FM / pod

/usr/share/perl5/pod

Name	Size	Mode	Actions
perl.pod	16270	0644	edit dl rm
perl56delta.pod	107201	0644	edit dl rm
perl58delta.pod	115165	0644	edit dl rm
perl561delta.pod	124713	0644	edit dl rm
perl581delta.pod	38061	0644	edit dl rm
perl582delta.pod	4470	0644	edit dl rm
perl583delta.pod	6335	0644	edit dl rm
perl584delta.pod	7363	0644	edit dl rm
perl585delta.pod	5889	0644	edit dl rm
perl586delta.pod	4651	0644	edit dl rm
perl587delta.pod	8357	0644	edit dl rm
perl588delta.pod	25272	0644	edit dl rm
perl589delta.pod	53900	0644	edit dl rm
perl5004delta.pod	56240	0644	edit dl rm
perl5005delta.pod	34283	0644	edit dl rm
perl5100delta.pod	55535	0644	edit dl rm
perl5101delta.pod	43888	0644	edit dl rm
perl5120delta.pod	89272	0644	edit dl rm
perl5121delta.pod	10141	0644	edit dl rm
perl5122delta.pod	9603	0644	edit dl rm
perl5123delta.pod	4100	0644	edit dl rm
perl5124delta.pod	3672	0644	edit dl rm
perl5125delta.pod	7683	0644	edit dl rm
perl5140delta.pod	144324	0644	edit dl rm
perl5141delta.pod	7966	0644	edit dl rm
perl5142delta.pod	6892	0644	edit dl rm
perl5143delta.pod	7760	0644	edit dl rm
perl5144delta.pod	6327	0644	edit dl rm
perl5160delta.pod	133651	0644	edit dl rm
perl5161delta.pod	6142	0644	edit dl rm
perl5162delta.pod	3594	0644	edit dl rm
perl5163delta.pod	4085	0644	edit dl rm
perl5180delta.pod	119431	0644	edit dl rm
perl5181delta.pod	6595	0644	edit dl rm
perl5182delta.pod	5335	0644	edit dl rm
perl5184delta.pod	4642	0644	edit dl rm
perl5200delta.pod	115699	0644	edit dl rm
perl5201delta.pod	10899	0644	edit dl rm
perl5202delta.pod	12509	0644	edit dl rm
perl5203delta.pod	9392	0644	edit dl rm
perl5220delta.pod	130963	0644	edit dl rm
perl5221delta.pod	10767	0644	edit dl rm
perl5222delta.pod	12629	0644	edit dl rm
perl5223delta.pod	8456	0644	edit dl rm
perl5224delta.pod	4460	0644	edit dl rm
perl5240delta.pod	64927	0644	edit dl rm
perl5241delta.pod	8215	0644	edit dl rm
perl5242delta.pod	4113	0644	edit dl rm
perl5243delta.pod	11428	0644	edit dl rm
perl5244delta.pod	4510	0644	edit dl rm
perl5260delta.pod	101836	0644	edit dl rm
perl5261delta.pod	7927	0644	edit dl rm
perl5262delta.pod	7880	0644	edit dl rm
perl5263delta.pod	7063	0644	edit dl rm
perl5280delta.pod	72113	0644	edit dl rm
perlaix.pod	20437	0644	edit dl rm
perlamiga.pod	5749	0644	edit dl rm
perlandroid.pod	7871	0644	edit dl rm
perlapi.pod	443535	0644	edit dl rm
perlapio.pod	19285	0644	edit dl rm
perlartistic.pod	7010	0644	edit dl rm
perlbook.pod	8338	0644	edit dl rm
perlboot.pod	294	0644	edit dl rm
perlbot.pod	304	0644	edit dl rm
perlbs2000.pod	8058	0644	edit dl rm
perlcall.pod	56706	0644	edit dl rm
perlce.pod	14602	0644	edit dl rm
perlcheat.pod	4481	0644	edit dl rm
perlclib.pod	9619	0644	edit dl rm
perlcn.pod	4691	0644	edit dl rm
perlcommunity.pod	7217	0644	edit dl rm
perlcygwin.pod	27199	0644	edit dl rm
perldata.pod	46743	0644	edit dl rm
perldbmfilter.pod	4981	0644	edit dl rm
perldebguts.pod	38535	0644	edit dl rm
perldebtut.pod	22152	0644	edit dl rm
perldebug.pod	39258	0644	edit dl rm
perldelta.pod	7063	0644	edit dl rm
perldeprecation.pod	18169	0644	edit dl rm
perldiag.pod	284572	0644	edit dl rm
perldos.pod	10522	0644	edit dl rm
perldsc.pod	25614	0644	edit dl rm
perldtrace.pod	7958	0644	edit dl rm
perlebcdic.pod	84233	0644	edit dl rm
perlembed.pod	37196	0644	edit dl rm
perlexperiment.pod	7195	0644	edit dl rm
perlfork.pod	13355	0644	edit dl rm
perlform.pod	16608	0644	edit dl rm
perlfreebsd.pod	1610	0644	edit dl rm
perlfunc.pod	392957	0644	edit dl rm
perlgit.pod	33509	0644	edit dl rm
perlgpl.pod	13815	0644	edit dl rm
perlguts.pod	139329	0644	edit dl rm
perlhack.pod	40445	0644	edit dl rm
perlhacktips.pod	55509	0644	edit dl rm
perlhacktut.pod	6153	0644	edit dl rm
perlhaiku.pod	1508	0644	edit dl rm
perlhist.pod	53546	0644	edit dl rm
perlhpux.pod	30509	0644	edit dl rm
perlhurd.pod	1993	0644	edit dl rm
perlintern.pod	54572	0644	edit dl rm
perlinterp.pod	33687	0644	edit dl rm
perlintro.pod	22119	0644	edit dl rm
perliol.pod	34185	0644	edit dl rm
perlipc.pod	70829	0644	edit dl rm
perlirix.pod	4395	0644	edit dl rm
perljp.pod	7521	0644	edit dl rm
perlko.pod	12259	0644	edit dl rm
perllexwarn.pod	355	0644	edit dl rm
perllinux.pod	1488	0644	edit dl rm
perllocale.pod	68678	0644	edit dl rm
perllol.pod	9580	0644	edit dl rm
perlmacos.pod	1001	0644	edit dl rm
perlmacosx.pod	12060	0644	edit dl rm
perlmod.pod	26250	0644	edit dl rm
perlmodinstall.pod	12792	0644	edit dl rm
perlmodlib.pod	76482	0644	edit dl rm
perlmodstyle.pod	22575	0644	edit dl rm
perlmroapi.pod	3212	0644	edit dl rm
perlnetware.pod	6648	0644	edit dl rm
perlnewmod.pod	11036	0644	edit dl rm
perlnumber.pod	8353	0644	edit dl rm
perlobj.pod	35537	0644	edit dl rm
perlootut.pod	26783	0644	edit dl rm
perlop.pod	136252	0644	edit dl rm
perlopenbsd.pod	1204	0644	edit dl rm
perlopentut.pod	9455	0644	edit dl rm
perlos2.pod	93351	0644	edit dl rm
perlos390.pod	15674	0644	edit dl rm
perlos400.pod	4768	0644	edit dl rm
perlpacktut.pod	51282	0644	edit dl rm
perlperf.pod	49881	0644	edit dl rm
perlplan9.pod	5125	0644	edit dl rm
perlpod.pod	22196	0644	edit dl rm
perlpodspec.pod	68476	0644	edit dl rm
perlpolicy.pod	25629	0644	edit dl rm
perlport.pod	87602	0644	edit dl rm
perlpragma.pod	5176	0644	edit dl rm
perlqnx.pod	6673	0644	edit dl rm
perlre.pod	120901	0644	edit dl rm
perlreapi.pod	30334	0644	edit dl rm
perlrebackslash.pod	31817	0644	edit dl rm
perlrecharclass.pod	49029	0644	edit dl rm
perlref.pod	35304	0644	edit dl rm
perlreftut.pod	18790	0644	edit dl rm
perlreguts.pod	38328	0644	edit dl rm
perlrepository.pod	509	0644	edit dl rm
perlrequick.pod	18497	0644	edit dl rm
perlreref.pod	14744	0644	edit dl rm
perlretut.pod	121257	0644	edit dl rm
perlriscos.pod	1529	0644	edit dl rm
perlrun.pod	53550	0644	edit dl rm
perlsec.pod	26184	0644	edit dl rm
perlsolaris.pod	29822	0644	edit dl rm
perlsource.pod	6876	0644	edit dl rm
perlstyle.pod	8630	0644	edit dl rm
perlsub.pod	72967	0644	edit dl rm
perlsymbian.pod	15359	0644	edit dl rm
perlsyn.pod	44512	0644	edit dl rm
perlsynology.pod	7778	0644	edit dl rm
perlthrtut.pod	46459	0644	edit dl rm
perltie.pod	38607	0644	edit dl rm
perltoc.pod	694171	0644	edit dl rm
perltodo.pod	376	0644	edit dl rm
perltooc.pod	294	0644	edit dl rm
perltoot.pod	294	0644	edit dl rm
perltrap.pod	10620	0644	edit dl rm
perltru64.pod	8492	0644	edit dl rm
perltw.pod	4477	0644	edit dl rm
perlunicode.pod	82491	0644	edit dl rm
perlunicook.pod	25488	0644	edit dl rm
perlunifaq.pod	13647	0644	edit dl rm
perluniintro.pod	38340	0644	edit dl rm
perluniprops.pod	285306	0644	edit dl rm
perlunitut.pod	7951	0644	edit dl rm
perlutil.pod	7640	0644	edit dl rm
perlvar.pod	78364	0644	edit dl rm
perlvms.pod	50823	0644	edit dl rm
perlvos.pod	3843	0644	edit dl rm
perlwin32.pod	39298	0644	edit dl rm
perlxs.pod	78920	0644	edit dl rm
perlxstut.pod	50095	0644	edit dl rm
perlxstypemap.pod	24001	0644	edit dl rm

Edit: /usr/share/perl5/pod/perldeprecation.pod (18169B)

=head1 NAME

perldeprecation - list Perl deprecations

=head1 DESCRIPTION

The purpose of this document is to document what has been deprecated
in Perl, and by which version the deprecated feature will disappear,
or, for already removed features, when it was removed.

This document will try to discuss what alternatives for the deprecated
features are available.

The deprecated features will be grouped by the version of Perl in
which they will be removed.

=head2 Perl 5.32

=head3 Constants from lexical variables potentially modified elsewhere

You wrote something like

my $var;
    $sub = sub () { $var };

but $var is referenced elsewhere and could be modified after the C<sub>
expression is evaluated.  Either it is explicitly modified elsewhere
(C<$var = 3>) or it is passed to a subroutine or to an operator like
C<printf> or C<map>, which may or may not modify the variable.

Traditionally, Perl has captured the value of the variable at that
point and turned the subroutine into a constant eligible for inlining.
In those cases where the variable can be modified elsewhere, this
breaks the behavior of closures, in which the subroutine captures
the variable itself, rather than its value, so future changes to the
variable are reflected in the subroutine's return value.

If you intended for the subroutine to be eligible for inlining, then
make sure the variable is not referenced elsewhere, possibly by
copying it:

my $var2 = $var;
    $sub = sub () { $var2 };

If you do want this subroutine to be a closure that reflects future
changes to the variable that it closes over, add an explicit C<return>:

my $var;
    $sub = sub () { return $var };

This usage has been deprecated, and will no longer be allowed in Perl 5.32.

=head2 Perl 5.30

=head3 C<< $* >> is no longer supported

Before Perl 5.10, setting C<< $* >> to a true value globally enabled
multi-line matching within a string. This relique from the past lost
its special meaning in 5.10. Use of this variable will be a fatal error
in Perl 5.30, freeing the variable up for a future special meaning.

To enable multiline matching one should use the C<< /m >> regexp
modifier (possibly in combination with C<< /s >>). This can be set
on a per match bases, or can be enabled per lexical scope (including
a whole file) with C<< use re '/m' >>.

=head3 C<< $# >> is no longer supported

This variable used to have a special meaning -- it could be used
to control how numbers were formatted when printed. This seldom
used functionality was removed in Perl 5.10. In order to free up
the variable for a future special meaning, its use will be a fatal
error in Perl 5.30.

To specify how numbers are formatted when printed, one is adviced
to use C<< printf >> or C<< sprintf >> instead.

=head3 C<< File::Glob::glob() >> will disappear

C<< File::Glob >> has a function called C<< glob >>, which just calls
C<< bsd_glob >>. However, its prototype is different from the prototype
of C<< CORE::glob >>, and hence, C<< File::Glob::glob >> should not
be used.

C<< File::Glob::glob() >> was deprecated in Perl 5.8. A deprecation
message was issued from Perl 5.26 onwards, and the function will
disappear in Perl 5.30.

Code using C<< File::Glob::glob() >> should call
C<< File::Glob::bsd_glob() >> instead.

=head3 Unescaped left braces in regular expressions

The simple rule to remember, if you want to match a literal C<{>
character (U+007B C<LEFT CURLY BRACKET>) in a regular expression
pattern, is to escape each literal instance of it in some way.
Generally easiest is to precede it with a backslash, like C<\{>
or enclose it in square brackets (C<[{]>).  If the pattern
delimiters are also braces, any matching right brace (C<}>) should
also be escaped to avoid confusing the parser, for example,

qr{abc\{def\}ghi}

Forcing literal C<{> characters to be escaped will enable the Perl
language to be extended in various ways in future releases.  To avoid
needlessly breaking existing code, the restriction is is not enforced in
contexts where there are unlikely to ever be extensions that could
conflict with the use there of C<{> as a literal.

Literal uses of C<{> were deprecated in Perl 5.20, and some uses of it
started to give deprecation warnings since. These cases were made fatal
in Perl 5.26. Due to an oversight, not all cases of a use of a literal
C<{> got a deprecation warning. These cases started warning in Perl 5.26,
and they will be fatal by Perl 5.30.

=head3 Unqualified C<dump()>

Use of C<dump()> instead of C<CORE::dump()> was deprecated in Perl 5.8,
and an unqualified C<dump()> will no longer be available in Perl 5.30.

See L<perlfunc/dump>.

=head3 Using my() in false conditional.

There has been a long-standing bug in Perl that causes a lexical variable
not to be cleared at scope exit when its declaration includes a false
conditional.  Some people have exploited this bug to achieve a kind of
static variable.  Since we intend to fix this bug, we don't want people
relying on this behavior.

Instead, it's recommended one uses C<state> variables to achieve the
same effect:

use 5.10.0;
    sub count {state $counter; return ++ $counter}
    say count ();    # Prints 1
    say count ();    # Prints 2

C<state> variables were introduced in Perl 5.10.

Alternatively, you can achieve a similar static effect by
declaring the variable in a separate block outside the function, eg

sub f { my $x if 0; return $x++ }

becomes

{ my $x; sub f { return $x++ } }

The use of C<my()> in a false conditional has been deprecated in
Perl 5.10, and it will become a fatal error in Perl 5.30.

=head3 Reading/writing bytes from/to :utf8 handles.

The sysread(), recv(), syswrite() and send() operators are
deprecated on handles that have the C<:utf8> layer, either explicitly, or
implicitly, eg., with the C<:encoding(UTF-16LE)> layer.

Both sysread() and recv() currently use only the C<:utf8> flag for the stream,
ignoring the actual layers.  Since sysread() and recv() do no UTF-8
validation they can end up creating invalidly encoded scalars.

Similarly, syswrite() and send() use only the C<:utf8> flag, otherwise ignoring
any layers.  If the flag is set, both write the value UTF-8 encoded, even if
the layer is some different encoding, such as the example above.

Ideally, all of these operators would completely ignore the C<:utf8> state,
working only with bytes, but this would result in silently breaking existing
code.  To avoid this a future version of perl will throw an exception when
any of sysread(), recv(), syswrite() or send() are called on handle with the
C<:utf8> layer.

In Perl 5.30, it will no longer be possible to use sysread(), recv(),
syswrite() or send() to read or send bytes from/to :utf8 handles.

=head3 Use of unassigned code point or non-standalone grapheme for a delimiter.

A grapheme is what appears to a native-speaker of a language to be a
character.  In Unicode (and hence Perl) a grapheme may actually be
several adjacent characters that together form a complete grapheme.  For
example, there can be a base character, like "R" and an accent, like a
circumflex "^", that appear when displayed to be a single character with
the circumflex hovering over the "R".  Perl currently allows things like
that circumflex to be delimiters of strings, patterns, I<etc>.  When
displayed, the circumflex would look like it belongs to the character
just to the left of it.  In order to move the language to be able to
accept graphemes as delimiters, we have to deprecate the use of
delimiters which aren't graphemes by themselves.  Also, a delimiter must
already be assigned (or known to be never going to be assigned) to try
to future-proof code, for otherwise code that works today would fail to
compile if the currently unassigned delimiter ends up being something
that isn't a stand-alone grapheme.  Because Unicode is never going to
assign
L<non-character code points|perlunicode/Noncharacter code points>, nor
L<code points that are above the legal Unicode maximum|
perlunicode/Beyond Unicode code points>, those can be delimiters, and
their use won't raise this warning.

In Perl 5.30, delimiters which are unassigned code points, or which
are non-standalone graphemes will be fatal.

=head3 In XS code, use of various macros dealing with UTF-8.

These macros will require an extra parameter in Perl 5.30:
C<isALPHANUMERIC_utf8>,
C<isASCII_utf8>,
C<isBLANK_utf8>,
C<isCNTRL_utf8>,
C<isDIGIT_utf8>,
C<isIDFIRST_utf8>,
C<isPSXSPC_utf8>,
C<isSPACE_utf8>,
C<isVERTWS_utf8>,
C<isWORDCHAR_utf8>,
C<isXDIGIT_utf8>,
C<isALPHANUMERIC_LC_utf8>,
C<isALPHA_LC_utf8>,
C<isASCII_LC_utf8>,
C<isBLANK_LC_utf8>,
C<isCNTRL_LC_utf8>,
C<isDIGIT_LC_utf8>,
C<isGRAPH_LC_utf8>,
C<isIDCONT_LC_utf8>,
C<isIDFIRST_LC_utf8>,
C<isLOWER_LC_utf8>,
C<isPRINT_LC_utf8>,
C<isPSXSPC_LC_utf8>,
C<isPUNCT_LC_utf8>,
C<isSPACE_LC_utf8>,
C<isUPPER_LC_utf8>,
C<isWORDCHAR_LC_utf8>,
C<isXDIGIT_LC_utf8>,
C<toFOLD_utf8>,
C<toLOWER_utf8>,
C<toTITLE_utf8>,
and
C<toUPPER_utf8>.

There is now a macro that corresponds to each one of these, simply by
appending C<_safe> to the name.  It takes the extra parameter.
For example, C<isDIGIT_utf8_safe> corresponds to C<isDIGIT_utf8>, but
takes the extra parameter, and its use doesn't generate a deprecation
warning.  All are documented in L<perlapi/Character case changing> and
L<perlapi/Character classification>.

You can change to use these versions at any time, or, if you can live
with the deprecation messages, wait until 5.30 and add the parameter to
the existing calls, without changing the names.

=head2 Perl 5.28

=head3 Attribute "%s" is deprecated, and will disappear in 5.28

The attributes C<< :locked >> (on code references) and C<< :unique >>
(on array, hash and scalar references) have had no effect since 
Perl 5.005 and Perl 5.8.8 respectively. Their use has been deprecated
since.

These attributes will no longer be recognized in Perl 5.28, and will
then result in a syntax error. Since the attributes do not do anything,
removing them from your code fixes the deprecation warning; and removing
them will not influence the behaviour of your code.

=head3 Bare here-document terminators

Perl has allowed you to use a bare here-document terminator to have the
here-document end at the first empty line. This practise was deprecated
in Perl 5.000, and this will be a fatal error in Perl 5.28.

You are encouraged to use the explictly quoted form if you wish to
use an empty line as the terminator of the here-document:

print <<"";
    Print this line.

# Previous blank line ends the here-document.

=head3 Setting $/ to a reference to a non-positive integer

You assigned a reference to a scalar to C<$/> where the
referenced item is not a positive integer.  In older perls this B<appeared>
to work the same as setting it to C<undef> but was in fact internally
different, less efficient and with very bad luck could have resulted in
your file being split by a stringified form of the reference.

In Perl 5.20.0 this was changed so that it would be B<exactly> the same as
setting C<$/> to undef, with the exception that this warning would be
thrown.

In Perl 5.28, this will throw a fatal error.

You are recommended to change your code to set C<$/> to C<undef> explicitly
if you wish to slurp the file.

=head3 Limit on the value of Unicode code points.

Unicode only allows code points up to 0x10FFFF, but Perl allows much
larger ones. However, using code points exceeding the maximum value
of an integer (C<IV_MAX>) may break the perl interpreter in some constructs,
including causing it to hang in a few cases.  The known problem areas
are in C<tr///>, regular expression pattern matching using quantifiers,
as quote delimiters in C<qI<X>...I<X>> (where I<X> is the C<chr()> of a large
code point), and as the upper limits in loops.

The use of out of range code points was deprecated in Perl 5.24, and
it will be a fatal error in Perl 5.28.

If your code is to run on various platforms, keep in mind that the upper
limit depends on the platform.  It is much larger on 64-bit word sizes
than 32-bit ones.

=head3 Use of comma-less variable list in formats.

It's allowed to use a list of variables in a format, without
separating them with commas. This usage has been deprecated
for a long time, and it will be a fatal error in Perl 5.28.

=head3 Use of C<\N{}>

Use of C<\N{}> with nothing between the braces was deprecated in
Perl 5.24, and will throw a fatal error in Perl 5.28.

Since such a construct is equivalent to using an empty string,
you are recommended to remove such C<\N{}> constructs.

=head3 Using the same symbol to open a filehandle and a dirhandle

It used to be legal to use C<open()> to associate both a
filehandle and a dirhandle to the same symbol (glob or scalar).
This idiom is likely to be confusing, and it was deprecated in
Perl 5.10.

Using the same symbol to C<open()> a filehandle and a dirhandle
will be a fatal error in Perl 5.28.

You should be using two different symbols instead.

=head3 ${^ENCODING} is no longer supported.

The special variable C<${^ENCODING}> was used to implement
the C<encoding> pragma. Setting this variable to anything other
than C<undef> was deprecated in Perl 5.22. Full deprecation
of the variable happened in Perl 5.25.3.

Setting this variable will become a fatal error in Perl 5.28.

=head3 C<< B::OP::terse >>

This method, which just calls C<< B::Concise::b_terse >>, has been
deprecated, and will disappear in Perl 5.28. Please use 
C<< B::Concise >> instead.

=head3 Use of inherited AUTOLOAD for non-method %s() is deprecated

As an (ahem) accidental feature, C<AUTOLOAD> subroutines are looked
up as methods (using the C<@ISA> hierarchy) even when the subroutines
to be autoloaded were called as plain functions (e.g. C<Foo::bar()>),
not as methods (e.g. C<< Foo->bar() >> or C<< $obj->bar() >>).

This bug will be rectified in future by using method lookup only for
methods' C<AUTOLOAD>s.

The simple rule is:  Inheritance will not work when autoloading
non-methods.  The simple fix for old code is:  In any module that used
to depend on inheriting C<AUTOLOAD> for non-methods from a base class
named C<BaseClass>, execute C<*AUTOLOAD = \&BaseClass::AUTOLOAD> during
startup.

In code that currently says C<use AutoLoader; @ISA = qw(AutoLoader);>
you should remove AutoLoader from @ISA and change C<use AutoLoader;> to
C<use AutoLoader 'AUTOLOAD';>.

This feature was deprecated in Perl 5.004, and will be fatal in Perl 5.28.

=head3 Use of code points over 0xFF in string bitwise operators

The string bitwise operators, C<&>, C<|>, C<^>, and C<~>, treat
their operands as strings of bytes. As such, values above 0xFF 
are nonsensical. Using such code points with these operators
was deprecated in Perl 5.24, and will be fatal in Perl 5.28.

=head3 In XS code, use of C<to_utf8_case()>

This function is being removed; instead convert to call
the appropriate one of:
L<C<toFOLD_utf8_safe>|perlapi/toFOLD_utf8_safe>.
L<C<toLOWER_utf8_safe>|perlapi/toLOWER_utf8_safe>,
L<C<toTITLE_utf8_safe>|perlapi/toTITLE_utf8_safe>,
or
L<C<toUPPER_utf8_safe>|perlapi/toUPPER_utf8_safe>.

=head2 Perl 5.26

=head3 C<< --libpods >> in C<< Pod::Html >>

Since Perl 5.18, the option C<< --libpods >> has been deprecated, and
using this option did not do anything other than producing a warning.

The C<< --libpods >> option is no longer recognized in Perl 5.26.

=head3 The utilities C<< c2ph >> and C<< pstruct >>

These old, perl3-era utilities have been deprecated in favour of
C<< h2xs >> for a long time. In Perl 5.26, they have been removed.

=head3 Trapping C<< $SIG {__DIE__} >> other than during program exit.

The C<$SIG{__DIE__}> hook is called even inside an C<eval()>. It was
never intended to happen this way, but an implementation glitch made
this possible. This used to be deprecated, as it allowed strange action
at a distance like rewriting a pending exception in C<$@>. Plans to
rectify this have been scrapped, as users found that rewriting a
pending exception is actually a useful feature, and not a bug.

Perl never issued a deprecation warning for this; the deprecation
was by documentation policy only. But this deprecation has been 
lifted in Perl 5.26.

=head3 Malformed UTF-8 string in "%s"

This message indicates a bug either in the Perl core or in XS
code. Such code was trying to find out if a character, allegedly
stored internally encoded as UTF-8, was of a given type, such as
being punctuation or a digit.  But the character was not encoded
in legal UTF-8.  The C<%s> is replaced by a string that can be used
by knowledgeable people to determine what the type being checked
against was.

Passing malformed strings was deprecated in Perl 5.18, and
became fatal in Perl 5.26.

=head2 Perl 5.24

=head3 Use of C<< *glob{FILEHANDLE} >>

The use of C<< *glob{FILEHANDLE} >> was deprecated in Perl 5.8.
The intention was to use C<< *glob{IO} >> instead, for which 
C<< *glob{FILEHANDLE} >> is an alias.

However, this feature was undeprecated in Perl 5.24.

=head3 Calling POSIX::%s() is deprecated

The following functions in the C<POSIX> module are no longer available:
C<isalnum>, C<isalpha>, C<iscntrl>, C<isdigit>, C<isgraph>, C<islower>,  
C<isprint>, C<ispunct>, C<isspace>, C<isupper>, and C<isxdigit>.  The 
functions are buggy and don't work on UTF-8 encoded strings.  See their
entries in L<POSIX> for more information.

The functions were deprecated in Perl 5.20, and removed in Perl 5.24.

=head2 Perl 5.16

=head3 Use of %s on a handle without * is deprecated

It used to be possible to use C<tie>, C<tied> or C<untie> on a scalar
while the scalar holds a typeglob. This caused its filehandle to be
tied. It left no way to tie the scalar itself when it held a typeglob,
and no way to untie a scalar that had had a typeglob assigned to it.

This was deprecated in Perl 5.14, and the bug was fixed in Perl 5.16.

So now C<tie $scalar> will always tie the scalar, not the handle it holds.
To tie the handle, use C<tie *$scalar> (with an explicit asterisk).  The same
applies to C<tied *$scalar> and C<untie *$scalar>.

=head1 SEE ALSO

L<warnings>, L<diagnostics>.

=cut

=head1 NAME perldeprecation - list Perl deprecations =head1 DESCRIPTION The purpose of this document is to document what has been deprecated in Perl, and by which version the deprecated feature will disappear, or, for already removed features, when it was removed. This document will try to discuss what alternatives for the deprecated features are available. The deprecated features will be grouped by the version of Perl in which they will be removed. =head2 Perl 5.32 =head3 Constants from lexical variables potentially modified elsewhere You wrote something like my $var; $sub = sub () { $var }; but $var is referenced elsewhere and could be modified after the C_{expression is evaluated. Either it is explicitly modified elsewhere
(C<$var = 3>) or it is passed to a subroutine or to an operator like
C or C, which may or may not modify the variable.

Traditionally, Perl has captured the value of the variable at that
point and turned the subroutine into a constant eligible for inlining.
In those cases where the variable can be modified elsewhere, this
breaks the behavior of closures, in which the subroutine captures
the variable itself, rather than its value, so future changes to the
variable are reflected in the subroutine's return value.

If you intended for the subroutine to be eligible for inlining, then
make sure the variable is not referenced elsewhere, possibly by
copying it:

my $var2 = $var;
$sub = sub () { $var2 };

If you do want this subroutine to be a closure that reflects future
changes to the variable that it closes over, add an explicit C:

my $var;
$sub = sub () { return $var };

This usage has been deprecated, and will no longer be allowed in Perl 5.32.

=head2 Perl 5.30

=head3 C<< $* >> is no longer supported

Before Perl 5.10, setting C<< $* >> to a true value globally enabled
multi-line matching within a string. This relique from the past lost
its special meaning in 5.10. Use of this variable will be a fatal error
in Perl 5.30, freeing the variable up for a future special meaning.

To enable multiline matching one should use the C<< /m >> regexp
modifier (possibly in combination with C<< /s >>). This can be set
on a per match bases, or can be enabled per lexical scope (including
a whole file) with C<< use re '/m' >>.

=head3 C<< $# >> is no longer supported

This variable used to have a special meaning -- it could be used
to control how numbers were formatted when printed. This seldom
used functionality was removed in Perl 5.10. In order to free up
the variable for a future special meaning, its use will be a fatal
error in Perl 5.30.

To specify how numbers are formatted when printed, one is adviced
to use C<< printf >> or C<< sprintf >> instead.

=head3 C<< File::Glob::glob() >> will disappear

C<< File::Glob >> has a function called C<< glob >>, which just calls
C<< bsd_glob >>. However, its prototype is different from the prototype
of C<< CORE::glob >>, and hence, C<< File::Glob::glob >> should not
be used.

C<< File::Glob::glob() >> was deprecated in Perl 5.8. A deprecation
message was issued from Perl 5.26 onwards, and the function will
disappear in Perl 5.30.

Code using C<< File::Glob::glob() >> should call
C<< File::Glob::bsd_glob() >> instead.

=head3 Unescaped left braces in regular expressions

The simple rule to remember, if you want to match a literal C<{>
character (U+007B C) in a regular expression
pattern, is to escape each literal instance of it in some way.
Generally easiest is to precede it with a backslash, like C<\{>
or enclose it in square brackets (C<[{]>). If the pattern
delimiters are also braces, any matching right brace (C<}>) should
also be escaped to avoid confusing the parser, for example,

qr{abc\{def\}ghi}

Forcing literal C<{> characters to be escaped will enable the Perl
language to be extended in various ways in future releases. To avoid
needlessly breaking existing code, the restriction is is not enforced in
contexts where there are unlikely to ever be extensions that could
conflict with the use there of C<{> as a literal.

Literal uses of C<{> were deprecated in Perl 5.20, and some uses of it
started to give deprecation warnings since. These cases were made fatal
in Perl 5.26. Due to an oversight, not all cases of a use of a literal
C<{> got a deprecation warning. These cases started warning in Perl 5.26,
and they will be fatal by Perl 5.30.

=head3 Unqualified C

Use of C instead of C was deprecated in Perl 5.8,
and an unqualified C will no longer be available in Perl 5.30.

See L.

=head3 Using my() in false conditional.

There has been a long-standing bug in Perl that causes a lexical variable
not to be cleared at scope exit when its declaration includes a false
conditional. Some people have exploited this bug to achieve a kind of
static variable. Since we intend to fix this bug, we don't want people
relying on this behavior.

Instead, it's recommended one uses C variables to achieve the
same effect:

use 5.10.0;
sub count {state $counter; return ++ $counter}
say count (); # Prints 1
say count (); # Prints 2

C variables were introduced in Perl 5.10.

Alternatively, you can achieve a similar static effect by
declaring the variable in a separate block outside the function, eg

sub f { my $x if 0; return $x++ }

becomes

{ my $x; sub f { return $x++ } }

The use of C in a false conditional has been deprecated in
Perl 5.10, and it will become a fatal error in Perl 5.30.

=head3 Reading/writing bytes from/to :utf8 handles.

The sysread(), recv(), syswrite() and send() operators are
deprecated on handles that have the C<:utf8> layer, either explicitly, or
implicitly, eg., with the C<:encoding(UTF-16LE)> layer.

Both sysread() and recv() currently use only the C<:utf8> flag for the stream,
ignoring the actual layers. Since sysread() and recv() do no UTF-8
validation they can end up creating invalidly encoded scalars.

Similarly, syswrite() and send() use only the C<:utf8> flag, otherwise ignoring
any layers. If the flag is set, both write the value UTF-8 encoded, even if
the layer is some different encoding, such as the example above.

Ideally, all of these operators would completely ignore the C<:utf8> state,
working only with bytes, but this would result in silently breaking existing
code. To avoid this a future version of perl will throw an exception when
any of sysread(), recv(), syswrite() or send() are called on handle with the
C<:utf8> layer.

In Perl 5.30, it will no longer be possible to use sysread(), recv(),
syswrite() or send() to read or send bytes from/to :utf8 handles.

=head3 Use of unassigned code point or non-standalone grapheme for a delimiter.

A grapheme is what appears to a native-speaker of a language to be a
character. In Unicode (and hence Perl) a grapheme may actually be
several adjacent characters that together form a complete grapheme. For
example, there can be a base character, like "R" and an accent, like a
circumflex "^", that appear when displayed to be a single character with
the circumflex hovering over the "R". Perl currently allows things like
that circumflex to be delimiters of strings, patterns, I. When
displayed, the circumflex would look like it belongs to the character
just to the left of it. In order to move the language to be able to
accept graphemes as delimiters, we have to deprecate the use of
delimiters which aren't graphemes by themselves. Also, a delimiter must
already be assigned (or known to be never going to be assigned) to try
to future-proof code, for otherwise code that works today would fail to
compile if the currently unassigned delimiter ends up being something
that isn't a stand-alone grapheme. Because Unicode is never going to
assign
L, nor
L, those can be delimiters, and
their use won't raise this warning.

In Perl 5.30, delimiters which are unassigned code points, or which
are non-standalone graphemes will be fatal.

=head3 In XS code, use of various macros dealing with UTF-8.

These macros will require an extra parameter in Perl 5.30:
C,
C,
C,
C,
C,
C,
C,
C,
C,
C,
C,
C,
C,
C,
C,
C,
C,
C,
C,
C,
C,
C,
C,
C,
C,
C,
C,
C,
C,
C,
C,
and
C.

There is now a macro that corresponds to each one of these, simply by
appending C<_safe> to the name. It takes the extra parameter.
For example, C corresponds to C, but
takes the extra parameter, and its use doesn't generate a deprecation
warning. All are documented in L and
L.

You can change to use these versions at any time, or, if you can live
with the deprecation messages, wait until 5.30 and add the parameter to
the existing calls, without changing the names.

=head2 Perl 5.28

=head3 Attribute "%s" is deprecated, and will disappear in 5.28

The attributes C<< :locked >> (on code references) and C<< :unique >>
(on array, hash and scalar references) have had no effect since
Perl 5.005 and Perl 5.8.8 respectively. Their use has been deprecated
since.

These attributes will no longer be recognized in Perl 5.28, and will
then result in a syntax error. Since the attributes do not do anything,
removing them from your code fixes the deprecation warning; and removing
them will not influence the behaviour of your code.

=head3 Bare here-document terminators

Perl has allowed you to use a bare here-document terminator to have the
here-document end at the first empty line. This practise was deprecated
in Perl 5.000, and this will be a fatal error in Perl 5.28.

You are encouraged to use the explictly quoted form if you wish to
use an empty line as the terminator of the here-document:

print <<"";
Print this line.

# Previous blank line ends the here-document.

=head3 Setting $/ to a reference to a non-positive integer

You assigned a reference to a scalar to C<$/> where the
referenced item is not a positive integer. In older perls this B
to work the same as setting it to C but was in fact internally
different, less efficient and with very bad luck could have resulted in
your file being split by a stringified form of the reference.

In Perl 5.20.0 this was changed so that it would be B the same as
setting C<$/> to undef, with the exception that this warning would be
thrown.

In Perl 5.28, this will throw a fatal error.

You are recommended to change your code to set C<$/> to C explicitly
if you wish to slurp the file.

=head3 Limit on the value of Unicode code points.

Unicode only allows code points up to 0x10FFFF, but Perl allows much
larger ones. However, using code points exceeding the maximum value
of an integer (C) may break the perl interpreter in some constructs,
including causing it to hang in a few cases. The known problem areas
are in C, regular expression pattern matching using quantifiers,
as quote delimiters in C...I> (where I is the C of a large
code point), and as the upper limits in loops.

The use of out of range code points was deprecated in Perl 5.24, and
it will be a fatal error in Perl 5.28.

If your code is to run on various platforms, keep in mind that the upper
limit depends on the platform. It is much larger on 64-bit word sizes
than 32-bit ones.

=head3 Use of comma-less variable list in formats.

It's allowed to use a list of variables in a format, without
separating them with commas. This usage has been deprecated
for a long time, and it will be a fatal error in Perl 5.28.

=head3 Use of C<\N{}>

Use of C<\N{}> with nothing between the braces was deprecated in
Perl 5.24, and will throw a fatal error in Perl 5.28.

Since such a construct is equivalent to using an empty string,
you are recommended to remove such C<\N{}> constructs.

=head3 Using the same symbol to open a filehandle and a dirhandle

It used to be legal to use C to associate both a
filehandle and a dirhandle to the same symbol (glob or scalar).
This idiom is likely to be confusing, and it was deprecated in
Perl 5.10.

Using the same symbol to C a filehandle and a dirhandle
will be a fatal error in Perl 5.28.

You should be using two different symbols instead.

=head3 ${^ENCODING} is no longer supported.

The special variable C<${^ENCODING}> was used to implement
the C pragma. Setting this variable to anything other
than C was deprecated in Perl 5.22. Full deprecation
of the variable happened in Perl 5.25.3.

Setting this variable will become a fatal error in Perl 5.28.

=head3 C<< B::OP::terse >>

This method, which just calls C<< B::Concise::b_terse >>, has been
deprecated, and will disappear in Perl 5.28. Please use
C<< B::Concise >> instead.

=head3 Use of inherited AUTOLOAD for non-method %s() is deprecated

As an (ahem) accidental feature, C subroutines are looked
up as methods (using the C<@ISA> hierarchy) even when the subroutines
to be autoloaded were called as plain functions (e.g. C),
not as methods (e.g. C<< Foo->bar() >> or C<< $obj->bar() >>).

This bug will be rectified in future by using method lookup only for
methods' Cs.

The simple rule is: Inheritance will not work when autoloading
non-methods. The simple fix for old code is: In any module that used
to depend on inheriting C for non-methods from a base class
named C, execute C<*AUTOLOAD = \&BaseClass::AUTOLOAD> during
startup.

In code that currently says C
you should remove AutoLoader from @ISA and change C to
C.

This feature was deprecated in Perl 5.004, and will be fatal in Perl 5.28.

=head3 Use of code points over 0xFF in string bitwise operators

The string bitwise operators, C<&>, C<|>, C<^>, and C<~>, treat
their operands as strings of bytes. As such, values above 0xFF
are nonsensical. Using such code points with these operators
was deprecated in Perl 5.24, and will be fatal in Perl 5.28.

=head3 In XS code, use of C

This function is being removed; instead convert to call
the appropriate one of:
L|perlapi/toFOLD_utf8_safe>.
L|perlapi/toLOWER_utf8_safe>,
L|perlapi/toTITLE_utf8_safe>,
or
L|perlapi/toUPPER_utf8_safe>.

=head2 Perl 5.26

=head3 C<< --libpods >> in C<< Pod::Html >>

Since Perl 5.18, the option C<< --libpods >> has been deprecated, and
using this option did not do anything other than producing a warning.

The C<< --libpods >> option is no longer recognized in Perl 5.26.

=head3 The utilities C<< c2ph >> and C<< pstruct >>

These old, perl3-era utilities have been deprecated in favour of
C<< h2xs >> for a long time. In Perl 5.26, they have been removed.

=head3 Trapping C<< $SIG {__DIE__} >> other than during program exit.

The C<$SIG{__DIE__}> hook is called even inside an C. It was
never intended to happen this way, but an implementation glitch made
this possible. This used to be deprecated, as it allowed strange action
at a distance like rewriting a pending exception in C<$@>. Plans to
rectify this have been scrapped, as users found that rewriting a
pending exception is actually a useful feature, and not a bug.

Perl never issued a deprecation warning for this; the deprecation
was by documentation policy only. But this deprecation has been
lifted in Perl 5.26.

=head3 Malformed UTF-8 string in "%s"

This message indicates a bug either in the Perl core or in XS
code. Such code was trying to find out if a character, allegedly
stored internally encoded as UTF-8, was of a given type, such as
being punctuation or a digit. But the character was not encoded
in legal UTF-8. The C<%s> is replaced by a string that can be used
by knowledgeable people to determine what the type being checked
against was.

Passing malformed strings was deprecated in Perl 5.18, and
became fatal in Perl 5.26.

=head2 Perl 5.24

=head3 Use of C<< *glob{FILEHANDLE} >>

The use of C<< *glob{FILEHANDLE} >> was deprecated in Perl 5.8.
The intention was to use C<< *glob{IO} >> instead, for which
C<< *glob{FILEHANDLE} >> is an alias.

However, this feature was undeprecated in Perl 5.24.

=head3 Calling POSIX::%s() is deprecated

The following functions in the C module are no longer available:
C, C, C, C, C, C,
C, C, C, C, and C. The
functions are buggy and don't work on UTF-8 encoded strings. See their
entries in L for more information.

The functions were deprecated in Perl 5.20, and removed in Perl 5.24.

=head2 Perl 5.16

=head3 Use of %s on a handle without * is deprecated

It used to be possible to use C, C or C on a scalar
while the scalar holds a typeglob. This caused its filehandle to be
tied. It left no way to tie the scalar itself when it held a typeglob,
and no way to untie a scalar that had had a typeglob assigned to it.

This was deprecated in Perl 5.14, and the bug was fixed in Perl 5.16.

So now C will always tie the scalar, not the handle it holds.
To tie the handle, use C (with an explicit asterisk). The same
applies to C and C.

=head1 SEE ALSO

L, L.

=cut}