that expected a numeric value instead. If you're fortunate the message
will identify which operator was so unfortunate.
+Note that for the C<Inf> and C<NaN> (infinity and not-a-number) the
+definition of "numeric" is somewhat unusual: the strings themselves
+(like "Inf") are considered numeric, and anything following them is
+considered non-numeric.
+
=item Argument list not closed for PerlIO layer "%s"
(W layer) When pushing a layer with arguments onto the Perl I/O
(P) An internal request asked to add a hash entry to something that
wasn't a symbol table entry.
+=item Bad symbol for scalar
+
+(P) An internal request asked to add a scalar entry to something that
+wasn't a symbol table entry.
+
=item Bareword found in conditional
(W bareword) The compiler found a bareword where it expected a
(P) When starting a new thread or returning values from a thread, Perl
encountered an invalid data type.
+=item Both or neither range ends should be Unicode in regex; marked by
+S<<-- HERE> in m/%s/
+
+(W regexp) (only under C<S<use re 'strict'>> or within C<(?[...])>)
+
+In a bracketed character class in a regular expression pattern, you
+had a range which has exactly one end of it specified using C<\N{}>, and
+the other end is specified using a non-portable mechanism. Perl treats
+the range as a Unicode range, that is, all the characters in it are
+considered to be the Unicode characters, and which may be different code
+points on some platforms Perl runs on. For example, C<[\N{U+06}-\x08]>
+is treated as if you had instead said C<[\N{U+06}-\N{U+08}]>, that is it
+matches the characters whose code points in Unicode are 6, 7, and 8.
+But that C<\x08> might indicate that you meant something different, so
+the warning gets raised.
+
=item Buffer overflow in prime_env_iter: %s
(W internal) A warning peculiar to VMS. While Perl was preparing to
characters and Perl was unable to create a unique filename during
inplace editing with the B<-i> switch. The file was ignored.
+=item Can't do %s("%s") on non-UTF-8 locale; resolved to "%s".
+
+(W locale) You are 1) running under "C<use locale>"; 2) the current
+locale is not a UTF-8 one; 3) you tried to do the designated case-change
+operation on the specified Unicode character; and 4) the result of this
+operation would mix Unicode and locale rules, which likely conflict.
+Mixing of different rule types is forbidden, so the operation was not
+done; instead the result is the indicated value, which is the best
+available that uses entirely Unicode rules. That turns out to almost
+always be the original character, unchanged.
+
+It is generally a bad idea to mix non-UTF-8 locales and Unicode, and
+this issue is one of the reasons why. This warning is raised when
+Unicode rules would normally cause the result of this operation to
+contain a character that is in the range specified by the locale,
+0..255, and hence is subject to the locale's rules, not Unicode's.
+
+If you are using locale purely for its characteristics related to things
+like its numeric and time formatting (and not C<LC_CTYPE>), consider
+using a restricted form of the locale pragma (see L<perllocale/The "use
+locale" pragma>) like "S<C<use locale ':not_characters'>>".
+
+Note that failed case-changing operations done as a result of
+case-insensitive C</i> regular expression matching will show up in this
+warning as having the C<fc> operation (as that is what the regular
+expression engine calls behind the scenes.)
+
=item Can't do waitpid with flags
(F) This machine doesn't have either waitpid() or wait4(), so only
=item Can't use %s for loop variable
-(F) Only a simple scalar variable may be used as a loop variable on a
-foreach.
+(P) The parser got confused when trying to parse a C<foreach> loop.
=item Can't use global %s in "%s"
could be defined by a translator installed into C<$^H{charnames}>.
See L<charnames/CUSTOM ALIASES>.
-=item \C is deprecated in regex; marked by <-- HERE in m/%s/
+=item \C is deprecated in regex; marked by S<<-- HERE> in m/%s/
(D deprecated, regexp) The \C character class is deprecated, and will
become a compile-time error in a future release of perl (tentatively
usually indicates a syntax error in dereferencing the constant value.
See L<perlsub/"Constant Functions"> and L<constant>.
+=item Constants from lexical variables potentially modified elsewhere are
+deprecated
+
+(D deprecated) 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.
+
+This usage is deprecated, because the behavior is likely to change
+in a future version of Perl.
+
+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 };
+
=item Constant subroutine %s redefined
(W redefine)(S) You redefined a subroutine which had previously
(F) The parser found inconsistencies either while attempting
to define an overloaded constant, or when trying to find the
character name specified in the C<\N{...}> escape. Perhaps you
-forgot to load the corresponding L<overload> pragma?.
+forgot to load the corresponding L<overload> pragma?
+
+=item :const is experimental
+
+(S experimental::const_attr) The "const" attribute is experimental.
+If you want to use the feature, disable the warning with C<no warnings
+'experimental::const_attr'>, but know that in doing so you are taking
+the risk that your code may break in a future Perl version.
+
+=item :const is not permitted on named subroutines
+
+(F) The "const" attribute causes an anonymous subroutine to be run and
+its value captured at the time that it is cloned. Named subroutines are
+not cloned like this, so the attribute does not make sense on them.
=item Copy method did not return a reference
most likely cause of this error is that you left out a parenthesis inside
of the C<....> part.
-The <-- HERE shows whereabouts in the regular expression the problem was
+The S<<-- HERE> shows whereabouts in the regular expression the problem was
discovered.
=item %s defines neither package nor VERSION--version check failed
(F) You used a pattern that nested too many EVAL calls without consuming
any text. Restructure the pattern so that text is consumed.
-The <-- HERE shows whereabouts in the regular expression the problem was
+The S<<-- HERE> shows whereabouts in the regular expression the problem was
discovered.
=item Excessively long <> operator
S<<-- HERE> in m/%s/
(W regexp) Named Unicode character escapes (C<\N{...}>) may return a
-zero-length sequence. When such an escape is used in a character class
-its behaviour is not well defined. Check that the correct escape has
-been used, and the correct charname handler is in scope.
+zero-length sequence. When such an escape is used in a character
+class its behavior is not well defined. Check that the correct
+escape has been used, and the correct charname handler is in scope.
=item Illegal binary digit %s
with the B<-D> option with no flags to see the list of acceptable values.
See also L<perlrun/-Dletters>.
+=item Invalid quantifier in {,} in regex; marked by S<<-- HERE> in m/%s/
+
+(F) The pattern looks like a {min,max} quantifier, but the min or max
+could not be parsed as a valid number - either it has leading zeroes,
+or it represents too big a number to cope with. The S<<-- HERE> shows
+where in the regular expression the problem was discovered. See L<perlre>.
+
=item Invalid [] range "%s" in regex; marked by S<<-- HERE> in m/%s/
(F) The range specified in a character class had a minimum character
(F) Your machine doesn't implement the sockatmark() functionality,
neither as a system call nor an ioctl call (SIOCATMARK).
+=item '%s' is an unknown bound type in regex; marked by S<<-- HERE> in m/%s/
+
+(F) You used C<\b{...}> or C<\B{...}> and the C<...> is not known to
+Perl. The current valid ones are given in
+L<perlrebackslash/\b{}, \b, \B{}, \B>.
+
+=item "%s" is more clearly written simply as "%s" in regex; marked by S<<-- HERE> in m/%s/
+
+(W regexp) (only under C<S<use re 'strict'>> or within C<(?[...])>)
+
+You specified a character that has the given plainer way of writing it,
+and which is also portable to platforms running with different character
+sets.
+
=item $* is no longer supported
(D deprecated, syntax) The special variable C<$*>, deprecated in older
form of C<open> does not support pipes, such as C<open($pipe, '|-', @args)>.
Use the two-argument C<open($pipe, '|prog arg1 arg2...')> form instead.
+=item %s: loadable library and perl binaries are mismatched (got handshake key %p, needed %p)
+
+(P) A dynamic loading library C<.so> or C<.dll> was being loaded into the
+process that was built against a different build of perl than the
+said library was compiled against. Reinstalling the XS module will
+likely fix this error.
+
+=item Locale '%s' may not work well.%s
+
+(W locale) You are using the named locale, which is a non-UTF-8 one, and
+which Perl has determined is not fully compatible with Perl. The second
+C<%s> gives a reason.
+
+By far the most common reason is that the locale has characters in it
+that are represented by more than one byte. The only such locales that
+Perl can handle are the UTF-8 locales. Most likely the specified locale
+is a non-UTF-8 one for an East Asian language such as Chinese or
+Japanese. If the locale is a superset of ASCII, the ASCII portion of it
+may work in Perl.
+
+Some essentially obsolete locales that aren't supersets of ASCII, mainly
+those in ISO 646 or other 7-bit locales, such as ASMO 449, can also have
+problems, depending on what portions of the ASCII character set get
+changed by the locale and are also used by the program.
+The warning message lists the determinable conflicting characters.
+
+Note that not all incompatibilities are found.
+
+If this happens to you, there's not much you can do except switch to use a
+different locale or use L<Encode> to translate from the locale into
+UTF-8; if that's impracticable, you have been warned that some things
+may break.
+
+This message is output once each time a bad locale is switched into
+within the scope of C<S<use locale>>, or on the first possibly-affected
+operation if the C<S<use locale>> inherits a bad one. It is not raised
+for any operations from the L<POSIX> module.
+
=item localtime(%f) failed
(W overflow) You called C<localtime> with a number that it could not handle:
(F) Missing right brace in C<\x{...}>, C<\p{...}>, C<\P{...}>, or C<\N{...}>.
+=item Missing right brace on \N{}
+
=item Missing right brace on \N{} or unescaped left brace after \N
(F) C<\N> has two meanings.
class loses its specialness: it matches almost everything, which is
probably not what you want.
-=item \N{} in inverted character class or as a range end-point is restricted to one character in regex; marked
-by S<<-- HERE> in m/%s/
+=item \N{} in inverted character class or as a range end-point is restricted to one character in regex; marked by <-- HERE in m/%s/
(F) Named Unicode character escapes (C<\N{...}>) may return a
multi-character sequence. Even though a character class is
it throwing an exception, use C<maybe::next::method>
or C<next::can>. See L<mro>.
+=item Non-finite repeat count does nothing
+
+(W numeric) You tried to execute the
+L<C<x>|perlop/Multiplicative Operators> repetition operator C<Inf> (or
+C<-Inf>) or C<NaN> times, which doesn't make sense.
+
=item Non-hex character in regex; marked by S<<-- HERE> in m/%s/
(F) In a regular expression, there was a non-hexadecimal character where
(F) Fully qualified variable names are not allowed in "our"
declarations, because that doesn't make much sense under existing
-semantics. Such syntax is reserved for future extensions.
+rules. Such syntax is reserved for future extensions.
=item No Perl script found in input
imagine. The sole exceptions to this are that zero padding will
take place when going past the end of the string when either
C<sysread()>ing a file, or when seeking past the end of a scalar opened
-for I/O (in anticipation of future reads and to imitate the behaviour
+for I/O (in anticipation of future reads and to imitate the behavior
with real files).
=item %s() on unopened %s
=item Operation "%s" returns its argument for non-Unicode code point 0x%X
-(S non_unicode) You performed an operation requiring Unicode semantics
+(S non_unicode) You performed an operation requiring Unicode rules
on a code point that is not in Unicode, so what it should do is not
defined. Perl has chosen to have it do nothing, and warn you.
=item Operation "%s" returns its argument for UTF-16 surrogate U+%X
(S surrogate) You performed an operation requiring Unicode
-semantics on a Unicode surrogate. Unicode frowns upon the use
+rules on a Unicode surrogate. Unicode frowns upon the use
of surrogates for anything but storing strings in UTF-16, but
-semantics are (reluctantly) defined for the surrogates, and
+rules are (reluctantly) defined for the surrogates, and
they are to do nothing for this operation. Because the use of
surrogates can be dangerous, Perl warns.
command-line switch. (This output goes to STDOUT unless you've
redirected it with select().)
+=item Perl API version %s of %s does not match %s
+
+(F) The XS module in question was compiled against a different incompatible
+version of Perl than the one that has loaded the XS module.
+
=item Perl folding rules are not up-to-date for 0x%X; please use the perlbug
utility to report; in regex; marked by S<<-- HERE> in m/%s/
no warnings "experimental::autoderef";
-=item POSIX class [:%s:] unknown in regex; marked by S<< <-- HERE in m/%s/ >>
+=item POSIX class [:%s:] unknown in regex; marked by S<<-- HERE> in m/%s/
(F) The class in the character class [: :] syntax is unknown. The S<<-- HERE>
shows whereabouts in the regular expression the problem was discovered.
sub { 1 if die; }
-=item Possible precedence problem on bitwise %c operator
+=item Possible precedence problem on bitwise %s operator
(W precedence) Your program uses a bitwise logical operator in conjunction
with a numeric comparison operator, like this :
no warnings "experimental::autoderef";
-=item Quantifier follows nothing in regex; marked by S<< <-- HERE in m/%s/ >>
+=item Quantifier follows nothing in regex; marked by S<<-- HERE> in m/%s/
(F) You started a regular expression with a quantifier. Backslash it if
you meant it literally. The S<<-- HERE> shows whereabouts in the regular
expression the problem was discovered. See L<perlre>.
-=item Quantifier in {,} bigger than %d in regex; marked by S<<-- HERE> in
-m/%s/
+=item Quantifier in {,} bigger than %d in regex; marked by S<<-- HERE> in m/%s/
(F) There is currently a limit to the size of the min and max values of
the {min,max} construct. The S<<-- HERE> shows whereabouts in the regular
One possible workaround is to force Perl to use magical string increment
by prepending "0" to your numbers.
+=item Ranges of ASCII printables should be some subset of "0-9", "A-Z", or
+"a-z" in regex; marked by S<<-- HERE> in m/%s/
+
+(W regexp) (only under C<S<use re 'strict'>> or within C<(?[...])>)
+
+Stricter rules help to find typos and other errors. Perhaps you didn't
+even intend a range here, if the C<"-"> was meant to be some other
+character, or should have been escaped (like C<"\-">). If you did
+intend a range, the one that was used is not portable between ASCII and
+EBCDIC platforms, and doesn't have an obvious meaning to a casual
+reader.
+
+ [3-7] # OK; Obvious and portable
+ [d-g] # OK; Obvious and portable
+ [A-Y] # OK; Obvious and portable
+ [A-z] # WRONG; Not portable; not clear what is meant
+ [a-Z] # WRONG; Not portable; not clear what is meant
+ [%-.] # WRONG; Not portable; not clear what is meant
+ [\x41-Z] # WRONG; Not portable; not obvious to non-geek
+
+(You can force portability by specifying a Unicode range, which means that
+the endpoints are specified by
+L<C<\N{...}>|perlrecharclass/Character Ranges>, but the meaning may
+still not be obvious.)
+The stricter rules require that ranges that start or stop with an ASCII
+character that is not a control have all their endpoints be the literal
+character, and not some escape sequence (like C<"\x41">), and the ranges
+must be all digits, or all uppercase letters, or all lowercase letters.
+
+=item Ranges of digits should be from the same group in regex; marked by
+S<<-- HERE> in m/%s/
+
+(W regexp) (only under C<S<use re 'strict'>> or within C<(?[...])>)
+
+Stricter rules help to find typos and other errors. You included a
+range, and at least one of the end points is a decimal digit. Under the
+stricter rules, when this happens, both end points should be digits in
+the same group of 10 consecutive digits.
+
=item readdir() attempted on invalid dirhandle %s
(W io) The dirhandle you're reading from is either closed or not really
you wanted to have the character with ordinal 7 inserted into the regular
expression, prepend zeroes to make it three digits long: C<\007>
-The <-- HERE shows whereabouts in the regular expression the problem was
+The S<<-- HERE> shows whereabouts in the regular expression the problem was
discovered.
=item Reference to nonexistent named group in regex; marked by S<<-- HERE>
such as C<(?'NAME'...)> or C<< (?<NAME>...) >>. Check if the name has been
spelled correctly both in the backreference and the declaration.
-The <-- HERE shows whereabouts in the regular expression the problem was
+The S<<-- HERE> shows whereabouts in the regular expression the problem was
discovered.
=item Reference to nonexistent or unclosed group in regex; marked by
are not at least seven sets of closed capturing parentheses in the
expression before where the C<\g{-7}> was located.
-The <-- HERE shows whereabouts in the regular expression the problem was
+The S<<-- HERE> shows whereabouts in the regular expression the problem was
discovered.
=item regexp memory corruption
(W closed) The socket you're sending to got itself closed sometime
before now. Check your control flow.
+=item Sequence "\c{" invalid
+
+(F) These three characters may not appear in sequence in a
+double-quotish context. This message is raised only on non-ASCII
+platforms (a different error message is output on ASCII ones). If you
+were intending to specify a control character with this sequence, you'll
+have to use a different way to specify it.
+
=item Sequence (? incomplete in regex; marked by S<<-- HERE> in m/%s/
(F) A regular expression ended with an incomplete extension (?. The
S<<-- HERE> shows whereabouts in the regular expression the problem was
discovered.
-=item Sequence "\c{" invalid
-
-(F) These three characters may not appear in sequence in a
-double-quotish context. This message is raised only on non-ASCII
-platforms (a different error message is output on ASCII ones). If you
-were intending to specify a control character with this sequence, you'll
-have to use a different way to specify it.
-
=item Sequence \%s... not terminated in regex; marked by S<<-- HERE> in
m/%s/
forget to check the return value of your socket() call? See
L<perlfunc/setsockopt>.
+=item Setting ${^ENCODING} is deprecated
+
+(D deprecated) You assigned a non-C<undef> value to C<${^ENCODING}>.
+This is deprecated; see C<L<perlvar/${^ENCODING}>> for details.
+
=item Setting $/ to a reference to %s as a form of slurp is deprecated, treating as undef
-(W deprecated) You assigned a reference to a scalar to C<$/> where the
+(D deprecated) You assigned a reference to a scalar to C<$/> where the
referenced item is not a positive integer. In older perls this B<appeared>
to work the same as setting it to C<undef> but was in fact internally
different, less efficient and with very bad luck could have resulted in
eval "sub name { ... }";
}
+=item Subroutine "%s" will not stay shared
+
+(W closure) An inner (nested) I<named> subroutine is referencing a "my"
+subroutine defined in an outer named subroutine.
+
+When the inner subroutine is called, it will see the value of the outer
+subroutine's lexical subroutine as it was before and during the *first*
+call to the outer subroutine; in this case, after the first call to the
+outer subroutine is complete, the inner and outer subroutines will no
+longer share a common value for the lexical subroutine. In other words,
+it will no longer be shared. This will especially make a difference
+if the lexical subroutines accesses lexical variables declared in its
+surrounding scope.
+
+This problem can usually be solved by making the inner subroutine
+anonymous, using the C<sub {}> syntax. When inner anonymous subs that
+reference lexical subroutines in outer subroutines are created, they
+are automatically rebound to the current values of such lexical subs.
+
=item Substitution loop
(P) The substitution was looping infinitely. (Obviously, a substitution
(R&NAME) true if directly inside named capture
(DEFINE) always false; for defining named subpatterns
-The <-- HERE shows whereabouts in the regular expression the problem was
+The S<<-- HERE> shows whereabouts in the regular expression the problem was
discovered. See L<perlre>.
=item Switch (?(condition)... not terminated in regex; marked by
This is to prevent the problem of one module changing the array base out
from under another module inadvertently. See L<perlvar/$[> and L<arybase>.
+=item The bitwise feature is experimental
+
+(S experimental::bitwise) This warning is emitted if you use bitwise
+operators (C<& | ^ ~ &. |. ^. ~.>) with the "bitwise" feature enabled.
+Simply suppress the warning if you want to use the feature, but know
+that in doing so you are taking the risk of using an experimental
+feature which may change or be removed in a future Perl version:
+
+ no warnings "experimental::bitwise";
+ use feature "bitwise";
+ $x |.= $y;
+
=item The crypt() function is unimplemented due to excessive paranoia.
(F) Configure couldn't find the crypt() function on your machine,
Check the #! line, or manually feed your script into Perl yourself.
=item Unescaped left brace in regex is deprecated, passed through in regex;
-marked by <-- HERE in m/%s/
+marked by S<<-- HERE> in m/%s/
(D deprecated, regexp) You used a literal C<"{"> character in a regular
expression pattern. You should change to use C<"\{"> instead, because a
(R&NAME) true if directly inside named capture
(DEFINE) always false; for defining named subpatterns
-The <-- HERE shows whereabouts in the regular expression the problem was
+The S<<-- HERE> shows whereabouts in the regular expression the problem was
discovered. See L<perlre>.
=item Unknown Unicode option letter '%c'
if ($string =~ /$pattern/) { ... }
-The <-- HERE shows whereabouts in the regular expression the problem was
+The S<<-- HERE> shows whereabouts in the regular expression the problem was
discovered. See L<perlre>.
=item Useless localization of %s
if ($string =~ /$pattern/o) { ... }
-The <-- HERE shows whereabouts in the regular expression the problem was
+The S<<-- HERE> shows whereabouts in the regular expression the problem was
discovered. See L<perlre>.
+=item Useless use of attribute "const"
+
+(W misc) The "const" attribute has no effect except
+on anonymous closure prototypes. You applied it to
+a subroutine via L<attributes.pm|attributes>. This is only useful
+inside an attribute handler for an anonymous subroutine.
+
=item Useless use of /d modifier in transliteration operator
(W misc) You have used the /d modifier where the searchlist has the
form if you wish to use an empty line as the terminator of the
here-document.
+=item Use of \b{} for non-UTF-8 locale is wrong. Assuming a UTF-8 locale
+
+(W locale) You are matching a regular expression using locale rules,
+and a Unicode boundary is being matched, but the locale is not a Unicode
+one. This doesn't make sense. Perl will continue, assuming a Unicode
+(UTF-8) locale, but the results could well be wrong except if the locale
+happens to be ISO-8859-1 (Latin1) where this message is spurious and can
+be ignored.
+
=item Use of chdir('') or chdir(undef) as chdir() deprecated
(D deprecated) chdir() with no arguments is documented to change to
=item Use of literal non-graphic characters in variable names is deprecated
-(D deprecated) Using literal non-graphic (including control) characters
-in the source to refer to the ^FOO variables, like C<$^X> and
+(D deprecated) Using literal non-graphic (including control)
+characters in the source to refer to the ^FOO variables, like C<$^X> and
C<${^GLOBAL_PHASE}> is now deprecated. (We use C<^X> and C<^G> here for
legibility. They actually represent the non-printable control
characters, code points 0x18 and 0x07, respectively; C<^A> would mean
-the control character whose code point is 0x01.) This only affects code
-like
-C<$\cT>, where C<\cT> is a control in the source code; C<${"\cT"}> and
+the control character whose code point is 0x01.) This only affects
+code like C<$\cT>, where C<\cT> is a control in the source code; C<${"\cT"}> and
C<$^T> remain valid. Things that are non-controls and also not graphic
are NO-BREAK SPACE and SOFT HYPHEN, which were previously only allowed
for historical reasons.
C<concatenation (.)> operator, even though there is no C<.> in
your program.
+=item "use re 'strict'" is experimental
+
+(S experimental::re_strict) The things that are different when a regular
+expression pattern is compiled under C<'strict'> are subject to change
+in future Perl releases in incompatible ways. This means that a pattern
+that compiles today may not in a future Perl release. This warning is
+to alert you to that risk.
+
=item Use \x{...} for more than two hex characters in regex; marked by
S<<-- HERE> in m/%s/
these circumstances, Perl discards all but the first character
of the returned sequence, which is not likely what you want.
+=item Using /u for '%s' instead of /%s in regex; marked by S<<-- HERE> in m/%s/
+
+(W regexp) You used a Unicode boundary (C<\b{...}> or C<\B{...}>) in a
+portion of a regular expression where the character set modifiers C</a>
+or C</aa> are in effect. These two modifiers indicate an ASCII
+interpretation, and this doesn't make sense for a Unicode defintion.
+The generated regular expression will compile so that the boundary uses
+all of Unicode. No other portion of the regular expression is affected.
+
=item Using !~ with %s doesn't make sense
(F) Using the C<!~> operator with C<s///r>, C<tr///r> or C<y///r> is
-currently reserved for future use, as the exact behaviour has not
+currently reserved for future use, as the exact behavior has not
been decided. (Simply returning the boolean opposite of the
modified string is usually not particularly useful.)
cheating. In general, you are supposed to explicitly mark the
filehandle with an encoding, see L<open> and L<perlfunc/binmode>.
+=item Wide character (U+%X) in %s
+
+(W locale) While in a single-byte locale (I<i.e.>, a non-UTF-8
+one), a multi-byte character was encountered. Perl considers this
+character to be the specified Unicode code point. Combining non-UTF-8
+locales and Unicode is dangerous. Almost certainly some characters
+will have two different representations. For example, in the ISO 8859-7
+(Greek) locale, the code point 0xC3 represents a Capital Gamma. But so
+also does 0x393. This will make string comparisons unreliable.
+
+You likely need to figure out how this multi-byte character got mixed up
+with your single-byte locale (or perhaps you thought you had a UTF-8
+locale, but Perl disagrees).
+
=item Within []-length '%c' not allowed
(F) The count in the (un)pack template may be replaced by C<[TEMPLATE]>
https://perl5.git.perl.org / perl5.git / blobdiff