writers and Perl core
hackers.) [561+]
• perldebtut is a Perl debugging tutorial. [561+]
• perlebcdic contains considerations for running Perl on EBCDIC
platforms. [561+]
• perlintro is a gentle introduction to Perl.
• perliol documents the internals of PerlIO with layers.
• perlmodstyle is a style guide for writing modules.
• perlnewmod tells about writing and submitting a new module. [561+]
• perlpacktut is a ppaacckk(()) tutorial.
• perlpod has been rewritten to be clearer and to record the best
practices gathered over the years.
• perlpodspec is a more formal specification of the pod format, mainly
of interest for writers of pod applications, not to people writing in
pod.
• perlretut is a regular expression tutorial. [561+]
• perlrequick is a regular expressions quick-start guide. Yes, much
quicker than perlretut. [561]
• perltodo has been updated.
• perltootc has been renamed as perltooc (to not to conflict with
perltoot in filesystems restricted to "8.3" names).
• perluniintro is an introduction to using Unicode in Perl.
(perlunicode is more of a detailed reference and background
information)
• perlutil explains the command line utilities packaged with the Perl
distribution. [561+]
The following platform-specific documents are available before the
installation as README._p_l_a_t_f_o_r_m, and after the installation as
perl_p_l_a_t_f_o_r_m:
perlaix perlamiga perlapollo perlbeos perlbs2000
perlce perlcygwin perldgux perldos perlepoc perlfreebsd perlhpux
perlhurd perlirix perlmachten perlmacos perlmint perlmpeix
perlnetware perlos2 perlos390 perlplan9 perlqnx perlsolaris
perltru64 perluts perlvmesa perlvms perlvos perlwin32
These documents usually detail one or more of the following subjects:
configuring, building, testing, installing, and sometimes also using Perl
on the said platform.
Eastern Asian Perl users are now welcomed in their own languages:
README.jp (Japanese), README.ko (Korean), README.cn (simplified Chinese)
and README.tw (traditional Chinese), which are written in normal pod but
encoded in EUC-JP, EUC-KR, EUC-CN and Big5. These will get installed as
perljp perlko perlcn perltw
• The documentation for the POSIX-BC platform is called "BS2000", to
avoid confusion with the Perl POSIX module.
• The documentation for the WinCE platform is called perlce (README.ce
in the source code kit), to avoid confusion with the perlwin32
documentation on 8.3-restricted filesystems.
PPeerrffoorrmmaannccee EEnnhhaanncceemmeennttss • mmaapp(()) could get pathologically slow when the result list it generates is larger than the source list. The performance has been improved for common scenarios. [561]
• ssoorrtt(()) is also fully reentrant, in the sense that the sort function
can itself call ssoorrtt(()). This did not work reliably in previous
releases. [561]
• ssoorrtt(()) has been changed to use primarily mergesort internally as
opposed to the earlier quicksort. For very small lists this may
result in slightly slower sorting times, but in general the speedup
should be at least 20%. Additional bonuses are that the worst case
behaviour of ssoorrtt(()) is now better (in computer science terms it now
runs in time O(N log N), as opposed to quicksort's Theta(N**2) worst-
case run time behaviour), and that ssoorrtt(()) is now stable (meaning that
elements with identical keys will stay ordered as they were before
the sort). See the "sort" pragma for information.
The story in more detail: suppose you want to serve yourself a little
slice of Pi.
@digits = ( 3,1,4,1,5,9 );
A numerical sort of the digits will yield (1,1,3,4,5,9), as expected.
Which 1 comes first is hard to know, since one 1 looks pretty much
like any other. You can regard this as totally trivial, or somewhat
profound. However, if you just want to sort the even digits ahead of
the odd ones, then what will
sort { ($a % 2) <=> ($b % 2) } @digits;
yield? The only even digit, 4, will come first. But how about the
odd numbers, which all compare equal? With the quicksort algorithm
used to implement Perl 5.6 and earlier, the order of ties is left up
to the sort. So, as you add more and more digits of Pi, the order in
which the sorted even and odd digits appear will change. and, for
sufficiently large slices of Pi, the quicksort algorithm in Perl 5.8
won't return the same results even if reinvoked with the same input.
The justification for this rests with quicksort's worst case
behavior. If you run
sort { $a <=> $b } ( 1 .. $N , 1 .. $N );
(something you might approximate if you wanted to merge two sorted
arrays using sort), doubling $N doesn't just double the quicksort
time, it _q_u_a_d_r_u_p_l_e_s it. Quicksort has a worst case run time that can
grow like N**2, so-called _q_u_a_d_r_a_t_i_c behaviour, and it can happen on
patterns that may well arise in normal use. You won't notice this
for small arrays, but you _w_i_l_l notice it with larger arrays, and you
may not live long enough for the sort to complete on arrays of a
million elements. So the 5.8 quicksort scrambles large arrays before
sorting them, as a statistical defence against quadratic behaviour.
But that means if you sort the same large array twice, ties may be
broken in different ways.
Because of the unpredictability of tie-breaking order, and the
quadratic worst-case behaviour, quicksort was _a_l_m_o_s_t replaced
completely with a stable mergesort. _S_t_a_b_l_e means that ties are
broken to preserve the original order of appearance in the input
array. So
sort { ($a % 2) <=> ($b % 2) } (3,1,4,1,5,9);
will yield (4,3,1,1,5,9), guaranteed. The even and odd numbers
appear in the output in the same order they appeared in the input.
Mergesort has worst case O(N log N) behaviour, the best value
attainable. And, ironically, this mergesort does particularly well
where quicksort goes quadratic: mergesort sorts (1..$N, 1..$N) in
O(N) time. But quicksort was rescued at the last moment because it
is faster than mergesort on certain inputs and platforms. For
example, if you really _d_o_n_'_t care about the order of even and odd
digits, quicksort will run in O(N) time; it's very good at sorting
many repetitions of a small number of distinct elements. The
quicksort divide and conquer strategy works well on platforms with
relatively small, very fast, caches. Eventually, the problem gets
whittled down to one that fits in the cache, from which point it
benefits from the increased memory speed.
Quicksort was rescued by implementing a sort pragma to control
aspects of the sort. The ssttaabbllee subpragma forces stable behaviour,
regardless of algorithm. The __qquuiicckkssoorrtt and __mmeerrggeessoorrtt subpragmas
are heavy-handed ways to select the underlying implementation. The
leading "_" is a reminder that these subpragmas may not survive
beyond 5.8. More appropriate mechanisms for selecting the
implementation exist, but they wouldn't have arrived in time to save
quicksort.
• 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.
• uunnsshhiifftt(()) should now be noticeably faster.
IInnssttaallllaattiioonn aanndd CCoonnffiigguurraattiioonn IImmpprroovveemmeennttss GGeenneerriicc IImmpprroovveemmeennttss • INSTALL now explains how you can configure Perl to use 64-bit integers even on non-64-bit platforms.
• Policy.sh policy change: if you are reusing a Policy.sh file (see
INSTALL) and you use Configure -Dprefix=/foo/bar and in the old
Policy $prefix eq $siteprefix and $prefix eq $vendorprefix, all of
them will now be changed to the new prefix, /foo/bar. (Previously
only $prefix changed.) If you do not like this new behaviour,
specify prefix, siteprefix, and vendorprefix explicitly.
• A new optional location for Perl libraries, otherlibdirs, is
available. It can be used for example for vendor add-ons without
disturbing Perl's own library directories.
• In many platforms, the vendor-supplied 'cc' is too stripped-down to
build Perl (basically, 'cc' doesn't do ANSI C). If this seems to be
the case and 'cc' does not seem to be the GNU C compiler 'gcc', an
automatic attempt is made to find and use 'gcc' instead.
• gcc needs to closely track the operating system release to avoid
build problems. If Configure finds that gcc was built for a different
operating system release than is running, it now gives a clearly
visible warning that there may be trouble ahead.
• Since Perl 5.8 is not binary-compatible with previous releases of
Perl, Configure no longer suggests including the 5.005 modules in
@INC. #
• Configure "-S" can now run non-interactively. [561]
• Configure support for pdp11-style memory models has been removed due
to obsolescence. [561]
• configure.gnu now works with options with whitespace in them.
• installperl now outputs everything to STDERR.
• 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.
• 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.)
• In AFS installations, one can configure the root of the AFS to be
somewhere else than the default _/_a_f_s by using the Configure parameter
"-Dafsroot=/some/where/else".
• APPLLIB_EXP, a lesser-known 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.
• The version of Berkeley DB used when the Perl (and, presumably, the
DB_File extension) was built is now available as
@Config{qw(db_version_major db_version_minor db_version_patch)} from
Perl and as "DB_VERSION_MAJOR_CFG DB_VERSION_MINOR_CFG
DB_VERSION_PATCH_CFG" from C.
• Building Berkeley DB3 for compatibility modes for DB, NDBM, and ODBM
has been documented in INSTALL.
• If you have CPAN access (either network or a local copy such as a CD-
ROM) you can during specify extra modules to Configure to build and
install with Perl using the -Dextras=... option. See INSTALL for
more details.
• In addition to config.over, a new override file, config.arch, is
available. This file is supposed to be used by hints file writers
for architecture-wide changes (as opposed to config.over which is for
site-wide changes).
• 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.
[561]
• For Perl developers, several new make targets for profiling and
debugging have been added; see perlhack.
• Use of the _g_p_r_o_f tool to profile Perl has been documented in
perlhack. There is a make target called "perl.gprof" for
generating a gprofiled Perl executable.
• If you have GCC 3, there is a make target called "perl.gcov"
for creating a gcoved Perl executable for coverage analysis.
See perlhack.
• 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.
• Guidelines of how to construct minimal Perl installations have been
added to INSTALL.
• The Thread extension is now not built at all under ithreads
("Configure -Duseithreads") because it wouldn't work anyway (the
Thread extension requires being Configured with "-Duse5005threads").
NNoottee tthhaatt tthhee 55..000055 tthhrreeaaddss aarree uunnssuuppppoorrtteedd aanndd ddeepprreeccaatteedd:: iiff yyoouu
hhaavvee ccooddee wwrriitttteenn ffoorr tthhee oolldd tthhrreeaaddss yyoouu sshhoouulldd mmiiggrraattee iitt ttoo tthhee
nneeww iitthhrreeaaddss mmooddeell..
• The Gconvert macro ($Config{d_Gconvert}) used by perl for
stringifying floating-point numbers is now more picky about using
sprintf %.*g rules for the conversion. Some platforms that used to
use gcvt may now resort to the slower sprintf.
• The obsolete method of making a special (e.g., debugging) flavor of
perl by saying
make LIBPERL=libperld.a
has been removed. Use -DDEBUGGING instead.
NNeeww OOrr IImmpprroovveedd PPllaattffoorrmmss For the list of platforms known to support Perl, see “Supported Platforms” in perlport.
• AIX dynamic loading should be now better supported.
• AIX should now work better with gcc, threads, and 64-bitness. Also
the long doubles support in AIX should be better now. See perlaix.
• AtheOS ( http://www.atheos.cx/ ) is a new platform.
• BeOS has been reclaimed.
• The DG/UX platform now supports 5.005-style threads. See perldgux.
• The DYNIX/ptx platform (also known as dynixptx) is supported at or
near osvers 4.5.2.
• 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 perlos390,
perlbs2000 (for POSIX-BC), and perlvmesa for more information.
(NNoottee:: support for VM/ESA was removed in Perl v5.18.0. The relevant
information was in _R_E_A_D_M_E_._v_m_e_s_a)
• 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. [561]
• Mac OS Classic is now supported in the mainstream source package
(MacPerl has of course been available since perl 5.004 but now the
source code bases of standard Perl and MacPerl have been
synchronised) [561]
• Mac OS X (or Darwin) should now be able to build Perl even on HFS+
filesystems. (The case-insensitivity used to confuse the Perl build
process.)
• NCR MP-RAS is now supported. [561]
• All the NetBSD specific patches (except for the installation specific
ones) have been merged back to the main distribution.
• NetWare from Novell is now supported. See perlnetware.
• NonStop-UX is now supported. [561]
• NEC SUPER-UX is now supported.
• All the OpenBSD specific patches (except for the installation
specific ones) have been merged back to the main distribution.
• Perl has been tested with the GNU pth userlevel thread package (
http://www.gnu.org/software/pth/pth.html ). All thread tests of Perl
now work, but not without adding some yyiieelldd(())s to the tests, so while
pth (and other userlevel thread implementations) can be considered to
be "working" with Perl ithreads, keep in mind the possible non-
preemptability of the underlying thread implementation.
• Stratus VOS is now supported using Perl's native build method
(Configure). This is the recommended method to build Perl on VOS.
The older methods, which build miniperl, are still available. See
perlvos. [561+]
• The Amdahl UTS Unix mainframe platform is now supported. [561]
• WinCE is now supported. See perlce.
• z/OS (formerly known as OS/390, formerly known as MVS OE) now has
support for dynamic loading. This is not selected by default,
however, you must specify -Dusedl in the arguments of Configure.
[561]
SSeelleecctteedd BBuugg FFiixxeess Numerous memory leaks and uninitialized memory accesses have been hunted down. Most importantly, anonymous subs used to leak quite a bit. [561]
• The autouse pragma didn't work for Multi::Part::Function::Names.
• ccaalllleerr(()) could cause core dumps in certain situations. Carp was
sometimes affected by this problem. In particular, ccaalllleerr(()) now
returns a subroutine name of "(unknown)" for subroutines that have
been removed from the symbol table.
• chop(@list) in list context returned the characters chopped in
reverse order. This has been reversed to be in the right order.
[561]
• 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. [561]
• The behaviour of non-decimal but numeric string constants such as
"0x23" was platform-dependent: in some platforms that was seen as 35,
in some as 0, in some as a floating point number (don't ask). This
was caused by Perl's using the operating system libraries in a
situation where the result of the string to number conversion is
undefined: now Perl consistently handles such strings as zero in
numeric contexts.
• Several debugger fixes: exit code now reflects the script exit code,
condition "0" now treated correctly, the "d" command now checks line
number, $. no longer gets corrupted, and all debugger output now goes
correctly to the socket if RemotePort is set. [561]
• The debugger (perl5db.pl) has been modified to present a more
consistent commands interface, via (CommandSet=580). perl5db.t was
also added to test the changes, and as a placeholder for further
tests.
See perldebug.
• The debugger has a new "dumpDepth" option to control the maximum
depth to which nested structures are dumped. The "x" command has
been extended so that "x N EXPR" dumps out the value of _E_X_P_R to a
depth of at most _N levels.
• The debugger can now show lexical variables if you have the CPAN
module PadWalker installed.
• The order of DESTROYs has been made more predictable.
• Perl 5.6.0 could emit spurious warnings about redefinition of
ddll__eerrrroorr(()) when statically building extensions into perl. This has
been corrected. [561]
• dprofpp -R didn't work.
• *foo{FORMAT} now works.
• Infinity is now recognized as a number.
• UNIVERSAL::isa no longer caches methods incorrectly. (This broke the
Tk extension with 5.6.0.) [561]
• Lexicals I: lexicals outside an eval "" weren't resolved correctly
inside a subroutine definition inside the eval "" if they were not
already referenced in the top level of the eval""ed code.
• Lexicals II: lexicals leaked at file scope into subroutines that were
declared before the lexicals.
• Lexical warnings now propagating correctly between scopes and into
"eval "..."".
• "use warnings qw(FATAL all)" did not work as intended. This has been
corrected. [561]
• wwaarrnniinnggss::::eennaabblleedd(()) now reports the state of $^W correctly if the
caller isn't using lexical warnings. [561]
• Line renumbering with eval and "#line" now works. [561]
• Fixed numerous memory leaks, especially in eval "".
• Localised tied variables no longer leak memory
use Tie::Hash;
tie my %tied_hash => 'Tie::StdHash';
...
# Used to leak memory every time local() was called;
# in a loop, this added up.
local($tied_hash{Foo}) = 1;
• Localised hash elements (and %ENV) are correctly unlocalised to not
exist, if they didn't before they were localised.
use Tie::Hash;
tie my %tied_hash => 'Tie::StdHash';
...
# Nothing has set the FOO element so far
{ local $tied_hash{FOO} = 'Bar' }
# This used to print, but not now.
print "exists!\n" if exists $tied_hash{FOO};
As a side effect of this fix, tied hash interfaces mmuusstt define the
EXISTS and DELETE methods.
• mmkkddiirr(()) now ignores trailing slashes in the directory name, as
mandated by POSIX.
• Some versions of glibc have a broken mmooddffll(()). This affects builds
with "-Duselongdouble". This version of Perl detects this brokenness
and has a workaround for it. The glibc release 2.2.2 is known to
have fixed the mmooddffll(()) bug.
• Modulus of unsigned numbers now works (4063328477 % 65535 used to
return 27406, instead of 27047). [561]
• Some "not a number" warnings introduced in 5.6.0 eliminated to be
more compatible with 5.005. Infinity is now recognised as a number.
[561]
• Numeric conversions did not recognize changes in the string value
properly in certain circumstances. [561]
• Attributes (such as :shared) didn't work with oouurr(()).
• oouurr(()) variables will not cause bogus "Variable will not stay shared"
warnings. [561]
• "our" variables of the same name declared in two sibling blocks
resulted in bogus warnings about "redeclaration" of the variables.
The problem has been corrected. [561]
• pack "Z" now correctly terminates the string with "\0".
• Fix password routines which in some shadow password platforms (e.g.
HP-UX) caused ggeettppwweenntt(()) to return every other entry.
• The PERL5OPT environment variable (for passing command line arguments
to Perl) didn't work for more than a single group of options. [561]
• PERL5OPT with embedded spaces didn't work.
• pprriinnttff(()) no longer resets the numeric locale to "C".
• "qw(a\\b)" now parses correctly as 'a\\b': that is, as three
characters, not four. [561]
• ppooss(()) did not return the correct value within s///ge in earlier
versions. This is now handled correctly. [561]
• Printing quads (64-bit integers) with printf/sprintf now works
without the q L ll prefixes (assuming you are on a quad-capable
platform).
• Regular expressions on references and overloaded scalars now work.
[561+]
• Right-hand side magic (GMAGIC) could in many cases such as string
concatenation be invoked too many times.
• ssccaallaarr(()) now forces scalar context even when used in void context.
• SOCKS support is now much more robust.
• ssoorrtt(()) arguments are now compiled in the right wantarray context
(they were accidentally using the context of the ssoorrtt(()) itself). The
comparison block is now run in scalar context, and the arguments to
be sorted are always provided list context. [561]
• Changed the POSIX character class "[[:space:]]" to include the (very
rarely used) vertical tab character. Added a new POSIX-ish character
class "[[:blank:]]" which stands for horizontal whitespace
(currently, the space and the tab).
• The tainting behaviour of sspprriinnttff(()) has been rationalized. It does
not taint the result of floating point formats anymore, making the
behaviour consistent with that of string interpolation. [561]
• Some cases of inconsistent taint propagation (such as within hash
values) have been fixed.
• The RE engine found in Perl 5.6.0 accidentally pessimised certain
kinds of simple pattern matches. These are now handled better. [561]
• Regular expression debug output (whether through "use re 'debug'" or
via "-Dr") now looks better. [561]
• Multi-line matches like ""a\nxb\n" =~ /(?!\A)x/m" were flawed. The
bug has been fixed. [561]
• Use of $& could trigger a core dump under some situations. This is
now avoided. [561]
• The regular expression captured submatches ($1, $2, ...) are now more
consistently unset if the match fails, instead of leaving false data
lying around in them. [561]
• rreeaaddlliinnee(()) on files opened in "slurp" mode could return an extra ""
(blank line) at the end in certain situations. This has been
corrected. [561]
• Autovivification of symbolic references of special variables
described in perlvar (as in "${$num}") was accidentally disabled.
This works again now. [561]
• Sys::Syslog ignored the "LOG_AUTH" constant.
• $AUTOLOAD, ssoorrtt(()), lloocckk(()), and spawning subprocesses in multiple
threads simultaneously are now thread-safe.
• Tie::Array's SPLICE method was broken.
• Allow a read-only string on the left-hand side of a non-modifying
tr///.
• If "STDERR" is tied, warnings caused by "warn" and "die" now
correctly pass to it.
• Several Unicode fixes.
• BOMs (byte order marks) at the beginning of Perl files
(scripts, modules) should now be transparently skipped.
UTF-16 and UCS-2 encoded Perl files should now be read
correctly.
• The character tables have been updated to Unicode 3.2.0.
• Comparing with utf8 data does not magically upgrade non-utf8
data into utf8. (This was a problem for example if you were
mixing data from I/O and Unicode data: your output might have
got magically encoded as UTF-8.)
• Generating illegal Unicode code points such as U+FFFE, or the
UTF-16 surrogates, now also generates an optional warning.
• "IsAlnum", "IsAlpha", and "IsWord" now match titlecase.
• Concatenation with the "." operator or via variable
interpolation, "eq", "substr", "reverse", "quotemeta", the
"x" operator, substitution with "s///", single-quoted UTF-8,
should now work.
• The "tr///" operator now works. Note that the "tr///CU"
functionality has been removed (but see pack('U0', ...)).
• "eval "v200"" now works.
• Perl 5.6.0 parsed m/\x{ab}/ incorrectly, leading to spurious
warnings. This has been corrected. [561]
• Zero entries were missing from the Unicode classes such as
"IsDigit".
• Large unsigned numbers (those above 2**31) could sometimes lose their
unsignedness, causing bogus results in arithmetic operations. [561]
• The Perl parser has been stress tested using both random input and
Markov chain input and the few found crashes and lockups have been
fixed.
PPllaattffoorrmm SSppeecciiffiicc CChhaannggeess aanndd FFiixxeess
• BSDI 4.* #
Perl now works on post-4.0 BSD/OSes.
• All BSDs
Setting $0 now works (as much as possible; see perlvar for details).
• Cygwin
Numerous updates; currently synchronised with Cygwin 1.3.10.
• Previously DYNIX/ptx had problems in its Configure probe for non-
blocking I/O.
• EPOC #
EPOC now better supported. See README.epoc. [561]
• FreeBSD 3.*
Perl now works on post-3.0 FreeBSDs.
• HP-UX #
README.hpux updated; "Configure -Duse64bitall" now works; now uses
HP-UX malloc instead of Perl malloc.
• IRIX #
Numerous compilation flag and hint enhancements; accidental mixing of
32-bit and 64-bit libraries (a doomed attempt) made much harder.
• Linux
• Long doubles should now work (see INSTALL). [561]
• Linux previously had problems related to sockaddrlen when
using aacccceepptt(()), rreeccvvffrroomm(()) (in Perl: rreeccvv(())), ggeettppeeeerrnnaammee(()),
and ggeettssoocckknnaammee(()).
• Mac OS Classic
Compilation of the standard Perl distribution in Mac OS Classic
should now work if you have the Metrowerks development environment
and the missing Mac-specific toolkit bits. Contact the macperl
mailing list for details.
• MPE/iX
MPE/iX update after Perl 5.6.0. See README.mpeix. [561]
• NetBSD/threads: try installing the GNU pth (should be in the packages
collection, or http://www.gnu.org/software/pth/), and Configure with
-Duseithreads.
• NetBSD/sparc
Perl now works on NetBSD/sparc.
• OS/2 #
Now works with usethreads (see INSTALL). [561]
• Solaris
64-bitness using the Sun Workshop compiler now works.
• Stratus VOS
The native build method requires at least VOS Release 14.5.0 and GNU
C++/GNU Tools 2.0.1 or later. The Perl pack function now maps
overflowed values to +infinity and underflowed values to -infinity.
• Tru64 (aka Digital UNIX, aka DEC OSF/1)
The operating system version letter now recorded in $Config{osvers}.
Allow compiling with gcc (previously explicitly forbidden).
Compiling with gcc still not recommended because buggy code results,
even with gcc 2.95.2.
• Unicos
Fixed various alignment problems that lead into core dumps either
during build or later; no longer dies on math errors at runtime; now
using full quad integers (64 bits), previously was using only 46 bit
integers for speed.
• VMS #
See "Socket Extension Dynamic in VMS" and "IEEE-format Floating Point
Default on OpenVMS Alpha" for important changes not otherwise listed
here.
cchhddiirr(()) now works better despite a CRT bug; now works with
MULTIPLICITY (see INSTALL); now works with Perl's malloc.
The tainting of %ENV elements via "keys" or "values" was previously
unimplemented. It now works as documented.
The "waitpid" emulation has been improved. The worst bug (now fixed)
was that a pid of -1 would cause a wildcard search of all processes
on the system.
POSIX-style signals are now emulated much better on VMS versions
prior to 7.0.
The "system" function and backticks operator have improved
functionality and better error handling. [561]
File access tests now use current process privileges rather than the
user's default privileges, which could sometimes result in a mismatch
between reported access and actual access. This improvement is only
available on VMS v6.0 and later.
There is a new "kill" implementation based on "sys$sigprc" that
allows older VMS systems (pre-7.0) to use "kill" to send signals
rather than simply force exit. This implementation also allows later
systems to call "kill" from within a signal handler.
Iterative logical name translations are now limited to 10 iterations
in imitation of SHOW LOGICAL and other OpenVMS facilities.
• Windows
• Signal handling now works better than it used to. It is now
implemented using a Windows message loop, and is therefore
less prone to random crashes.
• ffoorrkk(()) emulation is now more robust, but still continues to
have a few esoteric bugs and caveats. See perlfork for
details. [561+]
• A failed (pseudo)fork now returns undef and sets errno to
EAGAIN. [561] #
• The following modules now work on Windows:
ExtUtils::Embed [561]
IO::Pipe
IO::Poll
Net::Ping
• IIOO::::FFiillee::::nneeww__ttmmppffiillee(()) is no longer limited to 32767
invocations per-process.
• Better cchhddiirr(()) return value for a non-existent directory.
• Compiling perl using the 64-bit Platform SDK tools is now
supported.
• The WWiinn3322::::SSeettCChhiillddSShhoowwWWiinnddooww(()) builtin can be used to
control the visibility of windows created by child processes.
See Win32 for details.
• Non-blocking waits for child processes (or pseudo-processes)
are supported via "waitpid($pid, &POSIX::WNOHANG)".
• The behavior of ssyysstteemm(()) with multiple arguments has been
rationalized. Each unquoted argument will be automatically
quoted to protect whitespace, and any existing whitespace in
the arguments will be preserved. This improves the
portability of system(@args) by avoiding the need for Windows
"cmd" shell specific quoting in perl programs.
Note that this means that some scripts that may have relied
on earlier buggy behavior may no longer work correctly. For
example, "system("nmake /nologo", @args)" will now attempt to
run the file "nmake /nologo" and will fail when such a file
isn't found. On the other hand, perl will now execute code
such as "system("c:/Program Files/MyApp/foo.exe", @args)"
correctly.
• The perl header files no longer suppress common warnings from
the Microsoft Visual C++ compiler. This means that
additional warnings may now show up when compiling XS code.
• 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++). [561]
• Duping socket handles with open(F, ">&MYSOCK") now works
under Windows 9x. [561]
• Current directory entries in %ENV are now correctly
propagated to child processes. [561]
• New %ENV entries now propagate to subprocesses. [561]
• WWiinn3322::::GGeettCCwwdd(()) correctly returns C:\ instead of C: when at
the drive root. Other bugs in cchhddiirr(()) and CCwwdd::::ccwwdd(()) have
also been fixed. [561]
• The makefiles now default to the features enabled in
ActiveState ActivePerl (a popular Win32 binary distribution).
[561]
• HTML files will now be installed in c:\perl\html instead of
c:\perl\lib\pod\html
• REG_EXPAND_SZ keys are now allowed in registry settings used
by perl. [561]
• Can now sseenndd(()) from all threads, not just the first one.
[561]
• ExtUtils::MakeMaker now uses $ENV{LIB} to search for
libraries. [561]
• Less stack reserved per thread so that more threads can run
concurrently. (Still 16M per thread.) [561]
• "File::Spec->tmpdir()" now prefers C:/temp over /tmp (works
better when perl is running as service).
• Better UNC path handling under ithreads. [561]
• wwaaiitt(()), wwaaiittppiidd(()), and backticks now return the correct exit
status under Windows 9x. [561]
• A socket handle leak in aacccceepptt(()) has been fixed. [561]
NNeeww oorr CChhaannggeedd DDiiaaggnnoossttiiccss Please see perldiag for more details.
• Ambiguous range in the transliteration operator (like a-z-9) now
gives a warning.
• chdir("") and chdir(undef) now give a deprecation warning because
they cause a possible unintentional chdir to the home directory. Say
cchhddiirr(()) if you really mean that.
• Two new debugging options have been added: if you have compiled your
Perl with debugging, you can use the -DT [561] and -DR options to
trace tokenising and to add reference counts to displaying variables,
respectively.
• The lexical warnings category "deprecated" is no longer a sub-
category of the "syntax" category. It is now a top-level category in
its own right.
• Unadorned dduummpp(()) will now give a warning suggesting to use explicit
CCOORREE::::dduummpp(()) if that's what really is meant.
• The "Unrecognized escape" warning has been extended to include "\8",
"\9", and "\_". There is no need to escape any of the "\w"
characters.
• All regular expression compilation error messages are now hopefully
easier to understand both because the error message now comes before
the failed regex and because the point of failure is now clearly
marked by a "<-- HERE" marker.
• Various I/O (and socket) functions like bbiinnmmooddee(()), cclloossee(()), and so
forth now more consistently warn if they are used illogically either
on a yet unopened or on an already closed filehandle (or socket).
• Using llssttaatt(()) on a filehandle now gives a warning. (It's a non-
sensical thing to do.)
• The "-M" and "-m" options now warn if you didn't supply the module
name.
• If you in "use" specify a required minimum version, modules matching
the name and but not defining a $VERSION will cause a fatal failure.
• Using negative offset for vveecc(()) in lvalue context is now a warnable
offense.
• Odd number of arguments to overload::constant now elicits a warning.
• Odd number of elements in anonymous hash now elicits a warning.
• The various "opened only for", "on closed", "never opened" warnings
drop the "main::" prefix for filehandles in the "main" package, for
example "STDIN" instead of "main::STDIN".
• Subroutine prototypes are now checked more carefully, you may get
warnings for example if you have used non-prototype characters.
• If an attempt to use a (non-blessed) reference as an array index is
made, a warning is given.
• "push @a;" and "unshift @a;" (with no values to push or unshift) now
give a warning. This may be a problem for generated and eval'ed
code.
• If you try to "pack" in perlfunc a number less than 0 or larger than
255 using the "C" format you will get an optional warning. Similarly
for the "c" format and a number less than -128 or more than 127.
• pack "P" format now demands an explicit size.
• unpack "w" now warns of unterminated compressed integers.
• Warnings relating to the use of PerlIO have been added.
• Certain regex modifiers such as "(?o)" make sense only if applied to
the entire regex. You will get an optional warning if you try to do
otherwise.
• Variable length lookbehind has not yet been implemented, trying to
use it will tell that.
• Using arrays or hashes as references (e.g. "%foo->{bar}" has been
deprecated for a while. Now you will get an optional warning.
• Warnings relating to the use of the new restricted hashes feature
have been added.
• Self-ties of arrays and hashes are not supported and fatal errors
will happen even at an attempt to do so.
• Using "sort" in scalar context now issues an optional warning. This
didn't do anything useful, as the sort was not performed.
• Using the /g modifier in sspplliitt(()) is meaningless and will cause a
warning.
• Using sspplliiccee(()) past the end of an array now causes a warning.
• Malformed Unicode encodings (UTF-8 and UTF-16) cause a lot of
warnings, as does trying to use UTF-16 surrogates (which are
unimplemented).
• Trying to use Unicode characters on an I/O stream without marking the
stream's encoding (using ooppeenn(()) or bbiinnmmooddee(())) will cause "Wide
character" warnings.
• Use of v-strings in use/require causes a (backward) portability
warning.
• Warnings relating to the use interpreter threads and their shared
data have been added.
CChhaannggeedd IInntteerrnnaallss • PerlIO is now the default.
• perlapi.pod (a companion to perlguts) now attempts to document the
internal API.
• You can now build a really minimal perl called microperl. Building
microperl does not require even running Configure; "make -f
Makefile.micro" should be enough. Beware: microperl makes many
assumptions, some of which may be too bold; the resulting executable
may crash or otherwise misbehave in wondrous ways. For careful
hackers only.
• Added rrssiiggnnaall(()), wwhhiicchhssiigg(()), ddoo__jjooiinn(()), op_clear, op_null,
ppttrr__ttaabbllee__cclleeaarr(()), ppttrr__ttaabbllee__ffrreeee(()), ssvv__sseettrreeff__uuvv(()), and several
UTF-8 interfaces to the publicised API. For the full list of the
available APIs see perlapi.
• Made possible to propagate customised exceptions via ccrrooaakk(())ing.
• Now xsubs can have attributes just like subs. (Well, at least the
built-in attributes.)
• dTHR and djSP have been obsoleted; the former removed (because it's a
no-op) and the latter replaced with dSP.
• PERL_OBJECT has been completely removed.
• The MAGIC constants (e.g. 'P') have been macrofied (e.g.
"PERL_MAGIC_TIED") for better source code readability and
maintainability.
• The regex compiler now maintains a structure that identifies nodes in
the compiled bytecode with the corresponding syntactic features of
the original regex expression. The information is attached to the
new "offsets" member of the "struct regexp". See perldebguts for more
complete information.
• The C code has been made much more "gcc -Wall" clean. Some warning
messages still remain in some platforms, so if you are compiling with
gcc you may see some warnings about dubious practices. The warnings
are being worked on.
• _p_e_r_l_y_._c, _s_v_._c, and _s_v_._h have now been extensively commented.
• Documentation on how to use the Perl source repository has been added
to _P_o_r_t_i_n_g_/_r_e_p_o_s_i_t_o_r_y_._p_o_d.
• There are now several profiling make targets.
SSeeccuurriittyy VVuullnneerraabbiilliittyy CClloosseedd [[556611]] (This change was already made in 5.7.0 but bears repeating here.) (5.7.0 came out before 5.6.1: the development branch 5.7 released earlier than the maintenance branch 5.6)
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 November 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
Perl 5.8.0 (and the maintenance release 5.6.1, and it was removed also
from all the Perl 5.7 releases), so that particular vulnerability isn't
there anymore. However, further security vulnerabilities are,
unfortunately, always possible. The suidperl functionality is most
probably going to be removed in Perl 5.10. 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/ ).
NNeeww TTeessttss Several new tests have been added, especially for the _l_i_b and _e_x_t subsections. There are now about 69 000 individual tests (spread over about 700 test scripts), in the regression suite (5.6.1 has about 11 700 tests, in 258 test scripts) The exact numbers depend on the platform and Perl configuration used. Many of the new tests are of course introduced by the new modules, but still in general Perl is now more thoroughly tested.
Because of the large number of tests, running the regression suite will
take considerably longer time than it used to: expect the suite to take
up to 4-5 times longer to run than in perl 5.6. On a really fast machine
you can hope to finish the suite in about 6-8 minutes (wallclock time).
The tests are now reported in a different order than in earlier Perls.
(This happens because the test scripts from under t/lib have been moved
to be closer to the library/extension they are testing.)
KKnnoowwnn PPrroobblleemmss TThhee CCoommppiilleerr SSuuiittee IIss SSttiillll VVeerryy EExxppeerriimmeennttaall The compiler suite is slowly getting better but it continues to be highly experimental. Use in production environments is discouraged.
LLooccaalliissiinngg TTiieedd AArrrraayyss aanndd HHaasshheess IIss BBrrookkeenn local %tied_array;
doesn't work as one would expect: the old value is restored incorrectly.
This will be changed in a future release, but we don't know yet what the
new semantics will exactly be. In any case, the change will break
existing code that relies on the current (ill-defined) semantics, so just
avoid doing this in general.
BBuuiillddiinngg EExxtteennssiioonnss CCaann FFaaiill BBeeccaauussee OOff LLaarrggeeffiilleess 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 they may 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 to) link together at all binaries with different ideas about file offsets; all this is platform-dependent.
MMooddiiffyyiinngg $$ IInnssiiddee ffoorr((....)) for (1..5) { $_++ }
works without complaint. It shouldn't. (You should be able to modify
only lvalue elements inside the loops.) You can see the correct
behaviour by replacing the 1..5 with 1, 2, 3, 4, 5.
mmoodd__ppeerrll 11..2266 DDooeessnn’’tt BBuuiilldd WWiitthh TThhrreeaaddeedd PPeerrll Use mod_perl 1.27 or higher.
lliibb//ffttmmpp--sseeccuurriittyy tteessttss wwaarrnn ‘’ssyysstteemm ppoossssiibbllyy iinnsseeccuurree’’ Don’t panic. Read the ‘make test’ section of INSTALL instead.
lliibbwwwwww--ppeerrll ((LLWWPP)) ffaaiillss bbaassee//ddaattee ##5511 Use libwww-perl 5.65 or later.
PPDDLL ffaaiilliinngg ssoommee tteessttss Use PDL 2.3.4 or later.
PPeerrll__ggeett__ssvv You may get errors like ‘Undefined symbol “Perl_get_sv”’ or “can’t resolve symbol ‘Perl_get_sv’”, or the symbol may be “Perl_sv_2pv”. This probably means that you are trying to use an older shared Perl library (or extensions linked with such) with Perl 5.8.0 executable. Perl used to have such a subroutine, but that is no more the case. Check your shared library path, and any shared Perl libraries in those directories.
Sometimes this problem may also indicate a partial Perl 5.8.0
installation, see "Mac OS X dyld undefined symbols" for an example and
how to deal with it.
SSeellff--ttyyiinngg PPrroobblleemmss 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 forbidden for now (you will get a fatal error even from an attempt).
A change to self-tying of globs has caused them to be recursively
referenced (see: "Two-Phased Garbage Collection" in perlobj). You will
now need an explicit untie to destroy a self-tied glob. This behaviour
may be fixed at a later date.
Self-tying of scalars and IO thingies works.
eexxtt//tthhrreeaaddss//tt//lliibbcc If this test fails, it indicates that your libc (C library) is not threadsafe. This particular test stress tests the llooccaallttiimmee(()) call to find out whether it is threadsafe. See perlthrtut for more information.
FFaaiilluurree ooff TThhrreeaadd ((55..000055--ssttyyllee)) tteessttss NNoottee tthhaatt ssuuppppoorrtt ffoorr 55..000055--ssttyyllee tthhrreeaaddiinngg iiss ddeepprreeccaatteedd,, eexxppeerriimmeennttaall aanndd pprraaccttiiccaallllyy uunnssuuppppoorrtteedd.. IInn 55..1100,, iitt iiss eexxppeecctteedd ttoo bbee rreemmoovveedd.. YYoouu sshhoouulldd mmiiggrraattee yyoouurr ccooddee ttoo iitthhrreeaaddss..
The following tests 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.
../ext/B/t/xref.t 255 65280 14 12 85.71% 3-14
../ext/List/Util/t/first.t 255 65280 7 4 57.14% 2 5-7
../lib/English.t 2 512 54 2 3.70% 2-3
../lib/FileCache.t 5 1 20.00% 5
../lib/Filter/Simple/t/data.t 6 3 50.00% 1-3
../lib/Filter/Simple/t/filter_only. 9 3 33.33% 1-2 5
../lib/Math/BigInt/t/bare_mbf.t 1627 4 0.25% 8 11 1626-1627
../lib/Math/BigInt/t/bigfltpm.t 1629 4 0.25% 10 13 1628-
1629
../lib/Math/BigInt/t/sub_mbf.t 1633 4 0.24% 8 11 1632-1633
../lib/Math/BigInt/t/with_sub.t 1628 4 0.25% 9 12 1627-1628
../lib/Tie/File/t/31_autodefer.t 255 65280 65 32 49.23% 34-65
../lib/autouse.t 10 1 10.00% 4
op/flip.t 15 1 6.67% 15
These failures are unlikely to get fixed as 5.005-style threads are
considered fundamentally broken. (Basically what happens is that
competing threads can corrupt shared global state, one good example being
regular expression engine's state.)
TTiimmiinngg pprroobblleemmss The following tests may fail intermittently because of timing problems, for example if the system is heavily loaded.
t/op/alarm.t
ext/Time/HiRes/HiRes.t
lib/Benchmark.t
lib/Memoize/t/expmod_t.t
lib/Memoize/t/speed.t
In case of failure please try running them manually, for example
./perl -Ilib ext/Time/HiRes/HiRes.t
TTiieedd//MMaaggiiccaall AArrrraayy//HHaasshh EElleemmeennttss DDoo NNoott AAuuttoovviivviiffyy For normal arrays “$foo = $bar[1]” will assign “undef” to $bar[1] (assuming that it didn’t exist before), but for tied/magical arrays and hashes such autovivification does not happen because there is currently no way to catch the reference creation. The same problem affects slicing over non-existent indices/keys of a tied/magical array/hash.
UUnniiccooddee iinn ppaacckkaaggee//ccllaassss aanndd ssuubbrroouuttiinnee nnaammeess ddooeess nnoott wwoorrkk One can have Unicode in identifier names, but not in package/class or subroutine names. While some limited functionality towards this does exist as of Perl 5.8.0, that is more accidental than designed; use of Unicode for the said purposes is unsupported.
One reason of this unfinishedness is its (currently) inherent
unportability: since both package names and subroutine names may need to
be mapped to file and directory names, the Unicode capability of the
filesystem becomes important-- and there unfortunately aren't portable
answers.
PPllaattffoorrmm SSppeecciiffiicc PPrroobblleemmss
AAIIXX #
• If using the AIX native make command, instead of just "make" issue
"make all". In some setups the former has been known to spuriously
also try to run "make install". Alternatively, you may want to use
GNU make.
• In AIX 4.2, Perl extensions that use C++ functions that use statics
may have problems in that the statics are not getting initialized.
In newer AIX releases, this has been solved by linking Perl with the
libC_r library, but unfortunately in AIX 4.2 the said library has an
obscure bug where the various functions related to time (such as
ttiimmee(()) and ggeettttiimmeeooffddaayy(())) return broken values, and therefore in AIX
4.2 Perl is not linked against libC_r.
• 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 a few random tests failing when run as part of "make
test", 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. See README.aix.
• If building threaded Perl, you may get compilation warning from
pp_sys.c:
"pp_sys.c", line 4651.39: 1506-280 (W) Function argument assignment between types "unsigned char*" and "const void*" is not allowed.
This is harmless; it is caused by the ggeettnneettbbyyaaddddrr(()) and
ggeettnneettbbyyaaddddrr__rr(()) having slightly different types for their first
argument.
AAllpphhaa ssyysstteemmss wwiitthh oolldd ggccccss ffaaiill sseevveerraall tteessttss If you see op/pack, op/pat, op/regexp, or ext/Storable tests failing in a Linux/alpha or *BSD/Alpha, it’s probably time to upgrade your gcc. gccs prior to 2.95.3 are definitely not good enough, and gcc 3.1 may be even better. (RedHat Linux/alpha with gcc 3.1 reported no problems, as did Linux 2.4.18 with gcc 2.95.4.) (In Tru64, it is preferable to use the bundled C compiler.)
AAmmiiggaaOOSS Perl 5.8.0 doesn’t build in AmigaOS. It broke at some point during the ithreads work and we could not find Amiga experts to unbreak the problems. Perl 5.6.1 still works for AmigaOS (as does the 5.7.2 development release).
BBeeOOSS The following tests fail on 5.8.0 Perl in BeOS Personal 5.03:
t/op/lfs............................FAILED at test 17
t/op/magic..........................FAILED at test 24
ext/Fcntl/t/syslfs..................FAILED at test 17
ext/File/Glob/t/basic...............FAILED at test 3
ext/POSIX/t/sigaction...............FAILED at test 13
ext/POSIX/t/waitpid.................FAILED at test 1
(NNoottee:: more information was available in _R_E_A_D_M_E_._b_e_o_s until support for
BeOS was removed in Perl v5.18.0)
CCyyggwwiinn “"uunnaabbllee ttoo rreemmaapp"” For example when building the Tk extension for Cygwin, you may get an error message saying “unable to remap”. This is known problem with Cygwin, and a workaround is detailed in here: http://sources.redhat.com/ml/cygwin/2001-12/msg00894.html
CCyyggwwiinn nnddbbmm tteessttss ffaaiill oonn FFAATT One can build but not install (or test the build of) the NDBM_File on FAT filesystems. Installation (or build) on NTFS works fine. If one attempts the test on a FAT install (or build) the following failures are expected:
../ext/NDBM_File/ndbm.t 13 3328 71 59 83.10% 1-2 4 16-71
../ext/ODBM_File/odbm.t 255 65280 ?? ?? % ??
../lib/AnyDBM_File.t 2 512 12 2 16.67% 1 4
../lib/Memoize/t/errors.t 0 139 11 5 45.45% 7-11
../lib/Memoize/t/tie_ndbm.t 13 3328 4 4 100.00% 1-4
run/fresh_perl.t 97 1 1.03% 91
NDBM_File fails and ODBM_File just coredumps.
If you intend to run only on FAT (or if using AnyDBM_File on FAT), run
Configure with the -Ui_ndbm and -Ui_dbm options to prevent NDBM_File and
ODBM_File being built.
DDJJGGPPPP FFaaiilluurreess t/op/stat……………………….FAILED at test 29 lib/File/Find/t/find……………..FAILED at test 1 lib/File/Find/t/taint…………….FAILED at test 1 lib/h2xs………………………..FAILED at test 15 lib/Pod/t/eol……………………FAILED at test 1 lib/Test/Harness/t/strap-analyze…..FAILED at test 8 lib/Test/Harness/t/test-harness……FAILED at test 23 lib/Test/Simple/t/exit……………FAILED at test 1
The above failures are known as of 5.8.0 with native builds with long
filenames, but there are a few more if running under dosemu because of
limitations (and maybe bugs) of dosemu:
t/comp/cpp...........................FAILED at test 3
t/op/inccode.........................(crash)
and a few lib/ExtUtils tests, and several hundred Encode/t/Aliases.t
failures that work fine with long filenames. So you really might prefer
native builds and long filenames.
FFrreeeeBBSSDD bbuuiilltt wwiitthh iitthhrreeaaddss ccoorreedduummppss rreeaaddiinngg llaarrggee ddiirreeccttoorriieess This is a known bug in FreeBSD 4.5’s rreeaaddddiirr__rr(()), it has been fixed in FreeBSD 4.6 (see perlfreebsd (README.freebsd)).
FFrreeeeBBSSDD FFaaiilliinngg llooccaallee TTeesstt 111177 FFoorr IISSOO 88885599--1155 LLooccaalleess The ISO 8859-15 locales may fail the locale test 117 in FreeBSD. This is caused by the characters \xFF (y with diaeresis) and \xBE (Y with diaeresis) not behaving correctly when being matched case-insensitively. Apparently this problem has been fixed in the latest FreeBSD releases. ( http://www.freebsd.org/cgi/query-pr.cgi?pr=34308 )
IIRRIIXX ffaaiillss eexxtt//LLiisstt//UUttiill//tt//sshhuuffffllee..tt oorr DDiiggeesstt::::MMDD55 IRIX with MIPSpro 7.3.1.2m or 7.3.1.3m compiler may fail the List::Util test ext/List/Util/t/shuffle.t by dumping core. This seems to be a compiler error since if compiled with gcc no core dump ensues, and no failures have been seen on the said test on any other platform.
Similarly, building the Digest::MD5 extension has been known to fail with
"*** Termination code 139 (bu21)".
The cure is to drop optimization level (Configure -Doptimize=-O2).
HHPP--UUXX lliibb//ppoossiixx SSuubbtteesstt 99 FFaaiillss WWhheenn LLPP6644--CCoonnffiigguurreedd 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.
LLiinnuuxx wwiitthh gglliibbcc 22..22..55 ffaaiillss tt//oopp//iinntt ssuubbtteesstt ##66 wwiitthh --DDuussee6644bbiittiinntt This is a known bug in the glibc 2.2.5 with long long integers. ( http://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=65612 )
LLiinnuuxx WWiitthh SSffiioo FFaaiillss oopp//mmiisscc TTeesstt 4488 No known fix.
MMaacc OOSS XX Please remember to set your environment variable LC_ALL to “C” (setenv LC_ALL C) before running “make test” to avoid a lot of warnings about the broken locales of Mac OS X.
The following tests are known to fail in Mac OS X 10.1.5 because of buggy
(old) implementations of Berkeley DB included in Mac OS X:
Failed Test Stat Wstat Total Fail Failed List of Failed
-------------------------------------------------------------------------
../ext/DB_File/t/db-btree.t 0 11 ?? ?? % ??
../ext/DB_File/t/db-recno.t 149 3 2.01% 61 63 65
If you are building on a UFS partition, you will also probably see
t/op/stat.t subtest #9 fail. This is caused by Darwin's UFS not
supporting inode change time.
Also the ext/POSIX/t/posix.t subtest #10 fails but it is skipped for now
because the failure is Apple's fault, not Perl's (blocked signals are
lost).
If you Configure with ithreads, ext/threads/t/libc.t will fail. Again,
this is not Perl's fault-- the libc of Mac OS X is not threadsafe (in
this particular test, the llooccaallttiimmee(()) call is found to be threadunsafe.)
MMaacc OOSS XX ddyylldd uunnddeeffiinneedd ssyymmbboollss If after installing Perl 5.8.0 you are getting warnings about missing symbols, for example
dyld: perl Undefined symbols
_perl_sv_2pv
_perl_get_sv
you probably have an old pre-Perl-5.8.0 installation (or parts of one) in
/Library/Perl (the undefined symbols used to exist in pre-5.8.0 Perls).
It seems that for some reason "make install" doesn't always completely
overwrite the files in /Library/Perl. You can move the old Perl shared
library out of the way like this:
cd /Library/Perl/darwin/CORE
mv libperl.dylib libperlold.dylib
and then reissue "make install". Note that the above of course is
extremely disruptive for anything using the /usr/local/bin/perl. If that
doesn't help, you may have to try removing all the .bundle files from
beneath /Library/Perl, and again "make install"-ing.
OOSS//22 TTeesstt FFaaiilluurreess The following tests are known to fail on OS/2 (for clarity only the failures are shown, not the full error messages):
../lib/ExtUtils/t/Mkbootstrap.t 1 256 18 1 5.56% 8
../lib/ExtUtils/t/Packlist.t 1 256 34 1 2.94% 17
../lib/ExtUtils/t/basic.t 1 256 17 1 5.88% 14
lib/os2_process.t 2 512 227 2 0.88% 174 209
lib/os2_process_kid.t 227 2 0.88% 174 209
lib/rx_cmprt.t 255 65280 18 3 16.67% 16-18
oopp//sspprriinnttff tteessttss 9911,, 112299,, aanndd 113300 The op/sprintf tests 91, 129, and 130 are known to fail on some platforms. Examples include any platform using sfio, and Compaq/Tandem’s NonStop-UX.
Test 91 is known to fail on QNX6 (nto), because "sprintf '%e',0"
incorrectly produces 0.000000e+0 instead of 0.000000e+00.
For tests 129 and 130, the failing platforms do not comply with the ANSI
C Standard: lines 19ff on page 134 of ANSI X3.159 1989, to be exact.
(They produce something other than "1" and "-1" when formatting 0.6 and
-0.6 using the printf format "%.0f"; most often, they produce "0" and
"-0".)
SSCCOO #
The socketpair tests are known to be unhappy in SCO 3.2v5.0.4:
ext/Socket/socketpair.t...............FAILED tests 15-45
SSoollaarriiss 22..55 In case you are still using Solaris 2.5 (aka SunOS 5.5), you may experience failures (the test core dumping) in lib/locale.t. The suggested cure is to upgrade your Solaris.
SSoollaarriiss xx8866 FFaaiillss TTeessttss WWiitthh --DDuussee6644bbiittiinntt The following tests are known to fail in Solaris x86 with Perl configured to use 64 bit integers:
ext/Data/Dumper/t/dumper.............FAILED at test 268
ext/Devel/Peek/Peek..................FAILED at test 7
SSUUPPEERR--UUXX ((NNEECC SSXX)) #
The following tests are known to fail on SUPER-UX:
op/64bitint...........................FAILED tests 29-30, 32-33, 35-36
op/arith..............................FAILED tests 128-130
op/pack...............................FAILED tests 25-5625
op/pow................................
op/taint..............................# msgsnd failed
../ext/IO/lib/IO/t/io_poll............FAILED tests 3-4
../ext/IPC/SysV/ipcsysv...............FAILED tests 2, 5-6
../ext/IPC/SysV/t/msg.................FAILED tests 2, 4-6
../ext/Socket/socketpair..............FAILED tests 12
../lib/IPC/SysV.......................FAILED tests 2, 5-6
../lib/warnings.......................FAILED tests 115-116, 118-119
The op/pack failure ("Cannot compress negative numbers at op/pack.t line
126") is serious but as of yet unsolved. It points at some problems with
the signedness handling of the C compiler, as do the 64bitint, arith, and
pow failures. Most of the rest point at problems with SysV IPC.
TTeerrmm::::RReeaaddKKeeyy nnoott wwoorrkkiinngg oonn WWiinn3322 Use Term::ReadKey 2.20 or later.
UUNNIICCOOSS//mmkk • During Configure, the test
Guessing which symbols your C compiler and preprocessor define...
will probably fail with error messages like
CC-20 cc: ERROR File = try.c, Line = 3
The identifier "bad" is undefined.
bad switch yylook 79bad switch yylook 79bad switch yylook 79bad switch yylook 79#ifdef A29K
^
CC-65 cc: ERROR File = try.c, Line = 3
A semicolon is expected at this point.
This is caused by a bug in the awk utility of UNICOS/mk. You can
ignore the error, but it does cause a slight problem: you cannot
fully benefit from the h2ph utility (see h2ph) that can be used to
convert C headers to Perl libraries, mainly used to be able to access
from Perl the constants defined using C preprocessor, cpp. Because
of the above error, parts of the converted headers will be invisible.
Luckily, these days the need for h2ph is rare.
• If building Perl with interpreter threads (ithreads), the ggeettggrreenntt(()),
ggeettggrrnnaamm(()), and ggeettggrrggiidd(()) functions cannot return the list of the
group members due to a bug in the multithreaded support of UNICOS/mk.
What this means is that in list context the functions will return
only three values, not four.
UUTTSS #
There are a few known test failures. (NNoottee:: the relevant information was
available in _R_E_A_D_M_E_._u_t_s until support for UTS was removed in Perl
v5.18.0)
VVOOSS ((SSttrraattuuss)) When Perl is built using the native build process on VOS Release 14.5.0 and GNU C++/GNU Tools 2.0.1, all attempted tests either pass or result in TODO (ignored) failures.
VVMMSS #
There should be no reported test failures with a default configuration,
though there are a number of tests marked TODO that point to areas
needing further debugging and/or porting work.
WWiinn3322 In multi-CPU boxes, there are some problems with the I/O buffering: some output may appear twice.
XXMMLL::::PPaarrsseerr nnoott wwoorrkkiinngg Use XML::Parser 2.31 or later.
zz//OOSS ((OOSS//339900)) z/OS has rather many test failures but the situation is actually much better than it was in 5.6.0; it’s just that so many new modules and tests have been added.
Failed Test Stat Wstat Total Fail Failed List of Failed
---------------------------------------------------------------------------
../ext/Data/Dumper/t/dumper.t 357 8 2.24% 311 314 325 327
331 333 337 339
../ext/IO/lib/IO/t/io_unix.t 5 4 80.00% 2-5
../ext/Storable/t/downgrade.t 12 3072 169 12 7.10% 14-15 46-47 78-79
110-111 150 161
../lib/ExtUtils/t/Constant.t 121 30976 48 48 100.00% 1-48
../lib/ExtUtils/t/Embed.t 9 9 100.00% 1-9
op/pat.t 922 7 0.76% 665 776 785 832-
834 845
op/sprintf.t 224 3 1.34% 98 100 136
op/tr.t 97 5 5.15% 63 71-74
uni/fold.t 780 6 0.77% 61 169 196 661
710-711
The failures in dumper.t and downgrade.t are problems in the tests, those
in io_unix and sprintf are problems in the USS (UDP sockets and printf
formats). The pat, tr, and fold failures are genuine Perl problems
caused by EBCDIC (and in the pat and fold cases, combining that with
Unicode). The Constant and Embed are probably problems in the tests
(since they test Perl's ability to build extensions, and that seems to be
working reasonably well.)
UUnniiccooddee SSuuppppoorrtt oonn EEBBCCDDIICC SSttiillll SSppoottttyy Though mostly working, Unicode support still has problem spots on EBCDIC platforms. One such known spot are the “\p{}” and “\P{}” regular expression constructs for code points less than 256: the “pP” are testing for Unicode code points, not knowing about EBCDIC.
SSeeeenn IInn PPeerrll 55..77 BBuutt GGoonnee NNooww “Time::Piece” (previously known as “Time::Object”) was removed because it was felt that it didn’t have enough value in it to be a core module. It is still a useful module, though, and is available from the CPAN.
Perl 5.8 unfortunately does not build anymore on AmigaOS; this broke
accidentally at some point. Since there are not that many Amiga
developers available, we could not get this fixed and tested in time for
5.8.0. Perl 5.6.1 still works for AmigaOS (as does the 5.7.2 development
release).
The "PerlIO::Scalar" and "PerlIO::Via" (capitalised) were renamed as
"PerlIO::scalar" and "PerlIO::via" (all lowercase) just before 5.8.0.
The main rationale was to have all core PerlIO layers to have all
lowercase names. The "plugins" are named as usual, for example
"PerlIO::via::QuotedPrint".
The "threads::shared::queue" and "threads::shared::semaphore" were
renamed as "Thread::Queue" and "Thread::Semaphore" just before 5.8.0.
The main rationale was to have thread modules to obey normal naming,
"Thread::" (the "threads" and "threads::shared" themselves are more
pragma-like, they affect compile-time, so they stay lowercase).
RReeppoorrttiinngg BBuuggss 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/ , the Perl Home Page.
If you believe you have an unreported bug, please run the ppeerrllbbuugg 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 "perl
-V", will be sent off to perlbug@perl.org to be analysed by the Perl
porting team.
SSEEEE AALLSSOO #
The _C_h_a_n_g_e_s file for exhaustive details on what changed.
The _I_N_S_T_A_L_L file for how to build Perl.
The _R_E_A_D_M_E file for general stuff.
The _A_r_t_i_s_t_i_c and _C_o_p_y_i_n_g files for copyright information.
HHIISSTTOORRYY #
Written by Jarkko Hietaniemi <_j_h_i_@_i_k_i_._f_i>.
perl v5.36.3 2023-02-15 PERL58DELTA(1)