3 perldelta - what's new for perl5.004
7 This document describes differences between the 5.003 release (as
8 documented in I<Programming Perl>, second edition--the Camel Book) and
11 =head1 Supported Environments
13 Perl5.004 builds out of the box on Unix, Plan9, LynxOS, VMS, OS/2,
18 Most importantly, many bugs were fixed. See the F<Changes>
19 file in the distribution for details.
21 =head2 Compilation Option: Binary Compatibility With 5.003
23 There is a new Configure question that asks if you want to maintain
24 binary compatibility with Perl 5.003. If you choose binary
25 compatibility, you do not have to recompile your extensions, but you
26 might have symbol conflicts if you embed Perl in another application,
27 just as in the 5.003 release. By default, binary compatibility
28 is preserved at the expense of symbol table pollution.
30 =head2 New Opcode Module and Revised Safe Module
32 A new Opcode module supports the creation, manipulation and
33 application of opcode masks. The revised Safe module has a new API
34 and is implemented using the new Opcode module. Please read the new
35 Opcode and Safe documentation.
37 =head2 Internal Change: FileHandle Deprecated
39 Filehandles are now stored internally as type IO::Handle.
40 Although C<use FileHandle> and C<*STDOUT{FILEHANDLE}>
41 are still supported for backwards compatibility,
42 C<use IO::Handle> (or C<IO::Seekable> or C<IO::File>) and
43 C<*STDOUT{IO}> are the way of the future.
45 =head2 Internal Change: PerlIO internal IO abstraction interface
47 It is now possible to build Perl with AT&T's sfio IO package
48 instead of stdio. See L<perlapio> for more details, and
49 the F<INSTALL> file for how to use it.
51 =head2 New and Changed Built-in Variables
57 Extended error message under some platforms ($EXTENDED_OS_ERROR
58 if you C<use English>).
62 The current set of syntax checks enabled by C<use strict>. See the
63 documentation of C<strict> for more details. Not actually new, but
65 Because it is intended for internal use by Perl core components,
66 there is no C<use English> long name for this variable.
70 By default, running out of memory it is not trappable. However, if
71 compiled for this, Perl may use the contents of C<$^M> as an emergency
72 pool after die()ing with this message. Suppose that your Perl were
73 compiled with -DEMERGENCY_SBRK and used Perl's malloc. Then
77 would allocate a 64K buffer for use when in emergency.
78 See the F<INSTALL> file for information on how to enable this option.
79 As a disincentive to casual use of this advanced feature,
80 there is no C<use English> long name for this variable.
84 =head2 New and Changed Built-in Functions
88 =item delete on slices
90 This now works. (e.g. C<delete @ENV{'PATH', 'MANPATH'}>)
94 is now supported on more platforms, and prefers fcntl
95 to lockf when emulating.
97 =item keys as an lvalue
99 As an lvalue, C<keys> allows you to increase the number of hash buckets
100 allocated for the given associative array. This can gain you a measure
101 of efficiency if you know the hash is going to get big. (This is
102 similar to pre-extending an array by assigning a larger number to
107 then C<%hash> will have at least 200 buckets allocated for it. These
108 buckets will be retained even if you do C<%hash = ()>; use C<undef
109 %hash> if you want to free the storage while C<%hash> is still in scope.
110 You can't shrink the number of buckets allocated for the hash using
111 C<keys> in this way (but you needn't worry about doing this by accident,
112 as trying has no effect).
114 =item my() in Control Structures
116 You can now use my() (with or without the parentheses) in the control
117 expressions of control structures such as:
119 while (my $line = <>) {
125 if ((my $answer = <STDIN>) =~ /^y(es)?$/i) {
127 } elsif ($answer =~ /^n(o)?$/i) {
131 die "`$answer' is neither `yes' nor `no'";
134 Also, you can declare a foreach loop control variable as lexical by
135 preceding it with the word "my". For example, in:
137 foreach my $i (1, 2, 3) {
141 $i is a lexical variable, and the scope of $i extends to the end of
142 the loop, but not beyond it.
144 Note that you still cannot use my() on global punctuation variables
145 such as $_ and the like.
147 =item unpack() and pack()
149 A new format 'w' represents a BER compressed integer (as defined in
150 ASN.1). Its format is a sequence of one or more bytes, each of which
151 provides seven bits of the total value, with the most significant
152 first. Bit eight of each byte is set, except for the last byte, in
153 which bit eight is clear.
157 If the first argument to C<use> is a number, it is treated as a version
158 number instead of a module name. If the version of the Perl interpreter
159 is less than VERSION, then an error message is printed and Perl exits
160 immediately. Because C<use> occurs at compile time, this check happens
161 immediately during the compilation process, unlike C<require VERSION>,
162 which waits until run-time for the check. This is often useful if you
163 need to check the current Perl version before C<use>ing library modules
164 which have changed in incompatible ways from older versions of Perl.
165 (We try not to do this more than we have to.)
167 =item use Module VERSION LIST
169 If the VERSION argument is present between Module and LIST, then the
170 C<use> will call the VERSION method in class Module with the given
171 version as an argument. The default VERSION method, inherited from
172 the Universal class, croaks if the given version is larger than the
173 value of the variable $Module::VERSION. (Note that there is not a
174 comma after VERSION!)
176 This version-checking mechanism is similar to the one currently used
177 in the Exporter module, but it is faster and can be used with modules
178 that don't use the Exporter. It is the recommended method for new
181 =item prototype(FUNCTION)
183 Returns the prototype of a function as a string (or C<undef> if the
184 function has no prototype). FUNCTION is a reference to or the name of the
185 function whose prototype you want to retrieve.
186 (Not actually new; just never documented before.)
190 Functions documented in the Camel to default to $_ now in
191 fact do, and all those that do are so documented in L<perlfunc>.
193 =item C<m//g> does not trigger a pos() reset on failure
195 The C<m//g> match iteration construct used to reset the iteration
196 when it failed to match (so that the next C<m//g> match would start at
197 the beginning of the string). You now have to explicitly do a
198 C<pos $str = 0;> to reset the "last match" position, or modify the
199 string in some way. This change makes it practical to chain C<m//g>
200 matches together in conjunction with ordinary matches using the C<\G>
201 zero-width assertion. See L<perlop> and L<perlre>.
203 =item nested C<sub{}> closures work now
205 Prior to the 5.004 release, nested anonymous functions
206 didn't work right. They do now.
208 =item formats work right on changing lexicals
210 Just like anonymous functions that contain lexical variables
211 that change (like a lexical index variable for a C<foreach> loop),
212 formats now work properly. For example, this silently failed
213 before, and is fine now:
216 foreach $i ( 1 .. 10 ) {
226 =head2 New Built-in Methods
228 The C<UNIVERSAL> package automatically contains the following methods that
229 are inherited by all other classes:
235 C<isa> returns I<true> if its object is blessed into a sub-class of C<CLASS>
237 C<isa> is also exportable and can be called as a sub with two arguments. This
238 allows the ability to check what a reference points to. Example:
240 use UNIVERSAL qw(isa);
242 if(isa($ref, 'ARRAY')) {
248 C<can> checks to see if its object has a method called C<METHOD>,
249 if it does then a reference to the sub is returned; if it does not then
250 I<undef> is returned.
252 =item VERSION( [NEED] )
254 C<VERSION> returns the version number of the class (package). If the
255 NEED argument is given then it will check that the current version (as
256 defined by the $VERSION variable in the given package) not less than
257 NEED; it will die if this is not the case. This method is normally
258 called as a class method. This method is called automatically by the
259 C<VERSION> form of C<use>.
261 use A 1.2 qw(some imported subs);
267 C<class> returns the class name of its object.
271 C<is_instance> returns true if its object is an instance of some
272 class, false if its object is the class (package) itself. Example
274 A->is_instance(); # False
277 $var->is_instance(); # False
279 $ref = bless [], 'A';
280 $ref->is_instance(); # True
282 This can be useful for methods that wish to easily distinguish
283 whether they were invoked as class or as instance methods.
286 my $classname = shift;
287 if ($classname->is_instance()) {
288 die "unexpectedly called as instance not class method";
295 B<NOTE:> C<can> directly uses Perl's internal code for method lookup, and
296 C<isa> uses a very similar method and caching strategy. This may cause
297 strange effects if the Perl code dynamically changes @ISA in any package.
299 You may add other methods to the UNIVERSAL class via Perl or XS code.
300 You do not need to C<use UNIVERSAL> in order to make these methods
301 available to your program. This is necessary only if you wish to
302 have C<isa> available as a plain subroutine in the current package.
304 =head2 TIEHANDLE Now Supported
306 See L<perltie> for other kinds of tie()s.
310 =item TIEHANDLE classname, LIST
312 This is the constructor for the class. That means it is expected to
313 return an object of some sort. The reference can be used to
314 hold some internal information.
319 return bless \$i, shift;
322 =item PRINT this, LIST
324 This method will be triggered every time the tied handle is printed to.
325 Beyond its self reference it also expects the list that was passed to
331 return print join( $, => map {uc} @_), $\;
336 This method will be called when the handle is read from. The method
337 should return undef when there is no more data.
341 return "PRINT called $$r times\n";
346 As with the other types of ties, this method will be called when the
347 tied handle is about to be destroyed. This is useful for debugging and
348 possibly for cleaning up.
356 =item Efficiency Enhancements
358 All hash keys with the same string are only allocated once, so
359 even if you have 100 copies of the same hash, the immutable keys
360 never have to be re-allocated.
362 Functions that have an empty prototype and that do nothing but return
363 a fixed value are now inlined (e.g. C<sub PI () { 3.14159 }>).
367 Three new pragmatic modules exist:
375 Looks for MakeMaker-like I<'blib'> directory structure starting in
376 I<dir> (or current directory) and working back up to five levels of
379 Intended for use on command line with B<-M> option as a way of testing
380 arbitrary scripts against an uninstalled version of a package.
384 Tells the compiler to enable (or disable) the use of POSIX locales for
387 When C<use locale> is in effect, the current LC_CTYPE locale is used
388 for regular expressions and case mapping; LC_COLLATE for string
389 ordering; and LC_NUMERIC for numeric formating in printf and sprintf
390 (but B<not> in print). LC_NUMERIC is always used in write, since
391 lexical scoping of formats is problematic at best.
393 Each C<use locale> or C<no locale> affects statements to the end of
394 the enclosing BLOCK or, if not inside a BLOCK, to the end of the
395 current file. Locales can be switched and queried with
398 See L<perllocale> for more information.
402 Disable unsafe opcodes, or any named opcodes, when compiling Perl code.
410 New constants in the existing Fcntl modules are now supported,
411 provided that your operating system happens to support them:
414 O_ASYNC O_DEFER O_DSYNC O_FSYNC O_SYNC
417 These constants are intended for use with the Perl operators sysopen()
418 and fcntl() and the basic database modules like SDBM_File. For the
419 exact meaning of these and other Fcntl constants please refer to your
420 operating system's documentation for fcntl() and open().
422 In addition, the Fcntl module now provides these constants for use
423 with the Perl operator flock():
425 LOCK_SH LOCK_EX LOCK_NB LOCK_UN
427 These constants are defined in all environments (because where there is
428 no flock() system call, Perl emulates it). However, for historical
429 reasons, these constants are not exported unless they are explicitly
430 requested with the ":flock" tag (e.g. C<use Fcntl ':flock'>).
432 =head2 Module Information Summary
434 Brand new modules, arranged by topic rather than strictly
437 CPAN interface to Comprehensive Perl Archive Network
438 CPAN::FirstTime create a CPAN configuration file
439 CPAN::Nox run CPAN while avoiding compiled extensions
441 IO.pm Top-level interface to IO::* classes
442 IO/File.pm IO::File extension Perl module
443 IO/Handle.pm IO::Handle extension Perl module
444 IO/Pipe.pm IO::Pipe extension Perl module
445 IO/Seekable.pm IO::Seekable extension Perl module
446 IO/Select.pm IO::Select extension Perl module
447 IO/Socket.pm IO::Socket extension Perl module
449 Opcode.pm Disable named opcodes when compiling Perl code
451 ExtUtils/Embed.pm Utilities for embedding Perl in C programs
452 ExtUtils/testlib.pm Fixes up @INC to use just-built extension
454 Fatal.pm Make do-or-die equivalents of functions
455 FindBin.pm Find path of currently executing program
457 Class/Template.pm Structure/member template builder
458 File/stat.pm Object-oriented wrapper around CORE::stat
459 Net/hostent.pm Object-oriented wrapper around CORE::gethost*
460 Net/netent.pm Object-oriented wrapper around CORE::getnet*
461 Net/protoent.pm Object-oriented wrapper around CORE::getproto*
462 Net/servent.pm Object-oriented wrapper around CORE::getserv*
463 Time/gmtime.pm Object-oriented wrapper around CORE::gmtime
464 Time/localtime.pm Object-oriented wrapper around CORE::localtime
465 Time/tm.pm Perl implementation of "struct tm" for {gm,local}time
466 User/grent.pm Object-oriented wrapper around CORE::getgr*
467 User/pwent.pm Object-oriented wrapper around CORE::getpw*
469 Tie/RefHash.pm Base class for tied hashes with references as keys
471 UNIVERSAL.pm Base class for *ALL* classes
475 The IO module provides a simple mechanism to load all of the IO modules at one
476 go. Currently this includes:
484 For more information on any of these modules, please see its
485 respective documentation.
489 The Math::Complex module has been totally rewritten, and now supports
490 more operations. These are overloaded:
492 + - * / ** <=> neg ~ abs sqrt exp log sin cos atan2 "" (stringify)
494 And these functions are now exported:
498 tan cotan asin acos atan acotan
499 sinh cosh tanh cotanh asinh acosh atanh acotanh
504 There have been quite a few changes made to DB_File. Here are a few of
511 Fixed a handful of bugs.
515 By public demand, added support for the standard hash function exists().
519 Made it compatible with Berkeley DB 1.86.
523 Made negative subscripts work with RECNO interface.
527 Changed the default flags from O_RDWR to O_CREAT|O_RDWR and the default
528 mode from 0640 to 0666.
532 Made DB_File automatically import the open() constants (O_RDWR,
533 O_CREAT etc.) from Fcntl, if available.
537 Updated documentation.
541 Refer to the HISTORY section in DB_File.pm for a complete list of
542 changes. Everything after DB_File 1.01 has been added since 5.003.
546 Major rewrite - support added for both udp echo and real icmp pings.
548 =head2 Overridden Built-ins
550 Many of the Perl built-ins returning lists now have
551 object-oriented overrides. These are:
563 For example, you can now say
567 $his = (stat($filename)->st_uid == pwent($whoever)->pw_uid);
569 =head1 Utility Changes
575 =item C<void> XSUBs now default to returning nothing
577 Due to a documentation/implementation bug in previous versions of
578 Perl, XSUBs with a return type of C<void> have actually been
579 returning one value. Usually that value was the GV for the XSUB,
580 but sometimes it was some already freed or reused value, which would
581 sometimes lead to program failure.
583 In Perl 5.004, if an XSUB is declared as returning C<void>, it
584 actually returns no value, i.e. an empty list (though there is a
585 backward-compatibility exception; see below). If your XSUB really
586 does return an SV, you should give it a return type of C<SV *>.
588 For backward compatibility, I<xsubpp> tries to guess whether a
589 C<void> XSUB is really C<void> or if it wants to return an C<SV *>.
590 It does so by examining the text of the XSUB: if I<xsubpp> finds
591 what looks like an assignment to C<ST(0)>, it assumes that the
592 XSUB's return type is really C<SV *>.
596 =head1 C Language API Changes
600 =item C<gv_fetchmethod> and C<perl_call_sv>
602 The C<gv_fetchmethod> function finds a method for an object, just like
603 in Perl 5.003. The GV it returns may be a method cache entry.
604 However, in Perl 5.004, method cache entries are not visible to users;
605 therefore, they can no longer be passed directly to C<perl_call_sv>.
606 Instead, you should use the C<GvCV> macro on the GV to extract its CV,
607 and pass the CV to C<perl_call_sv>.
609 The most likely symptom of passing the result of C<gv_fetchmethod> to
610 C<perl_call_sv> is Perl's producing an "Undefined subroutine called"
611 error on the I<second> call to a given method (since there is no cache
616 =head1 Documentation Changes
618 Many of the base and library pods were updated. These
619 new pods are included in section 1:
629 Locale support (internationalization and localization).
633 Tutorial on Perl OO programming.
637 Perl internal IO abstraction interface.
641 Although not new, this has been massively updated.
645 Although not new, this has been massively updated.
649 =head1 New Diagnostics
651 Several new conditions will trigger warnings that were
652 silent before. Some only affect certain platforms.
653 The following new warnings and errors outline these.
654 These messages are classified as follows (listed in
655 increasing order of desperation):
657 (W) A warning (optional).
658 (D) A deprecation (optional).
659 (S) A severe warning (mandatory).
660 (F) A fatal error (trappable).
661 (P) An internal error you should never see (trappable).
662 (X) A very fatal error (non-trappable).
663 (A) An alien error message (not generated by Perl).
667 =item "my" variable %s masks earlier declaration in same scope
669 (S) A lexical variable has been redeclared in the same scope, effectively
670 eliminating all access to the previous instance. This is almost always
671 a typographical error. Note that the earlier variable will still exist
672 until the end of the scope or until all closure referents to it are
675 =item %s argument is not a HASH element or slice
677 (F) The argument to delete() must be either a hash element, such as
680 $ref->[12]->{"susie"}
682 or a hash slice, such as
684 @foo{$bar, $baz, $xyzzy}
685 @{$ref->[12]}{"susie", "queue"}
687 =item Allocation too large: %lx
689 (X) You can't allocate more than 64K on an MSDOS machine.
691 =item Allocation too large
693 (F) You can't allocate more than 2^31+"small amount" bytes.
695 =item Attempt to free non-existent shared string
697 (P) Perl maintains a reference counted internal table of strings to
698 optimize the storage and access of hash keys and other strings. This
699 indicates someone tried to decrement the reference count of a string
700 that can no longer be found in the table.
702 =item Attempt to use reference as lvalue in substr
704 (W) You supplied a reference as the first argument to substr() used
705 as an lvalue, which is pretty strange. Perhaps you forgot to
706 dereference it first. See L<perlfunc/substr>.
708 =item Unsupported function fork
710 (F) Your version of executable does not support forking.
712 Note that under some systems, like OS/2, there may be different flavors of
713 Perl executables, some of which may support fork, some not. Try changing
714 the name you call Perl by to C<perl_>, C<perl__>, and so on.
716 =item Ill-formed logical name |%s| in prime_env_iter
718 (W) A warning peculiar to VMS. A logical name was encountered when preparing
719 to iterate over %ENV which violates the syntactic rules governing logical
720 names. Since it cannot be translated normally, it is skipped, and will not
721 appear in %ENV. This may be a benign occurrence, as some software packages
722 might directly modify logical name tables and introduce non-standard names,
723 or it may indicate that a logical name table has been corrupted.
725 =item Can't use bareword ("%s") as %s ref while "strict refs" in use
727 (F) Only hard references are allowed by "strict refs". Symbolic references
728 are disallowed. See L<perlref>.
730 =item Constant subroutine %s redefined
732 (S) You redefined a subroutine which had previously been eligible for
733 inlining. See L<perlsub/"Constant Functions"> for commentary and
738 (F) You passed die() an empty string (the equivalent of C<die "">) or
739 you called it with no args and both C<$@> and C<$_> were empty.
741 =item Integer overflow in hex number
743 (S) The literal hex number you have specified is too big for your
744 architecture. On a 32-bit architecture the largest hex literal is
747 =item Integer overflow in octal number
749 (S) The literal octal number you have specified is too big for your
750 architecture. On a 32-bit architecture the largest octal literal is
753 =item Name "%s::%s" used only once: possible typo
755 (W) Typographical errors often show up as unique variable names.
756 If you had a good reason for having a unique name, then just mention
757 it again somehow to suppress the message (the C<use vars> pragma is
758 provided for just this purpose).
760 =item Null picture in formline
762 (F) The first argument to formline must be a valid format picture
763 specification. It was found to be empty, which probably means you
764 supplied it an uninitialized value. See L<perlform>.
766 =item Offset outside string
768 (F) You tried to do a read/write/send/recv operation with an offset
769 pointing outside the buffer. This is difficult to imagine.
770 The sole exception to this is that C<sysread()>ing past the buffer
771 will extend the buffer and zero pad the new area.
773 =item Stub found while resolving method `%s' overloading `%s' in package `%s'
775 (P) Overloading resolution over @ISA tree may be broken by importing stubs.
776 Stubs should never be implicitely created, but explicit calls to C<can>
779 =item Cannot resolve method `%s' overloading `%s' in package `s'
781 (P) Internal error trying to resolve overloading specified by a method
782 name (as opposed to a subroutine reference).
786 (X|F) The malloc() function returned 0, indicating there was insufficient
787 remaining memory (or virtual memory) to satisfy the request.
789 The request was judged to be small, so the possibility to trap it
790 depends on the way Perl was compiled. By default it is not trappable.
791 However, if compiled for this, Perl may use the contents of C<$^M> as
792 an emergency pool after die()ing with this message. In this case the
793 error is trappable I<once>.
795 =item Out of memory during request for %s
797 (F) The malloc() function returned 0, indicating there was insufficient
798 remaining memory (or virtual memory) to satisfy the request. However,
799 the request was judged large enough (compile-time default is 64K), so
800 a possibility to shut down by trapping this error is granted.
802 =item Possible attempt to put comments in qw() list
804 (W) qw() lists contain items separated by whitespace; as with literal
805 strings, comment characters are not ignored, but are instead treated
806 as literal data. (You may have used different delimiters than the
807 exclamation marks parentheses shown here; braces are also frequently
810 You probably wrote something like this:
817 when you should have written this:
824 If you really want comments, build your list the
825 old-fashioned way, with quotes and commas:
829 'b', # another comment
832 =item Possible attempt to separate words with commas
834 (W) qw() lists contain items separated by whitespace; therefore commas
835 aren't needed to separate the items. (You may have used different
836 delimiters than the parentheses shown here; braces are also frequently
839 You probably wrote something like this:
843 which puts literal commas into some of the list items. Write it without
844 commas if you don't want them to appear in your data:
848 =item Scalar value @%s{%s} better written as $%s{%s}
850 (W) You've used a hash slice (indicated by @) to select a single element of
851 a hash. Generally it's better to ask for a scalar value (indicated by $).
852 The difference is that C<$foo{&bar}> always behaves like a scalar, both when
853 assigning to it and when evaluating its argument, while C<@foo{&bar}> behaves
854 like a list when you assign to it, and provides a list context to its
855 subscript, which can do weird things if you're expecting only one subscript.
857 =item untie attempted while %d inner references still exist
859 (W) A copy of the object returned from C<tie> (or C<tied>) was still
860 valid when C<untie> was called.
862 =item Value of %s construct can be "0"; test with defined()
864 (W) In a conditional expression, you used <HANDLE>, <*> (glob), or
865 C<readdir> as a boolean value. Each of these constructs can return a
866 value of "0"; that would make the conditional expression false, which
867 is probably not what you intended. When using these constructs in
868 conditional expressions, test their values with the C<defined> operator.
870 =item Variable "%s" may be unavailable
872 (W) An inner (nested) I<anonymous> subroutine is inside a I<named>
873 subroutine, and outside that is another subroutine; and the anonymous
874 (innermost) subroutine is referencing a lexical variable defined in
875 the outermost subroutine. For example:
877 sub outermost { my $a; sub middle { sub { $a } } }
879 If the anonymous subroutine is called or referenced (directly or
880 indirectly) from the outermost subroutine, it will share the variable
881 as you would expect. But if the anonymous subroutine is called or
882 referenced when the outermost subroutine is not active, it will see
883 the value of the shared variable as it was before and during the
884 *first* call to the outermost subroutine, which is probably not what
887 In these circumstances, it is usually best to make the middle
888 subroutine anonymous, using the C<sub {}> syntax. Perl has specific
889 support for shared variables in nested anonymous subroutines; a named
890 subroutine in between interferes with this feature.
892 =item Variable "%s" will not stay shared
894 (W) An inner (nested) I<named> subroutine is referencing a lexical
895 variable defined in an outer subroutine.
897 When the inner subroutine is called, it will probably see the value of
898 the outer subroutine's variable as it was before and during the
899 *first* call to the outer subroutine; in this case, after the first
900 call to the outer subroutine is complete, the inner and outer
901 subroutines will no longer share a common value for the variable. In
902 other words, the variable will no longer be shared.
904 Furthermore, if the outer subroutine is anonymous and references a
905 lexical variable outside itself, then the outer and inner subroutines
906 will I<never> share the given variable.
908 This problem can usually be solved by making the inner subroutine
909 anonymous, using the C<sub {}> syntax. When inner anonymous subs that
910 reference variables in outer subroutines are called or referenced,
911 they are automatically re-bound to the current values of such
914 =item Warning: something's wrong
916 (W) You passed warn() an empty string (the equivalent of C<warn "">) or
917 you called it with no args and C<$_> was empty.
919 =item Got an error from DosAllocMem
921 (P) An error peculiar to OS/2. Most probably you're using an obsolete
922 version of Perl, and this should not happen anyway.
924 =item Malformed PERLLIB_PREFIX
926 (F) An error peculiar to OS/2. PERLLIB_PREFIX should be of the form
934 with non-empty prefix1 and prefix2. If C<prefix1> is indeed a prefix of
935 a builtin library search path, prefix2 is substituted. The error may appear
936 if components are not found, or are too long. See L<perlos2/"PERLLIB_PREFIX">.
938 =item PERL_SH_DIR too long
940 (F) An error peculiar to OS/2. PERL_SH_DIR is the directory to find the
941 C<sh>-shell in. See L<perlos2/"PERL_SH_DIR">.
943 =item Process terminated by SIG%s
945 (W) This is a standard message issued by OS/2 applications, while *nix
946 applications die in silence. It is considered a feature of the OS/2
947 port. One can easily disable this by appropriate sighandlers, see
948 L<perlipc/"Signals">. See L<perlos2/"Process terminated by SIGTERM/SIGINT">.
954 If you find what you think is a bug, you might check the headers of
955 recently posted articles in the comp.lang.perl.misc newsgroup.
956 There may also be information at http://www.perl.com/perl/, the Perl
959 If you believe you have an unreported bug, please run the B<perlbug>
960 program included with your release. Make sure you trim your bug
961 down to a tiny but sufficient test case. Your bug report, along
962 with the output of C<perl -V>, will be sent off to perlbug@perl.com
963 to be analysed by the Perl porting team.
967 The F<Changes> file for exhaustive details on what changed.
969 The F<INSTALL> file for how to build Perl. This file has been
970 significantly updated for 5.004, so even veteran users should
973 The F<README> file for general stuff.
975 The F<Copying> file for copyright information.
979 Constructed by Tom Christiansen, grabbing material with permission
980 from innumerable contributors, with kibitzing by more than a few Perl
983 Last update: Tue Jan 14 14:03:02 EST 1997