 | Part 5: Reference Material |
These messages are classified as follows (listed in increasing order of desperation):
| Class | Meaning |
|---|---|
| (W) | A warning (optional) |
| (D) | A deprecation (optional) |
| (S) | A severe warning (mandatory) |
| (F) | A fatal error (trappable) |
| (P) | An internal error (panic) that you should never see (trappable) |
| (X) | A very fatal error (nontrappable) |
| (A) | An alien error message (not generated by Perl) |
The majority of messages from the first three classifications above (W, D, and S) can be controlled using the warnings pragma or the -w and -W switches. If a message can be controlled by the warnings pragma, its warning category is given after the classification letter; for example, (W misc) indicates a miscellaneous warning. The warnings pragma is described in Chapter 31, "Pragmatic Modules".
Warnings may be captured rather than printed by setting $SIG{__WARN__} to a reference to a routine that will be called on each warning. You can also capture control before a trappable error "dies" by setting $SIG{__DIE__} to a subroutine reference, but if you don't call die within the handler, the exception is still thrown when you return from it. In other words, you're not allowed to "de-fatalize" an exception that way. You must use eval for that.
Default warnings are always enabled unless they are explicitly disabled with the warnings pragma or the -X switch.
In the following messages, %s stands for an interpolated string that is determined only when the message is generated. (Similarly, %d stands for an interpolated number--think printf formats, but we use %d to mean a number in any base here.) Note that some messages begin with %s--which means that listing them alphabetically is problematical. You should search among these messages if the one you are looking for does not appear in the expected place. The symbols "%-?@ sort before alphabetic characters, while [ and \ sort after.
If you decide a bug is a Perl bug and not your bug, you should try to reduce it to a minimal test case and then report it with the perlbug program that comes with Perl.
(W misc) A my or our variable has been redeclared in the current scope or statement, effectively eliminating all access to the previous instance. This is almost always a typographical error. Note that the earlier variable will still exist until the end of the scope or until all closure referents to it are destroyed.
(F) Lexically scoped subroutines are not yet implemented. Don't try that yet.
(F) Lexically scoped variables aren't in a package, so it doesn't make sense to try to declare one with a package qualifier in front. Use local if you want to localize a package variable.
(F) The no keyword is recognized and executed at compile time and returns no useful value.
(W misc) You seem to have already declared the same global once before in the current lexical scope.
(F) The use keyword is recognized and executed at compile time and returns no useful value.
(F) The '!' is allowed in pack and unpack only after certain types.
(F) This is an error peculiar to VMS. Perl does its own command-line redirection. It found that STDIN was a pipe and that you also tried to redirect STDIN using <. Only one STDIN stream to a customer, please.
(F) This is an error peculiar to VMS. Perl does its own command-line redirection and thinks you tried to redirect STDOUT both to a file and into a pipe to another command. You need to choose one or the other, though nothing's stopping you from piping into a program or Perl script that splits the output into two streams, such as:
open(OUT,">$ARGV[0]") or die "Can't write to $ARGV[0]: $!";
while (<STDIN>) {
print;
print OUT;
}
close OUT;
(F) You had an unpack template indicating a counted-length string, but you have also specified an explicit size for the string.
(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.
(F) You had a pack template indicating a counted-length string. Currently, the only things that can have their length counted are a*, A* or Z*.
(F) You had an unpack template that contained a #, but this did not follow some numeric unpack specification.
(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.
(F) You can't specify a repeat count so large that it overflows your signed integers.
(F) You can't specify a repeat count so large that it overflows your signed integers.
(W regexp) You used a backslash-character combination that is not recognized by Perl. This combination appears in an interpolated variable or a '-delimited regular expression. The character was understood literally.
(W regexp) You used a backslash-character combination that is not recognized by Perl inside character classes. The character was understood literally.
(W syntax) You have used a pattern where Perl expected to find a string, as in the first argument to join. Perl will treat the true or false result of matching the pattern against $_ as the string, which is probably not what you had in mind.
(W syntax) You've run afoul of the rule that says that any list operator followed by parentheses turns into a function, with all the list operators arguments found inside the parentheses.
(W prototype) 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.
(F) The argument to exists must be a hash or array element, such as:
$foo{$bar}
$ref->{"susie"}[12]
(F) The argument to delete must be either a hash or array element, such as:
$foo{$bar}
$ref->{"susie"}[12]
or a hash or array slice, such as:
@foo[$bar, $baz, $xyzzy]
@{$ref->[12]}{"susie", "queue"}
(F) The argument to exists for exists &sub must be a subroutine name, and not a subroutine call. exists &sub() will generate this error.
(F) A required (or used) file must return a true value to indicate that it compiled correctly and ran its initialization code correctly. It's traditional to end such a file with a 1;, though any true value would do.
(S) The Perl lexer knows whether to expect a term or an operator. If it sees what it knows to be a term when it was expecting to see an operator, it gives you this warning. Usually it indicates that an operator or delimiter was omitted, such as a semicolon.
(F) The final summary message when a perl -c fails.
(F) The parser has given up trying to parse the program after 10 errors. Further error messages would likely be uninformative.
(W regexp) The pattern you've specified would be an infinite loop if the regular expression engine didn't specifically check for that.
(S internal) The symbol in question was declared but somehow went out of scope before it could possibly have been used.
(W reserved) 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.
(F) The final summary message when a perl -c succeeds.
(A) You've accidentally run your script through csh instead of Perl. Check the #! line, or manually feed your script into Perl yourself with perl scriptname.
(A) You've accidentally run your script through csh instead of Perl. Check the #! line, or manually feed your script into Perl yourself with perl scriptname.
(A) You've accidentally run your script through csh instead of Perl. Check the #! line, or manually feed your script into Perl yourself with perl scriptname.
(A) You've accidentally run your script through the Bourne shell instead of Perl. Check the #! line, or manually feed your script Perl yourself with perl scriptname.
(W misc) This prefix usually indicates that a DESTROY method raised the indicated exception. Since destructors are usually called by the system at arbitrary points during execution, and often a vast number of times, the warning is issued only once for any number of failures that would otherwise result in the same message being repeated.
Failure of user callbacks dispatched using the G_KEEPERR flag could also result in this warning. See perlcall(1).
(S) This is an educated guess made in conjunction with the message "%sfound where operator expected." Don't automatically put a semicolon on the previous line just because you saw this message.
(F) The script would have to be opened by the C preprocessor by name, which provides a race condition that breaks security.
(F) Perl can't peek at the standard I/O buffer of filehandles when it doesn't know about your kind of standard I/O. You'll have to use a filename instead.
(F) An error occurred during the implicit output invoked by the -p command-line switch. (This output goes to STDOUT unless you've redirected it with select.)
See Server error.
(F) You started a regular expression with a quantifier. Backslash it if you meant it literally.
(F) You had a pack template that specified an absolute position outside the string being unpacked.
(F) You wrote require <file> when you should have written require 'file'.
(W syntax) Outside of patterns, backreferences live on as variables. The use of backslashes is grandfathered on the righthand side of a substitution, but stylistically it's better to use the variable form because other Perl programmers will expect it, and it works better if there are more than nine backreferences.
(W closed) You tried to do an accept on a closed socket. Did you forget to check the return value of your socket call?
(X) You can't allocate more than 64K on an MS-DOS machine.
(W misc) The pattern match (//), substitution (s///), and transliteration (tr///) operators work on scalar values. If you apply one of them to an array or a hash, it will convert the array or hash to a scalar value--the length of an array or the population info of a hash--and then work on that scalar value. This is probably not what you meant to do.
(F) msgsnd requires a string at least as long as sizeof(long).
(W ambiguous|S) You said something that may not be interpreted the way you thought. Normally it's pretty easy to disambiguate it by supplying a missing quote, operator, pair of parentheses, or declaration.
(W ambiguous) A subroutine you have declared has the same name as a Perl keyword, and you have used the name without qualification for calling one or the other. Perl decided to call the built-in because the subroutine is not imported.
To force interpretation as a subroutine call, either put an ampersand before the subroutine name or qualify the name with its package. Alternatively, you can import the subroutine (or pretend that it's imported with the use subs pragma).
To silently interpret it as the Perl operator, use the CORE:: prefix on the operator (e.g., CORE::log($x)) or declare the subroutine to be an object method.
(F) The setuid emulator requires that the arguments Perl was invoked with match the arguments specified on the #! line. Since some systems impose a one-argument limit on the #! line, try combining switches; for example, turn -w -U into -wU.
(W numeric) The indicated string was fed as an argument to an operator that expected a numeric value instead. If you're fortunate, the message will identify which operator was so unfortunate.
(D deprecated) Really old Perls let you omit the @ on array names in some spots. This is now heavily deprecated.
(P) The malloc package that comes with Perl had an internal failure.
(P) A general assertion failed. The file in question must be examined.
(F) If you assign to a conditional operator, the second and third arguments must either both be scalars or both be lists. Otherwise, Perl won't know which context to supply to the right side.
(P internal) All SV objects are supposed to be allocated from arenas that will be garbage collected on exit. An SV was discovered to be outside any of those arenas.
(P internal) Perl maintains a reference-counted internal table of strings to optimize the storage and access of hash keys and other strings. This message indicates that someone tried to decrement the reference count of a string that can no longer be found in the table.
(W debugging) Mortalized values are supposed to be freed by the internal free_tmps routine. This message indicates that something else is freeing the SV before the free_tmps routine gets a chance, which means that the free_tmps routine will be freeing an unreferenced scalar when it does try to free it.
(P internal) The reference counts got screwed up on symbol aliases.
(W internal) Perl went to decrement the reference count of a scalar to see if it would go to 0, and discovered that it had already gone to 0 earlier and should have been freed and, in fact, probably was freed. This could indicate that SvREFCNT_dec was called too many times, or that 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.
(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.
(W pack) You tried to pass a temporary value (like the result of a function, or a computed expression) to the p template of pack template. This means the result contains a pointer to a location that could become invalid anytime, even before the end of the current statement. Use literals or global values as arguments to the p template of pack to avoid this warning.
(W substr) You supplied a reference as the first argument to substr used as an lvalue, which is pretty strange. Perhaps you forgot to dereference it first.
(F) You passed a buffer of the wrong size to one of msgctl, semctl or shmctl. In C parlance, the correct sizes are, respectively, sizeof(struct msqid_ds *), sizeof(struct semid_ds *), and sizeof(struct shmid_ds *).
(F) A symbol was passed to something wanting a filehandle, but the symbol has no filehandle associated with it. Perhaps you didn't do an open, or did it in another package.
(S malloc) An internal routine called free on something that had never been malloced in the first place. Mandatory, but can be disabled by setting environment variable PERL_BADFREE to 1.
This message can be seen quite often with DB_File on systems with "hard" dynamic linking, like AIX and OS/2. It's a bug in Berkeley DB.
(P) One of the internal hash routines was passed a null HV pointer.
(F) The index looked up in the hash found as the 0th element of a pseudohash is not legal. Index values must be 1 or greater.
(F) You started to name a symbol by using a package prefix and then didn't finish the symbol. In particular, you can't interpolate outside of quotes, so:
is not the same as:$var = 'myvar'; $sym = mypack::$var;
$var = 'myvar'; $sym = "mypack::$var";
(S malloc) An internal routine called realloc on something that had never been malloced in the first place. Mandatory, but can be disabled by setting environment variable PERL_BADFREE to 1.
(P) An internal request asked to add an array entry to something that wasn't a symbol table entry.
(P) An internal request asked to add a filehandle entry to something that wasn't a symbol table entry.
(P) An internal request asked to add a hash entry to something that wasn't a symbol table entry.
(A) You've accidentally run your script through csh instead of Perl. Check the #! line, or manually feed your script into Perl yourself with perl scriptname.
(F) With strict subs in use, a bareword is only allowed as a subroutine identifier, in curly brackets or to the left of the => symbol. Perhaps you need to predeclare a subroutine?
(W bareword) You used a qualified bareword of the form Foo::, but the compiler saw no other uses of that namespace before that point. Perhaps you need to predeclare a package?
(W bareword) The compiler found a bareword where it expected a conditional, which often indicates that an || or && was parsed as part of the last argument of the previous construct, for example:
It may also indicate a misspelled constant that has been interpreted as a bareword:open FOO || die;
use constant TYPO => 1;
if (TYOP) { print "foo" }
The strict pragma is useful in avoiding such errors.
(F) An untrapped exception was raised while executing a BEGIN subroutine. Compilation stops immediately and the interpreter is exited.
(F) Perl found a BEGIN subroutine (or a use directive, which implies a BEGIN) after one or more compilation errors had already occurred. Since the intended environment for the BEGIN could not be guaranteed (due to the errors), and since subsequent code likely depends on its correct operation, Perl just gave up.
(W portable) The binary number you specified is larger than 2**32-1 (4,294,967,295) and therefore nonportable between systems.
(W closed) You tried to do a bind on a closed socket. Did you forget to check the return value of your socket call?
(W portable) Using bit vector sizes larger than 32 is nonportable.
(P) Perl detected an attempt to copy an internal value that is not copiable.
(W internal) 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.
(F) A subroutine invoked from an external package via call_sv exited by calling exit.
(F) A goto statement was executed to jump out of what might look like a block, except that it isn't a proper block. This usually occurs if you tried to jump out of a sort block or subroutine, which is a no-no.
(F) A goto statement was executed to jump into the middle of a foreach loop. You can't get there from here.
(F) A last statement was executed to break out of the current block, except that there's this itty-bitty problem called there isn't a current block. Note that an if or else block doesn't count as a "loopish" block, nor does a block given to sort, map, or grep. You can usually double the curlies to get the same effect, though, because the inner curlies will be considered a block that loops once.
(F) A next statement was executed to reiterate the current block, but there isn't a current block. Note that an if or else block doesn't count as a "loopish" block, nor does a block given to sort, map, or grep. You can usually double the curlies to get the same effect though, because the inner curlies will be considered a block that loops once.
(S) This is 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 PERL_ENV_TABLES (see perlvms(1)) so that the environ array is not searched.
(F) A redo statement was executed to restart the current block, but there isn't a current block. Note that an if or else block doesn't count as a "loopish" block, nor does a block given to sort, map, or grep. You can usually double the curlies to get the same effect though, because the inner curlies will be considered a block that loops once.
(F) Only hard references may be blessed. This is how Perl "enforces" encapsulation of objects.
(S internal) This warning is intended to be printed only while running within the debugger, indicating the line number specified wasn't the location of a statement that could be stopped at.
(F) You called a method correctly, and it correctly indicated a package functioning as a class, but that package doesn't have anything defined in it, let alone methods.
(F) A method call must know in what package it's supposed to run. It ordinarily finds this out from the object reference you supply, but you didn't supply an object reference in this case. A reference isn't an object reference until it has been blessed.
(F) You used the syntax of a method call, but the slot filled by the object reference or package name contains an expression that returns a defined value that is neither an object reference nor a package name. Something like this will reproduce the error:
$BADREF = 42; process $BADREF 1,2,3; $BADREF->process(1,2,3);
(F) You used the syntax of a method call, but the slot filled by the object reference or package name contains an undefined value. Something like this will reproduce the error:
$BADREF = undef; process $BADREF 1,2,3; $BADREF->process(1,2,3);
(F) You called perl -x/foo/bar, but /foo/bar is not a directory that you can chdir to, possibly because it doesn't exist.
(P) For some reason you can't check the filesystem of the script for nosuid.
(F) Certain types of SVs, in particular symbol table entries (typeglobs), can't be forced to stop being what they are. So you can't say things like:
You can say:*foo += 1;
but then $foo no longer contains a glob.$foo = *foo; $foo += 1;
(F) Certain types of SVs, in particular symbol table entries (typeglobs), can't be forced to stop being what they are.
(F) Certain types of SVs, in particular symbol table entries (typeglobs), can't be forced to stop being what they are.
(F) You used an array where a hash was expected, but the array has no information on how to map from keys to array indices. You can do that only with arrays that have a hash reference at index 0.
(P) This is an error peculiar to VMS. The process is suffering from exhausted quotas or other plumbing problems.
(S) Currently, only scalar variables can declared with a specific class qualifier in a my or our declaration. The semantics may be extended for other types of variables in future.
(F) Only scalar, array, and hash variables may be declared as my or our variables. They must have ordinary identifiers as names.
(S inplace) The creation of the new file failed for the indicated reason.
(F) You're on a system such as MS-DOS that gets confused if you try reading from a deleted (but still opened) file. You have to say -i.bak, or some such.
(S inplace) Your filesystem does not support filenames longer than 14 characters and Perl was unable to create a unique filename during inplace editing with the -i switch. The file was ignored.
(S inplace) You tried to use the -i switch on a special file, such as a file in /dev, or a FIFO. The file was ignored.
(P) The setegid call failed for some reason in the setuid emulator of suidperl.
(P) The setuid emulator of suidperl failed for some reason.
(F) This typically means that ordinary perl tried to execsuidperl to do setuid emulation, but couldn't exec it. It looks for a name of the form sperl5.000 in the same directory that the perl executable resides under the name perl5.000, typically /usr/local/bin on Unix machines. If the file is there, check the execute permissions. If it isn't, ask your sysadmin why not.
(F) This machine doesn't have either waitpid or wait4, so only waitpid without flags is emulated.
(F) Minima must be less than or equal to maxima. If you really want your regexp to match something 0 times, just use {0}.
(F) The #! line specifies a switch that doesn't make sense at this point. For example, it would be kind of silly to put a -x on the #! line.
(W exec) A system, exec, or piped open call could not execute the named program for the indicated reason. Typical reasons include the permissions were wrong on the file, the file wasn't found in $ENV{PATH}, the executable in question was compiled for another architecture, or the #! line in a script points to an interpreter that can't be run for similar reasons. (Or maybe your system doesn't support #! at all.)
(F) Perl was trying to execute the indicated program for you because that's what the #! line said to do. If that's not what you wanted, you may need to mention perl on the #! line somewhere.
(F) You used the -S switch, but the copies of the script to execute found in the PATH did not have correct permissions.
(F) You used the -S switch, but the script to execute could not be found in the PATH, or at least not with the correct permissions. The script exists in the current directory, but PATH prohibits running it.
(F) You used the -S switch, but the script to execute could not be found in the PATH.
(F) You said to goto a label that isn't mentioned anywhere that it's possible for us to go to.
(F) Perl strings can stretch over multiple lines. This message means that the closing delimiter was omitted. Because bracketed quotes count nesting levels, the following is missing its final parenthesis:
print q(The character '(' starts a side comment.);
If you're getting this error from a here document, you may have
included unseen whitespace before or after your closing tag. A good
programmer's editor will have a way to help you find these characters.
(F) A fatal error occurred trying to fork.
(S) This warning is peculiar to VMS. This arises because of the difference between access checks under VMS and under the Unix model Perl assumes. Under VMS, access checks are done by filename, rather than by bits in the stat buffer, so that ACLs and other protections can be taken into account. Unfortunately, Perl assumes that the stat buffer contains all the necessary information and passes it, instead of the filespec, to the access-checking routine. It will try to retrieve the filespec using the device name and FID present in the stat buffer, but if you have made a subsequent call to the CRTL stat routine, this won't work because the device name is overwritten with each call. If this warning appears, the name lookup failed and the access-checking routine gave up and returned false, just to be conservative. (Note: the access-checking routine knows about the Perl stat operator and file tests, so you shouldn't ever see this warning in response to a Perl command; it arises only if some internal code takes stat buffers lightly.)
(P) This error is peculiar to VMS. After creating a mailbox to act as a pipe, Perl can't retrieve its name for later use.
(P) This error is peculiar to VMS. Perl asked $GETSYI how big you want your mailbox buffers to be, and it didn't get an answer.
(F) The deeply magical gotoSUBROUTINE call can only replace one subroutine call for another. It can't manufacture one out of whole cloth. In general, you should be calling it out of only an AUTOLOAD routine anyway.
(F) The gotoSUBROUTINE call can't be used to jump out of an eval string. (You can use it to jump out of an evalBLOCK, but you probably don't want to.)
(W signal) Perl has detected that it is being run with the SIGCHLD signal (sometimes known as SIGCLD) disabled. Since disabling this signal will interfere with proper determination of exit status of child processes, Perl has reset the signal to its default value. This situation typically indicates that the parent program under which Perl may be running (e.g., cron) is being very careless.
(F) You said something like local $$ref, which Perl can't currently handle because when it goes to restore the old value of whatever $ref pointed to after the scope of the local is finished, it can't be sure that $ref will still be a reference.
(F) You used local on a variable name that was previously declared as a lexical variable using my. This is not allowed. If you want to localize a package variable of the same name, qualify it with the package name.
(F) You said something like local $ar->{'key'}, where $ar is a reference to a pseudohash. That hasn't been implemented yet, but you can get a similar effect by localizing the corresponding array element directly--local $ar->[$ar->[0]{'key'}].
(F) A function (or method) was called in a package that allows autoloading, but there is no function to autoload. Most probable causes are a misprint in a function/method name or a failure to AutoSplit the file, say, by doing make install.
(F) You said to do (or require, or use) a file that couldn't be found. Perl looks for the file in all the locations mentioned in @INC, unless the filename 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.
(F) You called a method correctly, and it correctly indicated a package functioning as a class, but that package doesn't define that particular method, nor does any of its base classes.
(W syntax) The @ISA array contained the name of another package that doesn't seem to exist.
(F) List assignment to %ENV is not supported on some systems, notably VMS.
(F) You aren't allowed to assign to the item indicated or otherwise try to change it, such as with an autoincrement.
(F) Subroutines meant to be used in lvalue context should be declared as such.
(P) The internal routine that does assignment to a substr was handed a NULL.
(F) The target of a msgrcv must be modifiable to be used as a receive buffer.
(S inplace) The implicit opening of a file through use of the <> filehandle, either implicitly under the -n or -p command-line switches or explicitly, failed for the indicated reason. Usually this is because you don't have read permission for a file which you named on the command line.
(W pipe) You tried to say open(CMD, "|cmd|"), which is not supported. You can try any of several modules in the Perl library to do this, such as IPC::Open2. Alternatively, direct the pipe's output to a file using >, and then read it in under a different filehandle.
(F) This is an error peculiar to VMS. Perl does its own command-line redirection, and it couldn't open the file specified after 2> or 2>> on the command line for writing.
(F) This is an error peculiar to VMS. Perl does its own command-line redirection, and it couldn't open the file specified after < on the command line for reading.
(F) This is an error peculiar to VMS. Perl does its own command-line redirection, and it couldn't open the file specified after > or >> on the command line for writing.
(P) This is an error peculiar to VMS. Perl does its own command-line redirection, and it couldn't open the pipe into which to send data destined for STDOUT.
(F) The script you specified can't be opened for the indicated reason.
(F) Perl optimizes the internal handling of sort subroutines and keeps pointers into them. You tried to redefine one such sort subroutine when it was currently active, which is not allowed. If you really want to do this, you should write sort { &func } @x instead of sort func @x.
(S inplace) You requested an inplace edit without creating a backup file. Perl was unable to remove the original file to replace it with the modified file. The file was left unmodified.
(S inplace) The rename done by the -i switch failed for some reason, probably because you don't have write permission to the directory.
(P) An error peculiar to VMS. Perl thought STDIN was a pipe, and tried to reopen it to accept binary data. Alas, it failed.
(P) The setreuid call failed for some reason in the setuid emulator of suidperl.
(F) The return statement was executed in mainline code, that is, where there was no subroutine call to return out of.
(F) Perl detected an attempt to return illegal lvalues (such as temporary or readonly values) from a subroutine used as an lvalue. This is not allowed.
(P) For some reason, you can't fstat the script even though you have it open already. Bizarre.
(P) The setreuid call failed for some reason in the setuid emulator of suidperl.
(F) For ordinary real numbers, you can't take the logarithm of a negative number or zero. There's a Math::Complex package that comes standard with Perl, though, if you really want to do that for the negative numbers.
(F) For ordinary real numbers, you can't take the square root of a negative number. There's a Math::Complex package that comes standard with Perl, though, if you really want to do that.
(F) You can't undefine a routine that's currently running. You can, however, redefine it while it's running, and you can even undef the redefined subroutine while the old routine is running. Go figure.
(F) You tried to unshift an "unreal" array that can't be unshifted, such as the main Perl stack.
(P) The internal sv_upgrade routine adds "members" to an SV, making it into a more specialized kind of SV. The top several SV types are so specialized, however, that they cannot be interconverted. This message indicates that such a conversion was attempted.
(P) The undefined SV is the bottom of the totem pole, in the scheme of upgradability. Upgrading to undef indicates an error in the code calling sv_upgrade.
(F) The first time the %! hash is used, Perl automatically loads the Errno module. The Errno module is expected to tie the %! hash to provide symbolic names for $! errno values.
(F) The global variables $a and $b are reserved for sort comparisons. You mentioned $a or $b in the same line as the <=> or cmp operator, and the variable had earlier been declared as a lexical variable. Either qualify the sort variable with the package name, or rename the lexical variable.
(F) You've used the /e switch to evaluate the replacement for a substitution, but Perl found a syntax error in the code to evaluate, most likely an unexpected right brace }.
(F) Only a simple scalar variable may be used as a loop variable on a foreach.
(F) You've mixed up your reference types. You have to dereference a reference of the type needed. You can use the ref function to test the type of the reference, if need be.
(W syntax) In an ordinary expression, backslash is a unary operator that creates a reference to its argument. The use of backslash to indicate a backreference to a matched substring is valid only as part of a regular expression pattern. Trying to do this in ordinary Perl code produces a value that prints out looking like SCALAR(0xdecaf). Use the $1 form instead.
(F) Only hard references are allowed by strict refs. Symbolic references are disallowed.
(F) Only hard references are allowed by strict refs. Symbolic references are disallowed.
(F) A value used as either a hard reference or a symbolic reference must be a defined value. This helps to delurk some insidious errors.
(F) You tried to declare a magical variable as a lexical variable. This is not allowed because the magic can be tied to only one location (namely the global variable) and it would be incredibly confusing to have variables in your program that looked like magical variables but weren't.
(F) The compiler tried to interpret a bracketed expression as a subscript. But to the left of the brackets was an expression that didn't look like an array reference, or anything else subscriptable.
(F) You attempted to weaken something that was not a reference. Only references can be weakened.
(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 variable, and repeat that.
(F) A string of a form CORE::word was given to prototype, but there is no built-in with the name word.
(F|P) An error occurred when resolving overloading specified by a method name (as opposed to a subroutine reference): no such method callable via the package. If the method name is ???, this is an internal error.
(F) The class in the character class [: :] syntax is unknown.
(W unsafe) The character class constructs [: :], [= =], and [. .] go inside character classes, for example: /[012[:alpha:]345]/. Note that the [= =] and [. .] constructs are not currently implemented; they are simply placeholders for future extensions.
(W regexp) 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: \[. and .\].
(W regexp) 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: \[= and =\].
(W chmod) A novice will sometimes say:
not realizing that 777 will be interpreted as a decimal number, equivalent to 01411. Octal constants are introduced with a leading 0 in Perl, as in C.chmod 777, $filename
(W unopened) You tried to close a filehandle that was never opened.
(F) Perl could not compile a file specified in a require statement. Perl uses this generic message when none of the errors that it encountered were severe enough to halt compilation immediately.
(W regexp) The regular expression engine uses recursion in complex situations where backtracking is required. Recursion depth is limited to 32,766, or perhaps less in architectures where the stack cannot grow arbitrarily. ("Simple" and "medium" situations are handled without recursion and are not subject to a limit.) Try shortening the string under examination; looping in Perl code (e.g., with while) rather than in the regular expression engine; or rewriting the regular expression so that it is simpler or backtracks less.
(W closed) You tried to do a connect on a closed socket. Did you forget to check the return value of your socket call?
(F) A constant value (perhaps declared using the use constant pragma) is being dereferenced, but it amounts to the wrong type of reference. The message indicates the type of reference that was expected. This usually indicates a syntax error in dereferencing the constant value.
(S|W redefine) You redefined a subroutine that had previously been eligible for inlining.
(W misc) You undefined a subroutine that had previously been eligible for inlining.
(F) The parser found inconsistencies either while attempting to define an overloaded constant or when trying to find the character name specified in the \N{...} escape. Perhaps you forgot to load the corresponding overload or charnames pragma?
(F) The method that overloads = is buggy.
(F) The CORE:: namespace is reserved for Perl keywords.
(P) The malloc package that comes with Perl had an internal failure.
(P) The regular expression engine got confused by what the regular expression compiler gave it.
(P) The regular expression engine got passed a regexp program without a valid magic number.
(W recursion) This subroutine has called itself (directly or indirectly) 100 times more than it has returned. This probably indicates an infinite recursion, unless you're writing strange benchmark programs, in which case it indicates something else.
(D deprecated) defined is not usually useful on arrays because it checks for an undefined scalar value. If you want to see if the array is empty, just use if (@array) { # not empty }.
(D deprecated) defined is not usually useful on hashes because it checks for an undefined scalar value. If you want to see if the hash is empty, just use if (%hash) { # not empty }.
(F) In a here document construct like <<FOO, the label FOO is too long for Perl to handle. You have to be seriously twisted to write code that triggers this error.
See Server error.
(W) You probably referred to an imported subroutine &FOO as $FOO or some such.
(W misc) Remember that our does not localize the declared global variable. You have declared it again in the same lexical scope, which seems superfluous.
(W) You probably said %hash{$key} when you meant $hash{$key} or @hash{@keys}. On the other hand, maybe you just meant %hash and got carried away.
(F) You passed die an empty string (the equivalent of die "") or you called it with no args and both $@ and $_ were empty.
(S) This is an educated guess made in conjunction with the message "%s found where operator expected". It often means a subroutine or module name is being referenced that hasn't been declared yet. This may be because of ordering problems in your file or because of a missing sub, package, require, or use statement. If you're referencing something that isn't defined yet, you don't actually have to define the subroutine or package before the current location. You can use an empty sub foo; or package FOO; to enter a "forward" declaration.
See Server error.
(P) The internal handling of magical variables has been cursed.
(P) This should have been caught by safemalloc instead.
(S malloc) An internal routine called free on something that had already been freed.
(S) There is no keyword "elseif" in Perl because Larry thinks it's ugly. Your code will be interpreted as an attempt to call a method named elseif for the class returned by the following block. This is unlikely to be what you want.
(F) An untrapped exception was raised while executing a CHECK, INIT, or END subroutine. Processing of the remainder of the queue of such routines has been prematurely ended.
(F) While under the use filetest pragma, switching the real and effective UIDs or GIDs failed.
(F) This is an error peculiar to VMS. Because Perl may have to deal with file specifications in either VMS or Unix syntax, it converts them to a single form when it must operate on them directly. Either you've passed an invalid file specification to Perl, or you've found a case the conversion routines don't handle. Drat.
(F) Perl detected tainted data when trying to compile a regular expression that contains the (?{ ... }) zero-width assertion, which is unsafe.
(F) A regular expression contained the (?{ ... }) zero-width assertion, but that construct is only allowed when the use re 'eval' pragma is in effect.
(F) Perl tried to compile a regular expression containing the (?{ ... }) zero-width assertion at run time, as it would when the pattern contains interpolated values. Since that is a security risk, it is not allowed. If you insist, you may still do this by explicitly building the pattern from an interpolated string at run time and using that in an eval.
(F) The contents of a <> operator may not exceed the maximum size of a Perl identifier. If you're just trying to glob a long list of filenames, try using the glob operator or putting the filenames into a variable and globbing that.
(F) The final summary message when a Perl compilation fails.
(W exiting) You are exiting an eval by unconventional means, such as a goto or a loop control statement.
(W exiting) You are exiting a format by unconventional means, such as a goto or a loop control statement.
(W exiting) You are exiting a rather special block construct (like a sort block or subroutine) by unconventional means, such as a goto or a loop control statement.
(W exiting) You are exiting a subroutine by unconventional means, such as a goto or a loop control statement.
(W exiting) You are exiting a substitution by unconventional means, such as a return, a goto, or a loop control statement.
(W misc) You are blessing a reference to a zero-length string. This has the effect of blessing the reference into the package main. This is usually not what you want. Consider providing a default target package, such as bless($ref, $p || 'MyPackage');
(W regexp) A character class range must start and end at a literal character, not another character class like \d or [:alpha:]. The - in your false range is interpreted as a literal -. Consider quoting the - like this: \-.
(P) This is an error peculiar to VMS. Something untoward happened in a VMS system service or RTL routine; Perl's exit status should provide more details. The filename in at%s and the line number in line%d tell you which section of the Perl source code is distressed.
(F) Your machine apparently doesn't implement fcntl. What is this, a PDP-11 or something?
(W unopened) An I/O operation was attempted on a filehandle that was never initialized. You need to do an open or a socket call, or call a constructor from the FileHandle module.
(W io) 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 +< or +> or +>> instead of with < or nothing. If you intended only to write the file, use > or >>.
(W io) 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 +< or +> or +>> instead of with < or nothing. If you intended only to read from the file, use <.
(F) You must now decide whether the final $ in a string was meant to be a literal dollar sign or was meant to introduce a variable name that happens to be missing. So you have to add either the backslash or the name.
(F) You must now decide whether the final @ in a string was meant to be a literal "at" sign or was meant to introduce a variable name that happens to be missing. So you have to add either the backslash or the name.
(W closed) The filehandle you're attempting to flock got itself closed some time before now. Check your logic flow. flock operates on filehandles. Are you attempting to call flock on a dirhandle by the same name?
(W redefine) You redefined a format. To suppress this warning, say:
{
no warnings;
eval "format NAME =...";
}
(F) A format must be terminated by a line with a solitary dot. Perl got to the end of your file without finding such a line.
(W syntax) You said:
when you meant:if ($foo = 123)
(or something like that).if ($foo == 123)
(S) A warning from the GDBM_File extension that a store failed.
(F) Your C library apparently doesn't implement gethostent, probably because if it did, it'd feel morally obligated to return every hostname on the Internet.
(W closed) You tried to get a socket or peer socket name on a closed socket. Did you forget to check the return value of your socket call?
(S) A warning peculiar to VMS. The call to sys$getuai underlying the getpwnam operator returned an invalid UIC.
(W closed) You tried to get a socket option on a closed socket. Did you forget to check the return value of your socket call?
(W glob) Something went wrong with the external program(s) used for glob and <*.c>. Usually, this means that you supplied a glob pattern that caused the external program to fail and exit with a nonzero status. If the message indicates that the abnormal exit resulted in a core dump, this may also mean that your csh (C shell) is broken. If so, you should change all of the csh-related variables in config.sh: If you have tcsh, make the variables refer to it as if it were csh (e.g., full_csh='/usr/bin/tcsh'); otherwise, make them all empty (except that d_csh should be 'undef') so that Perl will think csh is missing. In either case, after editing config.sh, run ./Configure -S and rebuild Perl.
(F) The lexer saw a left angle bracket in a place where it was expecting a term, so it's looking for the corresponding right angle bracket and not finding it. Chances are you left some needed parentheses out earlier in the line, and you really meant a < symbol.
(F) You've said use strict vars, which indicates that all variables must either be lexically scoped (using my), declared beforehand using our, or explicitly qualified to say which package the global variable is in (using ::).
(P) This is an error peculiar to OS/2. Most probably you're using an obsolete version of Perl, so this error should not happen anyway.
(F) Unlike with next or last, you're not allowed to goto an unspecified destination.
(S internal) A routine asked for a symbol from a symbol table that ought to have existed already, but for some reason it didn't and had to be created on an emergency basis to prevent a core dump.
(D deprecated) Really old Perl let you omit the % on hash names in some spots. This is now heavily deprecated.
(W portable) The hexadecimal number you specified is larger than 2**32-1 (4,294,967,295) and therefore nonportable between systems.
(F) Perl limits identifiers (names for variables, functions, etc.) to about 250 characters for simple names, and somewhat more for compound names (like $A::B). You've exceeded Perl's limits. Future versions of Perl are likely to eliminate these arbitrary limitations.
(W internal) This is a warning peculiar to VMS. Perl tried to read the CRTL's internal environ array and encountered an element without the = delimiter used to separate keys from values. The element is ignored.
(W internal) This is 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.
(F) Perl normally treats carriage returns in the program text as it would any other whitespace, which means you should never see this error when Perl was built using standard options. For some reason, your version of Perl appears to have been built without this support. Talk to your Perl administrator.
(F) You tried to divide a number by 0. Either something was wrong in your logic, or you need to put a conditional in to guard against meaningless input.
(F) You tried to divide a number by 0 to get the remainder. Most numbers don't take to this kindly.
(F) You used a digit other than 0 or 1 in a binary number.
(F) You used an 8 or 9 in a octal number.
(W digit) You may have tried to use a digit other than 0 or 1 in a binary number. Interpretation of the binary number stopped before the offending digit.
(W digit) 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.
(W digit) You may have tried to use a character other than 0 through 9, A through F, or a through f in a hexadecimal number. Interpretation of the hexadecimal number stopped before the illegal character.
(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).
(X) The PERL5OPT environment variable may only be used to set the following switches: -[DIMUdmw].
(F) It used to be that Perl would try to guess whether you wanted an array interpolated or a literal @. It did this when the string was first used at run time. Now strings are parsed at compile time, and ambiguous instances of @ must be disambiguated, either by prepending a backslash to indicate a literal, or by declaring (or using) the array within the program before the string (lexically). (Someday it will simply assume that an unbackslashed @ interpolates an array.)
(F) You tried to do something that the tainting mechanism didn't like. The tainting mechanism is turned on when you're running setuid or setgid, or when you specify -T to turn it on explicitly. The tainting mechanism labels all data that's derived directly or indirectly from the user, who is considered to be unworthy of your trust. If any such data is used in a "dangerous" operation, you get this error.
(F) You can't use system, exec, or a piped open in a setuid or setgid script if $ENV{PATH} contains a directory that is writable by the world.
(F) You can't use system, exec, or a piped open in a setuid or setgid script if any of $ENV{PATH}, $ENV{IFS}, $ENV{CDPATH}, $ENV{ENV}, or $ENV{BASH_ENV} are derived from data supplied (or potentially supplied) by the user. The script must set the path to a known value, using trustworthy data.
(W overflow) The hexadecimal, octal, or binary number you have specified either as a literal or as an argument to hex or oct is too big for your architecture and has been converted to a floating-point number. On 32-bit machines, the largest hex, 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.
(S) This is a warning peculiar to VMS. Perl keeps track of the number of times you've called fork and exec, to determine whether the current call to exec should affect the current script or a subprocess (see "exec LIST" in perlvms(1)). Somehow, this count has become scrambled, so Perl is making a guess and treating this exec as a request to terminate the Perl script and execute the specified command.
(P) Something went badly wrong in the regular expression parser.
(P) Something went badly awry in the regular expression parser.
(F) The indicated attribute for a subroutine or variable was not recognized by Perl or by a user-supplied handler.
(F) The indicated attributes for a subroutine or variable were not recognized by Perl or by a user-supplied handler.
(F) The range specified in a character class had a minimum character greater than the maximum character.
(W printf) Perl does not understand the given format conversion.
(F) Something other than a colon or whitespace was seen between the elements of an attribute list. If the previous attribute had a parenthesized parameter list, perhaps that list was terminated too soon.
(F) The given character is not a valid pack type.
(W pack) The given character is not a valid pack type, but it used to be silently ignored.
(F) The given character is not a valid unpack type.
(W unpack) The given character is not a valid unpack type, but it used to be silently ignored.
(F) Your machine apparently doesn't implement ioctl, which is pretty strange for a machine that supports C.
(P) The regular expression parser is confused.
(F) You named a loop to break out of, but you're not currently in a loop of that name, not even if you count where you were called from.
(F) You named a loop to continue, but you're not currently in a loop of that name, not even if you count where you were called from.
(F) You named a loop to restart, but you're not currently in a loop of that name, not even if you count where you were called from.
(F) While under the use filetest pragma, switching the real and effective UIDs or GIDs failed.
(W closed) You tried to do a listen on a closed socket. Did you forget to check the return value of your socket call?
(F) Due to limitations in the current implementation, array and hash values cannot be returned in subroutines used in lvalue context.
(F) This is an error peculiar to OS/2. PERLLIB_PREFIX should be of the form:
or:prefix1;prefix2
with nonempty prefix1 and prefix2. If prefix1 is indeed a prefix of a built-in library search path, prefix2 is substituted. The error may appear if components are not found, or are too long. See PERLLIB_PREFIX in the README.os2 file bundled with the Perl distribution.prefix1 prefix2
(F) An attempt was made to specify an entry in an overloading table that doesn't resolve to a valid subroutine.
See Server error.
(S) An advisory indicating that the previous error may have been caused by a missing delimiter on a string or pattern, because the string eventually ended earlier on the current line.
(W syntax) An underline in a decimal constant wasn't at a 3-digit boundary.
(F) Apparently, you've been programming in csh too much. Variables are always mentioned with the $ in Perl, unlike in the shells, where it can vary from one line to the next.
(F) You used the wrong syntax of character name literal \N{charname} within double-quotish context.
(F) While certain functions allow you to specify a filehandle or an "indirect object" before the argument list, this ain't one of them.
(W pipe) You used the open(FH, "| command") or open(FH, "command |") construction, but the command was missing or blank.
(S) This is an educated guess made in conjunction with the message "%s found where operator expected". Often the missing operator is a comma.
(F) The lexer counted more opening curly or square brackets than closing ones. As a general rule, you'll find it's missing near the place you were last editing.
(F) You tried, directly or indirectly, to change the value of a constant. You didn't, of course, try 2 = 1, because the compiler catches that. But an easy way to do the same thing is:
sub mod { $_[0] = 1 }
mod(2);
Another way is to assign to a substr that's off the end of the string.
(F) You tried to make an array value spring into existence, and the subscript was probably negative, even counting from end of the array backward.
(P) You tried to make a hash value spring into existence, and it couldn't be created for some peculiar reason.
(F) Only a bare module name is allowed as the first argument to a use.
(F) You don't have System V message IPC on your system.
(W syntax) Multidimensional arrays aren't written like $foo[1,2,3]. They're written like $foo[1][2][3], as in C.
(F) The reserved syntax for lexically scoped subroutines requires that they have a name with which they can be found.
(W once) Typographical errors often show up as unique variable names. If you had a good reason for having a unique name, then just mention it again somehow to suppress the message. The our declaration is provided for this purpose.
(F) You tried to do a read/write/send/recv operation with a buffer length that is less than 0. This is difficult to imagine.
(F) You can't quantify a quantifier without intervening parentheses. So things like ** or +* or ?* are illegal.
Note, however, that the minimal matching quantifiers, *?, +?, and ?? appear to be nested quantifiers, but aren't.
(F) The setuid emulator requires that scripts have a well-formed #! line even on machines that don't support the #! construct.
(F) Certain operations are deemed to be too insecure for a setuid or setgid script to even attempt. Generally speaking, there will be another way to do what you want that is, if not secure, at least securable.
(F) A setuid script can't be specified by the user.
(F) The indicated command-line switch needs a mandatory argument, but you haven't specified one.
(F) A list operator that has a filehandle or "indirect object" is not allowed to have a comma between that and the following arguments. Otherwise, it would be interpreted as just another argument.
One obscure situation where this message occurs is when you expect a constant to be imported into your namespace with use or import, but no such importing took place (say, because your operating system doesn't support that particular constant). You should have used an explicit import list for the constants you expect to see. An explicit import list would probably have caught this error earlier. Or maybe there's just a typo in the name of the constant.
(F) This is an error peculiar to VMS. Perl handles its own command-line redirection and found a | at the end of the command line, so it doesn't know where you want to pipe the output from this command.
(F) The currently executing code was compiled with the -d switch, but for some reason the perl5db.pl file (or some facsimile thereof) didn't define a routine to be called at the beginning of each statement. Which is odd, because the file should have been required automatically and should have blown up the require if it didn't parse right.
(P) This is counted as an internal error; every machine should supply a DBM nowadays because Perl comes with SDBM.
(F) The currently executing code was compiled with the -d switch, but for some reason the perl5db.pl file (or some facsimile thereof) didn't define a DB::sub routine to be called at the beginning of each ordinary subroutine call.
(F) This is an error peculiar to VMS. Perl handles its own command-line redirection, and found a 2> or a 2>> on the command line, but it can't find the name of the file to which to write data destined for STDERR.
(F) This is an error peculiar to VMS. Perl handles its own command-line redirection and found a < on the command line, but it can't find the name of the file from which to read data for STDIN.
(F) This is an error peculiar to VMS. Perl handles its own command-line redirection and found a lone > at the end of the command line, but it doesn't know where you wanted to redirect STDOUT.
(F) This is an error peculiar to VMS. Perl handles its own command-line redirection and found a > or a >> on the command line, but it can't find the name of the file to which to write data destined for STDOUT.
(F) Fully qualified variable names are not allowed in our declarations, because they don't make much sense under existing semantics. Such syntax is reserved for future extensions.
(F) You called perl -x, but no line was found in the file beginning with #! and containing the word "perl".
(F) Configure didn't find anything resembling the setregid call for your system.
(F) Configure didn't find anything resembling the setreuid call for your system.
(F) The argument to the indicated command-line switch must follow immediately after the switch, without intervening spaces.
(F) You tried to access an array as a hash, but the field name used is not defined. The hash at index 0 should map all valid field names to array indices for that to work.
(F) You tried to access a field of a typed variable, but the type does not know about the field name. The field names are looked up in the %FIELDS hash in the type package at compile time. The %FIELDS hash is usually set up with the fields pragma.
(P) This is an error peculiar to VMS. The internal routine my_pclose tried to close a pipe that hadn't been opened. This should have been caught earlier as an attempt to close an unopened filehandle.
(W signal) The signal name you specified as a subscript to %SIG was not recognized. Say kill -l in your shell to see the valid signal names on your system.
(S) This is a warning peculiar to VMS. Perl was unable to find the local time zone offset, so it assumes that the local system time and the UTC are equivalent. If they're not, define the logical name SYS$TIMEZONE_DIFFERENTIAL to translate to the number of seconds that need to be added to UTC to get local time.
(F) Perl was trying to evaluate a reference to a code value (that is, a subroutine) but found a reference to something else instead. You can use the ref function to find out what kind of ref it really was.
(F) We're not sure how you managed to generate a reference to an anonymous format, but this message indicates that you did and that it didn't exist.
(F) Perl was trying to evaluate a reference to a "typeglob" (that is, a symbol table entry that looks like *foo) but found a reference to something else instead. You can use the ref function to find out what kind of ref it really was.
(F) Perl was trying to evaluate a reference to a hash value but found a reference to something else instead. You can use the ref function to find out what kind of ref it really was.
(F) The setuid emulator requires that scripts have a well-formed #! line even on machines that don't support the #! construct. The line must mention "perl".
(F) Perl was trying to evaluate a reference to a scalar value but found a reference to something else instead. You can use the ref function to find out what kind of ref it really was.
(F) Perl was trying to evaluate a reference to a code value (that is, a subroutine) but found a reference to something else instead. You can use the ref function to find out what kind of ref it really was.
(F) An attempt was made to specify an entry in an overloading table that doesn't somehow point to a valid subroutine.
(F) Perl was trying to evaluate a reference to an array value but found a reference to something else instead. You can use the ref function to find out what kind of ref it really was.
(F) The function requires more arguments than you specified.
(W syntax) A format specified more picture fields than the next line supplied.
(F) You can't require the null filename, especially because on many machines that means the current directory!
(F) The first argument to formline must be a valid format picture specification. The argument was found to be empty, which probably means you supplied it an uninitialized value.
(P debugging) Some internal routine called run with a null opcode pointer.
(P) An attempt was made to realloc NULL.
(P) The internal pattern-matching routines blew it big time.
(P) The internal pattern-matching routines are out of their gourd.
(F) Perl limits the representation of decimal numbers in programs to about about 250 characters. You've exceeded that length. Future versions of Perl are likely to eliminate this arbitrary limitation. In the meantime, try using scientific notation (e.g., 1e6 instead of 1_000_000).
(W portable) The octal number you specified is larger than 2**32-1 (4,294,967,295) and therefore nonportable between systems.
(F) Numbers with a leading 0 are not currently allowed in vectors. The octal number interpretation of such numbers may be supported in a future version.
(W misc) You specified an odd number of elements to initialize a hash, which is odd because hashes come in key/value pairs.
(F) You tried to do a read/write/send/recv operation with an offset pointing outside the buffer. This is difficult to imagine. The sole exception to this rule is that sysreading past the buffer will extend the buffer and zero-pad the new area.
(S internal) An internal warning indicating that the grammar is screwed up.
(S internal) An internal warning indicating that the grammar is screwed up.
(F) An attempt was made to perform an overloaded operation for which no handler was defined. While some handlers can be autogenerated in terms of other handlers, there is no default handler for any operation, unless the fallback overloading key is specified to be true.
(S ambiguous) You used a variable or subroutine call when the parser was expecting an operator. The parser has assumed you really meant to use an operator, but this is highly likely to be incorrect. For example, if you accidentally say *foo*foo, it will be interpreted as if you'd said *foo * 'foo'.
(X) Perl's internal malloc function returned 0, indicating that the remaining memory (or virtual memory) was insufficient to satisfy the request. Perl has no option but to exit immediately.
(F) The yacc parser wanted to grow its stack so it could continue parsing, but realloc wouldn't give it more memory, virtual or otherwise.
(X|F) The malloc function returned 0, indicating that the remaining memory (or virtual memory) was insufficient to satisfy the request.
The request was judged to be small, so the possibility to trap it depends on the way Perl was compiled. By default, it is not trappable. However, if compiled for this purpose, Perl may use the contents of $^M as an emergency pool after dieing with this messag