Optional warnings are enabled by using the B<-w> switch. Warnings may
be captured by setting C<$SIG{__WARN__}> to a reference to a routine that
will be called on each warning instead of printing it. See L<perlvar>.
+
Trappable errors may be trapped using the eval operator. See
-L<perlfunc/eval>.
+L<perlfunc/eval>. In almost all cases, warnings may be selectively
+disabled or promoted to fatal errors using the C<warnings> pragma.
+See L<warnings>.
Some of these messages are generic. Spots that vary are denoted with a %s,
just as in a printf format. Note that some messages start with a %s!
=over 4
+=item "my sub" not yet implemented
+
+(F) Lexically scoped subroutines are not yet implemented. Don't try that
+yet.
+
=item "my" variable %s can't be in a package
(F) Lexically scoped variables aren't in a package, so it doesn't make sense
(F) The '!' is allowed in pack() and unpack() only after certain types.
See L<perlfunc/pack>.
+=item # cannot take a count
+
+(F) You had an unpack template indicating a counted-length string,
+but you have also specified an explicit size for the string.
+See L<perlfunc/pack>.
+
+=item # must be followed by a, A or Z
+
+(F) You had an unpack template indicating a counted-length string,
+which must be followed by one of the letters a, A or Z
+to indicate what sort of string is to be unpacked.
+See L<perlfunc/pack>.
+
+=item # must be followed by a*, A* or Z*
+
+(F) You had an pack template indicating a counted-length string,
+Currently the only things that can have their length counted are a*, A* or Z*.
+See L<perlfunc/pack>.
+
+=item # must follow a numeric type
+
+(F) You had an unpack template that contained a '#',
+but this did not follow some numeric unpack specification.
+See L<perlfunc/pack>.
+
=item % may only be used in unpack
(F) You can't pack a string by supplying a checksum, because the
checksumming process loses information, and you can't go the other
way. See L<perlfunc/unpack>.
+=item Repeat count in pack overflows
+
+(F) You can't specify a repeat count so large that it overflows
+your signed integers. See L<perlfunc/pack>.
+
+=item Repeat count in unpack overflows
+
+(F) You can't specify a repeat count so large that it overflows
+your signed integers. See L<perlfunc/unpack>.
+
=item /%s/: Unrecognized escape \\%c passed through
(W) You used a backslash-character combination which is not recognized
by parentheses turns into a function, with all the list operators arguments
found inside the parentheses. See L<perlop/Terms and List Operators (Leftward)>.
+=item %s() called too early to check prototype
+
+(W) You've called a function that has a prototype before the parser saw a
+definition or declaration for it, and Perl could not check that the call
+conforms to the prototype. You need to either add an early prototype
+declaration for the subroutine in question, or move the subroutine
+definition ahead of the call to get proper prototype checking. Alternatively,
+if you are certain that you're calling the function correctly, you may put
+an ampersand before the name to avoid the warning. See L<perlsub>.
+
=item %s argument is not a HASH element
(F) The argument to exists() must be a hash element, such as
(S) The symbol in question was declared but somehow went out of scope
before it could possibly have been used.
+=item %s package attribute may clash with future reserved word: %s
+
+(W) A lowercase attribute name was used that had a package-specific handler.
+That name might have a meaning to Perl itself some day, even though it
+doesn't yet. Perhaps you should use a mixed-case attribute name, instead.
+See L<attributes>.
+
=item %s syntax OK
(F) The final summary message when a C<perl -c> succeeds.
(F) You had a pack template that specified an absolute position outside
the string being unpacked. See L<perlfunc/pack>.
+=item <> should be quotes
+
+(F) You wrote C<require E<lt>fileE<gt>> when you should have written
+C<require 'file'>.
+
=item accept() on closed fd
(W) You tried to do an accept on a closed socket. Did you forget to check
To silently interpret it as the Perl operator, use the C<CORE::> prefix
on the operator (e.g. C<CORE::log($x)>) or by declaring the subroutine
-to be an object method (see L<attrs>).
+to be an object method (see L<perlsub/"Subroutine Attributes">
+or L<attributes>).
=item Args must match #! line
SvREFCNT_inc() was called too few times, or that the SV was mortalized
when it shouldn't have been, or that memory has been corrupted.
+=item Attempt to join self
+
+(F) You tried to join a thread from within itself, which is an
+impossible task. You may be joining the wrong thread, or you may
+need to move the join() to some other thread.
+
=item Attempt to pack pointer to temporary value
(W) You tried to pass a temporary value (like the result of a
could not be guaranteed (due to the errors), and since subsequent code
likely depends on its correct operation, Perl just gave up.
+=item Binary number > 0b11111111111111111111111111111111 non-portable
+
+(W) The binary number you specified is larger than 2**32-1
+(4294967295) and therefore non-portable between systems. See
+L<perlport> for more on portability concerns.
+
=item bind() on closed fd
(W) You tried to do a bind on a closed socket. Did you forget to check
the return value of your socket() call? See L<perlfunc/bind>.
+=item Bit vector size > 32 non-portable
+
+(W) Using bit vector sizes larger than 32 is non-portable.
+
=item Bizarre copy of %s in %s
(P) Perl detected an attempt to copy an internal value that is not copiable.
+=item Buffer overflow in prime_env_iter: %s
+
+(W) A warning peculiar to VMS. While Perl was preparing to iterate over
+%ENV, it encountered a logical name or symbol definition which was too long,
+so it was truncated to the string shown.
+
=item Callback called exit
(F) A subroutine invoked from an external package via perl_call_sv()
usually double the curlies to get the same effect though, because the inner
curlies will be considered a block that loops once. See L<perlfunc/next>.
+=item Can't read CRTL environ
+
+(S) A warning peculiar to VMS. Perl tried to read an element of %ENV
+from the CRTL's internal environment array and discovered the array was
+missing. You need to figure out where your CRTL misplaced its environ
+or define F<PERL_ENV_TABLES> (see L<perlvms>) so that environ is not searched.
+
=item Can't "redo" outside a block
(F) A "redo" statement was executed to restart the current block, but
in a function/method name or a failure to C<AutoSplit> the file, say, by
doing C<make install>.
-=item Can't locate %s in @INC
+=item Can't locate %s
-(F) You said to do (or require, or use) a file that couldn't be found
-in any of the libraries mentioned in @INC. Perhaps you need to set the
-PERL5LIB or PERL5OPT environment variable to say where the extra library
-is, or maybe the script needs to add the library name to @INC. Or maybe
-you just misspelled the name of the file. See L<perlfunc/require>.
+(F) You said to C<do> (or C<require>, or C<use>) a file that couldn't be
+found. Perl looks for the file in all the locations mentioned in @INC,
+unless the file name included the full path to the file. Perhaps you need
+to set the PERL5LIB or PERL5OPT environment variable to say where the extra
+library is, or maybe the script needs to add the library name to @INC. Or
+maybe you just misspelled the name of the file. See L<perlfunc/require>
+and L<lib>.
=item Can't locate object method "%s" via package "%s"
subscript. But to the left of the brackets was an expression that
didn't look like an array reference, or anything else subscriptable.
+=item Can't weaken a nonreference
+
+(F) You attempted to weaken something that was not a reference. Only
+references can be weakened.
+
=item Can't x= to read-only value
(F) You tried to repeat a constant value (often the undefined value) with
an assignment operator, which implies modifying the value itself.
Perhaps you need to copy the value to a temporary, and repeat that.
-=item Cannot find an opnumber for "%s"
+=item Can't find an opnumber for "%s"
(F) A string of a form C<CORE::word> was given to prototype(), but
there is no builtin with the name C<word>.
-=item Cannot resolve method `%s' overloading `%s' in package `%s'
+=item Can't resolve method `%s' overloading `%s' in package `%s'
(F|P) Error resolving overloading specified by a method name (as
opposed to a subroutine reference): no such method callable via the
package. If method name is C<???>, this is an internal error.
+=item Character class [:%s:] unknown
+
+(F) The class in the character class [: :] syntax is unknown.
+
+=item Character class syntax [%s] belongs inside character classes
+
+(W) The character class constructs [: :], [= =], and [. .] go
+I<inside> character classes, the [] are part of the construct,
+for example: /[012[:alpha:]345]/. Note that the last two constructs
+are not currently implemented, they are placeholders for future extensions.
+
=item Character class syntax [. .] is reserved for future extensions
(W) Within regular expression character classes ([]) the syntax beginning
expression character class, just quote the square brackets with the
backslash: "\[." and ".\]".
-=item Character class syntax [: :] is reserved for future extensions
-
-(W) Within regular expression character classes ([]) the syntax beginning
-with "[:" and ending with ":]" is reserved for future extensions.
-If you need to represent those character sequences inside a regular
-expression character class, just quote the square brackets with the
-backslash: "\[:" and ":\]".
-
=item Character class syntax [= =] is reserved for future extensions
(W) Within regular expression character classes ([]) the syntax
inlining. See L<perlsub/"Constant Functions"> for commentary and
workarounds.
+=item constant(%s): %%^H is not localized
+
+(F) When setting compile-time-lexicalized hash %^H one should set the
+corresponding bit of $^H as well.
+
+=item constant(%s): %s
+
+(F) Compile-time-substitutions (such as overloaded constants and
+character names) were not correctly set up.
+
=item Copy method did not return a reference
(F) The method which overloads "=" is buggy. See L<overload/Copy Constructor>.
recursion, unless you're writing strange benchmark programs, in which
case it indicates something else.
+=item defined(@array) is deprecated
+
+(D) defined() is not usually useful on arrays because it checks for an
+undefined I<scalar> value. If you want to see if the array is empty,
+just use C<if (@array) { # not empty }> for example.
+
+=item defined(%hash) is deprecated
+
+(D) defined() is not usually useful on hashes because it checks for an
+undefined I<scalar> value. If you want to see if the hash is empty,
+just use C<if (%hash) { # not empty }> for example.
+
=item Delimiter for here document is too long
(F) In a here document construct like C<E<lt>E<lt>FOO>, the label
You need to do an open() or a socket() call, or call a constructor from
the FileHandle package.
-=item Filehandle %s opened for only input
+=item Filehandle %s opened only for input
(W) You tried to write on a read-only filehandle. If you
intended it to be a read-write filehandle, you needed to open it with
you intended only to write the file, use "E<gt>" or "E<gt>E<gt>". See
L<perlfunc/open>.
-=item Filehandle opened for only input
+=item Filehandle %s opened only for output
-(W) You tried to write on a read-only filehandle. If you
+(W) You tried to read from a filehandle opened only for writing. If you
intended it to be a read-write filehandle, you needed to open it with
"+E<lt>" or "+E<gt>" or "+E<gt>E<gt>" instead of with "E<lt>" or nothing. If
-you intended only to write the file, use "E<gt>" or "E<gt>E<gt>". See
+you intended only to read from the file, use "E<lt>". See
L<perlfunc/open>.
=item Final $ should be \$ or $name
(W) You redefined a format. To suppress this warning, say
{
- local $^W = 0;
+ no warnings;
eval "format NAME =...";
}
(D) Really old Perl let you omit the % on hash names in some spots. This
is now heavily deprecated.
+=item Hexadecimal number > 0xffffffff non-portable
+
+(W) The hexadecimal number you specified is larger than 2**32-1
+(4294967295) and therefore non-portable between systems. See
+L<perlport> for more on portability concerns.
+
=item Identifier too long
(F) Perl limits identifiers (names for variables, functions, etc.) to
names (like C<$A::B>). You've exceeded Perl's limits. Future
versions of Perl are likely to eliminate these arbitrary limitations.
-=item Ill-formed logical name |%s| in prime_env_iter
+=item Ill-formed CRTL environ value "%s"
+
+(W) A warning peculiar to VMS. Perl tried to read the CRTL's internal
+environ array, and encountered an element without the C<=> delimiter
+used to spearate keys from values. The element is ignored.
-(W) A warning peculiar to VMS. A logical name was encountered when preparing
-to iterate over %ENV which violates the syntactic rules governing logical
-names. Because it cannot be translated normally, it is skipped, and will not
-appear in %ENV. This may be a benign occurrence, as some software packages
-might directly modify logical name tables and introduce nonstandard names,
-or it may indicate that a logical name table has been corrupted.
+=item Ill-formed message in prime_env_iter: |%s|
+
+(W) A warning peculiar to VMS. Perl tried to read a logical name
+or CLI symbol definition when preparing to iterate over %ENV, and
+didn't see the expected delimiter between key and value, so the
+line was ignored.
=item Illegal character %s (carriage return)
(W) You may have tried to use an 8 or 9 in a octal number. Interpretation
of the octal number stopped before the 8 or 9.
-=item Illegal hex digit %s ignored
+=item Illegal hexadecimal digit %s ignored
-(W) You may have tried to use a character other than 0 - 9 or A - F in a
-hexadecimal number. Interpretation of the hexadecimal number stopped
+(W) You may have tried to use a character other than 0 - 9 or A - F, a - f
+in a hexadecimal number. Interpretation of the hexadecimal number stopped
before the illegal character.
+=item Illegal number of bits in vec
+
+(F) The number of bits in vec() (the third argument) must be a power of
+two from 1 to 32 (or 64, if your platform supports that).
+
=item Illegal switch in PERL5OPT: %s
(X) The PERL5OPT environment variable may only be used to set the
=item Integer overflow in %s number
-(S) The literal hex, octal or binary number you have specified is
-too big for your architecture. On a 32-bit architecture the largest
-literal hex, octal or binary number representable without overflow
-is 0xFFFFFFFF, 037777777777, or 0b11111111111111111111111111111111
-respectively. Note that Perl transparently promotes decimal literals
-to a floating point representation internally--subject to loss of
-precision errors in subsequent operations--so this limit usually
-doesn't apply to decimal literals.
+(W) The hexadecimal, octal or binary number you have specified either
+as a literal in your code or as a scalar is too big for your
+architecture, and has been converted to a floating point number. On a
+32-bit architecture the largest hexadecimal, octal or binary number
+representable without overflow is 0xFFFFFFFF, 037777777777, or
+0b11111111111111111111111111111111 respectively. Note that Perl
+transparently promotes all numbers to a floating point representation
+internally--subject to loss of precision errors in subsequent
+operations.
=item Internal inconsistency in tracking vforks
(P) Something went badly awry in the regular expression parser.
+=item Invalid %s attribute: %s
+
+The indicated attribute for a subroutine or variable was not recognized
+by Perl or by a user-supplied handler. See L<attributes>.
+
+=item Invalid %s attributes: %s
+
+The indicated attributes for a subroutine or variable were not recognized
+by Perl or by a user-supplied handler. See L<attributes>.
+
=item invalid [] range in regexp
(F) The range specified in a character class had a minimum character
-greater than the maximum character. See L<perlre>.
+greater than the maximum character, or the range didn't start/end with
+a literal character. See L<perlre>.
=item Invalid conversion in %s: "%s"
(W) Perl does not understand the given format conversion.
See L<perlfunc/sprintf>.
+=item Invalid separator character %s in attribute list
+
+(F) Something other than a comma or whitespace was seen between the
+elements of an attribute list. If the previous attribute
+had a parenthesised parameter list, perhaps that list was terminated
+too soon. See L<attributes>.
+
=item Invalid type in pack: '%s'
(F) The given character is not a valid pack type. See L<perlfunc/pack>.
mentioned with the $ in Perl, unlike in the shells, where it can vary from
one line to the next.
+=item Missing %sbrace%s on \N{}
+
+(F) Wrong syntax of character name literal C<\N{charname}> within
+double-quotish context.
+
=item Missing comma after first argument to %s function
(F) While certain functions allow you to specify a filehandle or an
(W) Multidimensional arrays aren't written like C<$foo[1,2,3]>. They're written
like C<$foo[1][2][3]>, as in C.
+=item Missing name in "my sub"
+
+(F) The reserved syntax for lexically scoped subroutines requires that they
+have a name with which they can be found.
+
=item Name "%s::%s" used only once: possible typo
(W) Typographical errors often show up as unique variable names.
=item no UTC offset information; assuming local time is UTC
-(S) A warning peculiar to VMS. Per was unable to find the local
+(S) A warning peculiar to VMS. Perl was unable to find the local
timezone offset, so it's assuming that local system time is equivalent
to UTC. If it's not, define the logical name F<SYS$TIMEZONE_DIFFERENTIAL>
to translate to the number of seconds which need to be added to UTC to
Perl are likely to eliminate this arbitrary limitation. In the meantime,
try using scientific notation (e.g. "1e6" instead of "1_000_000").
+=item Octal number > 037777777777 non-portable
+
+(W) The octal number you specified is larger than 2**32-1 (4294967295)
+and therefore non-portable between systems. See L<perlport> for more
+on portability concerns.
+
+See also L<perlport> for writing portable code.
+
=item Odd number of elements in hash assignment
(S) You specified an odd number of elements to initialize a hash, which
(P) The savestack was requested to restore more localized values than there
are in the savestack.
+=item panic: del_backref
+
+(P) Failed an internal consistency check while trying to reset a weak
+reference.
+
=item panic: die %s
(P) We popped the context stack to an eval context, and then discovered
(P) The lexer got into a bad state parsing a string with brackets.
+=item panic: kid popen errno read
+
+(F) forked child returned an incomprehensible message about its errno.
+
=item panic: last
(P) We popped the context stack to a block context, and then discovered
(P) Something requested a negative number of bytes of malloc.
+=item panic: magic_killbackrefs
+
+(P) Failed an internal consistency check while trying to reset all weak
+references to an object.
+
=item panic: mapstart
(P) The compiler is screwed up with respect to the map() function.
One possible workaround is to force Perl to use magical string
increment by prepending "0" to your numbers.
-=item Read on closed filehandle E<lt>%sE<gt>
+=item Read on closed filehandle %s
(W) The filehandle you're reading from got itself closed sometime before now.
Check your logic flow.
%hash = ( one => 1, two => 2, ); # right
%hash = qw( one 1 two 2 ); # also fine
+=item Reference is already weak
+
+(W) You have attempted to weaken a reference that is already weak.
+Doing so has no effect.
+
=item Reference miscount in sv_replace()
(W) The internal sv_replace() function was handed a new SV with a
(F) A sort comparison subroutine may not return a list value with more
or less than one element. See L<perlfunc/sort>.
+=item split /^/ better written as split /^/m
+
+(W) Implicit translation of /^/ to mean /^/m in split is deprecated.
+
=item Split loop
(P) The split was looping infinitely. (Obviously, a split shouldn't iterate
(W) You redefined a subroutine. To suppress this warning, say
{
- local $^W = 0;
+ no warnings;
eval "sub name { ... }";
}
if the last stat that wrote to the stat buffer already went past
the symlink to get to the real file. Use an actual filename instead.
+=item This Perl can't reset CRTL eviron elements (%s)
+
+=item This Perl can't set CRTL environ elements (%s=%s)
+
+(W) Warnings peculiar to VMS. You tried to change or delete an element
+of the CRTL's internal environ array, but your copy of Perl wasn't
+built with a CRTL that contained the setenv() function. You'll need to
+rebuild Perl with a CRTL that does, or redefine F<PERL_ENV_TABLES> (see
+L<perlvms>) so that the environ array isn't the target of the change to
+%ENV which produced the warning.
+
=item times not implemented
(F) Your version of the C library apparently doesn't do times(). I suspect
(F) There are no byte-swapping functions for a machine with this byte order.
+=item Unknown open() mode '%s'
+
+(F) The second argument of 3-arguments open is not one from the list
+of C<L<lt>>, C<L<gt>>, C<E<gt>E<gt>>, C<+L<lt>>, C<+L<gt>>,
+C<+E<gt>E<gt>>, C<-|>, C<|-> of possible open() modes.
+
+=item Unknown process %x sent message to prime_env_iter: %s
+
+(P) An error peculiar to VMS. Perl was reading values for %ENV before
+iterating over it, and someone else stuck a message in the stream of
+data Perl expected. Someone's very confused, or perhaps trying to
+subvert Perl's population of %ENV for nefarious purposes.
+
=item unmatched () in regexp
(F) Unbackslashed parentheses must always be balanced in regular
finding it. Chances are you left some needed parentheses out earlier in
the line, and you really meant a "less than".
+=item Unterminated attribute parameter in attribute list
+
+(F) The lexer saw an opening (left) parenthesis character while parsing an
+attribute list, but the matching closing (right) parenthesis
+character was not found. You may need to add (or remove) a backslash
+character to get your parentheses to balance. See L<attributes>.
+
+=item Unterminated attribute list
+
+(F) The lexer found something other than a simple identifier at the start
+of an attribute, and it wasn't a semicolon or the start of a
+block. Perhaps you terminated the parameter list of the previous attribute
+too soon. See L<attributes>.
+
=item Use of $# is deprecated
(D) This was an ill-advised attempt to emulate a poorly defined B<awk> feature.
probably not what you intended. When using these constructs in conditional
expressions, test their values with the C<defined> operator.
+=item Value of CLI symbol "%s" too long
+
+(W) A warning peculiar to VMS. Perl tried to read the value of an %ENV
+element from a CLI symbol table, and found a resultant string longer
+than 1024 characters. The return value has been truncated to 1024
+characters.
+
=item Variable "%s" is not imported%s
(F) While "use strict" in effect, you referred to a global variable
So put in parentheses to say what you really mean.
-=item Write on closed filehandle
+=item Write on closed filehandle %s
(W) The filehandle you're writing to got itself closed sometime before now.
Check your logic flow.