=head1 NAME
-perlnews - what's new for perl5.004
+perldelta - what's new for perl5.005
=head1 DESCRIPTION
-This document describes differences between the 5.003 release (as
-documented in I<Programming Perl>, second edition--the Camel Book) and
-this one.
+This document describes differences between the 5.004 release and this one.
-=head1 Supported Environments
+[XXX this needs more verbose summaries of the sub topics, instead of just
+the "See foo." Scheduled for a second iteration. GSAR]
-Perl5.004 builds out of the box on Unix, Plan9, LynxOS, VMS, OS/2,
-QNX, and AmigaOS.
+=head1 About the new versioning system
+
+=head1 Incompatible Changes
+
+=head2 WARNING: This version is not binary compatible with Perl 5.004.
+
+Starting with Perl 5.004_50 there were many deep and far-reaching changes
+to the language internals. If you have dynamically loaded extensions
+that you built under perl 5.003 or 5.004, you can continue to use them
+with 5.004, but you will need to rebuild and reinstall those extensions
+to use them 5.005. See L<INSTALL> for detailed instructions on how to
+upgrade.
+
+=head2 Default installation structure has changed
+
+The new Configure defaults are designed to allow a smooth upgrade from
+5.004 to 5.005, but you should read L<INSTALL> for a detailed
+discussion of the changes in order to adapt them to your system.
+
+=head2 Perl Source Compatibility
+
+When none of the experimental features are enabled, there should be
+no user-visible Perl source compatibility issue.
+
+If threads are enabled, then some caveats apply. C<@_> and C<$_> become
+lexical variables. The effect of this should be largely transparent to
+the user, but there are some boundary conditions under which user will
+need to be aware of the issues. [XXX Add e.g. here.]
+
+Some new keywords have been introduced. These are generally expected to
+have very little impact on compatibility. See L</New C<INIT> keyword>,
+L</New C<lock> keyword>, and L</New C<qr//> operator>.
+
+Certain barewords are now reserved. Use of these will provoke a warning
+if you have asked for them with the C<-w> switch.
+See L</C<our> is now a reserved word>.
+
+=head2 C Source Compatibility
+
+=item Core sources now require ANSI C compiler
+
+=item Enabling threads has source compatibility issues
+
+=head2 Binary Compatibility
+
+This version is NOT binary compatible with older versions. All extensions
+will need to be recompiled.
+
+=head2 Security fixes may affect compatibility
+
+A few taint leaks and taint omissions have been corrected. This may lead
+to "failure" of scripts that used to work with older versions. Compiling
+with -DINCOMPLETE_TAINTS provides a perl with minimal amounts of changes
+to the tainting behavior. But note that the resulting perl will have
+known insecurities.
+
+Oneliners with the C<-e> switch do not create temporary files anymore.
+
+=head2 Relaxed new mandatory warnings introduced in 5.004
+
+Many new warnings that were introduced in 5.004 have been made
+optional. Some of these warnings are still present, but perl's new
+features make them less often a problem. See L<New Diagnostics>.
+
+=head2 Licensing
+
+Perl has a new Social Contract for contributors. See F<Porting/Contract>.
+
+The license included in much of the Perl documentation has changed.
+[XXX See where?]
=head1 Core Changes
-Most importantly, many bugs were fixed. See the F<Changes>
-file in the distribution for details.
-=head2 Compilation Option: Binary Compatibility With 5.003
+=head2 Threads
-There is a new Configure question that asks if you want to maintain
-binary compatibility with Perl 5.003. If you choose binary
-compatibility, you do not have to recompile your extensions, but you
-might have symbol conflicts if you embed Perl in another application,
-just as in the 5.003 release.
+WARNING: Threading is considered an experimental feature. Details of the
+implementation may change without notice. There are known limitations
+and and some bugs.
-=head2 New Opcode Module and Revised Safe Module
+See L<README.threads>.
-A new Opcode module supports the creation, manipulation and
-application of opcode masks. The revised Safe module has a new API
-and is implemented using the new Opcode module. Please read the new
-Opcode and Safe documentation.
+=head2 Compiler
-=head2 Internal Change: FileHandle Deprecated
+WARNING: The Compiler and related tools are considered experimental.
+Features may change without notice, and there are known limitations
+and bugs.
-Filehandles are now stored internally as type IO::Handle.
-Although C<use FileHandle> and C<*STDOUT{FILEHANDLE}>
-are still supported for backwards compatibility
-C<use IO::Handle> (or C<IO::Seekable> or C<IO::File>) and
-C<*STDOUT{IO}> are the way of the future.
+The Compiler produces three different types of transformations of a
+perl program. The C backend generates C code that captures perl's state
+just before execution begins. It eliminates the compile-time overheads
+of the regular perl interpreter, but the run-time performance remains
+comparatively the same. The CC backend generates optimized C code
+equivivalent to the code path at run-time. The CC backend has greater
+potential for big optimizations, but only a few optimizations are
+implemented currently. The Bytecode backend generates a platform
+independent bytecode representation of the interpreter's state
+just before execution. Thus, the Bytecode back end also eliminates
+much of the compilation overhead of the interpreter.
-=head2 Internal Change: PerlIO internal IO abstraction interface
+The compiler comes with several valuable utilities.
-It is now possible to build Perl with AT&T's sfio IO package
-instead of stdio. See L<perlapio> for more details, and
-the F<INSTALL> file for how to use it.
+C<B::Lint> is an experimental module to detect and warn about suspicious
+code, especially the cases that the C<-w> switch does not detect.
-=head2 New and Changed Built-in Variables
+C<B::Deparse> can be used to demystify perl code, and understand
+how perl optimizes certain constructs.
-=over
+C<B::Xref> generates cross reference reports of all definition and use
+of variables, subroutines and formats in a program.
-=item $^E
+C<B::Showlex> show the lexical variables used by a subroutine or file
+at a glance.
-Extended error message under some platforms ($EXTENDED_OS_ERROR
-if you C<use English>).
+C<perlcc> is a simple frontend for compiling perl.
-=item $^H
+See C<ext/B/README>.
-The current set of syntax checks enabled by C<use strict>. See the
-documentation of C<strict> for more details. Not actually new, but
-newly documented.
-Because it is intended for internal use by Perl core components,
-there is no C<use English> long name for this variable.
+=head2 Regular Expressions
-=item $^M
+See L<perlre> and L<perlop>.
-By default, running out of memory it is not trappable. However, if
-compiled for this, Perl may use the contents of C<$^M> as an emergency
-pool after die()ing with this message. Suppose that your Perl were
-compiled with -DEMERGENCY_SBRK and used Perl's malloc. Then
+=head2 Improved malloc()
- $^M = 'a' x (1<<16);
+See banner at the beginning of C<malloc.c> for details.
-would allocate 64K buffer for use when in emergency.
-See the F<INSTALL> file for information on how to enable this option.
-As a disincentive to casual use of this advanced feature,
-there is no C<use English> long name for this variable.
+=head2 Quicksort is internally implemented
-=back
+See C<perlfunc/sort>.
-=head2 New and Changed Built-in Functions
+=head2 Reliable signals
-=over
+Two kinds.
-=item delete on slices
+Via C<Thread::Signal>.
-This now works. (e.g. C<delete @ENV{'PATH', 'MANPATH'}>)
+Via switched runtime op loop. [XXX Not yet available.]
-=item flock
+=head2 Reliable stack pointers
-is now supported on more platforms, and prefers fcntl
-to lockf when emulating.
+The internals now reallocate the perl stack only at predictable times.
+In particular, magic calls never trigger reallocations of the stack,
+because all reentrancy of the runtime is handled using a "stack of stacks".
+This should improve reliability of cached stack pointers in the internals
+and in XSUBs.
-=item keys as an lvalue
+=head2 Behavior of local() on composites is now well-defined
-As an lvalue, C<keys> allows you to increase the number of hash buckets
-allocated for the given associative array. This can gain you a measure
-of efficiency if you know the hash is going to get big. (This is
-similar to pre-extending an array by assigning a larger number to
-$#array.) If you say
+See L<perlfunc/local>.
- keys %hash = 200;
+=head2 C<%!> is transparently tied to the L<Errno> module
-then C<%hash> will have at least 200 buckets allocated for it. These
-buckets will be retained even if you do C<%hash = ()>; use C<undef
-%hash> if you want to free the storage while C<%hash> is still in scope.
-You can't shrink the number of buckets allocated for the hash using
-C<keys> in this way (but you needn't worry about doing this by accident,
-as trying has no effect).
+See L<perlvar>, and L<Errno>.
-=item my() in Control Structures
+=head2 Pseudo-hashes are supported
-You can now use my() (with or without the parentheses) in the control
-expressions of control structures such as:
+See L<perlref>.
- while (my $line = <>) {
- $line = lc $line;
- } continue {
- print $line;
- }
+=head2 C<EXPR foreach EXPR> is supported
- if ((my $answer = <STDIN>) =~ /^yes$/i) {
- user_agrees();
- } elsif ($answer =~ /^no$/i) {
- user_disagrees();
- } else {
- chomp $answer;
- die "'$answer' is neither 'yes' nor 'no'";
- }
+See L<perlsyn>.
-Also, you can declare a foreach loop control variable as lexical by
-preceding it with the word "my". For example, in:
+=head2 Slice notation on glob elements is supported
- foreach my $i (1, 2, 3) {
- some_function();
- }
+[XXX See what?]
-$i is a lexical variable, and the scope of $i extends to the end of
-the loop, but not beyond it.
+=head2 Keywords can be globally overridden
-Note that you still cannot use my() on global punctuation variables
-such as $_ and the like.
+See L<perlsub>.
-=item unpack() and pack()
+=head2 C<$^E> is meaningful on Win32
-A new format 'w' represents a BER compressed integer (as defined in
-ASN.1). Its format is a sequence of one or more bytes, each of which
-provides seven bits of the total value, with the most significant
-first. Bit eight of each byte is set, except for the last byte, in
-which bit eight is clear.
+See L<perlvar>.
-=item use VERSION
+=head2 C<foreach (1..1000000)> optimized
-If the first argument to C<use> is a number, it is treated as a version
-number instead of a module name. If the version of the Perl interpreter
-is less than VERSION, then an error message is printed and Perl exits
-immediately. This is often useful if you need to check the current
-Perl version before C<use>ing library modules which have changed in
-incompatible ways from older versions of Perl. (We try not to do
-this more than we have to.)
+C<foreach (1..1000000)> is now optimized into a counting loop. It does
+not try to allocate a 1000000-size list anymore.
-=item use Module VERSION LIST
+=head2 C<Foo::> can be used as implicitly quoted package name
-If the VERSION argument is present between Module and LIST, then the
-C<use> will call the VERSION method in class Module with the given
-version as an argument. The default VERSION method, inherited from
-the Universal class, croaks if the given version is larger than the
-value of the variable $Module::VERSION. (Note that there is not a
-comma after VERSION!)
+[XXX See what?]
-This version-checking mechanism is similar to the one currently used
-in the Exporter module, but it is faster and can be used with modules
-that don't use the Exporter. It is the recommended method for new
-code.
+=head2 C<exists $Foo::{Bar::}> tests existence of a package
-=item prototype(FUNCTION)
+[XXX See what?]
-Returns the prototype of a function as a string (or C<undef> if the
-function has no prototype). FUNCTION is a reference to or the name of the
-function whose prototype you want to retrieve.
-(Not actually new; just never documented before.)
+=head2 Better locale support
-=item $_ as Default
+See L<perllocale>.
-Functions documented in the Camel to default to $_ now in
-fact do, and all those that do are so documented in L<perlfunc>.
+=head2 Experimental support for 64-bit platforms
-=head2 C<m//g> does not trigger a pos() reset on failure
+Perl5 has always had 64-bit support on systems with 64-bit longs.
+Starting with 5.005, the beginnings of experimental support for systems
+with 32-bit long and 64-bit 'long long' integers has been added.
+If you add -DUSE_LONG_LONG to your ccflags in config.sh (or manually
+define it in perl.h) then perl will be built with 'long long' support.
+There will be many compiler warnings, and the resultant perl may not
+work on all systems. There are many other issues related to
+third-party extensions and libraries. This option exists to allow
+people to work on those issues.
-The C<m//g> match iteration construct used to reset the iteration
-when it failed to match (so that the next C<m//g> match would start at
-the beginning of the string). You now have to explicitly do a
-C<pos $str = 0;> to reset the "last match" position, or modify the
-string in some way. This change makes it practical to chain C<m//g>
-matches together in conjunction with ordinary matches using the C<\G>
-zero-width assertion. See L<perlop> and L<perlre>.
+=head2 prototype() returns useful results on builtins
-=back
+See L<perlfunc/prototype>.
-=head2 New Built-in Methods
+=head2 Extended support for exception handling
-The C<UNIVERSAL> package automatically contains the following methods that
-are inherited by all other classes:
+C<die()> now accepts a reference value, and C<$@> gets set to that
+value in exception traps. This makes it possible to propagate
+exception objects. See L<perlfunc/eval>. [XXX there's nothing
+about this in perlfunc/eval yet.]
-=over 4
+=head2 Re-blessing in DESTROY() supported for chaining DESTROY() methods
-=item isa(CLASS)
+See L<perlobj/Destructors>.
-C<isa> returns I<true> if its object is blessed into a sub-class of C<CLASS>
+=head2 All C<printf> format conversions are handled internally
-C<isa> is also exportable and can be called as a sub with two arguments. This
-allows the ability to check what a reference points to. Example:
+See L<perlfunc/printf>.
- use UNIVERSAL qw(isa);
+=head2 New C<INIT> keyword
- if(isa($ref, 'ARRAY')) {
- ...
- }
+C<INIT> subs are like C<BEGIN> and C<END>, but they get run just before
+the perl runtime begins execution. e.g., the Perl Compiler makes use of
+C<INIT> blocks to initialize and resolve pointers to XSUBs.
-=item can(METHOD)
+[XXX Needs to be documented in perlsub or perlmod.]
-C<can> checks to see if its object has a method called C<METHOD>,
-if it does then a reference to the sub is returned; if it does not then
-I<undef> is returned.
+=head2 New C<lock> keyword
-=item VERSION( [NEED] )
+The C<lock> keyword is the fundamental synchronization primitive
+in threaded perl. When threads are not enabled, it is currently a noop.
-C<VERSION> returns the version number of the class (package). If the
-NEED argument is given then it will check that the current version (as
-defined by the $VERSION variable in the given package) not less than
-NEED; it will die if this is not the case. This method is normally
-called as a class method. This method is called automatically by the
-C<VERSION> form of C<use>.
+To minimize impact on source compatibility this keyword is "weak", i.e., any
+user-defined subroutine of the same name overrides it, unless a C<use Thread>
+has been seen.
- use A 1.2 qw(some imported subs);
- # implies:
- A->VERSION(1.2);
+=head2 New C<qr//> operator
-=item class()
+The C<qr//> operator, which is syntactically similar to the other quote-like
+operators, is used to create precompiled regular expressions. This compiled
+form can now be explicitly passed around in variables, and interpolated in
+other regular expressions. See L<perlop>.
-C<class> returns the class name of its object.
+=head2 C<our> is now a reserved word
-=item is_instance()
+=head2 Tied arrays are now fully supported
-C<is_instance> returns true if its object is an instance of some
-class, false if its object is the class (package) itself. Example
+See L<Tie::Array>.
- A->is_instance(); # False
+=head2 Tied handles support is better
- $var = 'A';
- $var->is_instance(); # False
+Several missing hooks have been added. There is also a new base class for
+TIEARRAY implementations. See L<Tie::Array>.
- $ref = bless [], 'A';
- $ref->is_instance(); # True
+=head2 4th argument to substr
-=back
+substr() can now both return and replace in one operation. The optional
+4th argument is the replacement string. See L<perlfunc/substr>.
+
+=head2 Negative LENGTH argument to splice
-B<NOTE:> C<can> directly uses Perl's internal code for method lookup, and
-C<isa> uses a very similar method and cache-ing strategy. This may cause
-strange effects if the Perl code dynamically changes @ISA in any package.
+Splice() with a negative LENGTH argument now work similar to what the
+LENGTH did for substr(). Previously a negative LENGTH was treated as
+0. See L<perlfunc/splice>.
-You may add other methods to the UNIVERSAL class via Perl or XS code.
-You do not need to C<use UNIVERSAL> in order to make these methods
-available to your program. This is necessary only if you wish to
-have C<isa> available as a plain subroutine in the current package.
-=head2 TIEHANDLE Now Supported
+=head1 Supported Platforms
+
+Configure has many incremental improvements. Site-wide policy for building
+perl can now be made persistent, via Policy.sh. Configure also records
+the command-line arguments used in F<config.sh>.
+
+=head2 New Platforms
+
+BeOS is now supported. See L<README.beos>.
+
+DOS is now supported under the DJGPP tools. See L<README.dos>.
+
+MPE/iX is now supported. See L<README.mpeix>.
+
+=head2 Changes in existing support
+
+Win32 support has been vastly enhanced. Support for Perl Object, a C++
+encapsulation of Perl. GCC and EGCS are now supported on Win32.
+[XXX Perl Object needs a big explanation elsewhere, and a pointer to
+that location here.]
+
+VMS configuration system has been rewritten. See L<README.vms>.
+
+OpenBSD better supported. [XXX what others?]
+
+=head1 Modules and Pragmata
+
+=head2 New Modules
=over
-=item TIEHANDLE classname, LIST
+=item B
-This is the constructor for the class. That means it is expected to
-return an object of some sort. The reference can be used to
-hold some internal information.
+Perl compiler and tools. See [XXX what?].
- sub TIEHANDLE { print "<shout>\n"; my $i; bless \$i, shift }
+=item Data::Dumper
-=item PRINT this, LIST
+A module to pretty print Perl data. See L<Data::Dumper>.
-This method will be triggered every time the tied handle is printed to.
-Beyond its self reference it also expects the list that was passed to
-the print function.
+=item Errno
- sub PRINT { $r = shift; $$r++; print join($,,map(uc($_),@_)),$\ }
+A module to look up errors more conveniently. See L<Errno>.
-=item READLINE this
+=item File::Spec
-This method will be called when the handle is read from. The method
-should return undef when there is no more data.
+A portable API for file operations.
- sub READLINE { $r = shift; "PRINT called $$r times\n"; }
+=item ExtUtils::Installed
-=item DESTROY this
+Query and manage installed modules.
-As with the other types of ties, this method will be called when the
-tied handle is about to be destroyed. This is useful for debugging and
-possibly for cleaning up.
+=item ExtUtils::Packlist
- sub DESTROY { print "</shout>\n" }
+Manipulate .packlist files.
-=back
+=item Fatal
-=head1 Pragmata
+Make functions/builtins succeed or die.
-Three new pragmatic modules exist:
+=item IPC::SysV
-=over
+Constants and other support infrastructure for System V IPC operations
+in perl.
-=item use blib
+=item Test
-Looks for MakeMaker-like I<'blib'> directory structure starting in
-I<dir> (or current directory) and working back up to five levels of
-parent directories.
+A framework for writing testsuites.
-Intended for use on command line with B<-M> option as a way of testing
-arbitrary scripts against an uninstalled version of a package.
+=item Tie::Array
-=item use locale
+Base class for tied arrays.
-Tells the compiler to enable (or disable) the use of POSIX locales for
-built-in operations.
+=item Tie::Handle
-When C<use locale> is in effect, the current LC_CTYPE locale is used
-for regular expressions and case mapping; LC_COLLATE for string
-ordering; and LC_NUMERIC for numeric formating in printf and sprintf
-(but B<not> in print). LC_NUMERIC is always used in write, since
-lexical scoping of formats is problematic at best.
+Base class for tied handles.
-Each C<use locale> or C<no locale> affects statements to the end of
-the enclosing BLOCK or, if not inside a BLOCK, to the end of the
-current file. Locales can be switched and queried with
-POSIX::setlocale().
+=item Thread
-See L<perllocale> for more information.
+Perl thread creation, manipulation, and support.
-=item use ops
+=item attrs
-Disable unsafe opcodes, or any named opcodes, when compiling Perl code.
+Set subroutine attributes.
-=back
+=item fields
-=head1 Modules
+Compile-time class fields.
-=head2 Module Information Summary
+=item re
-Brand new modules:
+Various pragmata to control behavior of regular expressions.
- IO.pm Top-level interface to IO::* classes
- IO/File.pm IO::File extension Perl module
- IO/Handle.pm IO::Handle extension Perl module
- IO/Pipe.pm IO::Pipe extension Perl module
- IO/Seekable.pm IO::Seekable extension Perl module
- IO/Select.pm IO::Select extension Perl module
- IO/Socket.pm IO::Socket extension Perl module
+=back
+
+=head2 Changes in existing modules
- Opcode.pm Disable named opcodes when compiling Perl code
+=over
- ExtUtils/Embed.pm Utilities for embedding Perl in C programs
- ExtUtils/testlib.pm Fixes up @INC to use just-built extension
+=item CGI
- Fatal.pm Make do-or-die equivalents of functions
- FindBin.pm Find path of currently executing program
+CGI has been updated to version 2.42.
- Class/Template.pm Structure/member template builder
- File/stat.pm Object-oriented wrapper around CORE::stat
- Net/hostent.pm Object-oriented wrapper around CORE::gethost*
- Net/netent.pm Object-oriented wrapper around CORE::getnet*
- Net/protoent.pm Object-oriented wrapper around CORE::getproto*
- Net/servent.pm Object-oriented wrapper around CORE::getserv*
- Time/gmtime.pm Object-oriented wrapper around CORE::gmtime
- Time/localtime.pm Object-oriented wrapper around CORE::localtime
- Time/tm.pm Perl implementation of "struct tm" for {gm,local}time
- User/grent.pm Object-oriented wrapper around CORE::getgr*
- User/pwent.pm Object-oriented wrapper around CORE::getpw*
+=item POSIX
- lib/Tie/RefHash.pm Base class for tied hashes with references as keys
+POSIX now has its own platform-specific hints files.
- UNIVERSAL.pm Base class for *ALL* classes
+=item DB_File
-=head2 IO
+DB_File supports version 2.x of Berkeley DB. See C<ext/DB_File/Changes>.
-The IO module provides a simple mechanism to load all of the IO modules at one
-go. Currently this includes:
+=item MakeMaker
- IO::Handle
- IO::Seekable
- IO::File
- IO::Pipe
- IO::Socket
+MakeMaker now supports writing empty makefiles, provides a way to
+specify that site umask() policy should be honored. There is also
+better support for manipulation of .packlist files, and getting
+information about installed modules.
-For more information on any of these modules, please see its
-respective documentation.
+Extensions that have both architecture-dependent and
+architecture-independent files are now always installed completely in
+the architecture-dependent locations. Previously, the shareable parts
+were shared both across architectures and across perl versions and were
+therefore liable to be overwritten with newer versions that might have
+subtle incompatibilities.
-=head2 Math::Complex
+=item CPAN
-The Math::Complex module has been totally rewritten, and now supports
-more operations. These are overloaded:
+[XXX What?]
- + - * / ** <=> neg ~ abs sqrt exp log sin cos atan2 "" (stringify)
+=item Cwd
-And these functions are now exported:
+Cwd::cwd is faster on most platforms.
- pi i Re Im arg
- log10 logn cbrt root
- tan cotan asin acos atan acotan
- sinh cosh tanh cotanh asinh acosh atanh acotanh
- cplx cplxe
+=item Benchmark
-=head2 Overridden Built-ins
+Keeps better time.
-Many of the Perl built-ins returning lists now have
-object-oriented overrides. These are:
+=back
- File::stat
- Net::hostent
- Net::netent
- Net::protoent
- Net::servent
- Time::gmtime
- Time::localtime
- User::grent
- User::pwent
+=head1 Utility Changes
-For example, you can now say
+h2ph and related utilities have been vastly overhauled.
- use File::stat;
- use User::pwent;
- $his = (stat($filename)->st_uid == pwent($whoever)->pw_uid);
+perlcc, a new experimental front end for the compiler is available.
-=head1 Efficiency Enhancements
+The crude GNU configure emulator is now called configure.gnu.
-All hash keys with the same string are only allocated once, so
-even if you have 100 copies of the same hash, the immutable keys
-never have to be re-allocated.
+=head1 API Changes
-Functions that have an empty prototype and that do nothing but return
-a fixed value are now inlined (e.g. C<sub PI () { 3.14159 }>).
+=head2 Incompatible Changes
+
+=head2 Deprecations, Extensions
+
+=head2 C++ Support
=head1 Documentation Changes
-Many of the base and library pods were updated. These
-new pods are included in section 1:
+Config.pm now has a glossary of variables.
+
+Porting/patching.pod has detailed instructions on how to create and
+submit patches for perl.
-=over 4
+=head1 New Diagnostics
-=item L<perlnews>
+=over
-This document.
+=item Ambiguous call resolved as CORE::%s(), qualify as such or use &
-=item L<perllocale>
+(W) A subroutine you have declared has the same name as a Perl keyword,
+and you have used the name without qualification for calling one or the
+other. Perl decided to call the builtin because the subroutine is
+not imported.
-Locale support (internationalization and localization).
+To force interpretation as a subroutine call, either put an ampersand
+before the subroutine name, or qualify the name with its package.
+Alternatively, you can import the subroutine (or pretend that it's
+imported with the C<use subs> pragma).
-=item L<perltoot>
+To silently interpret it as the Perl operator, use the C<CORE::> prefix
+on the operator (e.g. C<CORE::log($x)>) or by declaring the subroutine
+to be an object method (see L<attrs>).
-Tutorial on Perl OO programming.
+=item Bad index while coercing array into hash
-=item L<perlapio>
+(F) The index looked up in the hash found as the 0'th element of a
+pseudo-hash is not legal. Index values must be at 1 or greater.
+See L<perlref>.
-Perl internal IO abstraction interface.
+=item Bareword "%s" refers to nonexistent package
-=item L<perldebug>
+(W) You used a qualified bareword of the form C<Foo::>, but
+the compiler saw no other uses of that namespace before that point.
+Perhaps you need to predeclare a package?
-Although not new, this has been massively updated.
+=item Can't call method "%s" on an undefined value
-=item L<perlsec>
+(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:
-Although not new, this has been massively updated.
+ $BADREF = 42;
+ process $BADREF 1,2,3;
+ $BADREF->process(1,2,3);
-=back
+=item Can't coerce array into hash
-=head1 New Diagnostics
+(F) You used an array where a hash was expected, but the array has no
+information on how to map from keys to array indices. You can do that
+only with arrays that have a hash reference at index 0.
-Several new conditions will trigger warnings that were
-silent before. Some only affect certain platforms.
-The following new warnings and errors
-outline these:
+=item Can't goto subroutine from an eval-string
-=over 4
+(F) The "goto subroutine" call can't be used to jump out of an eval "string".
+(You can use it to jump out of an eval {BLOCK}, but you probably don't want to.)
-=item "my" variable %s masks earlier declaration in same scope
+=item Can't use %%! because Errno.pm is not available
-(S) A lexical variable has been redeclared in the same scope, effectively
-eliminating all access to the previous instance. This is almost always
-a typographical error. Note that the earlier variable will still exist
-until the end of the scope or until all closure referents to it are
-destroyed.
+(F) The first time the %! hash is used, perl automatically loads the
+Errno.pm module. The Errno module is expected to tie the %! hash to
+provide symbolic names for C<$!> errno values.
-=item Allocation too large: %lx
+=item Cannot find an opnumber for "%s"
-(X) You can't allocate more than 64K on an MSDOS machine.
+(F) A string of a form C<CORE::word> was given to prototype(), but
+there is no builtin with the name C<word>.
-=item Allocation too large
+=item Character class syntax [. .] is reserved for future extensions
-(F) You can't allocate more than 2^31+"small amount" bytes.
+(W) Within regular expression character classes ([]) the syntax beginning
+with "[." and ending with ".]" is reserved for future extensions.
+If you need to represent those character sequences inside a regular
+expression character class, just quote the square brackets with the
+backslash: "\[." and ".\]".
-=item Attempt to free non-existent shared string
+=item Character class syntax [: :] is reserved for future extensions
-(P) Perl maintains a reference counted internal table of strings to
-optimize the storage and access of hash keys and other strings. This
-indicates someone tried to decrement the reference count of a string
-that can no longer be found in the table.
+(W) Within regular expression character classes ([]) the syntax beginning
+with "[:" and ending with ":]" is reserved for future extensions.
+If you need to represent those character sequences inside a regular
+expression character class, just quote the square brackets with the
+backslash: "\[:" and ":\]".
-=item Attempt to use reference as lvalue in substr
+=item Character class syntax [= =] is reserved for future extensions
-(W) 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. See L<perlfunc/substr>.
+(W) Within regular expression character classes ([]) the syntax
+beginning with "[=" and ending with "=]" is reserved for future extensions.
+If you need to represent those character sequences inside a regular
+expression character class, just quote the square brackets with the
+backslash: "\[=" and "=\]".
-=item Unsupported function fork
+=item %s: Eval-group in insecure regular expression
-(F) Your version of executable does not support forking.
+(F) Perl detected tainted data when trying to compile a regular expression
+that contains the C<(?{ ... })> zero-width assertion, which is unsafe.
+See L<perlre/(?{ code })>, and L<perlsec>.
-Note that under some systems, like OS/2, there may be different flavors of
-Perl executables, some of which may support fork, some not. Try changing
-the name you call Perl by to C<perl_>, C<perl__>, and so on.
+=item %s: Eval-group not allowed, use re 'eval'
-=item Ill-formed logical name |%s| in prime_env_iter
+(F) A regular expression contained the C<(?{ ... })> zero-width assertion,
+but that construct is only allowed when the C<use re 'eval'> pragma is
+in effect. See L<perlre/(?{ code })>.
-(W) A warning peculiar to VMS. A logical name was encountered when preparing
-to iterate over %ENV which violates the syntactic rules governing logical
-names. Since it cannot be translated normally, it is skipped, and will not
-appear in %ENV. This may be a benign occurrence, as some software packages
-might directly modify logical name tables and introduce non-standard names,
-or it may indicate that a logical name table has been corrupted.
+=item %s: Eval-group not allowed at run time
-=item Integer overflow in hex number
+(F) Perl tried to compile a regular expression containing the C<(?{ ... })>
+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().
+See L<perlre/(?{ code })>.
-(S) The literal hex number you have specified is too big for your
-architecture. On a 32-bit architecture the largest hex literal is
-0xFFFFFFFF.
+=item Explicit blessing to '' (assuming package main)
-=item Integer overflow in octal number
+(W) 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, e.g. bless($ref, $p or 'MyPackage');
-(S) The literal octal number you have specified is too big for your
-architecture. On a 32-bit architecture the largest octal literal is
-037777777777.
+=item Illegal hex digit ignored
-=item Null picture in formline
+(W) You may have tried to use a character other than 0 - 9 or A - F in a
+hexadecimal number. Interpretation of the hexadecimal number stopped
+before the illegal character.
-(F) The first argument to formline must be a valid format picture
-specification. It was found to be empty, which probably means you
-supplied it an uninitialized value. See L<perlform>.
+=item No such array field
-=item Offset outside string
+(F) You tried to access an array as a hash, but the field name used is
+not defined. The hash at index 0 should map all valid field names to
+array indices for that to work.
-(F) You tried to do a read/write/send/recv operation with an offset
-pointing outside the buffer. This is difficult to imagine.
-The sole exception to this is that C<sysread()>ing past the buffer
-will extend the buffer and zero pad the new area.
+=item No such field "%s" in variable %s of type %s
-=item Out of memory!
+(F) You tried to access a field of a typed variable where the type
+does not know about the field name. The field names are looked up in
+the %FIELDS hash in the type package at compile time. The %FIELDS hash
+is usually set up with the 'fields' pragma.
-(X|F) The malloc() function returned 0, indicating there was insufficient
-remaining memory (or virtual memory) to satisfy the request.
+=item Out of memory during ridiculously large request
-The request was judged to be small, so the possibility to trap it
-depends on the way Perl was compiled. By default it is not trappable.
-However, if compiled for this, Perl may use the contents of C<$^M> as
-an emergency pool after die()ing with this message. In this case the
-error is trappable I<once>.
+(F) You can't allocate more than 2^31+"small amount" bytes. This error
+is most likely to be caused by a typo in the Perl program. e.g., C<$arr[time]>
+instead of C<$arr[$time]>.
-=item Out of memory during request for %s
+=item Range iterator outside integer range
-(F) The malloc() function returned 0, indicating there was insufficient
-remaining memory (or virtual memory) to satisfy the request. However,
-the request was judged large enough (compile-time default is 64K), so
-a possibility to shut down by trapping this error is granted.
+(F) One (or both) of the numeric arguments to the range operator ".."
+are outside the range which can be represented by integers internally.
+One possible workaround is to force Perl to use magical string
+increment by prepending "0" to your numbers.
-=item Possible attempt to put comments in qw() list
+=item Recursive inheritance detected while looking for method '%s' in package '%s'
-(W) You probably wrote something like this:
+(F) More than 100 levels of inheritance were encountered while invoking a
+method. Probably indicates an unintended loop in your inheritance hierarchy.
- qw( a # a comment
- b # another comment
- ) ;
+=item Reference found where even-sized list expected
-when you should have written this:
+(W) You gave a single reference where Perl was expecting a list with
+an even number of elements (for assignment to a hash). This
+usually means that you used the anon hash constructor when you meant
+to use parens. In any case, a hash requires key/value B<pairs>.
- qw( a
- b
- ) ;
+ %hash = { one => 1, two => 2, }; # WRONG
+ %hash = [ qw/ an anon array / ]; # WRONG
+ %hash = ( one => 1, two => 2, ); # right
+ %hash = qw( one 1 two 2 ); # also fine
-=item Possible attempt to separate words with commas
+=item Undefined value assigned to typeglob
-(W) You probably wrote something like this:
+(W) An undefined value was assigned to a typeglob, a la C<*foo = undef>.
+This does nothing. It's possible that you really mean C<undef *foo>.
- qw( a, b, c );
+=item Use of reserved word "%s" is deprecated
-when you should have written this:
+(D) The indicated bareword is a reserved word. Future versions of perl
+may use it as a keyword, so you're better off either explicitly quoting
+the word in a manner appropriate for its context of use, or using a
+different name altogether. The warning can be suppressed for subroutine
+names by either adding a C<&> prefix, or using a package qualifier,
+e.g. C<&our()>, or C<Foo::our()>.
- qw( a b c );
+=item perl: warning: Setting locale failed.
-=item untie attempted while %d inner references still exist
+(S) The whole warning message will look something like:
-(W) A copy of the object returned from C<tie> (or C<tied>) was still
-valid when C<untie> was called.
+ perl: warning: Setting locale failed.
+ perl: warning: Please check that your locale settings:
+ LC_ALL = "En_US",
+ LANG = (unset)
+ are supported and installed on your system.
+ perl: warning: Falling back to the standard locale ("C").
-=item Got an error from DosAllocMem:
+Exactly what were the failed locale settings varies. In the above the
+settings were that the LC_ALL was "En_US" and the LANG had no value.
+This error means that Perl detected that you and/or your system
+administrator have set up the so-called variable system but Perl could
+not use those settings. This was not dead serious, fortunately: there
+is a "default locale" called "C" that Perl can and will use, the
+script will be run. Before you really fix the problem, however, you
+will get the same error message each time you run Perl. How to really
+fix the problem can be found in L<perllocale> section B<LOCALE PROBLEMS>.
-(P) An error peculiar to OS/2. Most probably you use an obsolete version
-of Perl, and should not happen anyway.
+=back
-=item Malformed PERLLIB_PREFIX
-(F) An error peculiar to OS/2. PERLLIB_PREFIX should be of the form
+=head1 Obsolete Diagnostics
- prefix1;prefix2
+=over
-or
+=item Can't mktemp()
- prefix1 prefix2
+(F) The mktemp() routine failed for some reason while trying to process
+a B<-e> switch. Maybe your /tmp partition is full, or clobbered.
-with non-empty prefix1 and prefix2. If C<prefix1> is indeed a prefix of
-a builtin library search path, prefix2 is substituted. The error may appear
-if components are not found, or are too long. See L<perlos2/"PERLLIB_PREFIX">.
+=item Can't write to temp file for B<-e>: %s
-=item PERL_SH_DIR too long
+(F) The write routine failed for some reason while trying to process
+a B<-e> switch. Maybe your /tmp partition is full, or clobbered.
-(F) An error peculiar to OS/2. PERL_SH_DIR is the directory to find the
-C<sh>-shell in. See L<perlos2/"PERL_SH_DIR">.
+=item Cannot open temporary file
-=item Process terminated by SIG%s
+(F) The create routine failed for some reason while trying to process
+a B<-e> switch. Maybe your /tmp partition is full, or clobbered.
-(W) This is a standard message issued by OS/2 applications, while *nix
-applications die in silence. It is considered a feature of the OS/2
-port. One can easily disable this by appropriate sighandlers, see
-L<perlipc/"Signals">. See L<perlos2/"Process terminated by SIGTERM/SIGINT">.
=back
=head1 BUGS
-If you find what you think is a bug, you might check the headers
-of recently posted articles
-in the comp.lang.perl.misc newsgroup. There may also be
-information at http://www.perl.com/perl/, the Perl Home Page.
+If you find what you think is a bug, you might check the headers of
+recently posted articles in the comp.lang.perl.misc newsgroup.
+There may also be information at http://www.perl.com/perl/, the Perl
+Home Page.
If you believe you have an unreported bug, please run the B<perlbug>
-program included with your release. Make sure you trim your bug
-down to a tiny but sufficient test case. Your bug report, along
-with the output of C<perl -V>, will be sent off to perlbug@perl.com
-to be analysed by the Perl porting team.
+program included with your release. Make sure you trim your bug down
+to a tiny but sufficient test case. Your bug report, along with the
+output of C<perl -V>, will be sent off to <F<perlbug@perl.com>> to be
+analysed by the Perl porting team.
=head1 SEE ALSO
The F<Changes> file for exhaustive details on what changed.
-The F<INSTALL> file for how to build Perl. This file has been
-significantly updated for 5.004, so even veteran users should
-look through it.
+The F<INSTALL> file for how to build Perl.
The F<README> file for general stuff.
-The F<Copying> file for copyright information.
+The F<Artistic> and F<Copying> files for copyright information.
=head1 HISTORY
-Constructed by Tom Christiansen, grabbing material with permission
-from innumerable contributors, with kibitzing by more than a few Perl
-porters.
-
-Last update: Tue Jan 14 14:03:02 EST 1997
+=cut
projects / p5sagit/p5-mst-13.2.git / blobdiff