PERL5211DELTA(1pm) Perl Programmers Reference Guide PERL5211DELTA(1pm)
NAME
perl5211delta - what is new for perl v5.21.1
DESCRIPTION
This document describes differences between the 5.21.0 release and the
5.21.1 release.
If you are upgrading from an earlier release such as 5.20.0, first read
perl5210delta, which describes differences between 5.20.0 and 5.21.0.
Notice
This release removes a number of previously deprecated constructs, many
that have been around for a long time. Please see "Incompatible
Changes" for more information.
Core Enhancements
Unicode 7.0 is now supported
For details on what is in this release, see
<http://www.unicode.org/versions/Unicode7.0.0/>.
Experimental C Backtrace API
Starting from Perl 5.21.1, on some platforms Perl supports retrieving
the C level backtrace (similar to what symbolic debuggers like gdb do).
The backtrace returns the stack trace of the C call frames, with the
symbol names (function names), the object names (like "perl"), and if
it can, also the source code locations (file:line).
The supported platforms are Linux and OS X (some *BSD might work at
least partly, but they have not yet been tested).
The feature needs to be enabled with "Configure -Dusecbacktrace".
Also included is a C API to retrieve backtraces.
See "C backtrace" in perlhacktips for more information.
"qr/foo/x" now ignores any Unicode pattern white space
The "/x" regular expression modifier allows the pattern to contain
white space and comments, both of which are ignored, for improved
readability. Until now, not all the white space characters that
Unicode designates for this purpose were handled. The additional ones
now recognized are U+0085 NEXT LINE, U+200E LEFT-TO-RIGHT MARK, U+200F
RIGHT-TO-LEFT MARK, U+2028 LINE SEPARATOR, and U+2029 PARAGRAPH
SEPARATOR.
"use locale" can restrict which locale categories are affected
It is now possible to pass a parameter to "use locale" to specify a
subset of locale categories to be locale-aware, with the remaining ones
unaffected. See "The "use locale" pragma" in perllocale for details.
Incompatible Changes
"\N{}" with a sequence of multiple spaces is now a fatal error.
This has been deprecated since v5.18.
In double-quotish "\cX", X must now be a printable ASCII character
In prior releases, failure to do this raised a deprecation warning.
Splitting the tokens "(?" and "(*" in regular expressions is now a fatal
compilation error.
These had been deprecated since v5.18.
5 additional characters are treated as white space under "/x" in regex
patterns (unless escaped)
The use of these characters with "/x" outside bracketed character
classes and when not preceded by a backslash has raised a deprecation
warning since v5.18. Now they will be ignored. See "qr/foo/x" for the
list of the five characters.
Comment lines within "(?[ ])" now are ended only by a "\n"
"(?[ ])" is an experimental feature, introduced in v5.18. It operates
as if "/x" is always enabled. But there was a difference, comment
lines (following a "#" character) were terminated by anything matching
"\R" which includes all vertical whitespace, such as form feeds. For
consistency, this is now changed to match what terminates comment lines
outside "(?[ ])", namely a "\n" (even if escaped), which is the same as
what terminates a heredoc string and formats.
Omitting % and @ on hash and array names is no longer permitted
Really old Perl let you omit the @ on array names and the % on hash
names in some spots. This has issued a deprecation warning since Perl
5.0, and is no longer permitted.
"$!" text is now in English outside "use locale" scope
Previously, the text, unlike almost everything else, always came out
based on the current underlying locale of the program. (Also affected
on some systems is ""$^E"".) For programs that are unprepared to
handle locale, this can cause garbage text to be displayed. It's
better to display text that is translatable via some tool than garbage
text which is much harder to figure out.
"$!" text will be returned in UTF-8 when appropriate
The stringification of $! and $^E will have the UTF-8 flag set when the
text is actually non-ASCII UTF-8. This will enable programs that are
set up to be locale-aware to properly output messages in the user's
native language. Code that needs to continue the 5.20 and earlier
behavior can do the stringification within the scopes of both 'use
bytes' and 'use locale ":messages". No other Perl operations will be
affected by locale; only $! and $^E stringification. The 'bytes'
pragma causes the UTF-8 flag to not be set, just as in previous Perl
releases. This resolves [perl #112208].
Support for "?PATTERN?" without explicit operator has been removed
Starting regular expressions matching only once directly with the
question mark delimiter is now a syntax error, so that the question
mark can be available for use in new operators. Write "m?PATTERN?"
instead, explicitly using the "m" operator: the question mark delimiter
still invokes match-once behaviour.
"defined(@array)" and "defined(%hash)" are now fatal errors
These have been deprecated since v5.6.1 and have raised deprecation
warnings since v5.16.
Using a hash or an array as a reference are now fatal errors.
For example, "%foo->{"bar"}" now causes a fatal compilation error.
These have been deprecated since before v5.8, and have raised
deprecation warnings since then.
Deprecations
Using a NO-BREAK space in a character alias for "\N{...}" is now deprecated
This non-graphic character is essentially indistinguishable from a
regular space, and so should not be allowed. See "CUSTOM ALIASES" in
charnames.
A literal "{" should now be escaped in a pattern
If you want a literal left curly bracket (also called a left brace) in
a regular expression pattern, you should now escape it by either
preceding it with a backslash ("\{") or enclosing it within square
brackets "[{]", or by using "\Q"; otherwise a deprecation warning will
be raised. This was first announced as forthcoming in the v5.16
release; it will allow future extensions to the language to happen.
Performance Enhancements
o Many internal functions have been refactored to improve performance
and reduce their memory footprints.
[perl #121436] <https://rt.perl.org/Ticket/Display.html?id=121436>
[perl #121906] <https://rt.perl.org/Ticket/Display.html?id=121906>
[perl #121969] <https://rt.perl.org/Ticket/Display.html?id=121969>
o "-T" and "-B" filetests will return sooner when an empty file is
detected.
perl #121489 <https://rt.perl.org/Ticket/Display.html?id=121489>
Modules and Pragmata
Updated Modules and Pragmata
o The libnet collection of modules has been upgraded from version
1.25 to 1.27.
There are only whitespace changes to the installed files.
o A mismatch between the documentation and the code in
utf8::downgrade() was fixed in favour of the documentation. The
optional second argument is now correctly treated as a perl boolean
(true/false semantics) and not as an integer.
o The Locale-Codes collection of modules has been upgraded from
version 3.30 to 3.31.
Fixed a bug in the scripts used to extract data from spreadsheets
that prevented the SHP currency code from being found. [cpan
#94229] <https://rt.cpan.org/Ticket/Display.html?id=94229>
o Archive::Tar has been upgraded from version 1.96 to 2.00.
o autodie has been upgraded from version 2.23 to 2.25.
o B has been upgraded from version 1.48 to 1.49.
o B::Deparse has been upgraded from version 1.26 to 1.27.
o Benchmark has been upgraded from version 1.18 to 1.19.
o Carp has been upgraded from version 1.3301 to 1.34.
Carp::Heavy now ignores version mismatches with Carp if Carp is
newer than 1.12, since Carp::Heavy's guts were merged into Carp at
that point. [perl #121574]
<https://rt.perl.org/Ticket/Display.html?id=121574>
o charnames has been upgraded from version 1.40 to 1.41.
o CPAN::Meta has been upgraded from version 2.140640 to 2.141520.
o Data::Dumper has been upgraded from version 2.151 to 2.152.
Changes to resolve Coverity issues.
XS dumps incorrectly stored the name of code references stored in a
GLOB. [perl #122070]
<https://rt.perl.org/Ticket/Display.html?id=122070>
o Devel::Peek has been upgraded from version 1.16 to 1.17.
o Devel::PPPort has been upgraded from version 3.21 to 3.24.
o Digest::SHA has been upgraded from version 5.88 to 5.92.
o DynaLoader has been upgraded from version 1.25 to 1.26.
o Encode has been upgraded from version 2.60 to 2.62.
piconv now has better error handling when the encoding name is
nonexistent, and a build breakage when upgrading Encode in
perl-5.8.2 and earlier has been fixed.
o Errno has been upgraded from version 1.20_03 to 1.20_04.
o Exporter has been upgraded from version 5.70 to 5.71.
o ExtUtils::Install has been upgraded from version 1.67 to 1.68.
o ExtUtils::Miniperl has been upgraded from version 1.01 to 1.02.
o ExtUtils::ParseXS has been upgraded from version 3.24 to 3.25.
o ExtUtils::Typemaps has been upgraded from version 3.24 to 3.25.
o File::Spec has been upgraded from version 3.47 to 3.48.
o Hash::Util has been upgraded from version 0.16 to 0.17.
Minor bug fixes and documentation fixes to Hash::Util::hash_stats()
o IO has been upgraded from version 1.31 to 1.32.
o List::Util has been upgraded from version 1.38 to 1.39.
o locale has been upgraded from version 1.03 to 1.04.
o Locale::Codes has been upgraded from version 3.30 to 3.31.
o Math::BigInt has been upgraded from version 1.9993 to 1.9995.
Synchronize POD changes from the CPAN release.
"Math::BigFloat->blog(x)" would sometimes return blog(2*x) when the
accuracy was greater than 70 digits.
The result of "Math::BigFloat->bdiv()" in list context now
satisfies "x = quotient * divisor + remainder".
o Math::BigRat has been upgraded from version 0.2606 to 0.2608.
Synchronize POD changes from the CPAN release.
o Module::CoreList has been upgraded from version 5.021001 to
5.021001_01.
o Module::Metadata has been upgraded from version 1.000019 to
1.000024.
Support installations on older perls with an ExtUtils::MakeMaker
earlier than 6.63_03
o NDBM_File has been upgraded from version 1.12 to 1.13.
o OS2::Process has been upgraded from version 1.09 to 1.10.
o perl5db.pl has been upgraded from version 1.44 to 1.45.
fork() in the debugger under "tmux" will now create a new window
for the forked process. [perl #121333]
<https://rt.perl.org/Ticket/Display.html?id=121333>
The debugger now saves the current working directory on startup and
restores it when you restart your program with "R" or "rerun".
[perl #121509] <https://rt.perl.org/Ticket/Display.html?id=121509>
o PerlIO::encoding has been upgraded from version 0.18 to 0.19.
No changes in behaviour.
o PerlIO::mmap has been upgraded from version 0.011 to 0.013.
No changes in behaviour.
o PerlIO::scalar has been upgraded from version 0.18 to 0.19.
No changes in behaviour.
o PerlIO::via has been upgraded from version 0.14 to 0.15.
o Pod::Html has been upgraded from version 1.21 to 1.22.
o POSIX has been upgraded from version 1.38_03 to 1.40.
o Scalar::Util has been upgraded from version 1.38 to 1.39.
o SelfLoader has been upgraded from version 1.21 to 1.22.
o Socket has been upgraded from version 2.013 to 2.014.
o Storable has been upgraded from version 2.49 to 2.51.
o Term::ANSIColor has been upgraded from version 4.02 to 4.03.
o Test::Harness has been upgraded from version 3.30 to 3.32.
o Test::Simple has been upgraded from version 1.001002 to 1.001003.
o threads has been upgraded from version 1.93 to 1.94.
o Tie::File has been upgraded from version 1.00 to 1.01.
o Unicode::Collate has been upgraded from version 1.04 to 1.07.
Version 0.67's improved discontiguous contractions is invalidated
by default and is supported as a parameter 'long_contraction'.
o Unicode::Normalize has been upgraded from version 1.17 to 1.18.
The XSUB implementation has been removed in favour of pure Perl.
o Unicode::UCD has been upgraded from version 0.57 to 0.58.
o utf8 has been upgraded from version 1.13 to 1.14.
o warnings has been upgraded from version 1.23 to 1.24.
Documentation
Changes to Existing Documentation
perlfunc
o "-l" now notes that it will return false if symlinks aren't
supported by the file system.
[perl #121523] <https://rt.perl.org/Ticket/Display.html?id=121523>
o Note that "exec LIST" and "system LIST" may fall back to the shell
on Win32. Only "exec PROGRAM LIST" and "system PROGRAM LIST"
indirect object syntax will reliably avoid using the shell.
This has also been noted in perlport.
[perl #122046] <https://rt.perl.org/Ticket/Display.html?id=122046>
perlapi
o Note that "SvSetSV" doesn't do set magic.
o "sv_usepvn_flags" - Fix documentation to mention the use of "NewX"
instead of "malloc".
[perl #121869] <https://rt.perl.org/Ticket/Display.html?id=121869>
o Clarify where "NUL" may be embedded or is required to terminate a
string.
o Previously missing documentation due to formatting errors are now
included.
o Entries are now organized into groups rather than by file where
they are found.
o Alphabetical sorting of entries is now handled by the POD generator
to make entries easier to find when scanning.
perlhacktips
o Updated documentation for the "test.valgrind" "make" target.
[perl #121431] <https://rt.perl.org/Ticket/Display.html?id=121431>
perlre
o The "/x" modifier has been clarified to note that comments cannot
be continued onto the next line by escaping them.
Unicode::UCD
o The documentation includes many clarifications and fixes.
Diagnostics
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.
New Diagnostics
New Errors
o In '(?...)', the '(' and '?' must be adjacent in regex; marked by
<-- HERE in m/%s/
(F) The two-character sequence "(?" in this context in a regular
expression pattern should be an indivisible token, with nothing
intervening between the "(" and the "?", but you separated them.
o In '(*VERB...)', the '(' and '*' must be adjacent in regex; marked
by <-- HERE in m/%s/
(F) The two-character sequence "(*" in this context in a regular
expression pattern should be an indivisible token, with nothing
intervening between the "(" and the "*", but you separated them.
o charnames alias definitions may not contain a sequence of multiple
spaces
(F) You defined a character name which had multiple space
characters in a row. Change them to single spaces. Usually these
names are defined in the ":alias" import argument to "use
charnames", but
they could be defined by a translator installed into
$^H{charnames}.
See "CUSTOM ALIASES" in charnames.
o charnames alias definitions may not contain trailing white-space
(F) You defined a character name which ended in a space character.
Remove the trailing space(s). Usually these names are defined in
the ":alias" import argument to "use charnames", but they could be
defined by a translator installed into $^H{charnames}. See "CUSTOM
ALIASES" in charnames.
o Can't use a hash as a reference
(F) You tried to use a hash as a reference, as in "%foo->{"bar"}"
or "%$ref->{"hello"}". Versions of perl <= 5.6.1 used to allow
this syntax, but shouldn't have.
o Can't use an array as a reference
(F) You tried to use an array as a reference, as in "@foo->[23]" or
"@$ref->[99]". Versions of perl <= 5.6.1 used to allow this
syntax, but shouldn't have.
o Can't use 'defined(@array)' (Maybe you should just omit the
defined()?)
(F) defined() is not useful on arrays because it checks for an
undefined scalar value. If you want to see if the array is empty,
just use "if (@array) { # not empty }" for example.
o Can't use 'defined(%hash)' (Maybe you should just omit the
defined()?)
(F) "defined()" is not usually right on hashes.
Although "defined %hash" is false on a plain not-yet-used hash, it
becomes true in several non-obvious circumstances, including
iterators, weak references, stash names, even remaining true after
"undef %hash". These things make "defined %hash" fairly useless in
practice, so it now generates a fatal error.
If a check for non-empty is what you wanted then just put it in
boolean context (see "Scalar values" in perldata):
if (%hash) {
# not empty
}
If you had "defined %Foo::Bar::QUUX" to check whether such a
package variable exists then that's never really been reliable, and
isn't a good way to enquire about the features of a package, or
whether it's loaded, etc.
o Illegal suidscript
(F) The script run under suidperl was somehow illegal.
New Warnings
o Unescaped left brace in regex is deprecated, passed through in
regex; marked by <-- HERE in m/%s/
(D deprecated, regexp) You used a literal "{" character in a
regular expression pattern. You should change to use "\{" instead,
because a future version of Perl (tentatively v5.26) will consider
this to be a syntax error. If the pattern delimiters are also
braces, any matching right brace ("}") should also be escaped to
avoid confusing the parser, for example,
qr{abc\{def\}ghi}
o NO-BREAK SPACE in a charnames alias definition is deprecated
(D deprecated) You defined a character name which contained a no-
break space character. Change it to a regular space. Usually
these names are defined in the ":alias" import argument to "use
charnames", but they could be defined by a translator installed
into $^H{charnames}. See "CUSTOM ALIASES" in charnames.
o PerlIO layer ':win32' is experimental
(S experimental::win32_perlio) The ":win32" PerlIO layer is
experimental. If you want to take the risk of using this layer,
simply disable this warning:
no warnings "experimental::win32_perlio";
o Negative repeat count does nothing
(W numeric) You tried to execute the "x" repetition operator fewer
than 0 times, which doesn't make sense.
o localtime(%f) failed
(W overflow) You called "localtime" with a number that it could not
handle: too large, too small, or NaN. The returned value is
"undef".
o gmtime(%f) failed
(W overflow) You called "gmtime" with a number that it could not
handle: too large, too small, or NaN. The returned value is
"undef".
o PerlIO layer ':win32' is experimental:
(S experimental::win32_perlio) The ":win32" PerlIO layer is
experimental. If you want to take the risk of using this layer,
simply disable this warning:
no warnings "experimental::win32_perlio";
o Negative repeat count does nothing
(W numeric) This warns when the repeat count of the "x" repetition
operator is negative.
This warning may be changed or removed if it turn out that it was
unwise to have added it.
Changes to Existing Diagnostics
o Variable length lookbehind not implemented in regex m/%s/
Information about Unicode behaviour has been added.
o <> should be quotes
This warning has been changed to <> at require-statement should be
quotes to make the issue more identifiable.
o Unsuccessful %s on filename containing newline
This warning is now only produced when the newline is at the end of
the filename.
Utility Changes
x2p/
o The x2p/ directory has been removed from the Perl core.
This removes find2perl, s2p and a2p. They have all been released to
CPAN as separate distributions (App::find2perl, App::s2p,
App::a2p).
Configuration and Compilation
o "make test.valgrind" now supports parallel testing.
For example:
TEST_JOBS=9 make test.valgrind
See "valgrind" in perlhacktips for more information.
[perl #121431] <https://rt.perl.org/Ticket/Display.html?id=121431>
o The MAD (Misc Attribute Decoration) build option has been removed
This was an unmaintained attempt at preserving the Perl parse tree
more faithfully so that automatic conversion of Perl 5 to Perl 6
would have been easier.
This build-time configuration option had been unmaintained for
years, and had probably seriously diverged on both Perl 5 and Perl
6 sides.
Platform Support
Discontinued Platforms
NeXTSTEP/OPENSTEP
NeXTSTEP was proprietary OS bundled with NeXT's workstations in the
early to mid 90's; OPENSTEP was an API specification that provided
a NeXTSTEP-like environment on a non-NeXTSTEP system. Both are now
long dead, so support for building Perl on them has been removed.
Platform-Specific Notes
OpenBSD
On OpenBSD, Perl will now default to using the system "malloc" due
to the security features it provides. Perl's own malloc wrapper has
been in use since v5.14 due to performance reasons, but the OpenBSD
project believes the tradeoff is worth it and would prefer that
users who need the speed specifically ask for it.
[perl #122000] <https://rt.perl.org/Ticket/Display.html?id=122000>.
Internal Changes
o The deprecated variable "PL_sv_objcount" has been removed.
o Perl now tries to keep the locale category "LC_NUMERIC" set to "C"
except around operations that need it to be set to the program's
underlying locale. This protects the many XS modules that cannot
cope with the decimal radix character not being a dot. Prior to
this release, Perl initialized this category to "C", but a call to
"POSIX::setlocale()" would change it. Now such a call will change
the underlying locale of the "LC_NUMERIC" category for the program,
but the locale exposed to XS code will remain "C". There is an API
under development for those relatively few modules that need to use
the underlying locale. This API will be nailed down during the
course of developing v5.21. Send email to
<mailto:perl5-porters@perl.org> for guidance.
o A new macro "isUTF8_CHAR" has been written which efficiently
determines if the string given by its parameters begins with a
well-formed UTF-8 encoded character.
Selected Bug Fixes
o index() and rindex() no longer crash when used on strings over 2GB
in size. [perl #121562]
<https://rt.perl.org/Ticket/Display.html?id=121562>.
o A small previously intentional memory leak in
PERL_SYS_INIT/PERL_SYS_INIT3 on Win32 builds was fixed. This might
affect embedders who repeatedly create and destroy perl engines
within the same process.
o "POSIX::localeconv()" now returns the data for the program's
underlying locale even when called from outside the scope of
"use locale".
o "POSIX::localeconv()" now works properly on platforms which don't
have "LC_NUMERIC" and/or "LC_MONETARY", or for which Perl has been
compiled to disregard either or both of these locale categories.
In such circumstances, there are now no entries for the
corresponding values in the hash returned by "localeconv()".
o "POSIX::localeconv()" now marks appropriately the values it returns
as UTF-8 or not. Previously they were always returned as a bytes,
even if they were supposed to be encoded as UTF-8.
o On Microsoft Windows, within the scope of "use locale", the
following POSIX character classes gave results for many locales
that did not conform to the POSIX standard: "[[:alnum:]]",
"[[:alpha:]]", "[[:blank:]]", "[[:digit:]]", "[[:graph:]]",
"[[:lower:]]", "[[:print:]]", "[[:punct:]]", "[[:upper:]]",
"[[:word:]]", and "[[:xdigit:]]". These are because the underlying
Microsoft implementation does not follow the standard. Perl now
takes special precautions to correct for this.
o Many issues have been detected by Coverity
<http://www.coverity.com/> and fixed.
o system() and friends should now work properly on more Android
builds.
Due to an oversight, the value specified through -Dtargetsh to
Configure would end up being ignored by some of the build process.
This caused perls cross-compiled for Android to end up with
defective versions of system(), exec() and backticks: the commands
would end up looking for "/bin/sh" instead of "/system/bin/sh", and
so would fail for the vast majority of devices, leaving $! as
"ENOENT".
o "qr(...\(...\)...)", "qr[...\[...\]...]", and "qr{...\{...\}...}"
now work. Previously it was impossible to escape these three left-
characters with a backslash within a regular expression pattern
where otherwise they would be considered metacharacters, and the
pattern opening delimiter was the character, and the closing
delimiter was its mirror character.
Acknowledgements
Perl 5.21.1 represents approximately 3 weeks of development since Perl
5.21.0 and contains approximately 240,000 lines of changes across 680
files from 37 authors.
Excluding auto-generated files, documentation and release tools, there
were approximately 150,000 lines of changes to 420 .pm, .t, .c and .h
files.
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 5.21.1:
Alex Solovey, Andrew Fresh, Andy Dougherty, Brian Fraser, Chris
'BinGOs' Williams, Craig A. Berry, Dagfinn Ilmari Mannsaaker, Daniel
Dragan, Darin McBride, David Mitchell, Doug Bell, H.Merijn Brand, James
E Keenan, Jarkko Hietaniemi, kafka, Karen Etheridge, Karl Williamson,
Leon Timmermans, Matthew Horsfall, Michael Bunk, Nicholas Clark, Niels
Thykier, Norman Koch, Peter John Acklam, Pierre Bogossian, Reini Urban,
Ricardo Signes, Rob Hoelz, Shlomi Fish, Smylers, Steffen Mueller, Steve
Hay, Sullivan Beck, Thomas Sibley, Todd Rinaldo, Tony Cook, Yves Orton.
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.
Reporting Bugs
If you find what you think is a bug, you might check the articles
recently posted to the comp.lang.perl.misc newsgroup and the perl bug
database at https://rt.perl.org/ . 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 perlbug@perl.org 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 perl5-security-report@perl.org. This points to a closed
subscription unarchived mailing list, which includes all the 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 only use this address for security issues in the
Perl core, not for modules independently distributed on CPAN.
SEE ALSO
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.
perl v5.22.0 2015-05-13 PERL5211DELTA(1pm)
perl 5.22 - Generated Fri Aug 14 15:16:50 CDT 2015