1PERL5120DELTA(1) Perl Programmers Reference Guide PERL5120DELTA(1)
2
6 perl5120delta - what is new for perl v5.12.0
7
9 This document describes differences between the 5.10.0 release and the
10 5.12.0 release.
11 Many of the bug fixes in 5.12.0 are already included in the 5.10.1
13 maintenance release.
14 You can see the list of those changes in the 5.10.1 release notes
16 (perl5101delta).
17
19 New "package NAME VERSION" syntax
20 This new syntax allows a module author to set the $VERSION of a
21 namespace when the namespace is declared with 'package'. It eliminates
22 the need for "our $VERSION = ..." and similar constructs. E.g.
23 package Foo::Bar 1.23;
25 # $Foo::Bar::VERSION == 1.23
26 There are several advantages to this:
28 · $VERSION is parsed in exactly the same way as "use NAME VERSION"
30 · $VERSION is set at compile time
32 · $VERSION is a version object that provides proper overloading of
34 comparison operators so comparing $VERSION to decimal (1.23) or
35 dotted-decimal (v1.2.3) version numbers works correctly.
36 · Eliminates "$VERSION = ..." and "eval $VERSION" clutter
38 · As it requires VERSION to be a numeric literal or v-string literal,
40 it can be statically parsed by toolchain modules without "eval" the
41 way MM->parse_version does for "$VERSION = ..."
42 It does not break old code with only "package NAME", but code that uses
44 "package NAME VERSION" will need to be restricted to perl 5.12.0 or
45 newer This is analogous to the change to "open" from two-args to three-
46 args. Users requiring the latest Perl will benefit, and perhaps after
47 several years, it will become a standard practice.
48 However, "package NAME VERSION" requires a new, 'strict' version number
50 format. See "Version number formats" for details.
51 The "..." operator
53 A new operator, "...", nicknamed the Yada Yada operator, has been
54 added. It is intended to mark placeholder code that is not yet
55 implemented. See "Yada Yada Operator" in perlop.
56 Implicit strictures
58 Using the "use VERSION" syntax with a version number greater or equal
59 to 5.11.0 will lexically enable strictures just like "use strict" would
60 do (in addition to enabling features.) The following:
61 use 5.12.0;
63 means:
65 use strict;
67 use feature ':5.12';
68 Unicode improvements
70 Perl 5.12 comes with Unicode 5.2, the latest version available to us at
71 the time of release. This version of Unicode was released in October
72 2009. See <http://www.unicode.org/versions/Unicode5.2.0> for further
73 details about what's changed in this version of the standard. See
74 perlunicode for instructions on installing and using other versions of
75 Unicode.
76 Additionally, Perl's developers have significantly improved Perl's
78 Unicode implementation. For full details, see "Unicode overhaul" below.
79 Y2038 compliance
81 Perl's core time-related functions are now Y2038 compliant. (It may not
82 mean much to you, but your kids will love it!)
83 qr overloading
85 It is now possible to overload the "qr//" operator, that is, conversion
86 to regexp, like it was already possible to overload conversion to
87 boolean, string or number of objects. It is invoked when an object
88 appears on the right hand side of the "=~" operator or when it is
89 interpolated into a regexp. See overload.
90 Pluggable keywords
92 Extension modules can now cleanly hook into the Perl parser to define
93 new kinds of keyword-headed expression and compound statement. The
94 syntax following the keyword is defined entirely by the extension. This
95 allow a completely non-Perl sublanguage to be parsed inline, with the
96 correct ops cleanly generated.
97 See "PL_keyword_plugin" in perlapi for the mechanism. The Perl core
99 source distribution also includes a new module XS::APItest::KeywordRPN,
100 which implements reverse Polish notation arithmetic via pluggable
101 keywords. This module is mainly used for test purposes, and is not
102 normally installed, but also serves as an example of how to use the new
103 mechanism.
104 Perl's developers consider this feature to be experimental. We may
106 remove it or change it in a backwards-incompatible way in Perl 5.14.
107 APIs for more internals
109 The lowest layers of the lexer and parts of the pad system now have C
110 APIs available to XS extensions. These are necessary to support proper
111 use of pluggable keywords, but have other uses too. The new APIs are
112 experimental, and only cover a small proportion of what would be
113 necessary to take full advantage of the core's facilities in these
114 areas. It is intended that the Perl 5.13 development cycle will see the
115 addition of a full range of clean, supported interfaces.
116 Perl's developers consider this feature to be experimental. We may
118 remove it or change it in a backwards-incompatible way in Perl 5.14.
119 Overridable function lookup
121 Where an extension module hooks the creation of rv2cv ops to modify the
122 subroutine lookup process, this now works correctly for bareword
123 subroutine calls. This means that prototypes on subroutines referenced
124 this way will be processed correctly. (Previously bareword subroutine
125 names were initially looked up, for parsing purposes, by an unhookable
126 mechanism, so extensions could only properly influence subroutine names
127 that appeared with an "&" sigil.)
128 A proper interface for pluggable Method Resolution Orders
130 As of Perl 5.12.0 there is a new interface for plugging and using
131 method resolution orders other than the default linear depth first
132 search. The C3 method resolution order added in 5.10.0 has been re-
133 implemented as a plugin, without changing its Perl-space interface. See
134 perlmroapi for more information.
135 "\N" experimental regex escape
137 Perl now supports "\N", a new regex escape which you can think of as
138 the inverse of "\n". It will match any character that is not a newline,
139 independently from the presence or absence of the single line match
140 modifier "/s". It is not usable within a character class. "\N{3}"
141 means to match 3 non-newlines; "\N{5,}" means to match at least 5.
142 "\N{NAME}" still means the character or sequence named "NAME", but
143 "NAME" no longer can be things like 3, or "5,".
144 This will break a custom charnames translator which allows numbers for
146 character names, as "\N{3}" will now mean to match 3 non-newline
147 characters, and not the character whose name is 3. (No name defined by
148 the Unicode standard is a number, so only custom translators might be
149 affected.)
150 Perl's developers are somewhat concerned about possible user confusion
152 with the existing "\N{...}" construct which matches characters by their
153 Unicode name. Consequently, this feature is experimental. We may remove
154 it or change it in a backwards-incompatible way in Perl 5.14.
155 DTrace support
157 Perl now has some support for DTrace. See "DTrace support" in INSTALL.
158 Support for "configure_requires" in CPAN module metadata
160 Both "CPAN" and "CPANPLUS" now support the "configure_requires" keyword
161 in the META.yml metadata file included in most recent CPAN
162 distributions. This allows distribution authors to specify
163 configuration prerequisites that must be installed before running
164 Makefile.PL or Build.PL.
165 See the documentation for "ExtUtils::MakeMaker" or "Module::Build" for
167 more on how to specify "configure_requires" when creating a
168 distribution for CPAN.
169 "each", "keys", "values" are now more flexible
171 The "each", "keys", "values" function can now operate on arrays.
172 "when" as a statement modifier
174 "when" is now allowed to be used as a statement modifier.
175 $, flexibility
177 The variable $, may now be tied.
178 // in when clauses
180 // now behaves like || in when clauses
181 Enabling warnings from your shell environment
183 You can now set "-W" from the "PERL5OPT" environment variable
184 "delete local"
186 "delete local" now allows you to locally delete a hash entry.
187 New support for Abstract namespace sockets
189 Abstract namespace sockets are Linux-specific socket type that live in
190 AF_UNIX family, slightly abusing it to be able to use arbitrary
191 character arrays as addresses: They start with nul byte and are not
192 terminated by nul byte, but with the length passed to the socket()
193 system call.
194 32-bit limit on substr arguments removed
196 The 32-bit limit on "substr" arguments has now been removed. The full
197 range of the system's signed and unsigned integers is now available for
198 the "pos" and "len" arguments.
199
201 Deprecations warn by default
202 Over the years, Perl's developers have deprecated a number of language
203 features for a variety of reasons. Perl now defaults to issuing a
204 warning if a deprecated language feature is used. Many of the
205 deprecations Perl now warns you about have been deprecated for many
206 years. You can find a list of what was deprecated in a given release
207 of Perl in the "perl5xxdelta.pod" file for that release.
208 To disable this feature in a given lexical scope, you should use "no
210 warnings 'deprecated';" For information about which language features
211 are deprecated and explanations of various deprecation warnings, please
212 see perldiag. See "Deprecations" below for the list of features and
213 modules Perl's developers have deprecated as part of this release.
214 Version number formats
216 Acceptable version number formats have been formalized into "strict"
217 and "lax" rules. "package NAME VERSION" takes a strict version number.
218 "UNIVERSAL::VERSION" and the version object constructors take lax
219 version numbers. Providing an invalid version will result in a fatal
220 error. The version argument in "use NAME VERSION" is first parsed as a
221 numeric literal or v-string and then passed to "UNIVERSAL::VERSION"
222 (and must then pass the "lax" format test).
223 These formats are documented fully in the version module. To a first
225 approximation, a "strict" version number is a positive decimal number
226 (integer or decimal-fraction) without exponentiation or else a dotted-
227 decimal v-string with a leading 'v' character and at least three
228 components. A "lax" version number allows v-strings with fewer than
229 three components or without a leading 'v'. Under "lax" rules, both
230 decimal and dotted-decimal versions may have a trailing "alpha"
231 component separated by an underscore character after a fractional or
232 dotted-decimal component.
233 The version module adds "version::is_strict" and "version::is_lax"
235 functions to check a scalar against these rules.
236 @INC reorganization
238 In @INC, "ARCHLIB" and "PRIVLIB" now occur after after the current
239 version's "site_perl" and "vendor_perl". Modules installed into
240 "site_perl" and "vendor_perl" will now be loaded in preference to those
241 installed in "ARCHLIB" and "PRIVLIB".
242 REGEXPs are now first class
244 Internally, Perl now treates compiled regular expressions (such as
245 those created with "qr//") as first class entities. Perl modules which
246 serialize, deserialize or otherwise have deep interaction with Perl's
247 internal data structures need to be updated for this change. Most
248 affected CPAN modules have already been updated as of this writing.
249 Switch statement changes
251 The "given"/"when" switch statement handles complex statements better
252 than Perl 5.10.0 did (These enhancements are also available in 5.10.1
253 and subsequent 5.10 releases.) There are two new cases where "when" now
254 interprets its argument as a boolean, instead of an expression to be
255 used in a smart match:
256 flip-flop operators
258 The ".." and "..." flip-flop operators are now evaluated in boolean
259 context, following their usual semantics; see "Range Operators" in
260 perlop.
261 Note that, as in perl 5.10.0, "when (1..10)" will not work to test
263 whether a given value is an integer between 1 and 10; you should
264 use "when ([1..10])" instead (note the array reference).
265 However, contrary to 5.10.0, evaluating the flip-flop operators in
267 boolean context ensures it can now be useful in a "when()", notably
268 for implementing bistable conditions, like in:
269 when (/^=begin/ .. /^=end/) {
271 # do something
272 }
273 defined-or operator
275 A compound expression involving the defined-or operator, as in
276 "when (expr1 // expr2)", will be treated as boolean if the first
277 expression is boolean. (This just extends the existing rule that
278 applies to the regular or operator, as in "when (expr1 || expr2)".)
279 Smart match changes
281 Since Perl 5.10.0, Perl's developers have made a number of changes to
282 the smart match operator. These, of course, also alter the behaviour of
283 the switch statements where smart matching is implicitly used. These
284 changes were also made for the 5.10.1 release, and will remain in
285 subsequent 5.10 releases.
286 Changes to type-based dispatch
288 The smart match operator "~~" is no longer commutative. The behaviour
290 of a smart match now depends primarily on the type of its right hand
291 argument. Moreover, its semantics have been adjusted for greater
292 consistency or usefulness in several cases. While the general backwards
293 compatibility is maintained, several changes must be noted:
294 · Code references with an empty prototype are no longer treated
296 specially. They are passed an argument like the other code
297 references (even if they choose to ignore it).
298 · "%hash ~~ sub {}" and "@array ~~ sub {}" now test that the
300 subroutine returns a true value for each key of the hash (or
301 element of the array), instead of passing the whole hash or array
302 as a reference to the subroutine.
303 · Due to the commutativity breakage, code references are no longer
305 treated specially when appearing on the left of the "~~" operator,
306 but like any vulgar scalar.
307 · "undef ~~ %hash" is always false (since "undef" can't be a key in a
309 hash). No implicit conversion to "" is done (as was the case in
310 perl 5.10.0).
311 · "$scalar ~~ @array" now always distributes the smart match across
313 the elements of the array. It's true if one element in @array
314 verifies "$scalar ~~ $element". This is a generalization of the old
315 behaviour that tested whether the array contained the scalar.
316 The full dispatch table for the smart match operator is given in "Smart
318 matching in detail" in perlsyn.
319 Smart match and overloading
321 According to the rule of dispatch based on the rightmost argument type,
323 when an object overloading "~~" appears on the right side of the
324 operator, the overload routine will always be called (with a 3rd
325 argument set to a true value, see overload.) However, when the object
326 will appear on the left, the overload routine will be called only when
327 the rightmost argument is a simple scalar. This way, distributivity of
328 smart match across arrays is not broken, as well as the other
329 behaviours with complex types (coderefs, hashes, regexes). Thus,
330 writers of overloading routines for smart match mostly need to worry
331 only with comparing against a scalar, and possibly with stringification
332 overloading; the other common cases will be automatically handled
333 consistently.
334 "~~" will now refuse to work on objects that do not overload it (in
336 order to avoid relying on the object's underlying structure). (However,
337 if the object overloads the stringification or the numification
338 operators, and if overload fallback is active, it will be used instead,
339 as usual.)
340 Other potentially incompatible changes
342 · The definitions of a number of Unicode properties have changed to
343 match those of the current Unicode standard. These are listed above
344 under "Unicode overhaul". This change may break code that expects
345 the old definitions.
346 · The boolkeys op has moved to the group of hash ops. This breaks
348 binary compatibility.
349 · Filehandles are now always blessed into "IO::File".
351 The previous behaviour was to bless Filehandles into FileHandle (an
353 empty proxy class) if it was loaded into memory and otherwise to
354 bless them into "IO::Handle".
355 · The semantics of "use feature :5.10*" have changed slightly. See
357 "Modules and Pragmata" for more information.
358 · Perl's developers now use git, rather than Perforce. This should
360 be a purely internal change only relevant to people actively
361 working on the core. However, you may see minor difference in perl
362 as a consequence of the change. For example in some of details of
363 the output of "perl -V". See perlrepository for more information.
364 · As part of the "Test::Harness" 2.x to 3.x upgrade, the experimental
366 "Test::Harness::Straps" module has been removed. See "Modules and
367 Pragmata" for more details.
368 · As part of the "ExtUtils::MakeMaker" upgrade, the
370 "ExtUtils::MakeMaker::bytes" and "ExtUtils::MakeMaker::vmsish"
371 modules have been removed from this distribution.
372 · "Module::CoreList" no longer contains the %:patchlevel hash.
374 · "length undef" now returns undef.
376 · Unsupported private C API functions are now declared "static" to
378 prevent leakage to Perl's public API.
379 · To support the bootstrapping process, miniperl no longer builds
381 with UTF-8 support in the regexp engine.
382 This allows a build to complete with PERL_UNICODE set and a UTF-8
384 locale. Without this there's a bootstrapping problem, as miniperl
385 can't load the UTF-8 components of the regexp engine, because
386 they're not yet built.
387 · miniperl's @INC is now restricted to just "-I...", the split of
389 $ENV{PERL5LIB}, and "".""
390 · A space or a newline is now required after a "#line XXX" directive.
392 · Tied filehandles now have an additional method EOF which provides
394 the EOF type.
395 · To better match all other flow control statements, "foreach" may no
397 longer be used as an attribute.
398 · Perl's command-line switch "-P", which was deprecated in version
400 5.10.0, has now been removed.
401
403 From time to time, Perl's developers find it necessary to deprecate
404 features or modules we've previously shipped as part of the core
405 distribution. We are well aware of the pain and frustration that a
406 backwards-incompatible change to Perl can cause for developers building
407 or maintaining software in Perl. You can be sure that when we deprecate
408 a functionality or syntax, it isn't a choice we make lightly.
409 Sometimes, we choose to deprecate functionality or syntax because it
410 was found to be poorly designed or implemented. Sometimes, this is
411 because they're holding back other features or causing performance
412 problems. Sometimes, the reasons are more complex. Wherever possible,
413 we try to keep deprecated functionality available to developers in its
414 previous form for at least one major release. So long as a deprecated
415 feature isn't actively disrupting our ability to maintain and extend
416 Perl, we'll try to leave it in place as long as possible.
417 The following items are now deprecated:
419 suidperl
421 "suidperl" is no longer part of Perl. It used to provide a
422 mechanism to emulate setuid permission bits on systems that don't
423 support it properly.
424 Use of ":=" to mean an empty attribute list
426 An accident of Perl's parser meant that these constructions were
427 all equivalent:
428 my $pi := 4;
430 my $pi : = 4;
431 my $pi : = 4;
432 with the ":" being treated as the start of an attribute list, which
434 ends before the "=". As whitespace is not significant here, all are
435 parsed as an empty attribute list, hence all the above are
436 equivalent to, and better written as
437 my $pi = 4;
439 because no attribute processing is done for an empty list.
441 As is, this meant that ":=" cannot be used as a new token, without
443 silently changing the meaning of existing code. Hence that
444 particular form is now deprecated, and will become a syntax error.
445 If it is absolutely necessary to have empty attribute lists (for
446 example, because of a code generator) then avoid the warning by
447 adding a space before the "=".
448 "UNIVERSAL->import()"
450 The method "UNIVERSAL->import()" is now deprecated. Attempting to
451 pass import arguments to a "use UNIVERSAL" statement will result in
452 a deprecation warning.
453 Use of "goto" to jump into a construct
455 Using "goto" to jump from an outer scope into an inner scope is now
456 deprecated. This rare use case was causing problems in the
457 implementation of scopes.
458 Custom character names in \N{name} that don't look like names
460 In "\N{name}", name can be just about anything. The standard
461 Unicode names have a very limited domain, but a custom name
462 translator could create names that are, for example, made up
463 entirely of punctuation symbols. It is now deprecated to make names
464 that don't begin with an alphabetic character, and aren't
465 alphanumeric or contain other than a very few other characters,
466 namely spaces, dashes, parentheses and colons. Because of the added
467 meaning of "\N" (See ""\N" experimental regex escape"), names that
468 look like curly brace -enclosed quantifiers won't work. For
469 example, "\N{3,4}" now means to match 3 to 4 non-newlines; before a
470 custom name "3,4" could have been created.
471 Deprecated Modules
473 The following modules will be removed from the core distribution in
474 a future release, and should be installed from CPAN instead.
475 Distributions on CPAN which require these should add them to their
476 prerequisites. The core versions of these modules warnings will
477 issue a deprecation warning.
478 If you ship a packaged version of Perl, either alone or as part of
480 a larger system, then you should carefully consider the
481 reprecussions of core module deprecations. You may want to consider
482 shipping your default build of Perl with packages for some or all
483 deprecated modules which install into "vendor" or "site" perl
484 library directories. This will inhibit the deprecation warnings.
485 Alternatively, you may want to consider patching lib/deprecate.pm
487 to provide deprecation warnings specific to your packaging system
488 or distribution of Perl, consistent with how your packaging system
489 or distribution manages a staged transition from a release where
490 the installation of a single package provides the given
491 functionality, to a later release where the system administrator
492 needs to know to install multiple packages to get that same
493 functionality.
494 You can silence these deprecation warnings by installing the
496 modules in question from CPAN. To install the latest version of
497 all of them, just install "Task::Deprecations::5_12".
498 Class::ISA
500 Pod::Plainer
501 Shell
502 Switch
503 Switch is buggy and should be avoided. You may find Perl's new
504 "given"/"when" feature a suitable replacement. See "Switch
505 statements" in perlsyn for more information.
506 Assignment to $[
508 Use of the attribute :locked on subroutines
509 Use of "locked" with the attributes pragma
510 Use of "unique" with the attributes pragma
511 Perl_pmflag
512 "Perl_pmflag" is no longer part of Perl's public API. Calling it
513 now generates a deprecation warning, and it will be removed in a
514 future release. Although listed as part of the API, it was never
515 documented, and only ever used in toke.c, and prior to 5.10,
516 regcomp.c. In core, it has been replaced by a static function.
517 Numerous Perl 4-era libraries
519 termcap.pl, tainted.pl, stat.pl, shellwords.pl, pwd.pl, open3.pl,
520 open2.pl, newgetopt.pl, look.pl, find.pl, finddepth.pl,
521 importenv.pl, hostname.pl, getopts.pl, getopt.pl, getcwd.pl,
522 flush.pl, fastcwd.pl, exceptions.pl, ctime.pl, complete.pl,
523 cacheout.pl, bigrat.pl, bigint.pl, bigfloat.pl, assert.pl,
524 abbrev.pl, dotsh.pl, and timelocal.pl are all now deprecated.
525 Earlier, Perl's developers intended to remove these libraries from
526 Perl's core for the 5.14.0 release.
527 During final testing before the release of 5.12.0, several
529 developers discovered current production code using these ancient
530 libraries, some inside the Perl core itself. Accordingly, the
531 pumpking granted them a stay of execution. They will begin to warn
532 about their deprecation in the 5.14.0 release and will be removed
533 in the 5.16.0 release.
534
536 Perl's developers have made a concerted effort to update Perl to be in
537 sync with the latest Unicode standard. Changes for this include:
538 Perl can now handle every Unicode character property. New
540 documentation, perluniprops, lists all available non-Unihan character
541 properties. By default, perl does not expose Unihan, deprecated or
542 Unicode-internal properties. See below for more details on these;
543 there is also a section in the pod listing them, and explaining why
544 they are not exposed.
545 Perl now fully supports the Unicode compound-style of using "=" and ":"
547 in writing regular expressions: "\p{property=value}" and
548 "\p{property:value}" (both of which mean the same thing).
549 Perl now fully supports the Unicode loose matching rules for text
551 between the braces in "\p{...}" constructs. In addition, Perl allows
552 underscores between digits of numbers.
553 Perl now accepts all the Unicode-defined synonyms for properties and
555 property values.
556 "qr/\X/", which matches a Unicode logical character, has been expanded
558 to work better with various Asian languages. It now is defined as an
559 extended grapheme cluster. (See
560 <http://www.unicode.org/reports/tr29/>). Anything matched previously
561 and that made sense will continue to be accepted. Additionally:
562 · "\X" will not break apart a "CR LF" sequence.
564 · "\X" will now match a sequence which includes the "ZWJ" and "ZWNJ"
566 characters.
567 · "\X" will now always match at least one character, including an
569 initial mark. Marks generally come after a base character, but it
570 is possible in Unicode to have them in isolation, and "\X" will now
571 handle that case, for example at the beginning of a line, or after
572 a "ZWSP". And this is the part where "\X" doesn't match the things
573 that it used to that don't make sense. Formerly, for example, you
574 could have the nonsensical case of an accented LF.
575 · "\X" will now match a (Korean) Hangul syllable sequence, and the
577 Thai and Lao exception cases.
578 Otherwise, this change should be transparent for the non-affected
580 languages.
581 "\p{...}" matches using the Canonical_Combining_Class property were
583 completely broken in previous releases of Perl. They should now work
584 correctly.
585 Before Perl 5.12, the Unicode "Decomposition_Type=Compat" property and
587 a Perl extension had the same name, which led to neither matching all
588 the correct values (with more than 100 mistakes in one, and several
589 thousand in the other). The Perl extension has now been renamed to be
590 "Decomposition_Type=Noncanonical" (short: "dt=noncanon"). It has the
591 same meaning as was previously intended, namely the union of all the
592 non-canonical Decomposition types, with Unicode "Compat" being just one
593 of those.
594 "\p{Decomposition_Type=Canonical}" now includes the Hangul syllables.
596 "\p{Uppercase}" and "\p{Lowercase}" now work as the Unicode standard
598 says they should. This means they each match a few more characters
599 than they used to.
600 "\p{Cntrl}" now matches the same characters as "\p{Control}". This
602 means it no longer will match Private Use (gc=co), Surrogates (gc=cs),
603 nor Format (gc=cf) code points. The Format code points represent the
604 biggest possible problem. All but 36 of them are either officially
605 deprecated or strongly discouraged from being used. Of those 36, likely
606 the most widely used are the soft hyphen (U+00AD), and BOM, ZWSP, ZWNJ,
607 WJ, and similar characters, plus bidirectional controls.
608 "\p{Alpha}" now matches the same characters as "\p{Alphabetic}". Before
610 5.12, Perl's definition definition included a number of things that
611 aren't really alpha (all marks) while omitting many that were. The
612 definitions of "\p{Alnum}" and "\p{Word}" depend on Alpha's definition
613 and have changed accordingly.
614 "\p{Word}" no longer incorrectly matches non-word characters such as
616 fractions.
617 "\p{Print}" no longer matches the line control characters: Tab, LF, CR,
619 FF, VT, and NEL. This brings it in line with standards and the
620 documentation.
621 "\p{XDigit}" now matches the same characters as "\p{Hex_Digit}". This
623 means that in addition to the characters it currently matches,
624 "[A-Fa-f0-9]", it will also match the 22 fullwidth equivalents, for
625 example U+FF10: FULLWIDTH DIGIT ZERO.
626 The Numeric type property has been extended to include the Unihan
628 characters.
629 There is a new Perl extension, the 'Present_In', or simply 'In',
631 property. This is an extension of the Unicode Age property, but
632 "\p{In=5.0}" matches any code point whose usage has been determined as
633 of Unicode version 5.0. The "\p{Age=5.0}" only matches code points
634 added in precisely version 5.0.
635 A number of properties now have the correct values for unassigned code
637 points. The affected properties are Bidi_Class, East_Asian_Width,
638 Joining_Type, Decomposition_Type, Hangul_Syllable_Type, Numeric_Type,
639 and Line_Break.
640 The Default_Ignorable_Code_Point, ID_Continue, and ID_Start properties
642 are now up to date with current Unicode definitions.
643 Earlier versions of Perl erroneously exposed certain properties that
645 are supposed to be Unicode internal-only. Use of these in regular
646 expressions will now generate, if enabled, a deprecation warning
647 message. The properties are: Other_Alphabetic,
648 Other_Default_Ignorable_Code_Point, Other_Grapheme_Extend,
649 Other_ID_Continue, Other_ID_Start, Other_Lowercase, Other_Math, and
650 Other_Uppercase.
651 It is now possible to change which Unicode properties Perl understands
653 on a per-installation basis. As mentioned above, certain properties are
654 turned off by default. These include all the Unihan properties (which
655 should be accessible via the CPAN module Unicode::Unihan) and any
656 deprecated or Unicode internal-only property that Perl has never
657 exposed.
658 The generated files in the "lib/unicore/To" directory are now more
660 clearly marked as being stable, directly usable by applications. New
661 hash entries in them give the format of the normal entries, which
662 allows for easier machine parsing. Perl can generate files in this
663 directory for any property, though most are suppressed. You can find
664 instructions for changing which are written in perluniprops.
665
667 New Modules and Pragmata
668 "autodie"
669 "autodie" is a new lexically-scoped alternative for the "Fatal"
670 module. The bundled version is 2.06_01. Note that in this release,
671 using a string eval when "autodie" is in effect can cause the
672 autodie behaviour to leak into the surrounding scope. See "BUGS" in
673 autodie for more details.
674 Version 2.06_01 has been added to the Perl core.
676 "Compress::Raw::Bzip2"
678 Version 2.024 has been added to the Perl core.
679 "overloading"
681 "overloading" allows you to lexically disable or enable overloading
682 for some or all operations.
683 Version 0.001 has been added to the Perl core.
685 "parent"
687 "parent" establishes an ISA relationship with base classes at
688 compile time. It provides the key feature of "base" without further
689 unwanted behaviors.
690 Version 0.223 has been added to the Perl core.
692 "Parse::CPAN::Meta"
694 Version 1.40 has been added to the Perl core.
695 "VMS::DCLsym"
697 Version 1.03 has been added to the Perl core.
698 "VMS::Stdio"
700 Version 2.4 has been added to the Perl core.
701 "XS::APItest::KeywordRPN"
703 Version 0.003 has been added to the Perl core.
704 Updated Pragmata
706 "base"
707 Upgraded from version 2.13 to 2.15.
708 "bignum"
710 Upgraded from version 0.22 to 0.23.
711 "charnames"
713 "charnames" now contains the Unicode NameAliases.txt database file.
714 This has the effect of adding some extra "\N" character names that
715 formerly wouldn't have been recognised; for example, "\N{LATIN
716 CAPITAL LETTER GHA}".
717 Upgraded from version 1.06 to 1.07.
719 "constant"
721 Upgraded from version 1.13 to 1.20.
722 "diagnostics"
724 "diagnostics" now supports %.0f formatting internally.
725 "diagnostics" no longer suppresses "Use of uninitialized value in
727 range (or flip)" warnings. [perl #71204]
728 Upgraded from version 1.17 to 1.19.
730 "feature"
732 In "feature", the meaning of the ":5.10" and ":5.10.X" feature
733 bundles has changed slightly. The last component, if any (i.e. "X")
734 is simply ignored. This is predicated on the assumption that new
735 features will not, in general, be added to maintenance releases. So
736 ":5.10" and ":5.10.X" have identical effect. This is a change to
737 the behaviour documented for 5.10.0.
738 "feature" now includes the "unicode_strings" feature:
740 use feature "unicode_strings";
742 This pragma turns on Unicode semantics for the case-changing
744 operations ("uc", "lc", "ucfirst", "lcfirst") on strings that don't
745 have the internal UTF-8 flag set, but that contain single-byte
746 characters between 128 and 255.
747 Upgraded from version 1.11 to 1.16.
749 "less"
751 "less" now includes the "stash_name" method to allow subclasses of
752 "less" to pick where in %^H to store their stash.
753 Upgraded from version 0.02 to 0.03.
755 "lib"
757 Upgraded from version 0.5565 to 0.62.
758 "mro"
760 "mro" is now implemented as an XS extension. The documented
761 interface has not changed. Code relying on the implementation
762 detail that some "mro::" methods happened to be available at all
763 times gets to "keep both pieces".
764 Upgraded from version 1.00 to 1.02.
766 "overload"
768 "overload" now allow overloading of 'qr'.
769 Upgraded from version 1.06 to 1.10.
771 "threads"
773 Upgraded from version 1.67 to 1.75.
774 "threads::shared"
776 Upgraded from version 1.14 to 1.32.
777 "version"
779 "version" now has support for "Version number formats" as described
780 earlier in this document and in its own documentation.
781 Upgraded from version 0.74 to 0.82.
783 "warnings"
785 "warnings" has a new "warnings::fatal_enabled()" function. It also
786 includes a new "illegalproto" warning category. See also "New or
787 Changed Diagnostics" for this change.
788 Upgraded from version 1.06 to 1.09.
790 Updated Modules
792 "Archive::Extract"
793 Upgraded from version 0.24 to 0.38.
794 "Archive::Tar"
796 Upgraded from version 1.38 to 1.54.
797 "Attribute::Handlers"
799 Upgraded from version 0.79 to 0.87.
800 "AutoLoader"
802 Upgraded from version 5.63 to 5.70.
803 "B::Concise"
805 Upgraded from version 0.74 to 0.78.
806 "B::Debug"
808 Upgraded from version 1.05 to 1.12.
809 "B::Deparse"
811 Upgraded from version 0.83 to 0.96.
812 "B::Lint"
814 Upgraded from version 1.09 to 1.11_01.
815 "CGI"
817 Upgraded from version 3.29 to 3.48.
818 "Class::ISA"
820 Upgraded from version 0.33 to 0.36.
821 NOTE: "Class::ISA" is deprecated and may be removed from a future
823 version of Perl.
824 "Compress::Raw::Zlib"
826 Upgraded from version 2.008 to 2.024.
827 "CPAN"
829 Upgraded from version 1.9205 to 1.94_56.
830 "CPANPLUS"
832 Upgraded from version 0.84 to 0.90.
833 "CPANPLUS::Dist::Build"
835 Upgraded from version 0.06_02 to 0.46.
836 "Data::Dumper"
838 Upgraded from version 2.121_14 to 2.125.
839 "DB_File"
841 Upgraded from version 1.816_1 to 1.820.
842 "Devel::PPPort"
844 Upgraded from version 3.13 to 3.19.
845 "Digest"
847 Upgraded from version 1.15 to 1.16.
848 "Digest::MD5"
850 Upgraded from version 2.36_01 to 2.39.
851 "Digest::SHA"
853 Upgraded from version 5.45 to 5.47.
854 "Encode"
856 Upgraded from version 2.23 to 2.39.
857 "Exporter"
859 Upgraded from version 5.62 to 5.64_01.
860 "ExtUtils::CBuilder"
862 Upgraded from version 0.21 to 0.27.
863 "ExtUtils::Command"
865 Upgraded from version 1.13 to 1.16.
866 "ExtUtils::Constant"
868 Upgraded from version 0.2 to 0.22.
869 "ExtUtils::Install"
871 Upgraded from version 1.44 to 1.55.
872 "ExtUtils::MakeMaker"
874 Upgraded from version 6.42 to 6.56.
875 "ExtUtils::Manifest"
877 Upgraded from version 1.51_01 to 1.57.
878 "ExtUtils::ParseXS"
880 Upgraded from version 2.18_02 to 2.21.
881 "File::Fetch"
883 Upgraded from version 0.14 to 0.24.
884 "File::Path"
886 Upgraded from version 2.04 to 2.08_01.
887 "File::Temp"
889 Upgraded from version 0.18 to 0.22.
890 "Filter::Simple"
892 Upgraded from version 0.82 to 0.84.
893 "Filter::Util::Call"
895 Upgraded from version 1.07 to 1.08.
896 "Getopt::Long"
898 Upgraded from version 2.37 to 2.38.
899 "IO"
901 Upgraded from version 1.23_01 to 1.25_02.
902 "IO::Zlib"
904 Upgraded from version 1.07 to 1.10.
905 "IPC::Cmd"
907 Upgraded from version 0.40_1 to 0.54.
908 "IPC::SysV"
910 Upgraded from version 1.05 to 2.01.
911 "Locale::Maketext"
913 Upgraded from version 1.12 to 1.14.
914 "Locale::Maketext::Simple"
916 Upgraded from version 0.18 to 0.21.
917 "Log::Message"
919 Upgraded from version 0.01 to 0.02.
920 "Log::Message::Simple"
922 Upgraded from version 0.04 to 0.06.
923 "Math::BigInt"
925 Upgraded from version 1.88 to 1.89_01.
926 "Math::BigInt::FastCalc"
928 Upgraded from version 0.16 to 0.19.
929 "Math::BigRat"
931 Upgraded from version 0.21 to 0.24.
932 "Math::Complex"
934 Upgraded from version 1.37 to 1.56.
935 "Memoize"
937 Upgraded from version 1.01_02 to 1.01_03.
938 "MIME::Base64"
940 Upgraded from version 3.07_01 to 3.08.
941 "Module::Build"
943 Upgraded from version 0.2808_01 to 0.3603.
944 "Module::CoreList"
946 Upgraded from version 2.12 to 2.29.
947 "Module::Load"
949 Upgraded from version 0.12 to 0.16.
950 "Module::Load::Conditional"
952 Upgraded from version 0.22 to 0.34.
953 "Module::Loaded"
955 Upgraded from version 0.01 to 0.06.
956 "Module::Pluggable"
958 Upgraded from version 3.6 to 3.9.
959 "Net::Ping"
961 Upgraded from version 2.33 to 2.36.
962 "NEXT"
964 Upgraded from version 0.60_01 to 0.64.
965 "Object::Accessor"
967 Upgraded from version 0.32 to 0.36.
968 "Package::Constants"
970 Upgraded from version 0.01 to 0.02.
971 "PerlIO"
973 Upgraded from version 1.04 to 1.06.
974 "Pod::Parser"
976 Upgraded from version 1.35 to 1.37.
977 "Pod::Perldoc"
979 Upgraded from version 3.14_02 to 3.15_02.
980 "Pod::Plainer"
982 Upgraded from version 0.01 to 1.02.
983 NOTE: "Pod::Plainer" is deprecated and may be removed from a future
985 version of Perl.
986 "Pod::Simple"
988 Upgraded from version 3.05 to 3.13.
989 "Safe"
991 Upgraded from version 2.12 to 2.22.
992 "SelfLoader"
994 Upgraded from version 1.11 to 1.17.
995 "Storable"
997 Upgraded from version 2.18 to 2.22.
998 "Switch"
1000 Upgraded from version 2.13 to 2.16.
1001 NOTE: "Switch" is deprecated and may be removed from a future
1003 version of Perl.
1004 "Sys::Syslog"
1006 Upgraded from version 0.22 to 0.27.
1007 "Term::ANSIColor"
1009 Upgraded from version 1.12 to 2.02.
1010 "Term::UI"
1012 Upgraded from version 0.18 to 0.20.
1013 "Test"
1015 Upgraded from version 1.25 to 1.25_02.
1016 "Test::Harness"
1018 Upgraded from version 2.64 to 3.17.
1019 "Test::Simple"
1021 Upgraded from version 0.72 to 0.94.
1022 "Text::Balanced"
1024 Upgraded from version 2.0.0 to 2.02.
1025 "Text::ParseWords"
1027 Upgraded from version 3.26 to 3.27.
1028 "Text::Soundex"
1030 Upgraded from version 3.03 to 3.03_01.
1031 "Thread::Queue"
1033 Upgraded from version 2.00 to 2.11.
1034 "Thread::Semaphore"
1036 Upgraded from version 2.01 to 2.09.
1037 "Tie::RefHash"
1039 Upgraded from version 1.37 to 1.38.
1040 "Time::HiRes"
1042 Upgraded from version 1.9711 to 1.9719.
1043 "Time::Local"
1045 Upgraded from version 1.18 to 1.1901_01.
1046 "Time::Piece"
1048 Upgraded from version 1.12 to 1.15.
1049 "Unicode::Collate"
1051 Upgraded from version 0.52 to 0.52_01.
1052 "Unicode::Normalize"
1054 Upgraded from version 1.02 to 1.03.
1055 "Win32"
1057 Upgraded from version 0.34 to 0.39.
1058 "Win32API::File"
1060 Upgraded from version 0.1001_01 to 0.1101.
1061 "XSLoader"
1063 Upgraded from version 0.08 to 0.10.
1064 Removed Modules and Pragmata
1066 "attrs"
1067 Removed from the Perl core. Prior version was 1.02.
1068 "CPAN::API::HOWTO"
1070 Removed from the Perl core. Prior version was 'undef'.
1071 "CPAN::DeferedCode"
1073 Removed from the Perl core. Prior version was 5.50.
1074 "CPANPLUS::inc"
1076 Removed from the Perl core. Prior version was 'undef'.
1077 "DCLsym"
1079 Removed from the Perl core. Prior version was 1.03.
1080 "ExtUtils::MakeMaker::bytes"
1082 Removed from the Perl core. Prior version was 6.42.
1083 "ExtUtils::MakeMaker::vmsish"
1085 Removed from the Perl core. Prior version was 6.42.
1086 "Stdio"
1088 Removed from the Perl core. Prior version was 2.3.
1089 "Test::Harness::Assert"
1091 Removed from the Perl core. Prior version was 0.02.
1092 "Test::Harness::Iterator"
1094 Removed from the Perl core. Prior version was 0.02.
1095 "Test::Harness::Point"
1097 Removed from the Perl core. Prior version was 0.01.
1098 "Test::Harness::Results"
1100 Removed from the Perl core. Prior version was 0.01.
1101 "Test::Harness::Straps"
1103 Removed from the Perl core. Prior version was 0.26_01.
1104 "Test::Harness::Util"
1106 Removed from the Perl core. Prior version was 0.01.
1107 "XSSymSet"
1109 Removed from the Perl core. Prior version was 1.1.
1110 Deprecated Modules and Pragmata
1112 See "Deprecated Modules" above.
1113
1115 New Documentation
1116 · perlhaiku contains instructions on how to build perl for the Haiku
1117 platform.
1118 · perlmroapi describes the new interface for pluggable Method
1120 Resolution Orders.
1121 · perlperf, by Richard Foley, provides an introduction to the use of
1123 performance and optimization techniques which can be used with
1124 particular reference to perl programs.
1125 · perlrepository describes how to access the perl source using the
1127 git version control system.
1128 · perlpolicy extends the "Social contract about contributed modules"
1130 into the beginnings of a document on Perl porting policies.
1131 Changes to Existing Documentation
1133 · The various large Changes* files (which listed every change made to
1134 perl over the last 18 years) have been removed, and replaced by a
1135 small file, also called Changes, which just explains how that same
1136 information may be extracted from the git version control system.
1137 · Porting/patching.pod has been deleted, as it mainly described
1139 interacting with the old Perforce-based repository, which is now
1140 obsolete. Information still relevant has been moved to
1141 perlrepository.
1142 · The syntax "unless (EXPR) BLOCK else BLOCK" is now documented as
1144 valid, as is the syntax "unless (EXPR) BLOCK elsif (EXPR) BLOCK ...
1145 else BLOCK", although actually using the latter may not be the best
1146 idea for the readability of your source code.
1147 · Documented -X overloading.
1149 · Documented that "when()" treats specially most of the filetest
1151 operators
1152 · Documented "when" as a syntax modifier.
1154 · Eliminated "Old Perl threads tutorial", which described 5005
1156 threads.
1157 pod/perlthrtut.pod is the same material reworked for ithreads.
1159 · Correct previous documentation: v-strings are not deprecated
1161 With version objects, we need them to use MODULE VERSION syntax.
1163 This patch removes the deprecation notice.
1164 · Security contact information is now part of perlsec.
1166 · A significant fraction of the core documentation has been updated
1168 to clarify the behavior of Perl's Unicode handling.
1169 Much of the remaining core documentation has been reviewed and
1171 edited for clarity, consistent use of language, and to fix the
1172 spelling of Tom Christiansen's name.
1173 · The Pod specification (perlpodspec) has been updated to bring the
1175 specification in line with modern usage already supported by most
1176 Pod systems. A parameter string may now follow the format name in a
1177 "begin/end" region. Links to URIs with a text description are now
1178 allowed. The usage of "L<"section">" has been marked as deprecated.
1179 · if.pm has been documented in "use" in perlfunc as a means to get
1181 conditional loading of modules despite the implicit BEGIN block
1182 around "use".
1183 · The documentation for $1 in perlvar.pod has been clarified.
1185 · "\N{U+wide hex char}" is now documented.
1187
1189 · A new internal cache means that "isa()" will often be faster.
1190 · The implementation of "C3" Method Resolution Order has been
1192 optimised - linearisation for classes with single inheritance is
1193 40% faster. Performance for multiple inheritance is unchanged.
1194 · Under "use locale", the locale-relevant information is now cached
1196 on read-only values, such as the list returned by "keys %hash".
1197 This makes operations such as "sort keys %hash" in the scope of
1198 "use locale" much faster.
1199 · Empty "DESTROY" methods are no longer called.
1201 · "Perl_sv_utf8_upgrade()" is now faster.
1203 · "keys" on empty hash is now faster.
1205 · "if (%foo)" has been optimized to be faster than "if (keys %foo)".
1207 · The string repetition operator ("$str x $num") is now several times
1209 faster when $str has length one or $num is large.
1210 · Reversing an array to itself (as in "@a = reverse @a") in void
1212 context now happens in-place and is several orders of magnitude
1213 faster than it used to be. It will also preserve non-existent
1214 elements whenever possible, i.e. for non magical arrays or tied
1215 arrays with "EXISTS" and "DELETE" methods.
1216
1218 · perlapi, perlintern, perlmodlib and perltoc are now all generated
1219 at build time, rather than being shipped as part of the release.
1220 · If "vendorlib" and "vendorarch" are the same, then they are only
1222 added to @INC once.
1223 · $Config{usedevel} and the C-level "PERL_USE_DEVEL" are now defined
1225 if perl is built with "-Dusedevel".
1226 · Configure will enable use of "-fstack-protector", to provide
1228 protection against stack-smashing attacks, if the compiler supports
1229 it.
1230 · Configure will now determine the correct prototypes for re-entrant
1232 functions and for "gconvert" if you are using a C++ compiler rather
1233 than a C compiler.
1234 · On Unix, if you build from a tree containing a git repository, the
1236 configuration process will note the commit hash you have checked
1237 out, for display in the output of "perl -v" and "perl -V". Unpushed
1238 local commits are automatically added to the list of local patches
1239 displayed by "perl -V".
1240 · Perl now supports SystemTap's "dtrace" compatibility layer and an
1242 issue with linking "miniperl" has been fixed in the process.
1243 · perldoc now uses "less -R" instead of "less" for improved behaviour
1245 in the face of "groff"'s new usage of ANSI escape codes.
1246 · "perl -V" now reports use of the compile-time options
1248 "USE_PERL_ATOF" and "USE_ATTRIBUTES_FOR_PERLIO".
1249 · As part of the flattening of ext, all extensions on all platforms
1251 are built by make_ext.pl. This replaces the Unix-specific
1252 ext/util/make_ext, VMS-specific make_ext.com and Win32-specific
1253 win32/buildext.pl.
1254
1256 Each release of Perl sees numerous internal changes which shouldn't
1257 affect day to day usage but may still be notable for developers working
1258 with Perl's source code.
1259 · The J.R.R. Tolkien quotes at the head of C source file have been
1261 checked and proper citations added, thanks to a patch from Tom
1262 Christiansen.
1263 · The internal structure of the dual-life modules traditionally found
1265 in the lib/ and ext/ directories in the perl source has changed
1266 significantly. Where possible, dual-lifed modules have been
1267 extracted from lib/ and ext/.
1268 Dual-lifed modules maintained by Perl's developers as part of the
1270 Perl core now live in dist/. Dual-lifed modules maintained
1271 primarily on CPAN now live in cpan/. When reporting a bug in a
1272 module located under cpan/, please send your bug report directly to
1273 the module's bug tracker or author, rather than Perl's bug tracker.
1274 · "\N{...}" now compiles better, always forces UTF-8 internal
1276 representation
1277 Perl's developers have fixed several problems with the recognition
1279 of "\N{...}" constructs. As part of this, perl will store any
1280 scalar or regex containing "\N{name}" or "\N{U+wide hex char}" in
1281 its definition in UTF-8 format. (This was true previously for all
1282 occurences of "\N{name}" that did not use a custom translator, but
1283 now it's always true.)
1284 · Perl_magic_setmglob now knows about globs, fixing RT #71254.
1286 · "SVt_RV" no longer exists. RVs are now stored in IVs.
1288 · "Perl_vcroak()" now accepts a null first argument. In addition, a
1290 full audit was made of the "not NULL" compiler annotations, and
1291 those for several other internal functions were corrected.
1292 · New macros "dSAVEDERRNO", "dSAVE_ERRNO", "SAVE_ERRNO",
1294 "RESTORE_ERRNO" have been added to formalise the temporary saving
1295 of the "errno" variable.
1296 · The function "Perl_sv_insert_flags" has been added to augment
1298 "Perl_sv_insert".
1299 · The function "Perl_newSV_type(type)" has been added, equivalent to
1301 "Perl_newSV()" followed by "Perl_sv_upgrade(type)".
1302 · The function "Perl_newSVpvn_flags()" has been added, equivalent to
1304 "Perl_newSVpvn()" and then performing the action relevant to the
1305 flag.
1306 Two flag bits are currently supported.
1308 · "SVf_UTF8" will call "SvUTF8_on()" for you. (Note that this
1310 does not convert an sequence of ISO 8859-1 characters to
1311 UTF-8). A wrapper, "newSVpvn_utf8()" is available for this.
1312 · "SVs_TEMP" now calls "Perl_sv_2mortal()" on the new SV.
1314 There is also a wrapper that takes constant strings,
1316 "newSVpvs_flags()".
1317 · The function "Perl_croak_xs_usage" has been added as a wrapper to
1319 "Perl_croak".
1320 · Perl now exports the functions "PerlIO_find_layer" and
1322 "PerlIO_list_alloc".
1323 · "PL_na" has been exterminated from the core code, replaced by local
1325 STRLEN temporaries, or "*_nolen()" calls. Either approach is faster
1326 than "PL_na", which is a pointer dereference into the interpreter
1327 structure under ithreads, and a global variable otherwise.
1328 · "Perl_mg_free()" used to leave freed memory accessible via
1330 "SvMAGIC()" on the scalar. It now updates the linked list to remove
1331 each piece of magic as it is freed.
1332 · Under ithreads, the regex in "PL_reg_curpm" is now reference
1334 counted. This eliminates a lot of hackish workarounds to cope with
1335 it not being reference counted.
1336 · "Perl_mg_magical()" would sometimes incorrectly turn on
1338 "SvRMAGICAL()". This has been fixed.
1339 · The public IV and NV flags are now not set if the string value has
1341 trailing "garbage". This behaviour is consistent with not setting
1342 the public IV or NV flags if the value is out of range for the
1343 type.
1344 · Uses of "Nullav", "Nullcv", "Nullhv", "Nullop", "Nullsv" etc have
1346 been replaced by "NULL" in the core code, and non-dual-life
1347 modules, as "NULL" is clearer to those unfamiliar with the core
1348 code.
1349 · A macro MUTABLE_PTR(p) has been added, which on (non-pedantic) gcc
1351 will not cast away "const", returning a "void *". Macros
1352 "MUTABLE_SV(av)", "MUTABLE_SV(cv)" etc build on this, casting to
1353 "AV *" etc without casting away "const". This allows proper
1354 compile-time auditing of "const" correctness in the core, and
1355 helped picked up some errors (now fixed).
1356 · Macros "mPUSHs()" and "mXPUSHs()" have been added, for pushing SVs
1358 on the stack and mortalizing them.
1359 · Use of the private structure "mro_meta" has changed slightly.
1361 Nothing outside the core should be accessing this directly anyway.
1362 · A new tool, Porting/expand-macro.pl has been added, that allows you
1364 to view how a C preprocessor macro would be expanded when compiled.
1365 This is handy when trying to decode the macro hell that is the perl
1366 guts.
1367
1369 Testing improvements
1370 Parallel tests
1371 The core distribution can now run its regression tests in parallel
1372 on Unix-like platforms. Instead of running "make test", set
1373 "TEST_JOBS" in your environment to the number of tests to run in
1374 parallel, and run "make test_harness". On a Bourne-like shell, this
1375 can be done as
1376 TEST_JOBS=3 make test_harness # Run 3 tests in parallel
1378 An environment variable is used, rather than parallel make itself,
1380 because TAP::Harness needs to be able to schedule individual non-
1381 conflicting test scripts itself, and there is no standard interface
1382 to "make" utilities to interact with their job schedulers.
1383 Note that currently some test scripts may fail when run in parallel
1385 (most notably "ext/IO/t/io_dir.t"). If necessary run just the
1386 failing scripts again sequentially and see if the failures go away.
1387 Test harness flexibility
1389 It's now possible to override "PERL5OPT" and friends in t/TEST
1390 Test watchdog
1392 Several tests that have the potential to hang forever if they fail
1393 now incorporate a "watchdog" functionality that will kill them
1394 after a timeout, which helps ensure that "make test" and "make
1395 test_harness" run to completion automatically.
1396 New Tests
1398 Perl's developers have added a number of new tests to the core. In
1399 addition to the items listed below, many modules updated from CPAN
1400 incorporate new tests.
1401 · Significant cleanups to core tests to ensure that language and
1403 interpreter features are not used before they're tested.
1404 · "make test_porting" now runs a number of important pre-commit
1406 checks which might be of use to anyone working on the Perl core.
1407 · t/porting/podcheck.t automatically checks the well-formedness of
1409 POD found in all .pl, .pm and .pod files in the MANIFEST, other
1410 than in dual-lifed modules which are primarily maintained outside
1411 the Perl core.
1412 · t/porting/manifest.t now tests that all files listed in MANIFEST
1414 are present.
1415 · t/op/while_readdir.t tests that a bare readdir in while loop sets
1417 $_.
1418 · t/comp/retainedlines.t checks that the debugger can retain source
1420 lines from "eval".
1421 · t/io/perlio_fail.t checks that bad layers fail.
1423 · t/io/perlio_leaks.t checks that PerlIO layers are not leaking.
1425 · t/io/perlio_open.t checks that certain special forms of open work.
1427 · t/io/perlio.t includes general PerlIO tests.
1429 · t/io/pvbm.t checks that there is no unexpected interaction between
1431 the internal types "PVBM" and "PVGV".
1432 · t/mro/package_aliases.t checks that mro works properly in the
1434 presence of aliased packages.
1435 · t/op/dbm.t tests "dbmopen" and "dbmclose".
1437 · t/op/index_thr.t tests the interaction of "index" and threads.
1439 · t/op/pat_thr.t tests the interaction of esoteric patterns and
1441 threads.
1442 · t/op/qr_gc.t tests that "qr" doesn't leak.
1444 · t/op/reg_email_thr.t tests the interaction of regex recursion and
1446 threads.
1447 · t/op/regexp_qr_embed_thr.t tests the interaction of patterns with
1449 embedded "qr//" and threads.
1450 · t/op/regexp_unicode_prop.t tests Unicode properties in regular
1452 expressions.
1453 · t/op/regexp_unicode_prop_thr.t tests the interaction of Unicode
1455 properties and threads.
1456 · t/op/reg_nc_tie.t tests the tied methods of
1458 "Tie::Hash::NamedCapture".
1459 · t/op/reg_posixcc.t checks that POSIX character classes behave
1461 consistently.
1462 · t/op/re.t checks that exportable "re" functions in universal.c
1464 work.
1465 · t/op/setpgrpstack.t checks that "setpgrp" works.
1467 · t/op/substr_thr.t tests the interaction of "substr" and threads.
1469 · t/op/upgrade.t checks that upgrading and assigning scalars works.
1471 · t/uni/lex_utf8.t checks that Unicode in the lexer works.
1473 · t/uni/tie.t checks that Unicode and "tie" work.
1475 · t/comp/final_line_num.t tests whether line numbers are correct at
1477 EOF
1478 · t/comp/form_scope.t tests format scoping.
1480 · t/comp/line_debug.t tests whether "@{"_<$file"}" works.
1482 · t/op/filetest_t.t tests if -t file test works.
1484 · t/op/qr.t tests "qr".
1486 · t/op/utf8cache.t tests malfunctions of the utf8 cache.
1488 · t/re/uniprops.t test unicodes "\p{}" regex constructs.
1490 · t/op/filehandle.t tests some suitably portable filetest operators
1492 to check that they work as expected, particularly in the light of
1493 some internal changes made in how filehandles are blessed.
1494 · t/op/time_loop.t tests that unix times greater than "2**63", which
1496 can now be handed to "gmtime" and "localtime", do not cause an
1497 internal overflow or an excessively long loop.
1498
1500 New Diagnostics
1501 · SV allocation tracing has been added to the diagnostics enabled by
1502 "-Dm". The tracing can alternatively output via the "PERL_MEM_LOG"
1503 mechanism, if that was enabled when the perl binary was compiled.
1504 · Smartmatch resolution tracing has been added as a new diagnostic.
1506 Use "-DM" to enable it.
1507 · A new debugging flag "-DB" now dumps subroutine definitions,
1509 leaving "-Dx" for its original purpose of dumping syntax trees.
1510 · Perl 5.12 provides a number of new diagnostic messages to help you
1512 write better code. See perldiag for details of these new messages.
1513 · "Bad plugin affecting keyword '%s'"
1515 · "gmtime(%.0f) too large"
1517 · "Lexing code attempted to stuff non-Latin-1 character into
1519 Latin-1 input"
1520 · "Lexing code internal error (%s)"
1522 · "localtime(%.0f) too large"
1524 · "Overloaded dereference did not return a reference"
1526 · "Overloaded qr did not return a REGEXP"
1528 · "Perl_pmflag() is deprecated, and will be removed from the XS
1530 API"
1531 · "lvalue attribute ignored after the subroutine has been
1533 defined"
1534 This new warning is issued when one attempts to mark a
1536 subroutine as lvalue after it has been defined.
1537 · Perl now warns you if "++" or "--" are unable to change the
1539 value because it's beyond the limit of representation.
1540 This uses a new warnings category: "imprecision".
1542 · "lc", "uc", "lcfirst", and "ucfirst" warn when passed undef.
1544 · "Show constant in "Useless use of a constant in void context""
1546 · "Prototype after '%s'"
1548 · "panic: sv_chop %s"
1550 This new fatal error occurs when the C routine "Perl_sv_chop()"
1552 was passed a position that is not within the scalar's string
1553 buffer. This could be caused by buggy XS code, and at this
1554 point recovery is not possible.
1555 · The fatal error "Malformed UTF-8 returned by \N" is now
1557 produced if the "charnames" handler returns malformed UTF-8.
1558 · If an unresolved named character or sequence was encountered
1560 when compiling a regex pattern then the fatal error "\N{NAME}
1561 must be resolved by the lexer" is now produced. This can
1562 happen, for example, when using a single-quotish context like
1563 "$re = '\N{SPACE}'; /$re/;". See perldiag for more examples of
1564 how the lexer can get bypassed.
1565 · "Invalid hexadecimal number in \N{U+...}" is a new fatal error
1567 triggered when the character constant represented by "..." is
1568 not a valid hexadecimal number.
1569 · The new meaning of "\N" as "[^\n]" is not valid in a bracketed
1571 character class, just like "." in a character class loses its
1572 special meaning, and will cause the fatal error "\N in a
1573 character class must be a named character: \N{...}".
1574 · The rules on what is legal for the "..." in "\N{...}" have been
1576 tightened up so that unless the "..." begins with an alphabetic
1577 character and continues with a combination of alphanumerics,
1578 dashes, spaces, parentheses or colons then the warning
1579 "Deprecated character(s) in \N{...} starting at '%s'" is now
1580 issued.
1581 · The warning "Using just the first characters returned by \N{}"
1583 will be issued if the "charnames" handler returns a sequence of
1584 characters which exceeds the limit of the number of characters
1585 that can be used. The message will indicate which characters
1586 were used and which were discarded.
1587 Changed Diagnostics
1589 A number of existing diagnostic messages have been improved or
1590 corrected:
1591 · A new warning category "illegalproto" allows finer-grained control
1593 of warnings around function prototypes.
1594 The two warnings:
1596 "Illegal character in prototype for %s : %s"
1598 "Prototype after '%c' for %s : %s"
1599 have been moved from the "syntax" top-level warnings category into
1601 a new first-level category, "illegalproto". These two warnings are
1602 currently the only ones emitted during parsing of an
1603 invalid/illegal prototype, so one can now use
1604 no warnings 'illegalproto';
1606 to suppress only those, but not other syntax-related warnings.
1608 Warnings where prototypes are changed, ignored, or not met are
1609 still in the "prototype" category as before.
1610 · "Deep recursion on subroutine "%s""
1612 It is now possible to change the depth threshold for this warning
1614 from the default of 100, by recompiling the perl binary, setting
1615 the C pre-processor macro "PERL_SUB_DEPTH_WARN" to the desired
1616 value.
1617 · "Illegal character in prototype" warning is now more precise when
1619 reporting illegal characters after _
1620 · mro merging error messages are now very similar to those produced
1622 by Algorithm::C3.
1623 · Amelioration of the error message "Unrecognized character %s in
1625 column %d"
1626 Changes the error message to "Unrecognized character %s; marked by
1628 <-- HERE after %s<-- HERE near column %d". This should make it a
1629 little simpler to spot and correct the suspicious character.
1630 · Perl now explicitly points to $. when it causes an uninitialized
1632 warning for ranges in scalar context.
1633 · "split" now warns when called in void context.
1635 · "printf"-style functions called with too few arguments will now
1637 issue the warning "Missing argument in %s" [perl #71000]
1638 · Perl now properly returns a syntax error instead of segfaulting if
1640 "each", "keys", or "values" is used without an argument.
1641 · "tell()" now fails properly if called without an argument and when
1643 no previous file was read.
1644 "tell()" now returns "-1", and sets errno to "EBADF", thus
1646 restoring the 5.8.x behaviour.
1647 · "overload" no longer implicitly unsets fallback on repeated 'use
1649 overload' lines.
1650 · POSIX::strftime() can now handle Unicode characters in the format
1652 string.
1653 · The "syntax" category was removed from 5 warnings that should only
1655 be in "deprecated".
1656 · Three fatal "pack"/"unpack" error messages have been normalized to
1658 "panic: %s"
1659 · "Unicode character is illegal" has been rephrased to be more
1661 accurate
1662 It now reads "Unicode non-character is illegal in interchange" and
1664 the perldiag documentation has been expanded a bit.
1665 · Currently, all but the first of the several characters that the
1667 "charnames" handler may return are discarded when used in a regular
1668 expression pattern bracketed character class. If this happens then
1669 the warning "Using just the first character returned by \N{} in
1670 character class" will be issued.
1671 · The warning "Missing right brace on \N{} or unescaped left brace
1673 after \N. Assuming the latter" will be issued if Perl encounters a
1674 "\N{" but doesn't find a matching "}". In this case Perl doesn't
1675 know if it was mistakenly omitted, or if "match non-newline"
1676 followed by "match a "{"" was desired. It assumes the latter
1677 because that is actually a valid interpretation as written, unlike
1678 the other case. If you meant the former, you need to add the
1679 matching right brace. If you did mean the latter, you can silence
1680 this warning by writing instead "\N\{".
1681 · "gmtime" and "localtime" called with numbers smaller than they can
1683 reliably handle will now issue the warnings "gmtime(%.0f) too
1684 small" and "localtime(%.0f) too small".
1685 The following diagnostic messages have been removed:
1687 · "Runaway format"
1689 · "Can't locate package %s for the parents of %s"
1691 In general this warning it only got produced in conjunction with
1693 other warnings, and removing it allowed an ISA lookup optimisation
1694 to be added.
1695 · "v-string in use/require is non-portable"
1697
1699 · h2ph now looks in "include-fixed" too, which is a recent addition
1700 to gcc's search path.
1701 · h2xs no longer incorrectly treats enum values like macros. It also
1703 now handles C++ style comments ("//") properly in enums.
1704 · perl5db.pl now supports "LVALUE" subroutines. Additionally, the
1706 debugger now correctly handles proxy constant subroutines, and
1707 subroutine stubs.
1708 · perlbug now uses %Module::CoreList::bug_tracker to print out
1710 upstream bug tracker URLs. If a user identifies a particular
1711 module as the topic of their bug report and we're able to divine
1712 the URL for its upstream bug tracker, perlbug now provide a message
1713 to the user explaining that the core copies the CPAN version
1714 directly, and provide the URL for reporting the bug directly to the
1715 upstream author.
1716 perlbug no longer reports "Message sent" when it hasn't actually
1718 sent the message
1719 · perlthanks is a new utility for sending non-bug-reports to the
1721 authors and maintainers of Perl. Getting nothing but bug reports
1722 can become a bit demoralising. If Perl 5.12 works well for you,
1723 please try out perlthanks. It will make the developers smile.
1724 · Perl's developers have fixed bugs in a2p having to do with the
1726 "match()" operator in list context. Additionally, a2p no longer
1727 generates code that uses the $[ variable.
1728
1730 · U+0FFFF is now a legal character in regular expressions.
1731 · pp_qr now always returns a new regexp SV. Resolves RT #69852.
1733 Instead of returning a(nother) reference to the (pre-compiled)
1735 regexp in the optree, use reg_temp_copy() to create a copy of it,
1736 and return a reference to that. This resolves issues about
1737 Regexp::DESTROY not being called in a timely fashion (the original
1738 bug tracked by RT #69852), as well as bugs related to blessing
1739 regexps, and of assigning to regexps, as described in
1740 correspondence added to the ticket.
1741 It transpires that we also need to undo the SvPVX() sharing when
1743 ithreads cloning a Regexp SV, because mother_re is set to NULL,
1744 instead of a cloned copy of the mother_re. This change might fix
1745 bugs with regexps and threads in certain other situations, but as
1746 yet neither tests nor bug reports have indicated any problems, so
1747 it might not actually be an edge case that it's possible to reach.
1748 · Several compilation errors and segfaults when perl was built with
1750 "-Dmad" were fixed.
1751 · Fixes for lexer API changes in 5.11.2 which broke NYTProf's savesrc
1753 option.
1754 · "-t" should only return TRUE for file handles connected to a TTY
1756 The Microsoft C version of "isatty()" returns TRUE for all
1758 character mode devices, including the /dev/null-style "nul" device
1759 and printers like "lpt1".
1760 · Fixed a regression caused by commit fafafbaf which caused a panic
1762 during parameter passing [perl #70171]
1763 · On systems which in-place edits without backup files, -i'*' now
1765 works as the documentation says it does [perl #70802]
1766 · Saving and restoring magic flags no longer loses readonly flag.
1768 · The malformed syntax "grep EXPR LIST" (note the missing comma) no
1770 longer causes abrupt and total failure.
1771 · Regular expressions compiled with "qr{}" literals properly set "$'"
1773 when matching again.
1774 · Using named subroutines with "sort" should no longer lead to bus
1776 errors [perl #71076]
1777 · Numerous bugfixes catch small issues caused by the recently-added
1779 Lexer API.
1780 · Smart match against @_ sometimes gave false negatives. [perl
1782 #71078]
1783 · $@ may now be assigned a read-only value (without error or busting
1785 the stack).
1786 · "sort" called recursively from within an active comparison
1788 subroutine no longer causes a bus error if run multiple times.
1789 [perl #71076]
1790 · Tie::Hash::NamedCapture::* will not abort if passed bad input (RT
1792 #71828)
1793 · @_ and $_ no longer leak under threads (RT #34342 and #41138, also
1795 #70602, #70974)
1796 · "-I" on shebang line now adds directories in front of @INC as
1798 documented, and as does "-I" when specified on the command-line.
1799 · "kill" is now fatal when called on non-numeric process identifiers.
1801 Previously, an "undef" process identifier would be interpreted as a
1802 request to kill process 0, which would terminate the current
1803 process group on POSIX systems. Since process identifiers are
1804 always integers, killing a non-numeric process is now fatal.
1805 · 5.10.0 inadvertently disabled an optimisation, which caused a
1807 measurable performance drop in list assignment, such as is often
1808 used to assign function parameters from @_. The optimisation has
1809 been re-instated, and the performance regression fixed. (This fix
1810 is also present in 5.10.1)
1811 · Fixed memory leak on "while (1) { map 1, 1 }" [RT #53038].
1813 · Some potential coredumps in PerlIO fixed [RT #57322,54828].
1815 · The debugger now works with lvalue subroutines.
1817 · The debugger's "m" command was broken on modules that defined
1819 constants [RT #61222].
1820 · "crypt" and string complement could return tainted values for
1822 untainted arguments [RT #59998].
1823 · The "-i".suffix command-line switch now recreates the file using
1825 restricted permissions, before changing its mode to match the
1826 original file. This eliminates a potential race condition [RT
1827 #60904].
1828 · On some Unix systems, the value in $? would not have the top bit
1830 set ("$? & 128") even if the child core dumped.
1831 · Under some circumstances, $^R could incorrectly become undefined
1833 [RT #57042].
1834 · In the XS API, various hash functions, when passed a pre-computed
1836 hash where the key is UTF-8, might result in an incorrect lookup.
1837 · XS code including XSUB.h before perl.h gave a compile-time error
1839 [RT #57176].
1840 · "$object->isa('Foo')" would report false if the package "Foo"
1842 didn't exist, even if the object's @ISA contained "Foo".
1843 · Various bugs in the new-to 5.10.0 mro code, triggered by
1845 manipulating @ISA, have been found and fixed.
1846 · Bitwise operations on references could crash the interpreter, e.g.
1848 "$x=\$y; $x |= "foo"" [RT #54956].
1849 · Patterns including alternation might be sensitive to the internal
1851 UTF-8 representation, e.g.
1852 my $byte = chr(192);
1854 my $utf8 = chr(192); utf8::upgrade($utf8);
1855 $utf8 =~ /$byte|X}/i; # failed in 5.10.0
1856 · Within UTF8-encoded Perl source files (i.e. where "use utf8" is in
1858 effect), double-quoted literal strings could be corrupted where a
1859 "\xNN", "\0NNN" or "\N{}" is followed by a literal character with
1860 ordinal value greater than 255 [RT #59908].
1861 · "B::Deparse" failed to correctly deparse various constructs:
1863 "readpipe STRING" [RT #62428], "CORE::require(STRING)" [RT #62488],
1864 "sub foo(_)" [RT #62484].
1865 · Using "setpgrp" with no arguments could corrupt the perl stack.
1867 · The block form of "eval" is now specifically trappable by "Safe"
1869 and "ops". Previously it was erroneously treated like string
1870 "eval".
1871 · In 5.10.0, the two characters "[~" were sometimes parsed as the
1873 smart match operator ("~~") [RT #63854].
1874 · In 5.10.0, the "*" quantifier in patterns was sometimes treated as
1876 "{0,32767}" [RT #60034, #60464]. For example, this match would
1877 fail:
1878 ("ab" x 32768) =~ /^(ab)*$/
1880 · "shmget" was limited to a 32 bit segment size on a 64 bit OS [RT
1882 #63924].
1883 · Using "next" or "last" to exit a "given" block no longer produces a
1885 spurious warning like the following:
1886 Exiting given via last at foo.pl line 123
1888 · Assigning a format to a glob could corrupt the format; e.g.:
1890 *bar=*foo{FORMAT}; # foo format now bad
1892 · Attempting to coerce a typeglob to a string or number could cause
1894 an assertion failure. The correct error message is now generated,
1895 "Can't coerce GLOB to $type".
1896 · Under "use filetest 'access'", "-x" was using the wrong access
1898 mode. This has been fixed [RT #49003].
1899 · "length" on a tied scalar that returned a Unicode value would not
1901 be correct the first time. This has been fixed.
1902 · Using an array "tie" inside in array "tie" could SEGV. This has
1904 been fixed. [RT #51636]
1905 · A race condition inside "PerlIOStdio_close()" has been identified
1907 and fixed. This used to cause various threading issues, including
1908 SEGVs.
1909 · In "unpack", the use of "()" groups in scalar context was
1911 internally placing a list on the interpreter's stack, which
1912 manifested in various ways, including SEGVs. This is now fixed [RT
1913 #50256].
1914 · Magic was called twice in "substr", "\&$x", "tie $x, $m" and
1916 "chop". These have all been fixed.
1917 · A 5.10.0 optimisation to clear the temporary stack within the
1919 implicit loop of "s///ge" has been reverted, as it turned out to be
1920 the cause of obscure bugs in seemingly unrelated parts of the
1921 interpreter [commit ef0d4e17921ee3de].
1922 · The line numbers for warnings inside "elsif" are now correct.
1924 · The ".." operator now works correctly with ranges whose ends are at
1926 or close to the values of the smallest and largest integers.
1927 · "binmode STDIN, ':raw'" could lead to segmentation faults on some
1929 platforms. This has been fixed [RT #54828].
1930 · An off-by-one error meant that "index $str, ..." was effectively
1932 being executed as "index "$str\0", ...". This has been fixed [RT
1933 #53746].
1934 · Various leaks associated with named captures in regexes have been
1936 fixed [RT #57024].
1937 · A weak reference to a hash would leak. This was affecting "DBI" [RT
1939 #56908].
1940 · Using (?|) in a regex could cause a segfault [RT #59734].
1942 · Use of a UTF-8 "tr//" within a closure could cause a segfault [RT
1944 #61520].
1945 · Calling "Perl_sv_chop()" or otherwise upgrading an SV could result
1947 in an unaligned 64-bit access on the SPARC architecture [RT
1948 #60574].
1949 · In the 5.10.0 release, "inc_version_list" would incorrectly list
1951 "5.10.*" after "5.8.*"; this affected the @INC search order [RT
1952 #67628].
1953 · In 5.10.0, "pack "a*", $tainted_value" returned a non-tainted value
1955 [RT #52552].
1956 · In 5.10.0, "printf" and "sprintf" could produce the fatal error
1958 "panic: utf8_mg_pos_cache_update" when printing UTF-8 strings [RT
1959 #62666].
1960 · In the 5.10.0 release, a dynamically created "AUTOLOAD" method
1962 might be missed (method cache issue) [RT #60220,60232].
1963 · In the 5.10.0 release, a combination of "use feature" and "//ee"
1965 could cause a memory leak [RT #63110].
1966 · "-C" on the shebang ("#!") line is once more permitted if it is
1968 also specified on the command line. "-C" on the shebang line used
1969 to be a silent no-op if it was not also on the command line, so
1970 perl 5.10.0 disallowed it, which broke some scripts. Now perl
1971 checks whether it is also on the command line and only dies if it
1972 is not [RT #67880].
1973 · In 5.10.0, certain types of re-entrant regular expression could
1975 crash, or cause the following assertion failure [RT #60508]:
1976 Assertion rx->sublen >= (s - rx->subbeg) + i failed
1978 · Perl now includes previously missing files from the Unicode
1980 Character Database.
1981 · Perl now honors "TMPDIR" when opening an anonymous temporary file.
1983
1985 Perl is incredibly portable. In general, if a platform has a C
1986 compiler, someone has ported Perl to it (or will soon). We're happy to
1987 announce that Perl 5.12 includes support for several new platforms. At
1988 the same time, it's time to bid farewell to some (very) old friends.
1989 New Platforms
1991 Haiku
1992 Perl's developers have merged patches from Haiku's maintainers.
1993 Perl should now build on Haiku.
1994 MirOS BSD
1996 Perl should now build on MirOS BSD.
1997 Discontinued Platforms
1999 Domain/OS
2000 MiNT
2001 Tenon MachTen
2002 Updated Platforms
2004 AIX
2005 · Removed libbsd for AIX 5L and 6.1. Only "flock()" was used from
2006 libbsd.
2007 · Removed libgdbm for AIX 5L and 6.1 if libgdbm < 1.8.3-5 is
2009 installed. The libgdbm is delivered as an optional package
2010 with the AIX Toolbox. Unfortunately the versions below 1.8.3-5
2011 are broken.
2012 · Hints changes mean that AIX 4.2 should work again.
2014 Cygwin
2016 · Perl now supports IPv6 on Cygwin 1.7 and newer.
2017 · On Cygwin we now strip the last number from the DLL. This has
2019 been the behaviour in the cygwin.com build for years. The hints
2020 files have been updated.
2021 Darwin (Mac OS X)
2023 · Skip testing the be_BY.CP1131 locale on Darwin 10 (Mac OS X
2024 10.6), as it's still buggy.
2025 · Correct infelicities in the regexp used to identify buggy
2027 locales on Darwin 8 and 9 (Mac OS X 10.4 and 10.5,
2028 respectively).
2029 DragonFly BSD
2031 · Fix thread library selection [perl #69686]
2032 FreeBSD
2034 · The hints files now identify the correct threading libraries on
2035 FreeBSD 7 and later.
2036 Irix
2038 · We now work around a bizarre preprocessor bug in the Irix 6.5
2039 compiler: "cc -E -" unfortunately goes into K&R mode, but "cc
2040 -E file.c" doesn't.
2041 NetBSD
2043 · Hints now supports versions 5.*.
2044 OpenVMS
2046 · "-UDEBUGGING" is now the default on VMS.
2047 Like it has been everywhere else for ages and ages. Also make
2049 command-line selection of -UDEBUGGING and -DDEBUGGING work in
2050 configure.com; before the only way to turn it off was by saying
2051 no in answer to the interactive question.
2052 · The default pipe buffer size on VMS has been updated to 8192 on
2054 64-bit systems.
2055 · Reads from the in-memory temporary files of "PerlIO::scalar"
2057 used to fail if $/ was set to a numeric reference (to indicate
2058 record-style reads). This is now fixed.
2059 · VMS now supports "getgrgid".
2061 · Many improvements and cleanups have been made to the VMS file
2063 name handling and conversion code.
2064 · Enabling the "PERL_VMS_POSIX_EXIT" logical name now encodes a
2066 POSIX exit status in a VMS condition value for better
2067 interaction with GNV's bash shell and other utilities that
2068 depend on POSIX exit values. See "$?" in perlvms for details.
2069 · "File::Copy" now detects Unix compatibility mode on VMS.
2071 Stratus VOS
2073 · Various changes from Stratus have been merged in.
2074 Symbian
2076 · There is now support for Symbian S60 3.2 SDK and S60 5.0 SDK.
2077 Windows
2079 · Perl 5.12 supports Windows 2000 and later. The supporting code
2080 for legacy versions of Windows is still included, but will be
2081 removed during the next development cycle.
2082 · Initial support for building Perl with MinGW-w64 is now
2084 available.
2085 · perl.exe now includes a manifest resource to specify the
2087 "trustInfo" settings for Windows Vista and later. Without this
2088 setting Windows would treat perl.exe as a legacy application
2089 and apply various heuristics like redirecting access to
2090 protected file system areas (like the "Program Files" folder)
2091 to the users "VirtualStore" instead of generating a proper
2092 "permission denied" error.
2093 The manifest resource also requests the Microsoft Common-
2095 Controls version 6.0 (themed controls introduced in Windows
2096 XP). Check out the Win32::VisualStyles module on CPAN to
2097 switch back to old style unthemed controls for legacy
2098 applications.
2099 · The "-t" filetest operator now only returns true if the
2101 filehandle is connected to a console window. In previous
2102 versions of Perl it would return true for all character mode
2103 devices, including NUL and LPT1.
2104 · The "-p" filetest operator now works correctly, and the
2106 Fcntl::S_IFIFO constant is defined when Perl is compiled with
2107 Microsoft Visual C. In previous Perl versions "-p" always
2108 returned a false value, and the Fcntl::S_IFIFO constant was not
2109 defined.
2110 This bug is specific to Microsoft Visual C and never affected
2112 Perl binaries built with MinGW.
2113 · The socket error codes are now more widely supported: The
2115 POSIX module will define the symbolic names, like
2116 POSIX::EWOULDBLOCK, and stringification of socket error codes
2117 in $! works as well now;
2118 C:\>perl -MPOSIX -E "$!=POSIX::EWOULDBLOCK; say $!"
2120 A non-blocking socket operation could not be completed immediately.
2121 · flock() will now set sensible error codes in $!. Previous Perl
2123 versions copied the value of $^E into $!, which caused much
2124 confusion.
2125 · select() now supports all empty "fd_set"s more correctly.
2127 · '.\foo' and '..\foo' were treated differently than './foo' and
2129 '../foo' by "do" and "require" [RT #63492].
2130 · Improved message window handling means that "alarm" and "kill"
2132 messages will no longer be dropped under race conditions.
2133 · Various bits of Perl's build infrastructure are no longer
2135 converted to win32 line endings at release time. If this hurts
2136 you, please report the problem with the perlbug program
2137 included with perl.
2138
2140 This is a list of some significant unfixed bugs, which are regressions
2141 from either 5.10.x or 5.8.x.
2142 · Some CPANPLUS tests may fail if there is a functioning file
2144 ../../cpanp-run-perl outside your build directory. The failure
2145 shouldn't imply there's a problem with the actual functional
2146 software. The bug is already fixed in [RT #74188] and is scheduled
2147 for inclusion in perl-v5.12.1.
2148 · "List::Util::first" misbehaves in the presence of a lexical $_
2150 (typically introduced by "my $_" or implicitly by "given"). The
2151 variable which gets set for each iteration is the package variable
2152 $_, not the lexical $_ [RT #67694].
2153 A similar issue may occur in other modules that provide functions
2155 which take a block as their first argument, like
2156 foo { ... $_ ...} list
2158 · Some regexes may run much more slowly when run in a child thread
2160 compared with the thread the pattern was compiled into [RT #55600].
2161 · Things like ""\N{LATIN SMALL LIGATURE FF}" =~ /\N{LATIN SMALL
2163 LETTER F}+/" will appear to hang as they get into a very long
2164 running loop [RT #72998].
2165 · Several porters have reported mysterious crashes when Perl's entire
2167 test suite is run after a build on certain Windows 2000 systems.
2168 When run by hand, the individual tests reportedly work fine.
2169
2171 · This one is actually a change introduced in 5.10.0, but it was
2172 missed from that release's perldelta, so it is mentioned here
2173 instead.
2174 A bugfix related to the handling of the "/m" modifier and "qr"
2176 resulted in a change of behaviour between 5.8.x and 5.10.0:
2177 # matches in 5.8.x, doesn't match in 5.10.0
2179 $re = qr/^bar/; "foo\nbar" =~ /$re/m;
2180
2182 Perl 5.12.0 represents approximately two years of development since
2183 Perl 5.10.0 and contains over 750,000 lines of changes across over
2184 3,000 files from over 200 authors and committers.
2185 Perl continues to flourish into its third decade thanks to a vibrant
2187 community of users and developers. The following people are known to
2188 have contributed the improvements that became Perl 5.12.0:
2189 Aaron Crane, Abe Timmerman, Abhijit Menon-Sen, Abigail, Adam Russell,
2191 Adriano Ferreira, var Arnfjoerd` Bjarmason, Alan Grover, Alexandr
2192 Ciornii, Alex Davies, Alex Vandiver, Andreas Koenig, Andrew Rodland,
2193 andrew@sundale.net, Andy Armstrong, Andy Dougherty, Jose AUGUSTE-
2194 ETIENNE, Benjamin Smith, Ben Morrow, bharanee rathna, Bo Borgerson, Bo
2195 Lindbergh, Brad Gilbert, Bram, Brendan O'Dea, brian d foy, Charles
2196 Bailey, Chip Salzenberg, Chris 'BinGOs' Williams, Christoph Lamprecht,
2197 Chris Williams, chromatic, Claes Jakobsson, Craig A. Berry, Dan
2198 Dascalescu, Daniel Frederick Crisman, Daniel M. Quinlan, Dan Jacobson,
2199 Dan Kogai, Dave Mitchell, Dave Rolsky, David Cantrell, David Dick,
2200 David Golden, David Mitchell, David M. Syzdek, David Nicol, David
2201 Wheeler, Dennis Kaarsemaker, Dintelmann, Peter, Dominic Dunlop,
2202 Dr.Ruud, Duke Leto, Enrico Sorcinelli, Eric Brine, Father Chrysostomos,
2203 Florian Ragwitz, Frank Wiegand, Gabor Szabo, Gene Sullivan, Geoffrey T.
2204 Dairiki, George Greer, Gerard Goossen, Gisle Aas, Goro Fuji, Graham
2205 Barr, Green, Paul, Hans Dieter Pearcey, Harmen, H. Merijn Brand, Hugo
2206 van der Sanden, Ian Goodacre, Igor Sutton, Ingo Weinhold, James Bence,
2207 James Mastros, Jan Dubois, Jari Aalto, Jarkko Hietaniemi, Jay Hannah,
2208 Jerry Hedden, Jesse Vincent, Jim Cromie, Jody Belka, John E. Malmberg,
2209 John Malmberg, John Peacock, John Peacock via RT, John P. Linderman,
2210 John Wright, Josh ben Jore, Jos I. Boumans, Karl Williamson, Kenichi
2211 Ishigaki, Ken Williams, Kevin Brintnall, Kevin Ryde, Kurt Starsinic,
2212 Leon Brocard, Lubomir Rintel, Luke Ross, Marcel Gruenauer, Marcus
2213 Holland-Moritz, Mark Jason Dominus, Marko Asplund, Martin Hasch,
2214 Mashrab Kuvatov, Matt Kraai, Matt S Trout, Max Maischein, Michael
2215 Breen, Michael Cartmell, Michael G Schwern, Michael Witten, Mike
2216 Giroux, Milosz Tanski, Moritz Lenz, Nicholas Clark, Nick Cleaton, Niko
2217 Tyni, Offer Kaye, Osvaldo Villalon, Paul Fenwick, Paul Gaborit, Paul
2218 Green, Paul Johnson, Paul Marquess, Philip Hazel, Philippe Bruhat,
2219 Rafael Garcia-Suarez, Rainer Tammer, Rajesh Mandalemula, Reini Urban,
2220 Renee Baecker, Ricardo Signes, Ricardo SIGNES, Richard Foley, Rich
2221 Rauenzahn, Rick Delaney, Risto Kankkunen, Robert May, Roberto C.
2222 Sanchez, Robin Barker, SADAHIRO Tomoyuki, Salvador Ortiz Garcia, Sam
2223 Vilain, Scott Lanning, Sebastien Aperghis-Tramoni, Sergio Durigan
2224 Junior, Shlomi Fish, Simon 'corecode' Schubert, Sisyphus, Slaven Rezic,
2225 Smylers, Steffen Mueller, Steffen Ullrich, Stepan Kasal, Steve Hay,
2226 Steven Schubiger, Steve Peters, Tels, The Doctor, Tim Bunce, Tim
2227 Jenness, Todd Rinaldo, Tom Christiansen, Tom Hukins, Tom Wyant, Tony
2228 Cook, Torsten Schoenfeld, Tye McQueen, Vadim Konovalov, Vincent Pit,
2229 Hio YAMASHINA, Yasuhiro Matsumoto, Yitzchak Scott-Thoennes, Yuval
2230 Kogman, Yves Orton, Zefram, Zsban Ambrus
2231 This is woefully incomplete as it's automatically generated from
2233 version control history. In particular, it doesn't include the names
2234 of the (very much appreciated) contributors who reported issues in
2235 previous versions of Perl that helped make Perl 5.12.0 better. For a
2236 more complete list of all of Perl's historical contributors, please see
2237 the "AUTHORS" file in the Perl 5.12.0 distribution.
2238 Our "retired" pumpkings Nicholas Clark and Rafael Garcia-Suarez deserve
2240 special thanks for their brilliant and substantive ongoing
2241 contributions. Nicholas personally authored over 30% of the patches
2242 since 5.10.0. Rafael comes in second in patch authorship with 11%, but
2243 is first by a long shot in committing patches authored by others,
2244 pushing 44% of the commits since 5.10.0 in this category, often after
2245 providing considerable coaching to the patch authors. These statistics
2246 in no way comprise all of their contributions, but express in shorthand
2247 that we couldn't have done it without them.
2248 Many of the changes included in this version originated in the CPAN
2250 modules included in Perl's core. We're grateful to the entire CPAN
2251 community for helping Perl to flourish.
2252
2254 If you find what you think is a bug, you might check the articles
2255 recently posted to the comp.lang.perl.misc newsgroup and the perl bug
2256 database at <http://rt.perl.org/perlbug/>. There may also be
2257 information at <http://www.perl.org/>, the Perl Home Page.
2258 If you believe you have an unreported bug, please run the perlbug
2260 program included with your release. Be sure to trim your bug down to a
2261 tiny but sufficient test case. Your bug report, along with the output
2262 of "perl -V", will be sent off to perlbug@perl.org to be analyzed by
2263 the Perl porting team.
2264 If the bug you are reporting has security implications, which make it
2266 inappropriate to send to a publicly archived mailing list, then please
2267 send it to perl5-security-report@perl.org. This points to a closed
2268 subscription unarchived mailing list, which includes all the core
2269 committers, who be able to help assess the impact of issues, figure out
2270 a resolution, and help co-ordinate the release of patches to mitigate
2271 or fix the problem across all platforms on which Perl is supported.
2272 Please only use this address for security issues in the Perl core, not
2273 for modules independently distributed on CPAN.
2274
2276 The Changes file for an explanation of how to view exhaustive details
2277 on what changed.
2278 The INSTALL file for how to build Perl.
2280 The README file for general stuff.
2282 The Artistic and Copying files for copyright information.
2284 <http://dev.perl.org/perl5/errata.html> for a list of issues found
2286 after this release, as well as a list of CPAN modules known to be
2287 incompatible with this release.
2288perl v5.12.4 2011-06-07 PERL5120DELTA(1)