text:
perl5160delta - what is new for perl v5.16.0
This document describes differences between the 5.14.0 release and the 5.16.0 release.
If you are upgrading from an earlier release such as 5.12.0, first read perl5140delta, which describes differences between 5.12.0 and 5.14.0.
Some bug fixes in this release have been backported to later releases of 5.14.x. Those are indicated with the 5.14.x version in parentheses.
With the release of Perl 5.16.0, the 5.12.x series of releases is now out of its support period. There may be future 5.12.x releases, but only in the event of a critical security issue. Users of Perl 5.12 or earlier should consider upgrading to a more recent release of Perl.
This policy is described in greater detail in perlpolicy.
use VERSION
As of this release, version declarations like use v5.16
now disable
all features before enabling the new feature bundle. This means that
the following holds true:
use v5.12
and higher continue to enable strict, but explicit use
and no strict
now override the version declaration, even
when they come first:
There is a new ":default" feature bundle that represents the set of
features enabled before any version declaration or use feature
been seen. Version declarations below 5.10 now enable the ":default"
feature set. This does not actually change the behavior of use
, because features added to the ":default" set are those that were
traditionally enabled by default, before they could be turned off.
no feature
now resets to the default feature set. To disable all
features (which is likely to be a pretty special-purpose request, since
it presumably won't match any named set of semantics) you can now
write no feature ':all'
is now disabled under use v5.16
. It is part of the default
feature set and can be turned on or off explicitly with use feature
The new __SUB__
token, available under the current_sub
(see feature) or use v5.16
, returns a reference to the current
subroutine, making it easier to write recursive closures.
The eval
operator sometimes treats a string argument as a sequence of
characters and sometimes as a sequence of bytes, depending on the
internal encoding. The internal encoding is not supposed to make any
difference, but there is code that relies on this inconsistency.
The new unicode_eval
and evalbytes
features (enabled under use
) resolve this. The unicode_eval
feature causes eval
to treat the string always as Unicode. The evalbytes
features provides a function, itself called evalbytes
, which
evaluates its argument always as a string of bytes.
These features also fix oddities with source filters leaking to outer dynamic scopes.
See feature for more detail.
lvalue revampWhen substr
is called in lvalue or potential lvalue context with two
or three arguments, a special lvalue scalar is returned that modifies
the original string (the first argument) when assigned to.
Previously, the offsets (the second and third arguments) passed to
would be converted immediately to match the string, negative
offsets being translated to positive and offsets beyond the end of the
string being truncated.
Now, the offsets are recorded without modification in the special
lvalue scalar that is returned, and the original string is not even
looked at by substr
itself, but only when the returned lvalue is
read or modified.
These changes result in an incompatible change:
If the original string changes length after the call to substr
before assignment to its return value, negative offsets will remember
their position from the end of the string, affecting code like this:
The same thing happens with an omitted third argument. The returned lvalue will always extend to the end of the string, even if the string becomes longer.
Since this change also allowed many bugs to be fixed (see The substr operator), and since the behavior of negative offsets has never been specified, the change was deemed acceptable.
The value returned by tied
on a tied variable is now the actual
scalar that holds the object to which the variable is tied. This
lets ties be weakened with Scalar::Util::weaken(tied
Besides the addition of whole new scripts, and new characters in
existing scripts, this new version of Unicode, as always, makes some
changes to existing characters. One change that may trip up some
applications is that the General Category of two characters in the
Latin-1 range, PILCROW SIGN and SECTION SIGN, has been changed from
Other_Symbol to Other_Punctuation. The same change has been made for
a character in each of Tibetan, Ethiopic, and Aegean.
The code points U+3248..U+324F (CIRCLED NUMBER TEN ON BLACK SQUARE
through CIRCLED NUMBER EIGHTY ON BLACK SQUARE) have had their General
Category changed from Other_Symbol to Other_Numeric. The Line Break
property has changes for Hebrew and Japanese; and because of
other changes in 6.1, the Perl regular expression construct \X
works differently for some characters in Thai and Lao.
New aliases (synonyms) have been defined for many property values; these, along with the previously existing ones, are all cross-indexed in perluniprops.
The return value of charnames::viacode()
is affected by other
- Code point Old Name New Name
Perl will accept any of these names as input, but
now returns the new name of each pair. The
change for U+2118 is considered by Unicode to be a correction, that is
the original name was a mistake (but again, it will remain forever valid
to use it to refer to U+2118). But most of these changes are the
fallout of the mistake Unicode 6.0 made in naming a character used in
Japanese cell phones to be "BELL", which conflicts with the longstanding
industry use of (and Unicode's recommendation to use) that name
to mean the ASCII control character at U+0007. Therefore, that name
has been deprecated in Perl since v5.14, and any use of it will raise a
warning message (unless turned off). The name "ALERT" is now the
preferred name for this code point, with "BEL" an acceptable short
form. The name for the new cell phone character, at code point U+1F514,
remains undefined in this version of Perl (hence we don't
implement quite all of Unicode 6.1), but starting in v5.18, BELL will mean
this character, and not U+0007.
Unicode has taken steps to make sure that this sort of mistake does not happen again. The Standard now includes all generally accepted names and abbreviations for control characters, whereas previously it didn't (though there were recommended names for most of them, which Perl used). This means that most of those recommended names are now officially in the Standard. Unicode did not recommend names for the four code points listed above between U+008E and U+008F, and in standardizing them Unicode subtly changed the names that Perl had previously given them, by replacing the final blank in each name by a hyphen. Unicode also officially accepts names that Perl had deprecated, such as FILE SEPARATOR. Now the only deprecated name is BELL. Finally, Perl now uses the new official names instead of the old (now considered obsolete) names for the first four code points in the list above (the ones which have the parentheses in them).
Now that the names have been placed in the Unicode standard, these kinds of changes should not happen again, though corrections, such as to U+2118, are still possible.
Unicode also added some name abbreviations, which Perl now accepts: SP for SPACE; TAB for CHARACTER TABULATION; NEW LINE, END OF LINE, NL, and EOL for LINE FEED; LOCKING-SHIFT ONE for SHIFT OUT; LOCKING-SHIFT ZERO for SHIFT IN; and ZWNBSP for ZERO WIDTH NO-BREAK SPACE.
More details on this version of Unicode are provided in http://www.unicode.org/versions/Unicode6.1.0/.
use charnames
is no longer needed for \N{name}
When \N{name}
is encountered, the charnames
module is now
automatically loaded when needed as if the :full
and :short
options had been specified. See charnames for more information.
can now have Unicode loose name matchingThis is described in the charnames
item in
Updated Modules and Pragmata below.
Perl now has proper support for Unicode in symbol names. It used to be
that *{$foo}
would ignore the internal UTF8 flag and use the bytes of
the underlying representation to look up the symbol. That meant that
and *{"\xc4\x80"}
would return the same thing. All
these parts of Perl have been fixed to account for Unicode:
Method names (including those passed to use overload
Typeglob names (including names of variables, subroutines, and filehandles)
Package names
Symbolic dereferencing
Return value of ref()
Subroutine prototypes
Various warnings and error messages that mention variable names or values, methods, etc.
In addition, a parsing bug has been fixed that prevented *{é}
implicitly quoting the name, but instead interpreted it as *{+é}
, which
would cause a strict violation.
automatically strips off the * if it is followed by an ASCII
letter. That has been extended to all Unicode identifier characters.
One-character non-ASCII non-punctuation variables (like $é
) are now
subject to "Used only once" warnings. They used to be exempt, as they
were treated as punctuation variables.
Also, single-character Unicode punctuation variables (like $‰
) are now
supported [perl #69032].
An optional parameter has been added to use locale
- use locale ':not_characters';
which tells Perl to use all but the LC_CTYPE
and LC_COLLATE
portions of the current locale. Instead, the character set is assumed
to be Unicode. This lets locales and Unicode be seamlessly mixed,
including the increasingly frequent UTF-8 locales. When using this
hybrid form of locales, the :locale
layer to the open pragma can
be used to interface with the file system, and there are CPAN modules
available for ARGV and environment variable conversions.
Full details are in perllocale.
and corresponding escape sequence \F
for Unicode foldcaseUnicode foldcase is an extension to lowercase that gives better results
when comparing two strings case-insensitively. It has long been used
internally in regular expression /i
matching. Now it is available
explicitly through the new fc
function call (enabled by
"use feature 'fc'"
, or use v5.16
, or explicitly callable via
) or through the new \F
sequence in double-quotish
Full details are in fc.
property is now supported.New in Unicode 6.0, this is an improved Script
property. Details
are in Scripts in perlunicode.
Most XS authors will know there is a longstanding bug in the
OUTPUT typemap for T_AVREF (AV*
and T_SVREF (SVREF
or \$foo
) that requires manually decrementing
the reference count of the return value instead of the typemap taking
care of this. For backwards-compatibility, this cannot be changed in the
default typemaps. But we now provide additional typemaps
, etc. that do not exhibit this bug. Using
them in your extension is as simple as having one line in your
The XS-callable function is_utf8_char()
, when presented with
malformed UTF-8 input, can read up to 12 bytes beyond the end of the
string. This cannot be fixed without changing its API, and so its
use is now deprecated. Use is_utf8_char_buf()
(described just below)
This function is designed to replace the deprecated is_utf8_char() function. It includes an extra parameter to make sure it doesn't read past the end of the input buffer.
functions, as well as utf8_to_foo()
, etc.Most other XS-callable functions that take UTF-8 encoded input
implicitly assume that the UTF-8 is valid (not malformed) with respect to
buffer length. Do not do things such as change a character's case or
see if it is alphanumeric without first being sure that it is valid
UTF-8. This can be safely done for a whole string by using one of the
functions is_utf8_string()
, is_utf8_string_loc()
, and
Many new functions have been added to the API for manipulating lexical pads. See Pad Data Structures in perlapi for more information.
can be assigned to$$
was made read-only in Perl 5.8.0. But only sometimes: local $$
would make it writable again. Some CPAN modules were using local $$
XS code to bypass the read-only check, so there is no reason to keep $$
read-only. (This change also allowed a bug to be fixed while maintaining
backward compatibility.)
converted to an absolute path on FreeBSD, OS X and Solaris$^X
is now converted to an absolute path on OS X, FreeBSD (without
needing /proc mounted) and Solaris 10 and 11. This augments the
previous approach of using /proc on Linux, FreeBSD, and NetBSD
(in all cases, where mounted).
This makes relocatable perl installations more useful on these platforms. (See "Relocatable @INC" in INSTALL)
The current Perl's feature bundle is now enabled for commands entered in the interactive debugger.
The t command in the debugger, which toggles tracing mode, now accepts a numeric argument that determines how many levels of subroutine calls to trace.
and disable
The debugger now has disable
and enable
commands for disabling
existing breakpoints and re-enabling them. See perldebug.
The debugger's "b" command for setting breakpoints now lets a line number be prefixed with a file name. See b [file]:[line] [condition] in perldebug.
prefixThe CORE::
prefix can now be used on keywords enabled by
feature.pm, even outside the scope of use feature
namespaceMany Perl keywords are now available as subroutines in the CORE namespace. This lets them be aliased:
- BEGIN { *entangle = \&CORE::tie }
- entangle $variable, $package, @args;
And for prototypes to be bypassed:
Some of these cannot be called through references or via &foo
but must be called as barewords.
See CORE for details.
Automatically generated file handles are now named __ANONIO__ when the variable name cannot be determined, rather than $__ANONIO__.
Custom sort subroutines can now be autoloaded [perl #30661]:
- sub AUTOLOAD { ... }
- @sorted = sort foo @list; # uses AUTOLOAD
no longer requires the "switch" featureThe continue
keyword has two meanings. It can introduce a continue
block after a loop, or it can exit the current when
block. Up to now,
the latter meaning was valid only with the "switch" feature enabled, and
was a syntax error otherwise. Since the main purpose of feature.pm is to
avoid conflicts with user-defined subroutines, there is no reason for
to depend on it.
The phase-change
probes will fire when the interpreter's phase
changes, which tracks the ${^GLOBAL_PHASE}
variable. arg0
the new phase name; arg1
is the old one. This is useful
for limiting your instrumentation to one or more of: compile time,
run time, or destruct time.
SyntaxThe __FILE__
and __PACKAGE__
tokens can now be written
with an empty pair of parentheses after them. This makes them parse the
same way as time
, fork
and other built-in functions.
prototype accepts any scalar lvalueThe \$
and \[$]
subroutine prototypes now accept any scalar lvalue
argument. Previously they accepted only scalars beginning with $
hash and array elements. This change makes them consistent with the way
the built-in read
and recv
functions (among others) parse their
arguments. This means that one can override the built-in functions with
custom subroutines that parse their arguments the same way.
in subroutine prototypesThe _
character in subroutine prototypes is now allowed before @
and not is_utf8_char()
The latter function is now deprecated because its API is insufficient to guarantee that it doesn't read (up to 12 bytes in the worst case) beyond the end of its input string. See is_utf8_char_buf().
Two new XS-accessible functions, utf8_to_uvchr_buf()
are now available to prevent this, and the Perl
core has been converted to use them.
See Internal Changes.
memory error with GLOB_ALTDIRFUNC (CVE-2011-2728).Calling File::Glob::bsd_glob
with the unsupported flag
GLOB_ALTDIRFUNC would cause an access violation / segfault. A Perl
program that accepts a flags value from an external source could expose
itself to denial of service or arbitrary code execution attacks. There
are no known exploits in the wild. The problem has been corrected by
explicitly disabling all unsupported flags and setting unused function
pointers to null. Bug reported by Clément Lecigne. (5.14.2)
A hypothetical bug (probably unexploitable in practice) because the
incorrect setting of the effective group ID while setting $(
has been
fixed. The bug would have affected only systems that have setresgid()
but not setregid()
, but no such systems are known to exist.
It is now deprecated to directly read the Unicode data base files. These are stored in the lib/unicore directory. Instead, you should use the new functions in Unicode::UCD. These provide a stable API, and give complete information.
Perl may at some point in the future change or remove these files. The file which applications were most likely to have used is lib/unicore/ToDigit.pl. prop_invmap() in Unicode::UCD can be used to get at its data instead.
, utf8_to_uvchr()
This function is deprecated because it could read beyond the end of the
input string. Use the new is_utf8_char_buf(),
and utf8_to_uvuni_buf()
This section serves as a notice of features that are likely to be removed or deprecated in the next release of perl (5.18.0). If your code depends on these features, you should contact the Perl 5 Porters via the mailing list or perlbug to explain your use case and inform the deprecation process.
These modules may be marked as deprecated from the core. This only means that they will no longer be installed by default with the core distribution, but will remain available on the CPAN.
These platforms will probably have their special build support removed during the 5.17.0 development series.
Swapping of $< and $>
For more information about this future deprecation, see the relevant RT ticket.
sfio, stdio
Perl supports being built without PerlIO proper, using a stdio or sfio wrapper instead. A perl build like this will not support IO layers and thus Unicode IO, making it rather handicapped.
PerlIO supports a stdio
layer if stdio use is desired, and similarly a
sfio layer could be produced.
Unescaped literal "{"
in regular expressions.
Starting with v5.20, it is planned to require a literal "{"
to be
escaped, for example by preceding it with a backslash. In v5.18, a
deprecated warning message will be emitted for all such uses.
This affects only patterns that are to match a literal "{"
. Other
uses of this character, such as part of a quantifier or sequence as in
those below, are completely unaffected:
- /foo{3,5}/
- /\p{Alphabetic}/
Removing this will permit extensions to Perl's pattern syntax and better error checking for existing syntax. See Quantifiers in perlre for an example.
Revamping "\Q"
semantics in double-quotish strings when combined with other escapes.
There are several bugs and inconsistencies involving combinations
of \Q
and escapes like \x
, etc., within a \Q...\E
These need to be fixed, and doing so will necessarily change current
behavior. The changes have not yet been settled.
Special blocks (BEGIN
) are now
called in void context. This avoids wasteful copying of the result of the
last statement [perl #108794].
pragma and regexp objectsWith no overloading
, regular expression objects returned by qr//
now stringified as "Regexp=REGEXP(0xbe600d)" instead of the regular
expression itself [perl #108780].
Two presumably unused XS typemap entries have been removed from the core typemap: T_DATAUNIT and T_CALLBACK. If you are, against all odds, a user of these, please see the instructions on how to restore them in perlxstypemap.
These are detailed in Supports (almost) Unicode 6.1 above. You can compile this version of Perl to use Unicode 6.0. See Hacking Perl to work on earlier Unicode versions (for very serious hackers only) in perlunicode.
All support for the Borland compiler has been dropped. The code had not worked for a long time anyway.
Perl should never have exposed certain Unicode properties that are used by Unicode internally and not meant to be publicly available. Use of these has generated deprecated warning messages since Perl 5.12. The removed properties are Other_Alphabetic, Other_Default_Ignorable_Code_Point, Other_Grapheme_Extend, Other_ID_Continue, Other_ID_Start, Other_Lowercase, Other_Math, and Other_Uppercase.
Perl may be recompiled to include any or all of them; instructions are given in Unicode character properties that are NOT accepted by Perl in perluniprops.
The *{...}
operator, when passed a reference to an IO thingy (as in
), creates a new typeglob containing just that IO object.
Previously, it would stringify as an empty string, but some operators would
treat it as undefined, producing an "uninitialized" warning.
Now it stringifies as __ANONIO__ [perl #96326].
This feature was deprecated in Perl 5.14, and has now been removed. The CPAN module Unicode::Casing provides better functionality without the drawbacks that this feature had, as are detailed in the 5.14 documentation: http://perldoc.perl.org/5.14.0/perlunicode.html#User-Defined-Case-Mappings-%28for-serious-hackers-only%29
XSUB C functions are now 'static', that is, they are not visible from
outside the compilation unit. Users can use the new XS_EXTERNAL(name)
and XS_INTERNAL(name)
macros to pick the desired linking behavior.
The ordinary XS(name)
declaration for XSUBs will continue to declare
non-'static' XSUBs for compatibility, but the XS compiler,
ExtUtils::ParseXS (xsubpp
) will emit 'static' XSUBs by default.
ExtUtils::ParseXS's behavior can be reconfigured from XS using the
keyword. See perlxs for details.
Weakening read-only references is no longer permitted. It should never have worked anyway, and could sometimes result in crashes.
Attempting to tie a scalar after a typeglob was assigned to it would
instead tie the handle in the typeglob's IO slot. This meant that it was
impossible to tie the scalar itself. Similar problems affected tied
: tied $scalar
would return false on a tied scalar if the last
thing returned was a typeglob, and untie $scalar
on such a tied scalar
would do nothing.
We fixed this problem before Perl 5.14.0, but it caused problems with some CPAN modules, so we put in a deprecation cycle instead.
Now the deprecation has been removed and this bug has been fixed. So
tie $scalar
will always tie the scalar, not the handle it holds. To tie
the handle, use tie *$scalar
(with an explicit asterisk). The same
applies to tied *$scalar
and untie *$scalar
, xclose_on_exec()
and xpipe_anon()
All three functions were private, undocumented, and unexported. They do not appear to be used by any code on CPAN. Two have been inlined and one deleted entirely.
no longer caches PIDPreviously, if one called fork(3) from C, Perl's
notion of $$
could go out of sync with what getpid() returns. By always
fetching the value of $$
via getpid(), this potential bug is eliminated.
Code that depends on the caching behavior will break. As described in
Core Enhancements,
is now writable, but it will be reset during a
and getppid()
no longer emulate POSIX semantics under LinuxThreadsThe POSIX emulation of $$
and getppid()
under the obsolete
LinuxThreads implementation has been removed.
This only impacts users of Linux 2.4 and
users of Debian GNU/kFreeBSD up to and including 6.0, not the vast
majority of Linux installations that use NPTL threads.
This means that getppid()
, like $$
, is now always guaranteed to
return the OS's idea of the current state of the process, not perl's
cached version of it.
See the documentation for $$ for details.
, $>
, $(
and $)
are no longer cachedSimilarly to the changes to $$
and getppid()
, the internal
caching of $<
, $>
, $(
and $)
has been removed.
When we cached these values our idea of what they were would drift out
of sync with reality if someone (e.g., someone embedding perl) called
without updating PL_e?[ug]id
. Having to deal with
this complexity wasn't worth it given how cheap the gete?[ug]id()
system call is.
This change will break a handful of CPAN modules that use the XS-level
, PL_gid
, PL_euid
or PL_egid
The fix for those breakages is to use PerlProc_gete?[ug]id()
retrieve them (e.g., PerlProc_getuid()
), and not to assign to
if you change the UID/GID/EUID/EGID. There is no longer
any need to do so since perl will always retrieve the up-to-date
version of those values from the OS.
and \Q
has changedThis is unlikely to result in a real problem, as Perl does not attach special meaning to any non-ASCII character, so it is currently irrelevant which are quoted or not. This change fixes bug [perl #77654] and brings Perl's behavior more into line with Unicode's recommendations. See quotemeta.
Improved performance for Unicode properties in regular expressions
Matching a code point against a Unicode property is now done via a
binary search instead of linear. This means for example that the worst
case for a 1000 item property is 10 probes instead of 1000. This
inefficiency has been compensated for in the past by permanently storing
in a hash the results of a given probe plus the results for the adjacent
64 code points, under the theory that near-by code points are likely to
be searched for. A separate hash was used for each mention of a Unicode
property in each regular expression. Thus, qr/\p{foo}abc\p{foo}/
would generate two hashes. Any probes in one instance would be unknown
to the other, and the hashes could expand separately to be quite large
if the regular expression were used on many different widely-separated
code points.
Now, however, there is just one hash shared by all instances of a given
property. This means that if \p{foo}
is matched against "A" in one
regular expression in a thread, the result will be known immediately to
all regular expressions, and the relentless march of using up memory is
slowed considerably.
Version declarations with the use
keyword (e.g., use 5.012
) are now
faster, as they enable features without loading feature.pm.
local $_
is faster now, as it no longer iterates through magic that it
is not going to copy anyway.
Perl 5.12.0 sped up the destruction of objects whose classes define
empty DESTROY
methods (to prevent autoloading), by simply not
calling such empty methods. This release takes this optimization a
step further, by not calling any DESTROY
method that begins with a
statement. This can be useful for destructors that are only
used for debugging:
Constant-folding will reduce the first statement to return;
if DEBUG
is set to 0, triggering this optimization.
Assigning to a variable that holds a typeglob or copy-on-write scalar is now much faster. Previously the typeglob would be stringified or the copy-on-write scalar would be copied before being clobbered.
Assignment to substr
in void context is now more than twice its
previous speed. Instead of creating and returning a special lvalue
scalar that is then assigned to, substr
modifies the original string
no longer calculates a value to return when called in void
Due to changes in File::Glob, Perl's glob
function and its <...>
equivalent are now much faster. The splitting of the pattern
into words has been rewritten in C, resulting in speed-ups of 20% for
some cases.
This does not affect glob
on VMS, as it does not use File::Glob.
The short-circuiting operators &&
, ||
, and //
, when chained
(such as $a || $b || $c
), are now considerably faster to short-circuit,
due to reduced optree traversal.
The implementation of s///r
makes one fewer copy of the scalar's value.
Recursive calls to lvalue subroutines in lvalue scalar context use less memory.
Version::Requirements is now DEPRECATED, use CPAN::Meta::Requirements, which is a drop-in replacement. It will be deleted from perl.git blead in v5.17.0.
arybase -- this new module implements the $[
PerlIO::mmap 0.010 has been added to the Perl core.
The mmap
PerlIO layer is no longer implemented by perl itself, but has
been moved out into the new PerlIO::mmap module.
This is only an overview of selected module updates. For a complete list of updates, run:
- $ corelist --diff 5.14.0 5.16.0
You can substitute your favorite version in place of 5.14.0, too.
Archive::Extract has been upgraded from version 0.48 to 0.58.
Includes a fix for FreeBSD to only use unzip
if it is located in
, as FreeBSD 9.0 will ship with a limited unzip
Archive::Tar has been upgraded from version 1.76 to 1.82.
Adjustments to handle files >8gb (>0777777777777 octal) and a feature to return the MD5SUM of files in the archive.
base has been upgraded from version 2.16 to 2.18.
no longer sets a module's $VERSION
to "-1" when a module it
loads does not define a $VERSION
. This change has been made because
"-1" is not a valid version number under the new "lax" criteria used
internally by UNIVERSAL::VERSION
. (See version for more on "lax"
version criteria.)
no longer internally skips loading modules it has already loaded
and instead relies on require
to inspect %INC
. This fixes a bug
when base
is used with code that clear %INC
to force a module to
be reloaded.
Carp has been upgraded from version 1.20 to 1.26.
It now includes last read filehandle info and puts a dot after the file
and line number, just like errors from die
[perl #106538].
charnames has been updated from version 1.18 to 1.30.
can now be invoked with a new option, :loose
which is like the existing :full
option, but enables Unicode loose
name matching. Details are in LOOSE MATCHES in charnames.
B::Deparse has been upgraded from version 1.03 to 1.14. This fixes numerous deparsing bugs.
CGI has been upgraded from version 3.52 to 3.59.
It uses the public and documented FCGI.pm API in CGI::Fast. CGI::Fast was using an FCGI API that was deprecated and removed from documentation more than ten years ago. Usage of this deprecated API with FCGI >= 0.70 or FCGI <= 0.73 introduces a security issue. https://rt.cpan.org/Public/Bug/Display.html?id=68380 http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2011-2766
Things that may break your code:
was fixed to return PATH_INFO
when it is explicitly requested
with either the path=>1
or path_info=>1
If your code is running under mod_rewrite (or compatible) and you are
calling self_url()
or you are calling url()
and passing
, these methods will actually be returning
now, as you have explicitly requested or self_url()
has requested on your behalf.
The PATH_INFO
has been omitted in such URLs since the issue was
introduced in the 3.12 release in December, 2005.
This bug is so old your application may have come to depend on it or workaround it. Check for application before upgrading to this release.
Examples of affected method calls:
- $q->url(-absolute => 1, -query => 1, -path_info => 1);
- $q->url(-path=>1);
- $q->url(-full=>1,-path=>1);
- $q->url(-rewrite=>1,-path=>1);
- $q->self_url();
We no longer read from STDIN when the Content-Length is not set, preventing requests with no Content-Length from sometimes freezing. This is consistent with the CGI RFC 3875, and is also consistent with CGI::Simple. However, the old behavior may have been expected by some command-line uses of CGI.pm.
In addition, the DELETE HTTP verb is now supported.
Compress::Zlib has been upgraded from version 2.035 to 2.048.
IO::Compress::Zip and IO::Uncompress::Unzip now have support for LZMA (method 14). There is a fix for a CRC issue in IO::Compress::Unzip and it supports Streamed Stored context now. And fixed a Zip64 issue in IO::Compress::Zip when the content size was exactly 0xFFFFFFFF.
Digest::SHA has been upgraded from version 5.61 to 5.71.
Added BITS mode to the addfile method and shasum. This makes partial-byte inputs possible via files/STDIN and lets shasum check all 8074 NIST Msg vectors, where previously special programming was required to do this.
Encode has been upgraded from version 2.42 to 2.44.
Missing aliases added, a deep recursion error fixed and various documentation updates.
Addressed 'decode_xs n-byte heap-overflow' security bug in Unicode.xs (CVE-2011-2939). (5.14.2)
ExtUtils::CBuilder updated from version 0.280203 to 0.280206.
The new version appends CFLAGS and LDFLAGS to their Config.pm counterparts.
ExtUtils::ParseXS has been upgraded from version 2.2210 to 3.16.
Much of ExtUtils::ParseXS, the module behind the XS compiler xsubpp
was rewritten and cleaned up. It has been made somewhat more extensible
and now finally uses strictures.
The typemap logic has been moved into a separate module, ExtUtils::Typemaps. See New Modules and Pragmata, above.
For a complete set of changes, please see the ExtUtils::ParseXS changelog, available on the CPAN.
File::Glob has been upgraded from version 1.12 to 1.17.
On Windows, tilde (~) expansion now checks the USERPROFILE
variable, after checking HOME
It has a new :bsd_glob
export tag, intended to replace :glob
. Like
it overrides glob
with a function that does not split the glob
pattern into words, but, unlike :glob
, it iterates properly in scalar
context, instead of returning the last file.
There are other changes affecting Perl's own glob
operator (which uses
File::Glob internally, except on VMS). See Performance Enhancements
and Selected Bug Fixes.
FindBin updated from version 1.50 to 1.51.
It no longer returns a wrong result if a script of the same name as the current one exists in the path and is executable.
HTTP::Tiny has been upgraded from version 0.012 to 0.017.
Added support for using $ENV{http_proxy}
to set the default proxy host.
Adds additional shorthand methods for all common HTTP verbs,
a post_form()
method for POST-ing x-www-form-urlencoded data and
a www_form_urlencode()
utility method.
IO has been upgraded from version 1.25_04 to 1.25_06, and IO::Handle from version 1.31 to 1.33.
Together, these upgrades fix a problem with IO::Handle's getline
methods. When these methods are called on the special ARGV
handle, the next file is automatically opened, as happens with the built-in
and readline
functions. But, unlike the built-ins, these
methods were not respecting the caller's use of the open pragma and
applying the appropriate I/O layers to the newly-opened file
[rt.cpan.org #66474].
IPC::Cmd has been upgraded from version 0.70 to 0.76.
Capturing of command output (both STDOUT
and STDERR
) is now supported
using IPC::Open3 on MSWin32 without requiring IPC::Run.
IPC::Open3 has been upgraded from version 1.09 to 1.12.
Fixes a bug which prevented use of open3
on Windows when *STDIN
or *STDERR
had been localized.
Fixes a bug which prevented duplicating numeric file descriptors on Windows.
with "-" for the program name works once more. This was broken in
version 1.06 (and hence in Perl 5.14.0) [perl #95748].
Locale::Codes has been upgraded from version 3.16 to 3.21.
Added Language Extension codes (langext) and Language Variation codes (langvar) as defined in the IANA language registry.
Added language codes from ISO 639-5
Added language/script codes from the IANA language subtag registry
Fixed an uninitialized value warning [rt.cpan.org #67438].
Fixed the return value for the all_XXX_codes and all_XXX_names functions [rt.cpan.org #69100].
Reorganized modules to move Locale::MODULE to Locale::Codes::MODULE to allow for cleaner future additions. The original four modules (Locale::Language, Locale::Currency, Locale::Country, Locale::Script) will continue to work, but all new sets of codes will be added in the Locale::Codes namespace.
The code2XXX, XXX2code, all_XXX_codes, and all_XXX_names functions now support retired codes. All codesets may be specified by a constant or by their name now. Previously, they were specified only by a constant.
The alias_code function exists for backward compatibility. It has been replaced by rename_country_code. The alias_code function will be removed some time after September, 2013.
All work is now done in the central module (Locale::Codes). Previously, some was still done in the wrapper modules (Locale::Codes::*). Added Language Family codes (langfam) as defined in ISO 639-5.
Math::BigFloat has been upgraded from version 1.993 to 1.997.
The numify
method has been corrected to return a normalized Perl number
(the result of 0 + $thing
), instead of a string [rt.cpan.org #66732].
Math::BigInt has been upgraded from version 1.994 to 1.998.
It provides a new bsgn
method that complements the babs
It fixes the internal objectify
function's handling of "foreign objects"
so they are converted to the appropriate class (Math::BigInt or
Math::BigRat has been upgraded from version 0.2602 to 0.2603.
on a Math::BigRat object containing -1/2 now creates a
Math::BigInt containing 0, rather than -0. Math::BigInt does not even
support negative zero, so the resulting object was actually malformed
[perl #95530].
Math::Complex has been upgraded from version 1.56 to 1.59 and Math::Trig from version 1.2 to 1.22.
Fixes include: correct copy constructor usage; fix polarwise formatting with
numeric format specifier; and more stable great_circle_direction
Module::CoreList has been upgraded from version 2.51 to 2.66.
The corelist
utility now understands the -r
option for displaying
Perl release dates and the --diff
option to print the set of modlib
changes between two perl distributions.
Module::Metadata has been upgraded from version 1.000004 to 1.000009.
Adds provides
method to generate a CPAN META provides data structure
correctly; use of package_versions_from_directory
is discouraged.
ODBM_File has been upgraded from version 1.10 to 1.12.
The XS code is now compiled with PERL_NO_GET_CONTEXT
, which will aid
performance under ithreads.
open has been upgraded from version 1.08 to 1.10.
It no longer turns off layers on standard handles when invoked without the ":std" directive. Similarly, when invoked with the ":std" directive, it now clears layers on STDERR before applying the new ones, and not just on STDIN and STDOUT [perl #92728].
overload has been upgraded from version 1.13 to 1.18.
no longer calls can
on the class, but uses
another means to determine whether the object has overloading. It was
never correct for it to call can
, as overloading does not respect
AUTOLOAD. So classes that autoload methods and implement can
no longer
have to account for overloading [perl #40333].
A warning is now produced for invalid arguments. See New Diagnostics.
PerlIO::scalar has been upgraded from version 0.11 to 0.14.
(This is the module that implements open $fh, '>', \$scalar
It fixes a problem with open my $fh, ">", \$scalar
not working if
is a copy-on-write scalar. (5.14.2)
It also fixes a hang that occurs with readline
or <$fh>
if a
typeglob has been assigned to $scalar [perl #92258].
It no longer assumes during seek
that $scalar is a string internally.
If it didn't crash, it was close to doing so [perl #92706]. Also, the
internal print routine no longer assumes that the position set by seek
is valid, but extends the string to that position, filling the intervening
bytes (between the old length and the seek position) with nulls
[perl #78980].
Printing to an in-memory handle now works if the $scalar holds a reference, stringifying the reference before modifying it. References used to be treated as empty strings.
Printing to an in-memory handle no longer crashes if the $scalar happens to hold a number internally, but no string buffer.
Printing to an in-memory handle no longer creates scalars that confuse the regular expression engine [perl #108398].
Pod::Functions has been upgraded from version 1.04 to 1.05.
Functions.pm is now generated at perl build time from annotations in perlfunc.pod. This will ensure that Pod::Functions and perlfunc remain in synchronisation.
Pod::Html has been upgraded from version 1.11 to 1.1502.
This is an extensive rewrite of Pod::Html to use Pod::Simple under the hood. The output has changed significantly.
Pod::Perldoc has been upgraded from version 3.15_03 to 3.17.
It corrects the search paths on VMS [perl #90640]. (5.14.1)
The -v option now fetches the right section for $0
This upgrade has numerous significant fixes. Consult its changelog on the CPAN for more information.
POSIX has been upgraded from version 1.24 to 1.30.
POSIX no longer uses AutoLoader. Any code which was relying on this implementation detail was buggy, and may fail because of this change. The module's Perl code has been considerably simplified, roughly halving the number of lines, with no change in functionality. The XS code has been refactored to reduce the size of the shared object by about 12%, with no change in functionality. More POSIX functions now have tests.
and pause
now run signal handlers before returning, as the
whole point of these two functions is to wait until a signal has
arrived, and then return after it has been triggered. Delayed, or
"safe", signals were preventing that from happening, possibly resulting in
race conditions [perl #107216].
is now a direct call into the underlying OS sleep
function, instead of being a Perl wrapper on CORE::sleep
now returns the correct value on Win32 (i.e., the file
descriptor). POSIX::SigSet
and sigpending
now dispatch safe signals immediately before returning to
their caller.
now defaults the third argument to TCSANOW
instead of 0. On most platforms TCSANOW
is defined to be 0, but on some
0 is not a valid parameter, which caused a call with defaults to fail.
Socket has been upgraded from version 1.94 to 2.001.
It has new functions and constants for handling IPv6 sockets:
- pack_ipv6_mreq
- unpack_ipv6_mreq
Storable has been upgraded from version 2.27 to 2.34.
It no longer turns copy-on-write scalars into read-only scalars when freezing and thawing.
Sys::Syslog has been upgraded from version 0.27 to 0.29.
This upgrade closes many outstanding bugs.
Term::ANSIColor has been upgraded from version 3.00 to 3.01.
Only interpret an initial array reference as a list of colors, not any initial reference, allowing the colored function to work properly on objects with stringification defined.
Term::ReadLine has been upgraded from version 1.07 to 1.09.
Term::ReadLine now supports any event loop, including unpublished ones and simple IO::Select, loops without the need to rewrite existing code for any particular framework [perl #108470].
threads::shared has been upgraded from version 1.37 to 1.40.
Destructors on shared objects used to be ignored sometimes if the objects were referenced only by shared data structures. This has been mostly fixed, but destructors may still be ignored if the objects still exist at global destruction time [perl #98204].
Unicode::Collate has been upgraded from version 0.73 to 0.89.
Updated to CLDR 1.9.1
Locales updated to CLDR 2.0: mk, mt, nb, nn, ro, ru, sk, sr, sv, uk, zh__pinyin, zh__stroke
Newly supported locales: bn, fa, ml, mr, or, pa, sa, si, si__dictionary, sr_Latn, sv__reformed, ta, te, th, ur, wae.
Tailored compatibility ideographs as well as unified ideographs for the locales: ja, ko, zh__big5han, zh__gb2312han, zh__pinyin, zh__stroke.
Locale/*.pl files are now searched for in @INC.
Unicode::Normalize has been upgraded from version 1.10 to 1.14.
Fixes for the removal of unicore/CompositionExclusions.txt from core.
Unicode::UCD has been upgraded from version 0.32 to 0.43.
This adds four new functions: prop_aliases()
, which are used to find all Unicode-approved
synonyms for property names, or to convert from one name to another;
which returns all code points matching a given
Unicode binary property; and prop_invmap
which returns the complete
specification of a given Unicode property.
Win32API::File has been upgraded from version 0.1101 to 0.1200.
Added SetStdHandle and GetStdHandle functions
As promised in Perl 5.14.0's release notes, the following modules have been removed from the core distribution, and if needed should be installed from CPAN instead.
Devel::DProf has been removed from the Perl core. Prior version was 20110228.00.
Shell has been removed from the Perl core. Prior version was 0.72_01.
Several old perl4-style libraries which have been deprecated with 5.14 are now removed:
- abbrev.pl assert.pl bigfloat.pl bigint.pl bigrat.pl cacheout.pl
- complete.pl ctime.pl dotsh.pl exceptions.pl fastcwd.pl flush.pl
- getcwd.pl getopt.pl getopts.pl hostname.pl importenv.pl
- lib/find{,depth}.pl look.pl newgetopt.pl open2.pl open3.pl
- pwd.pl shellwords.pl stat.pl tainted.pl termcap.pl timelocal.pl
They can be found on CPAN as Perl4::CoreLibs.
perldtrace describes Perl's DTrace support, listing the provided probes and gives examples of their use.
This document is intended to provide a list of experimental features in Perl. It is still a work in progress.
This a new OO tutorial. It focuses on basic OO concepts, and then recommends that readers choose an OO framework from CPAN.
The new manual describes the XS typemapping mechanism in unprecedented detail and combines new documentation with information extracted from perlxs and the previously unofficial list of all core typemaps.
The HV API has long accepted negative lengths to show that the key is in UTF8. This is now documented.
The boolSV()
macro is now documented.
treats a 0 mode as a special case, that prevents a nonexistent
file from being created. This has been the case since Perl 5.000, but was
never documented anywhere. Now the perlfunc entry mentions it
[perl #90064].
As an accident of history, open $fh, '<:', ...
applies the default
layers for the platform (:raw
on Unix, :crlf
on Windows), ignoring
whatever is declared by open.pm. This seems such a useful feature
it has been documented in open and open.
The entry for split
has been rewritten. It is now far clearer than
A new section, Autoloading with XSUBs, has been added, which explains the two APIs for accessing the name of the autoloaded sub.
Some function descriptions in perlguts were confusing, as it was not clear whether they referred to the function above or below the description. This has been clarified [perl #91790].
This document has been rewritten from scratch, and its coverage of various OO concepts has been expanded.
Documentation of the smartmatch operator has been reworked and moved from perlsyn to perlop where it belongs.
It has also been corrected for the case of undef
on the left-hand
side. The list of different smart match behaviors had an item in the
wrong place.
Documentation of the ellipsis statement (...
) has been reworked and
moved from perlop to perlsyn.
The explanation of bitwise operators has been expanded to explain how they work on Unicode strings (5.14.1).
More examples for m//g
have been added (5.14.1).
The <<\FOO
here-doc syntax has been documented (5.14.1).
There is now a standard convention for naming keys in the %^H
documented under Key naming.
The example function for checking for taintedness contained a subtle
error. $@
needs to be localized to prevent its changing this
global's value outside the function. The preferred method to check for
this remains tainted in Scalar::Util.
perllol has been expanded with examples using the new push $scalar
syntax introduced in Perl 5.14.0 (5.14.1).
perlmod now states explicitly that some types of explicit symbol table manipulation are not supported. This codifies what was effectively already the case [perl #78074].
The tips on which formatting codes to use have been corrected and greatly expanded.
There are now a couple of example one-liners for previewing POD files after they have been edited.
The (*COMMIT)
directive is now listed in the right section
(Verbs without an argument).
perlrun has undergone a significant clean-up. Most notably, the -0x... form of the -0 flag has been clarified, and the final section on environment variables has been corrected and expanded (5.14.1).
The ($;) prototype syntax, which has existed for rather a long time, is now documented in perlsub. It lets a unary function have the same precedence as a list operator.
The required syntax for tying handles has been documented.
The documentation for $! has been corrected and clarified.
It used to state that $! could be undef
, which is not the case. It was
also unclear whether system calls set C's errno
or Perl's $!
[perl #91614].
Documentation for $$ has been amended with additional cautions regarding changing the process ID.
perlxs was extended with documentation on inline typemaps.
perlref has a new Circular References section explaining how circularities may not be freed and how to solve that with weak references.
Parts of perlapi were clarified, and Perl equivalents of some C functions have been added as an additional mode of exposition.
A few parts of perlre and perlrecharclass were clarified.
The old OO tutorials, perltoot, perltooc, and perlboot, have been removed. The perlbot (bag of object tricks) document has been removed as well.
The perldelta files for development releases are no longer packaged with perl. These can still be found in the perl source code repository.
The following additions or changes have been made to diagnostic output, including warnings and fatal error messages. For the complete list of diagnostic messages, see perldiag.
This error occurs when caller
tries to set @DB::args
but finds it
tied. Before this error was added, it used to crash instead.
This error is part of a safety check that the tie
operator does before
tying a special array like @_
. You should never see this message.
&CORE::%s cannot be called directly
This occurs when a subroutine in the CORE::
namespace is called
with &foo
syntax or through a reference. Some subroutines
in this package cannot yet be called that way, but must be
called as barewords. See Subroutines in the CORE namespace, above.
Source filters apply only to byte streams
This new error occurs when you try to activate a source filter (usually by
loading a source filter module) within a string passed to eval
under the
The long-deprecated defined(@array)
now also warns for package variables.
Previously it issued a warning for lexical variables only.
This new warning occurs when length
is used on an array or hash, instead
of scalar(@array)
or scalar(keys %hash)
lvalue attribute %s already-defined subroutine
attributes.pm now emits this warning when the :lvalue attribute is applied to a Perl subroutine that has already been defined, as doing so can have unexpected side-effects.
This warning, in the "overload" category, is produced when the overload pragma is given an argument it doesn't recognize, presumably a mistyped operator.
$[ used in %s (did you mean $] ?)
This new warning exists to catch the mistaken use of $[
in version
checks. $]
, not $[
, contains the version number.
Useless assignment to a temporary
Assigning to a temporary scalar returned from an lvalue subroutine now produces this warning [perl #31946].
does nothing unless preceded by \Q
or \U
"sort is now a reserved word"
This error used to occur when sort
was called without arguments,
followed by ;
or )
. (E.g., sort;
would die, but {sort}
OK.) This error message was added in Perl 3 to catch code like
which would no longer work. More than two decades later,
this message is no longer appropriate. Now sort
without arguments is
always allowed, and returns an empty list, as it did in those cases
where it was already allowed [perl #90030].
The "Applying pattern match..." or similar warning produced when an
array or hash is on the left-hand side of the =~
operator now
mentions the name of the variable.
The "Attempt to free non-existent shared string" has had the spelling of "non-existent" corrected to "nonexistent". It was already listed with the correct spelling in perldiag.
The error messages for using default
and when
outside a
topicalizer have been standardized to match the messages for continue
and loop controls. They now read 'Can't "default" outside a
topicalizer' and 'Can't "when" outside a topicalizer'. They both used
to be 'Can't use when() outside a topicalizer' [perl #91514].
The message, "Code point 0x%X is not Unicode, no properties match it; all inverse properties do" has been changed to "Code point 0x%X is not Unicode, all \p{} matches fail; all \P{} matches succeed".
Redefinition warnings for constant subroutines used to be mandatory,
even occurring under no warnings
. Now they respect the warnings
The "glob failed" warning message is now suppressible via no warnings
[perl #111656].
The Invalid version format error message now says "negative version number" within the parentheses, rather than "non-numeric data", for negative numbers.
The two warnings
Possible attempt to put comments in qw() list
Possible attempt to separate words with commas
are no longer mutually exclusive: the same qw
construct may produce
The uninitialized warning for y///r
when $_
is implicit and
undefined now mentions the variable name, just like the non-/r variation
of the operator.
The 'Use of "foo" without parentheses is ambiguous' warning has been extended to apply also to user-defined subroutines with a (;$) prototype, and not just to built-in functions.
Warnings that mention the names of lexical (my
) variables with
Unicode characters in them now respect the presence or absence of the
layer on the output handle, instead of outputting UTF8
regardless. Also, the correct names are included in the strings passed
to $SIG{__WARN__}
handlers, rather than the raw UTF8 bytes.
h2ph used to generate code of the form
But the subroutine is a compile-time declaration, and is hence unaffected
by the condition. It has now been corrected to emit a string eval
around the subroutine [perl #99368].
splain no longer emits backtraces with the first line number repeated.
- Uncaught exception from user code:
- Cannot fwiddle the fwuddle at -e line 1.
- at -e line 1
- main::baz() called at -e line 1
- main::bar() called at -e line 1
- main::foo() called at -e line 1
has become this:
- Uncaught exception from user code:
- Cannot fwiddle the fwuddle at -e line 1.
- main::baz() called at -e line 1
- main::bar() called at -e line 1
- main::foo() called at -e line 1
Some error messages consist of multiple lines that are listed as separate entries in perldiag. splain has been taught to find the separate entries in these cases, instead of simply failing to find the message.
This is a new utility, included as part of an IO::Compress::Base upgrade.
zipdetails displays information about the internal record structure of the zip file. It is not concerned with displaying any details of the compressed data stored in the zip file.
regexp.h has been modified for compatibility with GCC's -Werror option, as used by some projects that include perl's header files (5.14.1).
have been added the output of perl -V
as they have affect the behavior of the interpreter binary (albeit
in only a small area).
The code and tests for IPC::Open2 have been moved from ext/IPC-Open2
into ext/IPC-Open3, as IPC::Open2::open2()
is implemented as a thin
wrapper around IPC::Open3::_open3()
, and hence is very tightly coupled to
The magic types and magic vtables are now generated from data in a new script
regen/mg_vtable.pl, instead of being maintained by hand. As different
EBCDIC variants can't agree on the code point for '~', the character to code
point conversion is done at build time by generate_uudmap to a new generated
header mg_data.h. PL_vtbl_bm
and PL_vtbl_fm
are now defined by the
pre-processor as PL_vtbl_regexp
, instead of being distinct C variables.
has been removed.
Building with -DPERL_GLOBAL_STRUCT
works again. This configuration is not
generally used.
Perl configured with MAD now correctly frees MADPROP
structures when
OPs are freed. MADPROP
s are now allocated with PerlMemShared_malloc()
makedef.pl has been refactored. This should have no noticeable affect on any of the platforms that use it as part of their build (AIX, VMS, Win32).
can no longer be disabled.
The file global.sym is no longer needed, and has been removed. It contained a list of all exported functions, one of the files generated by regen/embed.pl from data in embed.fnc and regen/opcodes. The code has been refactored so that the only user of global.sym, makedef.pl, now reads embed.fnc and regen/opcodes directly, removing the need to store the list of exported functions in an intermediate file.
As global.sym was never installed, this change should not be visible outside the build process.
pod/buildtoc, used by the build process to build perltoc, has been refactored and simplified. It now contains only code to build perltoc; the code to regenerate Makefiles has been moved to Porting/pod_rules.pl. It's a bug if this change has any material effect on the build process.
pod/roffitall is now built by pod/buildtoc, instead of being shipped with the distribution. Its list of manpages is now generated (and therefore current). See also RT #103202 for an unresolved related issue.
The man page for XS::Typemap
is no longer installed. XS::Typemap
is a test module which is not installed, hence installing its
documentation makes no sense.
The -Dusesitecustomize and -Duserelocatableinc options now work together properly.
Since version 1.7, Cygwin supports native UTF-8 paths. If Perl is built under that environment, directory and filenames will be UTF-8 encoded.
Cygwin does not initialize all original Win32 environment variables. See
README.cygwin for a discussion of the newly-added
function [perl #110190] and for
further links.
HP-UX PA-RISC/64 now supports gcc-4.x
A fix to correct the socketsize now makes the test suite pass on HP-UX PA-RISC for 64bitall builds. (5.14.2)
Remove unnecessary includes, fix miscellaneous compiler warnings and close some unclosed comments on vms/vms.c.
Remove sockadapt layer from the VMS build.
Explicit support for VMS versions before v7.0 and DEC C versions before v6.0 has been removed.
Since Perl 5.10.1, the home-grown stat
wrapper has been unable to
distinguish between a directory name containing an underscore and an
otherwise-identical filename containing a dot in the same position
(e.g., t/test_pl as a directory and t/test.pl as a file). This problem
has been corrected.
The build on VMS now permits names of the resulting symbols in C code for
Perl longer than 31 characters. Symbols like
can now be
created freely without causing the VMS linker to seize up.
Numerous build and test failures on GNU/Hurd have been resolved with hints for building DBM modules, detection of the library search path, and enabling of large file support.
Perl is now built with dynamic linking on OpenVOS, the minimum supported version of which is now Release 17.1.0.
The CC workshop C++ compiler is now detected and used on systems that ship without cc.
The compiled representation of formats is now stored via the mg_ptr
their PERL_MAGIC_fm
. Previously it was stored in the string buffer,
beyond SvLEN()
, the regular end of the string. SvCOMPILED()
now exist solely for compatibility for XS code.
The first is always 0, the other two now no-ops. (5.14.1)
Some global variables have been marked const
, members in the interpreter
structure have been re-ordered, and the opcodes have been re-ordered. The
op OP_AELEMFAST
has been split into OP_AELEMFAST
and OP_AELEMFAST_LEX
When empting a hash of its elements (e.g., via undef(%h), or %h=()), HvARRAY
field is no longer temporarily zeroed. Any destructors called on the freed
elements see the remaining elements. Thus, %h=() becomes more like
delete $h{$_} for keys %h
Boyer-Moore compiled scalars are now PVMGs, and the Boyer-Moore tables are now
stored via the mg_ptr of their PERL_MAGIC_bm
Previously they were PVGVs, with the tables stored in
the string buffer, beyond SvLEN()
. This eliminates
the last place where the core stores data beyond SvLEN()
Simplified logic in Perl_sv_magic()
introduces a small change of
behavior for error cases involving unknown magic types. Previously, if
was passed a magic type unknown to it, it would
Croak "Modification of a read-only value attempted" if read only
Return without error if the SV happened to already have this magic
otherwise croak "Don't know how to handle magic of type \\%o"
Now it will always croak "Don't know how to handle magic of type \\%o", even on read-only values, or SVs which already have the unknown magic type.
The experimental fetch_cop_label
function has been renamed to
The cop_store_label
function has been added to the API, but is
embedvar.h has been simplified, and one level of macro indirection for
PL_* variables has been removed for the default (non-multiplicity)
configuration. PERLVAR*() macros now directly expand their arguments to
tokens such as PL_defgv
, instead of expanding to PL_Idefgv
, with
embedvar.h defining a macro to map PL_Idefgv
to PL_defgv
. XS code
which has unwarranted chumminess with the implementation may need updating.
An API has been added to explicitly choose whether to export XSUB symbols. More detail can be found in the comments for commit e64345f8.
The is_gv_magical_sv
function has been eliminated and merged with
. It used to be called to determine whether a GV
should be autovivified in rvalue context. Now it has been replaced with a
new GV_ADDMG
flag (not part of the API).
The returned code point from the function utf8n_to_uvuni()
when the input is malformed UTF-8, malformations are allowed, and
warnings are off is now the Unicode REPLACEMENT CHARACTER
whenever the malformation is such that no well-defined code point can be
computed. Previously the returned value was essentially garbage. The
only malformations that have well-defined values are a zero-length
string (0 is the return), and overlong UTF-8 sequences.
Padlists are now marked AvREAL
; i.e., reference-counted. They have
always been reference-counted, but were not marked real, because pad.c
did its own clean-up, instead of using the usual clean-up code in sv.c.
That caused problems in thread cloning, so now the AvREAL
flag is on,
but is turned off in pad.c right before the padlist is freed (after
pad.c has done its custom freeing of the pads).
All C files that make up the Perl core have been converted to UTF-8.
These new functions have been added as part of the work on Unicode symbols:
- HvNAMELEN
- HvNAMEUTF8
- HvENAMELEN
- HvENAMEUTF8
- gv_init_pv
- gv_init_pvn
- gv_init_pvsv
- gv_fetchmeth_pv
- gv_fetchmeth_pvn
- gv_fetchmeth_sv
- gv_fetchmeth_pv_autoload
- gv_fetchmeth_pvn_autoload
- gv_fetchmeth_sv_autoload
- gv_fetchmethod_pv_flags
- gv_fetchmethod_pvn_flags
- gv_fetchmethod_sv_flags
- gv_autoload_pv
- gv_autoload_pvn
- gv_autoload_sv
- newGVgen_flags
- sv_derived_from_pv
- sv_derived_from_pvn
- sv_derived_from_sv
- sv_does_pv
- sv_does_pvn
- sv_does_sv
- whichsig_pv
- whichsig_pvn
- whichsig_sv
- newCONSTSUB_flags
The gv_fetchmethod_*_flags functions, like gv_fetchmethod_flags, are experimental and may change in a future release.
The following functions were added. These are not part of the API:
- GvNAMEUTF8
- GvENAMELEN
- GvENAME_HEK
- CopSTASH_flags
- CopSTASH_flags_set
- PmopSTASH_flags
- PmopSTASH_flags_set
- sv_sethek
- HEKfARG
There is also a HEKf
macro corresponding to SVf
, for
interpolating HEKs in formatted strings.
takes a couple of new internal-only flags,
and SV_CATUTF8
, which tell it whether the char array to
be concatenated is UTF8. This allows for more efficient concatenation than
creating temporary SVs to pass to sv_catsv
For XS AUTOLOAD subs, $AUTOLOAD is set once more, as it was in 5.6.0. This
is in addition to setting SvPVX(cv)
, for compatibility with 5.8 to 5.14.
See Autoloading with XSUBs in perlguts.
Perl now checks whether the array (the linearized isa) returned by a MRO
plugin begins with the name of the class itself, for which the array was
created, instead of assuming that it does. This prevents the first element
from being skipped during method lookup. It also means that
may return an array with one more element than the
MRO plugin provided [perl #94306].
is now reference-counted.
There are now feature bundle hints in PL_hints
) that version
declarations use, to avoid having to load feature.pm. One setting of
the hint bits indicates a "custom" feature bundle, which means that the
entries in %^H
still apply. feature.pm uses that.
The HINT_FEATURE_MASK
macro is defined in perl.h along with other
hints. Other macros for setting and testing features and bundles are in
the new feature.h. FEATURE_IS_ENABLED
(which has moved to
feature.h) is no longer used throughout the codebase, but more specific
macros, e.g., FEATURE_SAY_IS_ENABLED
, that are defined in feature.h.
lib/feature.pm is now a generated file, created by the new regen/feature.pl script, which also generates feature.h.
Tied arrays are now always AvREAL
. If @_
or DB::args
is tied, it
is reified first, to make sure this is always the case.
Two new functions utf8_to_uvchr_buf()
and utf8_to_uvuni_buf()
been added. These are the same as utf8_to_uvchr
(which are now deprecated), but take an extra parameter
that is used to guard against reading beyond the end of the input
See utf8_to_uvchr_buf in perlapi and utf8_to_uvuni_buf in perlapi.
The regular expression engine now does TRIE case insensitive matches
under Unicode. This may change the output of use re 'debug';
and will speed up various things.
There is a new wrap_op_checker()
function, which provides a thread-safe
alternative to writing to PL_check
A bug has been fixed that would cause a "Use of freed value in iteration" error if the next two hash elements that would be iterated over are deleted [perl #85026]. (5.14.1)
Deleting the current hash iterator (the hash element that would be returned
by the next call to each
) in void context used not to free it
[perl #85026].
Deletion of methods via delete $Class::{method}
syntax used to update
method caches if called in void context, but not scalar or list context.
When hash elements are deleted in void context, the internal hash entry is now freed before the value is freed, to prevent destructors called by that latter freeing from seeing the hash in an inconsistent state. It was possible to cause double-frees if the destructor freed the hash itself [perl #100340].
A keys
optimization in Perl 5.12.0 to make it faster on empty hashes
caused each
not to reset the iterator if called after the last element
was deleted.
Freeing deeply nested hashes no longer crashes [perl #44225].
It is possible from XS code to create hashes with elements that have no values. The hash element and slice operators used to crash when handling these in lvalue context. They now produce a "Modification of non-creatable hash value attempted" error message.
If list assignment to a hash or array triggered destructors that freed the hash or array itself, a crash would ensue. This is no longer the case [perl #107440].
It used to be possible to free the typeglob of a localized array or hash
(e.g., local @{"x"}; delete $::{x}
), resulting in a crash on scope exit.
Some core bugs affecting Hash::Util have been fixed: locking a hash element that is a glob copy no longer causes the next assignment to it to corrupt the glob (5.14.2), and unlocking a hash element that holds a copy-on-write scalar no longer causes modifications to that scalar to modify other scalars that were sharing the same string buffer.
The newHVhv
XS function now works on tied hashes, instead of crashing or
returning an empty hash.
The SvIsCOW
C macro now returns false for read-only copies of typeglobs,
such as those created by:
- $hash{elem} = *foo;
- Hash::Util::lock_value %hash, 'elem';
It used to return true.
The SvPVutf8
C function no longer tries to modify its argument,
resulting in errors [perl #108994].
now works properly with magical variables.
now works properly non-PVs.
When presented with malformed UTF-8 input, the XS-callable functions
, is_utf8_string_loc()
, and
could read beyond the end of the input
string by up to 12 bytes. This no longer happens. [perl #32080].
However, currently, is_utf8_char()
still has this defect, see
is_utf8_char() above.
The C-level pregcomp
function could become confused about whether the
pattern was in UTF8 if the pattern was an overloaded, tied, or otherwise
magical scalar [perl #101940].
Tying %^H
no longer causes perl to crash or ignore the contents of
when entering a compilation scope [perl #106282].
eval $string
and require
used not to
localize %^H
during compilation if it
was empty at the time the eval
call itself was compiled. This could
lead to scary side effects, like use re "/m"
enabling other flags that
the surrounding code was trying to enable for its caller [perl #68750].
eval $string
and require
no longer localize hints ($^H
and %^H
at run time, but only during compilation of the $string or required file.
This makes BEGIN { $^H{foo}=7 }
equivalent to
BEGIN { eval '$^H{foo}=7' }
[perl #70151].
Creating a BEGIN block from XS code (via newXS
or newATTRSUB
) would,
on completion, make the hints of the current compiling code the current
hints. This could cause warnings to occur in a non-warning scope.
Copy-on-write or shared hash key scalars
were introduced in 5.8.0, but most Perl code
did not encounter them (they were used mostly internally). Perl
5.10.0 extended them, such that assigning __PACKAGE__
or a
hash key to a scalar would make it copy-on-write. Several parts
of Perl were not updated to account for them, but have now been fixed.
had a nasty bug that would modify copy-on-write scalars'
string buffers in place (i.e., skipping the copy). This could result in
hashes having two elements with the same key [perl #91834]. (5.14.2)
Lvalue subroutines were not allowing COW scalars to be returned. This was fixed for lvalue scalar context in Perl 5.12.3 and 5.14.0, but list context was not fixed until this release.
Elements of restricted hashes (see the fields pragma) containing
copy-on-write values couldn't be deleted, nor could such hashes be cleared
(%hash = ()
). (5.14.2)
Localizing a tied variable used to make it read-only if it contained a copy-on-write string. (5.14.2)
Assigning a copy-on-write string to a stash element no longer causes a double free. Regardless of this change, the results of such assignments are still undefined.
Assigning a copy-on-write string to a tied variable no longer stops that variable from being tied if it happens to be a PVMG or PVLV internally.
Doing a substitution on a tied variable returning a copy-on-write scalar used to cause an assertion failure or an "Attempt to free nonexistent shared string" warning.
This one is a regression from 5.12: In 5.14.0, the bitwise assignment
operators |=
, ^=
and &=
started leaving the left-hand side
undefined if it happened to be a copy-on-write string [perl #108480].
Storable, Devel::Peek and PerlIO::scalar had similar problems. See Updated Modules and Pragmata, above.
dumpvar.pl, and therefore the x
command in the debugger, have been
fixed to handle objects blessed into classes whose names contain "=". The
contents of such objects used not to be dumped [perl #101814].
The "R" command for restarting a debugger session has been fixed to work on
Windows, or any other system lacking a POSIX::_SC_OPEN_MAX
[perl #87740].
The #line 42 foo
directive used not to update the arrays of lines used
by the debugger if it occurred in a string eval. This was partially fixed
in 5.14, but it worked only for a single #line 42 foo
in each eval. Now
it works for multiple.
When subroutine calls are intercepted by the debugger, the name of the
subroutine or a reference to it is stored in $DB::sub
, for the debugger
to access. Sometimes (such as $foo = *bar; undef *bar; &$foo
would be set to a name that could not be used to find the
subroutine, and so the debugger's attempt to call it would fail. Now the
check to see whether a reference is needed is more robust, so those
problems should not happen anymore [rt.cpan.org #69862].
Every subroutine has a filename associated with it that the debugger uses. The one associated with constant subroutines used to be misallocated when cloned under threads. Consequently, debugging threaded applications could result in memory corruption [perl #96126].
, defined(*{"..."})
, etc., used to
return true for most, but not all built-in variables, if
they had not been used yet. This bug affected ${^GLOBAL_PHASE}
, among others. It also used to return false if the
package name was given as well (${"::!"}
) [perl #97978, #97492].
Perl 5.10.0 introduced a similar bug: defined(*{"foo"})
where "foo"
represents the name of a built-in global variable used to return false if
the variable had never been used before, but only on the first call.
This, too, has been fixed.
Since 5.6.0, *{ ... }
has been inconsistent in how it treats undefined
values. It would die in strict mode or lvalue context for most undefined
values, but would be treated as the empty string (with a warning) for the
specific scalar return by undef()
internally). This
has been corrected. undef()
is now treated like other undefined
scalars, as in Perl 5.005.
Perl has an internal variable that stores the last filehandle to be
accessed. It is used by $.
and by tell
and eof
It used to be possible to set this internal variable to a glob copy and then modify that glob copy to be something other than a glob, and still have the last-accessed filehandle associated with the variable after assigning a glob to it again:
- my $foo = *STDOUT; # $foo is a glob copy
- <$foo>; # $foo is now the last-accessed handle
- $foo = 3; # no longer a glob
- $foo = *STDERR; # still the last-accessed handle
Now the $foo = 3
assignment unsets that internal variable, so there
is no last-accessed filehandle, just as if <$foo>
had never
This also prevents some unrelated handle from becoming the last-accessed handle if $foo falls out of scope and the same internal SV gets used for another handle [perl #97988].
A regression in 5.14 caused these statements not to set that internal variable:
This is now fixed, but tell *{ *$fh }
still has the problem, and it
is not clear how to fix it [perl #106536].
The term "filetests" refers to the operators that consist of a hyphen
followed by a single letter: -r
, -x
, etc. The term "stacked"
when applied to filetests means followed by another filetest operator
sharing the same operand, as in -r -x -w $fooo
produces more consistent warnings. It no longer warns for "_"
[perl #71002] and no longer skips the warning at times for other unopened
handles. It no longer warns about an unopened handle when the operating
system's fstat
function fails.
would sometimes return negative numbers for large inode numbers,
because it was using the wrong internal C type. [perl #84590]
is documented to fall back to stat
(with a warning) when given
a filehandle. When passed an IO reference, it was actually doing the
equivalent of stat _
and ignoring the handle.
with no preceding stat
used to produce a
confusing "uninitialized" warning, even though there
is no visible uninitialized value to speak of.
, -l
and -t
now work
when stacked with other filetest operators
[perl #77388].
In 5.14.0, filetest ops (-r
, -x
, etc.) started calling FETCH on a
tied argument belonging to the previous argument to a list operator, if
called with a bareword argument or no argument at all. This has been
fixed, so push @foo, $tied, -r
no longer calls FETCH on $tied
In Perl 5.6, -l
followed by anything other than a bareword would treat
its argument as a file name. That was changed in 5.8 for glob references
), but not for globs themselves (*foo
). -l
returning undef
for glob references without setting the last
stat buffer that the "_" handle uses, but only if warnings
were turned on. With warnings off, it was the same as 5.6.
In other words, it was simply buggy and inconsistent. Now the 5.6
behavior has been restored.
followed by a bareword no longer "eats" the previous argument to
the list operator in whose argument list it resides. Hence,
print "bar", -l foo
now actually prints "bar", because -l
on longer eats it.
Perl keeps several internal variables to keep track of the last stat buffer, from which file(handle) it originated, what type it was, and whether the last stat succeeded.
There were various cases where these could get out of synch, resulting in
inconsistent or erratic behavior in edge cases (every mention of -T
applies to -B
as well):
, even though it does a stat
, was not resetting the last
stat type, so an lstat _
following it would merrily return the wrong
results. Also, it was not setting the success status.
Freeing the handle last used by stat
or a filetest could result in
using an unrelated handle.
with an IO reference would not reset the stat type or record the
filehandle for -T _
to use.
Fatal warnings could cause the stat buffer not to be reset
for a filetest operator on an unopened filehandle or -l
on any handle.
Fatal warnings also stopped -T
from setting $!
When the last stat was on an unreadable file, -T _
is supposed to
return undef
, leaving the last stat buffer unchanged. But it was
setting the stat type, causing lstat _
to stop working.
was not resetting the internal stat buffers for
unreadable files.
These have all been fixed.
Several edge cases have been fixed with formats and formline
in particular, where the format itself is potentially variable (such as
with ties and overloading), and where the format and data differ in their
encoding. In both these cases, it used to possible for the output to be
corrupted [perl #91032].
no longer converts its argument into a string in-place. So
passing a reference to formline
no longer destroys the reference
[perl #79532].
Assignment to $^A
(the format output accumulator) now recalculates
the number of lines output.
and when
was not scoping its implicit $_ properly, resulting in memory
leaks or "Variable is not available" warnings [perl #94682].
was not calling set-magic on the implicit lexical $_
that it
uses. This meant, for example, that pos
would be remembered from one
execution of the same given
block to the next, even if the input were a
different variable [perl #84526].
blocks are now capable of returning variables declared inside the
enclosing given
block [perl #93548].
operatorOn OSes other than VMS, Perl's glob
operator (and the <...>
use File::Glob underneath. File::Glob splits the pattern into words,
before feeding each word to its bsd_glob
There were several inconsistencies in the way the split was done. Now quotation marks (' and ") are always treated as shell-style word delimiters (that allow whitespace as part of a word) and backslashes are always preserved, unless they exist to escape quotation marks. Before, those would only sometimes be the case, depending on whether the pattern contained whitespace. Also, escaped whitespace at the end of the pattern is no longer stripped [perl #40470].
now works as a way to call the default globbing function. It
used to respect overrides, despite the CORE::
Under miniperl (used to configure modules when perl itself is built),
now clears %ENV before calling csh, since the latter croaks on some
systems if it does not like the contents of the LS_COLORS environment
variable [perl #98662].
Explicit return now returns the actual argument passed to return, instead of copying it [perl #72724, #72706].
Lvalue subroutines used to enforce lvalue syntax (i.e., whatever can go on
the left-hand side of =
) for the last statement and the arguments to
return. Since lvalue subroutines are not always called in lvalue context,
this restriction has been lifted.
Lvalue subroutines are less restrictive about what values can be returned.
It used to croak on values returned by shift
and delete
and from
other subroutines, but no longer does so [perl #71172].
Empty lvalue subroutines (sub :lvalue {}
) used to return @_
in list
context. All subroutines used to do this, but regular subs were fixed in
Perl 5.8.2. Now lvalue subroutines have been likewise fixed.
Autovivification now works on values returned from lvalue subroutines
[perl #7946], as does returning keys
in lvalue context.
Lvalue subroutines used to copy their return values in rvalue context. Not
only was this a waste of CPU cycles, but it also caused bugs. A ($)
prototype would cause an lvalue sub to copy its return value [perl #51408],
and while(lvalue_sub() =~ m/.../g) { ... }
would loop endlessly
[perl #78680].
When called in potential lvalue context
(e.g., subroutine arguments or a list
passed to for
), lvalue subroutines used to copy
any read-only value that was returned. E.g., sub :lvalue { $] }
would not return $]
, but a copy of it.
When called in potential lvalue context, an lvalue subroutine returning
arrays or hashes used to bind the arrays or hashes to scalar variables,
resulting in bugs. This was fixed in 5.14.0 if an array were the first
thing returned from the subroutine (but not for $scalar, @array
hashes being returned). Now a more general fix has been applied
[perl #23790].
Method calls whose arguments were all surrounded with my()
or our()
(as in $object->method(my($a,$b))
) used to force lvalue context on
the subroutine. This would prevent lvalue methods from returning certain
Lvalue sub calls that are not determined to be such at compile time
or &{"name"}) are no longer exempt from strict refs if they
occur in the last statement of an lvalue subroutine [perl #102486].
Sub calls whose subs are not visible at compile time, if they occurred in the last statement of an lvalue subroutine, would reject non-lvalue subroutines and die with "Can't modify non-lvalue subroutine call" [perl #102486].
Non-lvalue sub calls whose subs are visible at compile time exhibited the opposite bug. If the call occurred in the last statement of an lvalue subroutine, there would be no error when the lvalue sub was called in lvalue context. Perl would blindly assign to the temporary value returned by the non-lvalue subroutine.
routines used to take precedence over the actual sub being
called (i.e., when autoloading wasn't needed), for sub calls in lvalue or
potential lvalue context, if the subroutine was not visible at compile
Applying the :lvalue
attribute to an XSUB or to an aliased subroutine
stub with sub foo :lvalue;
syntax stopped working in Perl 5.12.
This has been fixed.
Applying the :lvalue attribute to subroutine that is already defined does not work properly, as the attribute changes the way the sub is compiled. Hence, Perl 5.12 began warning when an attempt is made to apply the attribute to an already defined sub. In such cases, the attribute is discarded.
But the change in 5.12 missed the case where custom attributes are also
present: that case still silently and ineffectively applied the attribute.
That omission has now been corrected. sub foo :lvalue :Whatever
is already defined) now warns about the :lvalue attribute, and does
not apply it.
A bug affecting lvalue context propagation through nested lvalue subroutine calls has been fixed. Previously, returning a value in nested rvalue context would be treated as lvalue context by the inner subroutine call, resulting in some values (such as read-only values) being rejected.
Arithmetic assignment ($left += $right
) involving overloaded objects
that rely on the 'nomethod' override no longer segfault when the left
operand is not overloaded.
Errors that occur when methods cannot be found during overloading now mention the correct package name, as they did in 5.8.x, instead of erroneously mentioning the "overload" package, as they have since 5.10.0.
Undefining %overload::
no longer causes a crash.
The prototype
function no longer dies for the __FILE__
and __PACKAGE__
directives. It now returns an empty-string prototype
for them, because they are syntactically indistinguishable from nullary
functions like time
now returns undef
for all overridable infix operators,
such as eq
, which are not callable in any way resembling functions.
It used to return incorrect prototypes for some and die for others
[perl #94984].
The prototypes of several built-in functions--getprotobynumber
, lock
and select
--have been corrected, or at least are now closer to
reality than before.
and /[[:blank:]]/
now use locale rules under
use locale
when the platform supports that. Previously, they used
the platform's native character set.
and /\p{ASCII}/i
now match identically (when not
under a differing locale). This fixes a regression introduced in 5.14
in which the first expression could match characters outside of ASCII,
such as the KELVIN SIGN.
would sometimes refuse to match at the end of a string that ends
with "\n". This has been fixed [perl #109206].
Starting with 5.12.0, Perl used to get its internal bookkeeping muddled up
after assigning ${ qr// }
to a hash element and locking it with
Hash::Util. This could result in double frees, crashes, or erratic
The new (in 5.14.0) regular expression modifier /a
when repeated like
forbids the characters outside the ASCII range that match
characters inside that range from matching under /i
. This did not
work under some circumstances, all involving alternation, such as:
- "\N{KELVIN SIGN}" =~ /k|foo/iaa;
succeeded inappropriately. This is now fixed.
5.14.0 introduced some memory leaks in regular expression character
classes such as [\w\s]
, which have now been fixed. (5.14.1)
An edge case in regular expression matching could potentially loop.
This happened only under /i
in bracketed character classes that have
characters with multi-character folds, and the target string to match
against includes the first portion of the fold, followed by another
character that has a multi-character fold that begins with the remaining
portion of the fold, plus some more.
- "s\N{U+DF}" =~ /[\x{DF}foo]/i
is one such case. \xDF
folds to "ss"
. (5.14.1)
A few characters in regular expression pattern matches did not
match correctly in some circumstances, all involving /i
. The
affected characters are:
A memory leak regression in regular expression compilation under threading has been fixed.
A regression introduced in 5.14.0 has been fixed. This involved an inverted bracketed character class in a regular expression that consisted solely of a Unicode property. That property wasn't getting inverted outside the Latin1 range.
Three problematic Unicode characters now work better in regex pattern matching under /i
In the past, three Unicode characters:
along with the sequences that they fold to
(including "ss" for LATIN SMALL LETTER SHARP S),
did not properly match under /i
. 5.14.0 fixed some of these cases,
but introduced others, including a panic when one of the characters or
sequences was used in the (?(DEFINE)
regular expression predicate.
The known bugs that were introduced in 5.14 have now been fixed; as well
as some other edge cases that have never worked until now. These all
involve using the characters and sequences outside bracketed character
classes under /i
. This closes [perl #98546].
There remain known problems when using certain characters with
multi-character folds inside bracketed character classes, including such
constructs as qr/[\N{LATIN SMALL LETTER SHARP}a-z]/i
. These
remaining bugs are addressed in [perl #89774].
RT #78266: The regex engine has been leaking memory when accessing named captures that weren't matched as part of a regex ever since 5.10 when they were introduced; e.g., this would consume over a hundred MB of memory:
In 5.14, /[[:lower:]]/i
and /[[:upper:]]/i
no longer matched the
opposite case. This has been fixed [perl #101970].
A regular expression match with an overloaded object on the right-hand side would sometimes stringify the object too many times.
A regression has been fixed that was introduced in 5.14, in /i
regular expression matching, in which a match improperly fails if the
pattern is in UTF-8, the target string is not, and a Latin-1 character
precedes a character in the string that should match the pattern.
[perl #101710]
In case-insensitive regular expression pattern matching, no longer on
UTF-8 encoded strings does the scan for the start of match look only at
the first possible position. This caused matches such as
"f\x{FB00}" =~ /ff/i
to fail.
The regexp optimizer no longer crashes on debugging builds when merging fixed-string nodes with inconvenient contents.
A panic involving the combination of the regular expression modifiers
and the \b
escape sequence introduced in 5.14.0 has been
fixed [perl #95964]. (5.14.2)
The combination of the regular expression modifiers /aa
and the \b
and \B
escape sequences did not work properly on UTF-8 encoded
strings. All non-ASCII characters under /aa
should be treated as
non-word characters, but what was happening was that Unicode rules were
used to determine wordness/non-wordness for non-ASCII characters. This
is now fixed [perl #95968].
(?foo: ...)
no longer loses passed in character set.
The trie optimization used to have problems with alternations containing
an empty (?:)
, causing "x" =~ /\A(?>(?:(?:)A|B|C?x))\z/
not to
match, whereas it should [perl #111842].
Use of lexical (my
) variables in code blocks embedded in regular
expressions will no longer result in memory corruption or crashes.
Nevertheless, these code blocks are still experimental, as there are still
problems with the wrong variables being closed over (in loops for instance)
and with abnormal exiting (e.g., die
) causing memory corruption.
The \h
, \v
and \V
regular expression metacharacters used to
cause a panic error message when trying to match at the end of the
string [perl #96354].
The abbreviations for four C1 control characters MW
, and
were previously unrecognized by \N{}
, vianame(), and
Mentioning a variable named "&" other than $&
(i.e., @&
or %&
) no
longer stops $&
from working. The same applies to variables named "'"
and "`" [perl #24237].
Creating a UNIVERSAL::AUTOLOAD
sub no longer stops %+
, %-
from working some of the time [perl #105024].
now correctly handles the precedence of Any~~Object, and is not tricked
by an overloaded object on the left-hand side.
In Perl 5.14.0, $tainted ~~ @array
stopped working properly. Sometimes
it would erroneously fail (when $tainted
contained a string that occurs
in the array after the first element) or erroneously succeed (when
occurred after the first element) [perl #93590].
was not treating sub {}
and sub {()}
as equivalent when
such a sub was provided as the comparison routine. It used to croak on
sub {()}
now works once more with custom sort routines that are XSUBs. It
stopped working in 5.10.0.
with a constant for a custom sort routine, although it produces
unsorted results, no longer crashes. It started crashing in 5.10.0.
Warnings emitted by sort
when a custom comparison routine returns a
non-numeric value now contain "in sort" and show the line number of the
operator, rather than the last line of the comparison routine. The
warnings also now occur only if warnings are enabled in the scope where
occurs. Previously the warnings would occur if enabled in the
comparison routine's scope.
sort { $a <=> $b }
, which is optimized internally, now produces
"uninitialized" warnings for NaNs (not-a-number values), since <=>
returns undef
for those. This brings it in line with
sort { 1; $a <=> $b }
and other more complex cases, which are not
optimized [perl #94390].
operatorTied (and otherwise magical) variables are no longer exempt from the "Attempt to use reference as lvalue in substr" warning.
That warning now occurs when the returned lvalue is assigned to, not
when substr
itself is called. This makes a difference only if the
return value of substr
is referenced and later assigned to.
Passing a substring of a read-only value or a typeglob to a function (potential lvalue context) no longer causes an immediate "Can't coerce" or "Modification of a read-only value" error. That error occurs only if the passed value is assigned to.
The same thing happens with the "substr outside of string" error. If
the lvalue is only read from, not written to, it is now just a warning, as
with rvalue substr
assignments no longer call FETCH twice if the first argument
is a tied variable, just once.
Some parts of Perl did not work correctly with nulls (chr 0
) embedded in
strings. That meant that, for instance, $m = "a\0b"; foo->$m
call the "a" method, instead of the actual method name contained in $m.
These parts of perl have been fixed to support nulls:
Method names
Typeglob names (including filehandle and subroutine names)
Package names, including the return value of ref()
Typeglob elements (*foo{"THING\0stuff"}
Signal names
Various warnings and error messages that mention variable names or values, methods, etc.
One side effect of these changes is that blessing into "\0" no longer
causes ref()
to return false.
Typeglobs returned from threads are no longer cloned if the parent thread already has a glob with the same name. This means that returned subroutines will now assign to the right package variables [perl #107366].
Some cases of threads crashing due to memory allocation during cloning have been fixed [perl #90006].
Thread joining would sometimes emit "Attempt to free unreferenced scalar"
warnings if caller
had been used from the DB
package before thread
creation [perl #98092].
Locking a subroutine (via lock &sub
) is no longer a compile-time error
for regular subs. For lvalue subroutines, it no longer tries to return the
sub as a scalar, resulting in strange side effects like ref \$_
returning "CODE" in some instances.
lock &sub
is now a run-time error if threads::shared is loaded (a
no-op otherwise), but that may be rectified in a future version.
Various cases in which FETCH was being ignored or called too many times have been fixed:
[perl #97956]
$tied =~ y/a/b/
, chop $tied
and chomp $tied
when $tied holds a
When calling local $_
[perl #105912]
Four-argument select
A tied buffer passed to sysread
$tied .= <>
Three-argument open
, the third being a tied file handle
(as in open $fh, ">&", $tied
with a reference to a tied glob for the comparison routine.
and ...
in list context [perl #53554].
, @{$tied}
, %{$tied}
and *{$tied}
where the tied
variable returns a string (&{}
was unaffected)
defined ${ $tied_variable }
Various functions that take a filehandle argument in rvalue context
, readline
, etc.) [perl #97482]
Some cases of dereferencing a complex expression, such as
${ (), $tied } = 1
, used to call FETCH
multiple times, but now call
it once.
where $tied returns a package name--even resulting in
a failure to call the method, due to memory corruption
Assignments like *$tied = \&{"..."}
and *glob = $tied
, chmod
, chown
, utime
, truncate
, stat
, lstat
the filetest ops (-r
, -x
, etc.)
sets @DB::args
to the subroutine arguments when called from
the DB package. It used to crash when doing so if @DB::args
happened to
be tied. Now it croaks instead.
Tying an element of %ENV or %^H
and then deleting that element would
result in a call to the tie object's DELETE method, even though tying the
element itself is supposed to be equivalent to tying a scalar (the element
is, of course, a scalar) [perl #67490].
When Perl autovivifies an element of a tied array or hash (which entails calling STORE with a new reference), it now calls FETCH immediately after the STORE, instead of assuming that FETCH would have returned the same reference. This can make it easier to implement tied objects [perl #35865, #43011].
Four-argument select
no longer produces its "Non-string passed as
bitmask" warning on tied or tainted variables that are strings.
Localizing a tied scalar that returns a typeglob no longer stops it from being tied till the end of the scope.
Attempting to goto
out of a tied handle method used to cause memory
corruption or crashes. Now it produces an error message instead
[perl #8611].
A bug has been fixed that occurs when a tied variable is used as a
subroutine reference: if the last thing assigned to or returned from the
variable was a reference or typeglob, the \&$tied
could either crash or
return the wrong subroutine. The reference case is a regression introduced
in Perl 5.10.0. For typeglobs, it has probably never worked till now.
The bitwise complement operator (and possibly other operators, too) when
passed a vstring would leave vstring magic attached to the return value,
even though the string had changed. This meant that
would create a version looking like "v1.2.3"
even though the string passed to version->new
was actually
"\376\375\374". This also caused B::Deparse to deparse ~v1.2.3
incorrectly, without the ~
[perl #29070].
Assigning a vstring to a magic (e.g., tied, $!
) variable and then
assigning something else used to blow away all magic. This meant that
tied variables would come undone, $!
would stop getting updated on
failed system calls, $|
would stop setting autoflush, and other
mischief would take place. This has been fixed.
and printf "%vd", "version"
no longer
crash [perl #102586].
Version comparisons, such as those that happen implicitly with use
, no longer cause locale settings to change [perl #105784].
Version objects no longer cause memory leaks in boolean context [perl #109762].
Subroutines from the autouse
namespace are once more exempt from
redefinition warnings. This used to work in 5.005, but was broken in
5.6 for most subroutines. For subs created via XS that redefine
subroutines from the autouse
package, this stopped working in 5.10.
New XSUBs now produce redefinition warnings if they overwrite existing
subs, as they did in 5.8.x. (The autouse
logic was reversed in
5.10-14. Only subroutines from the autouse
namespace would warn
when clobbered.)
used to use compile-time warning hints, instead of
run-time hints. The following code should never produce a redefinition
warning, but it used to, if newCONSTSUB
redefined an existing
Redefinition warnings for constant subroutines are on by default (what are known as severe warnings in perldiag). This occurred only when it was a glob assignment or declaration of a Perl subroutine that caused the warning. If the creation of XSUBs triggered the warning, it was not a default warning. This has been corrected.
The internal check to see whether a redefinition warning should occur used to emit "uninitialized" warnings in cases like this:
Various functions that take a filehandle argument in rvalue context
, readline
, etc.) used to warn twice for an undefined handle
[perl #97482].
now only warns once, rather than three times, if the mode
argument is undef
[perl #90064].
The +=
operator does not usually warn when the left-hand side is
, but it was doing so for tied variables. This has been fixed
[perl #44895].
A bug fix in Perl 5.14 introduced a new bug, causing "uninitialized"
warnings to report the wrong variable if the operator in question had
two operands and one was %{...}
or @{...}
. This has been fixed
[perl #103766].
and ...
in list context now mention the name of the variable in
"uninitialized" warnings for string (as opposed to numeric) ranges.
Weakening the first argument to an automatically-invoked DESTROY
could result in erroneous "DESTROY created new reference" errors or
crashes. Now it is an error to weaken a read-only reference.
Weak references to lexical hashes going out of scope were not going stale (becoming undefined), but continued to point to the hash.
Weak references to lexical variables going out of scope are now broken before any magical methods (e.g., DESTROY on a tie object) are called. This prevents such methods from modifying the variable that will be seen the next time the scope is entered.
Creating a weak reference to an @ISA array or accessing the array index
) could result in confused internal bookkeeping for elements
later added to the @ISA array. For instance, creating a weak
reference to the element itself could push that weak reference on to @ISA;
and elements added after use of $#ISA
would be ignored by method lookup
[perl #85670].
now quotes consistently the same non-ASCII characters under
use feature 'unicode_strings'
, regardless of whether the string is
encoded in UTF-8 or not, hence fixing the last vestiges (we hope) of the
notorious The Unicode Bug in perlunicode. [perl #77654].
Which of these code points is quoted has changed, based on Unicode's recommendations. See quotemeta for details.
is now a no-op, presumably fixing all outstanding bugs related to
study causing regex matches to behave incorrectly!
When one writes open foo || die
, which used to work in Perl 4, a
"Precedence problem" warning is produced. This warning used erroneously to
apply to fully-qualified bareword handle names not followed by ||
. This
has been corrected.
After package aliasing (*foo:: = *bar::
), select
with 0 or 1 argument
would sometimes return a name that could not be used to refer to the
filehandle, or sometimes it would return undef
even when a filehandle
was selected. Now it returns a typeglob reference in such cases.
no longer ignores some arguments that it thinks are
numeric, while treating others as filehandle names. It is now consistent
for flat scalars (i.e., not references).
Unrecognized switches on #!
If a switch, such as -x, that cannot occur on the #!
line is used
there, perl dies with "Can't emulate...".
It used to produce the same message for switches that perl did not
recognize at all, whether on the command line or the #!
Now it produces the "Unrecognized switch" error message [perl #104288].
now temporarily blocks the SIGCHLD signal handler, to prevent the
signal handler from stealing the exit status [perl #105700].
The %n formatting code for printf
and sprintf
, which causes the number
of characters to be assigned to the next argument, now actually
assigns the number of characters, instead of the number of bytes.
It also works now with special lvalue functions like substr
and with
nonexistent hash and array elements [perl #3471, #103492].
Perl skips copying values returned from a subroutine, for the sake of
speed, if doing so would make no observable difference. Because of faulty
logic, this would happen with the
result of delete
, shift
or splice
, even if the result was
referenced elsewhere. It also did so with tied variables about to be freed
[perl #91844, #95548].
now refuses to modify read-only scalars [perl #91850].
Freeing $_ inside a grep
or map
block, a code block embedded in a
regular expression, or an @INC filter (a subroutine returned by a
subroutine in @INC) used to result in double frees or crashes
[perl #91880, #92254, #92256].
returns undef
in scalar context or an empty list in list
context when there is a run-time error. When eval
was passed a
string in list context and a syntax error occurred, it used to return a
list containing a single undefined element. Now it returns an empty
list in list context for all errors [perl #80630].
goto &func
no longer crashes, but produces an error message, when
the unwinding of the current subroutine's scope fires a destructor that
undefines the subroutine being "goneto" [perl #99850].
Perl now holds an extra reference count on the package that code is currently compiling in. This means that the following code no longer crashes [perl #101486]:
- package Foo;
- BEGIN {*Foo:: = *Bar::}
- sub foo;
The x
repetition operator no longer crashes on 64-bit builds with large
repeat counts [perl #94560].
Calling require
on an implicit $_
when *CORE::GLOBAL::require
been overridden does not segfault anymore, and $_
is now passed to the
overriding subroutine [perl #78260].
and require
are no longer affected by the I/O layers active in
the caller's scope (enabled by open.pm) [perl #96008].
our $::é; $é
(which is invalid) no longer produces the "Compilation
error at lib/utf8_heavy.pl..." error message, which it started emitting in
5.10.0 [perl #99984].
On 64-bit systems, read()
now understands large string offsets beyond
the 32-bit range.
Errors that occur when processing subroutine attributes no longer cause the subroutine's op tree to leak.
Passing the same constant subroutine to both index
and formline
longer causes one or the other to fail [perl #89218]. (5.14.1)
List assignment to lexical variables declared with attributes in the same
statement (my ($x,@y) : blimp = (72,94)
) stopped working in Perl 5.8.0.
It has now been fixed.
Perl 5.10.0 introduced some faulty logic that made "U*" in the middle of a pack template equivalent to "U0" if the input string was empty. This has been fixed [perl #90160]. (5.14.2)
Destructors on objects were not called during global destruction on objects
that were not referenced by any scalars. This could happen if an array
element were blessed (e.g., bless \$a[0]
) or if a closure referenced a
blessed variable (bless \my @a; sub foo { @a }
Now there is an extra pass during global destruction to fire destructors on any objects that might be left after the usual passes that check for objects referenced by scalars [perl #36347].
Fixed a case where it was possible that a freed buffer may have been read from when parsing a here document [perl #90128]. (5.14.1)
is now wrapped in defined(...)
, like each(HASH)
inside a while
condition [perl #90888].
A problem with context propagation when a do
block is an argument to
has been fixed. It used to cause undef
to be returned in
certain cases of a return
inside an if
block which itself is followed by
another return
Calling index
with a tainted constant no longer causes constants in
subsequently compiled code to become tainted [perl #64804].
Infinite loops like 1 while 1
used to stop strict 'subs'
mode from
working for the rest of the block.
For list assignments like ($a,$b) = ($b,$a)
, Perl has to make a copy of
the items on the right-hand side before assignment them to the left. For
efficiency's sake, it assigns the values on the right straight to the items
on the left if no one variable is mentioned on both sides, as in ($a,$b) =
. The logic for determining when it can cheat was faulty, in that
and ||
on the right-hand side could fool it. So ($a,$b) =
$some_true_value && ($b,$a)
would end up assigning the value of $b
both scalars.
Perl no longer tries to apply lvalue context to the string in
("string", $variable) ||= 1
(which used to be an error). Since the
left-hand side of ||=
is evaluated in scalar context, that's a scalar
comma operator, which gives all but the last item void context. There is
no such thing as void lvalue context, so it was a mistake for Perl to try
to force it [perl #96942].
no longer leaks memory when called from the DB package if
was assigned to after the first call to caller
. Carp
was triggering this bug [perl #97010]. (5.14.2)
and similar filehandle functions, when called on built-in global
variables (like $+
), used to die if the variable happened to hold the
undefined value, instead of producing the usual "Use of uninitialized
value" warning.
When autovivified file handles were introduced in Perl 5.6.0, readline
was inadvertently made to autovivify when called as readline($foo)
not as <$foo>
). It has now been fixed never to autovivify.
Calling an undefined anonymous subroutine (e.g., what $x holds after
undef &{$x = sub{}}
) used to cause a "Not a CODE reference" error, which
has been corrected to "Undefined subroutine called" [perl #71154].
Causing @DB::args
to be freed between uses of caller
no longer
results in a crash [perl #93320].
used to be equivalent to ($foo, setpgrp)
, because
was ignoring its argument if there was just one. Now it is
equivalent to setpgrp($foo,0)
was not setting the scalar flags correctly when reading from
shared memory, causing the existing cached numeric representation in the
scalar to persist [perl #98480].
and --
now work on copies of globs, instead of dying.
doesn't warn when truncating
You can now limit the size of an array using splice(@a,MAX_LEN)
worrying about warnings.
is no longer tainted. Since this value comes directly from
, it is always safe.
The parser no longer leaks a filehandle if STDIN was closed before parsing started [perl #37033].
with a non-reference, non-string, or magical (e.g., tainted)
value in $@ now properly propagates that value [perl #111654].
On Solaris, we have two kinds of failure.
If make is Sun's make, we get an error about a badly formed macro assignment in the Makefile. That happens when ./Configure tries to make depends. Configure then exits 0, but further make-ing fails.
If make is gmake, Configure completes, then we get errors related to /usr/include/stdbool.h
On Win32, a number of tests hang unless STDERR is redirected. The cause of this is still under investigation.
When building as root with a umask that prevents files from being other-readable, t/op/filetest.t will fail. This is a test bug, not a bug in perl's behavior.
Configuring with a recent gcc and link-time-optimization, such as
Configure -Doptimize='-O2 -flto'
because the optimizer optimizes away some of Configure's tests. A
workaround is to omit the -flto
flag when running Configure, but add
it back in while actually building, something like
- sh Configure -Doptimize=-O2
- make OPTIMIZE='-O2 -flto'
The following CPAN modules have test failures with perl 5.16. Patches have been submitted for all of these, so hopefully there will be new releases soon:
Date::Pcalc version 6.1
Module::CPANTS::Analyse version 0.85
This fails due to problems in Module::Find 0.10 and File::MMagic 1.27.
PerlIO::Util version 0.72
Perl 5.16.0 represents approximately 12 months of development since Perl 5.14.0 and contains approximately 590,000 lines of changes across 2,500 files from 139 authors.
Perl continues to flourish into its third decade thanks to a vibrant community of users and developers. The following people are known to have contributed the improvements that became Perl 5.16.0:
Aaron Crane, Abhijit Menon-Sen, Abigail, Alan Haggai Alavi, Alberto Simões, Alexandr Ciornii, Andreas König, Andy Dougherty, Aristotle Pagaltzis, Bo Johansson, Bo Lindbergh, Breno G. de Oliveira, brian d foy, Brian Fraser, Brian Greenfield, Carl Hayter, Chas. Owens, Chia-liang Kao, Chip Salzenberg, Chris 'BinGOs' Williams, Christian Hansen, Christopher J. Madsen, chromatic, Claes Jacobsson, Claudio Ramirez, Craig A. Berry, Damian Conway, Daniel Kahn Gillmor, Darin McBride, Dave Rolsky, David Cantrell, David Golden, David Leadbeater, David Mitchell, Dee Newcum, Dennis Kaarsemaker, Dominic Hargreaves, Douglas Christopher Wilson, Eric Brine, Father Chrysostomos, Florian Ragwitz, Frederic Briere, George Greer, Gerard Goossen, Gisle Aas, H.Merijn Brand, Hojung Youn, Ian Goodacre, James E Keenan, Jan Dubois, Jerry D. Hedden, Jesse Luehrs, Jesse Vincent, Jilles Tjoelker, Jim Cromie, Jim Meyering, Joel Berger, Johan Vromans, Johannes Plunien, John Hawkinson, John P. Linderman, John Peacock, Joshua ben Jore, Juerd Waalboer, Karl Williamson, Karthik Rajagopalan, Keith Thompson, Kevin J. Woolley, Kevin Ryde, Laurent Dami, Leo Lapworth, Leon Brocard, Leon Timmermans, Louis Strous, Lukas Mai, Marc Green, Marcel Grünauer, Mark A. Stratman, Mark Dootson, Mark Jason Dominus, Martin Hasch, Matthew Horsfall, Max Maischein, Michael G Schwern, Michael Witten, Mike Sheldrake, Moritz Lenz, Nicholas Clark, Niko Tyni, Nuno Carvalho, Pau Amma, Paul Evans, Paul Green, Paul Johnson, Perlover, Peter John Acklam, Peter Martini, Peter Scott, Phil Monsen, Pino Toscano, Rafael Garcia-Suarez, Rainer Tammer, Reini Urban, Ricardo Signes, Robin Barker, Rodolfo Carvalho, Salvador Fandiño, Sam Kimbrel, Samuel Thibault, Shawn M Moore, Shigeya Suzuki, Shirakata Kentaro, Shlomi Fish, Sisyphus, Slaven Rezic, Spiros Denaxas, Steffen Müller, Steffen Schwigon, Stephen Bennett, Stephen Oberholtzer, Stevan Little, Steve Hay, Steve Peters, Thomas Sibley, Thorsten Glaser, Timothe Litt, Todd Rinaldo, Tom Christiansen, Tom Hukins, Tony Cook, Vadim Konovalov, Vincent Pit, Vladimir Timofeev, Walt Mankowski, Yves Orton, Zefram, Zsbán Ambrus, Ævar Arnfjörð Bjarmason.
The list above is almost certainly incomplete as it is automatically generated from version control history. In particular, it does not include the names of the (very much appreciated) contributors who reported issues to the Perl bug tracker.
Many of the changes included in this version originated in the CPAN modules included in Perl's core. We're grateful to the entire CPAN community for helping Perl to flourish.
For a more complete list of all of Perl's historical contributors, please see the AUTHORS file in the Perl source distribution.
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://rt.perl.org/perlbug/. There may also be information at http://www.perl.org/, the Perl Home Page.
If you believe you have an unreported bug, please run the perlbug
program included with your release. Be sure to trim your bug down
to a tiny but sufficient test case. Your bug report, along with the
output of perl -V
, will be sent off to email@example.com to be
analysed by the Perl porting team.
If the bug you are reporting has security implications, which make it inappropriate to send to a publicly archived mailing list, then please send it to email@example.com. This points to a closed subscription unarchived mailing list, which includes all core committers, who will be able to help assess the impact of issues, figure out a resolution, and help co-ordinate the release of patches to mitigate or fix the problem across all platforms on which Perl is supported. Please use this address only for security issues in the Perl core, not for modules independently distributed on CPAN.
The Changes file for an explanation of how to view exhaustive details on what changed.
The INSTALL file for how to build Perl.
The README file for general stuff.
The Artistic and Copying files for copyright information.