Provided by: perl-doc_5.28.1-6build1_all bug


       perl5005delta - what's new for perl5.005


       This document describes differences between the 5.004 release and this one.

About the new versioning system

       Perl is now developed on two tracks: a maintenance track that makes small, safe updates to
       released production versions with emphasis on compatibility; and a development track that
       pursues more aggressive evolution.  Maintenance releases (which should be considered
       production quality) have subversion numbers that run from 1 to 49, and development
       releases (which should be considered "alpha" quality) run from 50 to 99.

       Perl 5.005 is the combined product of the new dual-track development scheme.

Incompatible Changes

   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 INSTALL for detailed instructions on how to

   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 INSTALL for a detailed discussion of the changes in order to adapt them to
       your system.

   Perl Source Compatibility
       When none of the experimental features are enabled, there should be very few user-visible
       Perl source compatibility issues.

       If threads are enabled, then some caveats apply. @_ and $_ 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.  For example, "local(@_)"
       results in a "Can't localize lexical variable @_ ..." message.  This may be enabled in a
       future version.

       Some new keywords have been introduced.  These are generally expected to have very little
       impact on compatibility.  See "New "INIT" keyword", "New "lock" keyword", and "New "qr//"

       Certain barewords are now reserved.  Use of these will provoke a warning if you have asked
       for them with the "-w" switch.  See ""our" is now a reserved word".

   C Source Compatibility
       There have been a large number of changes in the internals to support the new features in
       this release.

       ·   Core sources now require ANSI C compiler

           An ANSI C compiler is now required to build perl.  See INSTALL.

       ·   All Perl global variables must now be referenced with an explicit prefix

           All Perl global variables that are visible for use by extensions now have a "PL_"
           prefix.  New extensions should "not" refer to perl globals by their unqualified names.
           To preserve sanity, we provide limited backward compatibility for globals that are
           being widely used like "sv_undef" and "na" (which should now be written as
           "PL_sv_undef", "PL_na" etc.)

           If you find that your XS extension does not compile anymore because a perl global is
           not visible, try adding a "PL_" prefix to the global and rebuild.

           It is strongly recommended that all functions in the Perl API that don't begin with
           "perl" be referenced with a "Perl_" prefix.  The bare function names without the
           "Perl_" prefix are supported with macros, but this support may cease in a future

           See perlapi.

       ·   Enabling threads has source compatibility issues

           Perl built with threading enabled requires extensions to use the new "dTHR" macro to
           initialize the handle to access per-thread data.  If you see a compiler error that
           talks about the variable "thr" not being declared (when building a module that has XS
           code),  you need to add "dTHR;" at the beginning of the block that elicited the error.

           The API function "perl_get_sv("@",GV_ADD)" should be used instead of directly
           accessing perl globals as "GvSV(errgv)".  The API call is backward compatible with
           existing perls and provides source compatibility with threading is enabled.

           See "C Source Compatibility" for more information.

   Binary Compatibility
       This version is NOT binary compatible with older versions.  All extensions will need to be
       recompiled.  Further binaries built with threads enabled are incompatible with binaries
       built without.  This should largely be transparent to the user, as all binary incompatible
       configurations have their own unique architecture name, and extension binaries get
       installed at unique locations.  This allows coexistence of several configurations in the
       same directory hierarchy.  See INSTALL.

   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 "-e" switch do not create temporary files anymore.

   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
       "New Diagnostics".

       Perl has a new Social Contract for contributors.  See Porting/Contract.

       The license included in much of the Perl documentation has changed.  Most of the Perl
       documentation was previously under the implicit GNU General Public License or the Artistic
       License (at the user's choice).  Now much of the documentation unambiguously states the
       terms under which it may be distributed.  Those terms are in general much less restrictive
       than the GNU GPL.  See perl and the individual perl manpages listed therein.

Core Changes

       WARNING: Threading is considered an experimental feature.  Details of the implementation
       may change without notice.  There are known limitations and some bugs.  These are expected
       to be fixed in future versions.

       See README.threads.

       WARNING: The Compiler and related tools are considered experimental.  Features may change
       without notice, and there are known limitations and bugs.  Since the compiler is fully
       external to perl, the default configuration will build and install it.

       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
       equivalent 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.

       The compiler comes with several valuable utilities.

       "B::Lint" is an experimental module to detect and warn about suspicious code, especially
       the cases that the "-w" switch does not detect.

       "B::Deparse" can be used to demystify perl code, and understand how perl optimizes certain

       "B::Xref" generates cross reference reports of all definition and use of variables,
       subroutines and formats in a program.

       "B::Showlex" show the lexical variables used by a subroutine or file at a glance.

       "perlcc" is a simple frontend for compiling perl.

       See "ext/B/README", B, and the respective compiler modules.

   Regular Expressions
       Perl's regular expression engine has been seriously overhauled, and many new constructs
       are supported.  Several bugs have been fixed.

       Here is an itemized summary:

       Many new and improved optimizations
           Changes in the RE engine:

                   Unneeded nodes removed;
                   Substrings merged together;
                   New types of nodes to process (SUBEXPR)* and similar expressions
                       quickly, used if the SUBEXPR has no side effects and matches
                       strings of the same length;
                   Better optimizations by lookup for constant substrings;
                   Better search for constants substrings anchored by $ ;

           Changes in Perl code using RE engine:

                   More optimizations to s/longer/short/;
                   study() was not working;
                   /blah/ may be optimized to an analogue of index() if $& $` $' not seen;
                   Unneeded copying of matched-against string removed;
                   Only matched part of the string is copying if $` $' were not seen;

       Many bug fixes
           Note that only the major bug fixes are listed here.  See Changes for others.

                   Backtracking might not restore start of $3.
                   No feedback if max count for * or + on "complex" subexpression
                       was reached, similarly (but at compile time) for {3,34567}
                   Primitive restrictions on max count introduced to decrease a
                       possibility of a segfault;
                   (ZERO-LENGTH)* could segfault;
                   (ZERO-LENGTH)* was prohibited;
                   Long REs were not allowed;
                   /RE/g could skip matches at the same position after a
                     zero-length match;

       New regular expression constructs
           The following new syntax elements are supported:

                   (?{ CODE })

       New operator for precompiled regular expressions
           See "New "qr//" operator".

       Other improvements
                   Better debugging output (possibly with colors),
                       even from non-debugging Perl;
                   RE engine code now looks like C, not like assembler;
                   Behaviour of RE modifiable by `use re' directive;
                   Improved documentation;
                   Test suite significantly extended;
                   Syntax [:^upper:] etc., reserved inside character classes;

       Incompatible changes
                   (?i) localized inside enclosing group;
                   $( is not interpolated into RE any more;
                   /RE/g may match at the same position (with non-zero length)
                       after a zero-length match (bug fix).

       See perlre and perlop.

   Improved malloc()
       See banner at the beginning of "malloc.c" for details.

   Quicksort is internally implemented
       Perl now contains its own highly optimized qsort() routine.  The new qsort() is resistant
       to inconsistent comparison functions, so Perl's "sort()" will not provoke coredumps any
       more when given poorly written sort subroutines.  (Some C library "qsort()"s that were
       being used before used to have this problem.)  In our testing, the new "qsort()" required
       the minimal number of pair-wise compares on average, among all known "qsort()"

       See "perlfunc/sort".

   Reliable signals
       Perl's signal handling is susceptible to random crashes, because signals arrive
       asynchronously, and the Perl runtime is not reentrant at arbitrary times.

       However, one experimental implementation of reliable signals is available when threads are
       enabled.  See "Thread::Signal".  Also see INSTALL for how to build a Perl capable of

   Reliable stack pointers
       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.

   More generous treatment of carriage returns
       Perl used to complain if it encountered literal carriage returns in scripts.  Now they are
       mostly treated like whitespace within program text.  Inside string literals and here
       documents, literal carriage returns are ignored if they occur paired with linefeeds, or
       get interpreted as whitespace if they stand alone.  This behavior means that literal
       carriage returns in files should be avoided.  You can get the older, more compatible (but
       less generous) behavior by defining the preprocessor symbol "PERL_STRICT_CR" when building
       perl.  Of course, all this has nothing whatever to do with how escapes like "\r" are
       handled within strings.

       Note that this doesn't somehow magically allow you to keep all text files in DOS format.
       The generous treatment only applies to files that perl itself parses.  If your C compiler
       doesn't allow carriage returns in files, you may still be unable to build modules that
       need a C compiler.

   Memory leaks
       "substr", "pos" and "vec" don't leak memory anymore when used in lvalue context.  Many
       small leaks that impacted applications that embed multiple interpreters have been fixed.

   Better support for multiple interpreters
       The build-time option "-DMULTIPLICITY" has had many of the details reworked.  Some
       previously global variables that should have been per-interpreter now are.  With care,
       this allows interpreters to call each other.  See the "PerlInterp" extension on CPAN.

   Behavior of local() on array and hash elements is now well-defined
       See "Temporary Values via local()" in perlsub.

   "%!" is transparently tied to the Errno module
       See perlvar, and Errno.

   Pseudo-hashes are supported
       See perlref.

   "EXPR foreach EXPR" is supported
       See perlsyn.

   Keywords can be globally overridden
       See perlsub.

   $^E is meaningful on Win32
       See perlvar.

   "foreach (1..1000000)" optimized
       "foreach (1..1000000)" is now optimized into a counting loop.  It does not try to allocate
       a 1000000-size list anymore.

   "Foo::" can be used as implicitly quoted package name
       Barewords caused unintuitive behavior when a subroutine with the same name as a package
       happened to be defined.  Thus, "new Foo @args", use the result of the call to "Foo()"
       instead of "Foo" being treated as a literal.  The recommended way to write barewords in
       the indirect object slot is "new Foo:: @args".  Note that the method "new()" is called
       with a first argument of "Foo", not "Foo::" when you do that.

   "exists $Foo::{Bar::}" tests existence of a package
       It was impossible to test for the existence of a package without actually creating it
       before.  Now "exists $Foo::{Bar::}" can be used to test if the "Foo::Bar" namespace has
       been created.

   Better locale support
       See perllocale.

   Experimental support for 64-bit platforms
       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 (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.

   prototype() returns useful results on builtins
       See "prototype" in perlfunc.

   Extended support for exception handling
       "die()" now accepts a reference value, and $@ gets set to that value in exception traps.
       This makes it possible to propagate exception objects.  This is an undocumented
       experimental feature.

   Re-blessing in DESTROY() supported for chaining DESTROY() methods
       See "Destructors" in perlobj.

   All "printf" format conversions are handled internally
       See "printf" in perlfunc.

   New "INIT" keyword
       "INIT" subs are like "BEGIN" and "END", but they get run just before the perl runtime
       begins execution.  e.g., the Perl Compiler makes use of "INIT" blocks to initialize and
       resolve pointers to XSUBs.

   New "lock" keyword
       The "lock" keyword is the fundamental synchronization primitive in threaded perl.  When
       threads are not enabled, it is currently a noop.

       To minimize impact on source compatibility this keyword is "weak", i.e., any user-defined
       subroutine of the same name overrides it, unless a "use Thread" has been seen.

   New "qr//" operator
       The "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 perlop.

   "our" is now a reserved word
       Calling a subroutine with the name "our" will now provoke a warning when using the "-w"

   Tied arrays are now fully supported
       See Tie::Array.

   Tied handles support is better
       Several missing hooks have been added.  There is also a new base class for TIEARRAY
       implementations.  See Tie::Array.

   4th argument to substr
       substr() can now both return and replace in one operation.  The optional 4th argument is
       the replacement string.  See "substr" in perlfunc.

   Negative LENGTH argument to splice
       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 "splice" in perlfunc.

   Magic lvalues are now more magical
       When you say something like "substr($x, 5) = "hi"", the scalar returned by substr() is
       special, in that any modifications to it affect $x.  (This is called a 'magic lvalue'
       because an 'lvalue' is something on the left side of an assignment.)  Normally, this is
       exactly what you would expect to happen, but Perl uses the same magic if you use substr(),
       pos(), or vec() in a context where they might be modified, like taking a reference with
       "\" or as an argument to a sub that modifies @_.  In previous versions, this 'magic' only
       went one way, but now changes to the scalar the magic refers to ($x in the above example)
       affect the magic lvalue too. For instance, this code now acts differently:

           $x = "hello";
           sub printit {
               $x = "g'bye";
               print $_[0], "\n";
           printit(substr($x, 0, 5));

       In previous versions, this would print "hello", but it now prints "g'bye".

   <> now reads in records
       If $/ is a reference to an integer, or a scalar that holds an integer, <> will read in
       records instead of lines. For more info, see "$/" in perlvar.

Supported Platforms

       Configure has many incremental improvements.  Site-wide policy for building perl can now
       be made persistent, via  Configure also records the command-line arguments used

   New Platforms
       BeOS is now supported.  See README.beos.

       DOS is now supported under the DJGPP tools.  See README.dos (installed as perldos on some

       MiNT is now supported.  See

       MPE/iX is now supported.  See README.mpeix.

       MVS (aka OS390, aka Open Edition) is now supported.  See README.os390 (installed as
       perlos390 on some systems).

       Stratus VOS is now supported.  See README.vos.

   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.  See README.win32, aka perlwin32.

       VMS configuration system has been rewritten.  See README.vms (installed as README_vms on
       some systems).

       The hints files for most Unix platforms have seen incremental improvements.

Modules and Pragmata

   New Modules
       B   Perl compiler and tools.  See B.

           A module to pretty print Perl data.  See Data::Dumper.

           A module to dump perl values to the screen. See Dumpvalue.

           A module to look up errors more conveniently.  See Errno.

           A portable API for file operations.

           Query and manage installed modules.

           Manipulate .packlist files.

           Make functions/builtins succeed or die.

           Constants and other support infrastructure for System V IPC operations in perl.

           A framework for writing test suites.

           Base class for tied arrays.

           Base class for tied handles.

           Perl thread creation, manipulation, and support.

           Set subroutine attributes.

           Compile-time class fields.

       re  Various pragmata to control behavior of regular expressions.

   Changes in existing modules
           You can now run tests for x seconds instead of guessing the right number of tests to

           Keeps better time.

           Carp has a new function cluck(). cluck() warns, like carp(), but also adds a stack
           backtrace to the error message, like confess().

       CGI CGI has been updated to version 2.42.

           More Fcntl constants added: F_SETLK64, F_SETLKW64, O_LARGEFILE for large (more than
           4G) file access (the 64-bit support is not yet working, though, so no need to get
           overly excited), Free/Net/OpenBSD locking behaviour flags F_FLOCK, F_POSIX, Linux
           F_SHLCK, and O_ACCMODE: the mask of O_RDONLY, O_WRONLY, and O_RDWR.

           The accessors methods Re, Im, arg, abs, rho, theta, methods can ($z->Re()) now also
           act as mutators ($z->Re(3)).

           A little bit of radial trigonometry (cylindrical and spherical) added, for example the
           great circle distance.

           POSIX now has its own platform-specific hints files.

           DB_File supports version 2.x of Berkeley DB.  See "ext/DB_File/Changes".

           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.

           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.

           See perlmodinstall and CPAN.

       Cwd Cwd::cwd is faster on most platforms.

Utility Changes

       "h2ph" and related utilities have been vastly overhauled.

       "perlcc", a new experimental front end for the compiler is available.

       The crude GNU "configure" emulator is now called "configure.gnu" to avoid trampling on
       "Configure" under case-insensitive filesystems.

       "perldoc" used to be rather slow.  The slower features are now optional.  In particular,
       case-insensitive searches need the "-i" switch, and recursive searches need "-r".  You can
       set these switches in the "PERLDOC" environment variable to get the old behavior.

Documentation Changes now has a glossary of variables.

       Porting/patching.pod has detailed instructions on how to create and submit patches for

       perlport specifies guidelines on how to write portably.

       perlmodinstall describes how to fetch and install modules from "CPAN" sites.

       Some more Perl traps are documented now.  See perltrap.

       perlopentut gives a tutorial on using open().

       perlreftut gives a tutorial on references.

       perlthrtut gives a tutorial on threads.

New Diagnostics

       Ambiguous call resolved as CORE::%s(), qualify as such or use &
           (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.

           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 by declaring the subroutine to be an object method (see

       Bad index while coercing array into hash
           (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 perlref.

       Bareword "%s" refers to nonexistent package
           (W) 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?

       Can't call method "%s" on an undefined value
           (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

               $BADREF = 42;
               process $BADREF 1,2,3;

       Can't check filesystem of script "%s" for nosuid
           (P) For some reason you can't check the filesystem of the script for nosuid.

       Can't coerce array into hash
           (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.

       Can't goto subroutine from an eval-string
           (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.)

       Can't localize pseudo-hash element
           (F) You said something like "local $ar->{'key'}", where $ar is a reference to a
           pseudo-hash.  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'}]".

       Can't use %%! because is not available
           (F) The first time the %! hash is used, perl automatically loads the module.
           The Errno module is expected to tie the %! hash to provide symbolic names for $! errno

       Cannot find an opnumber for "%s"
           (F) A string of a form "CORE::word" was given to prototype(), but there is no builtin
           with the name "word".

       Character class syntax [. .] is reserved for future extensions
           (W) Within regular expression character classes ([]) the syntax beginning with "[."
           and ending with ".]" is reserved for future extensions.  If you need to represent
           those character sequences inside a regular expression character class, just quote the
           square brackets with the backslash: "\[." and ".\]".

       Character class syntax [: :] is reserved for future extensions
           (W) Within regular expression character classes ([]) the syntax beginning with "[:"
           and ending with ":]" is reserved for future extensions.  If you need to represent
           those character sequences inside a regular expression character class, just quote the
           square brackets with the backslash: "\[:" and ":\]".

       Character class syntax [= =] is reserved for future extensions
           (W) Within regular expression character classes ([]) the syntax beginning with "[="
           and ending with "=]" is reserved for future extensions.  If you need to represent
           those character sequences inside a regular expression character class, just quote the
           square brackets with the backslash: "\[=" and "=\]".

       %s: Eval-group in insecure regular expression
           (F) Perl detected tainted data when trying to compile a regular expression that
           contains the "(?{ ... })" zero-width assertion, which is unsafe.  See "(?{ code })" in
           perlre, and perlsec.

       %s: Eval-group not allowed, use re 'eval'
           (F) A regular expression contained the "(?{ ... })" zero-width assertion, but that
           construct is only allowed when the "use re 'eval'" pragma is in effect.  See "(?{ code
           })" in perlre.

       %s: Eval-group not allowed at run time
           (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().  See "(?{ code })" in perlre.

       Explicit blessing to '' (assuming package main)
           (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 || 'MyPackage');

       Illegal hex digit ignored
           (W) You may have tried to use a character other than 0 - 9 or A - F in a hexadecimal
           number.  Interpretation of the hexadecimal number stopped before the illegal

       No such array field
           (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

       No such field "%s" in variable %s of type %s
           (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.

       Out of memory during ridiculously large request
           (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., $arr[time] instead of $arr[$time].

       Range iterator outside integer range
           (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.

       Recursive inheritance detected while looking for method '%s' %s
           (F) More than 100 levels of inheritance were encountered while invoking a method.
           Probably indicates an unintended loop in your inheritance hierarchy.

       Reference found where even-sized list expected
           (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

               %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

       Undefined value assigned to typeglob
           (W) An undefined value was assigned to a typeglob, a la "*foo = undef".  This does
           nothing.  It's possible that you really mean "undef *foo".

       Use of reserved word "%s" is deprecated
           (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 "&" prefix, or using a
           package qualifier, e.g. "&our()", or "Foo::our()".

       perl: warning: Setting locale failed.
           (S) The whole warning message will look something like:

                  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").

           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 "LOCALE
           PROBLEMS" in perllocale.

Obsolete Diagnostics

       Can't mktemp()
           (F) The mktemp() routine failed for some reason while trying to process a -e switch.
           Maybe your /tmp partition is full, or clobbered.

           Removed because -e doesn't use temporary files any more.

       Can't write to temp file for -e: %s
           (F) The write routine failed for some reason while trying to process a -e switch.
           Maybe your /tmp partition is full, or clobbered.

           Removed because -e doesn't use temporary files any more.

       Cannot open temporary file
           (F) The create routine failed for some reason while trying to process a -e switch.
           Maybe your /tmp partition is full, or clobbered.

           Removed because -e doesn't use temporary files any more.

       regexp too big
           (F) The current implementation of regular expressions uses shorts as address offsets
           within a string.  Unfortunately this means that if the regular expression compiles to
           longer than 32767, it'll blow up.  Usually when you want a regular expression this
           big, there is a better way to do it with multiple statements.  See perlre.

Configuration Changes

       You can use "Configure -Uinstallusrbinperl" which causes installperl to skip installing
       perl also as /usr/bin/perl.  This is useful if you prefer not to modify /usr/bin for some
       reason or another but harmful because many scripts assume to find Perl in /usr/bin/perl.


       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 , the Perl Home Page.

       If you believe you have an unreported bug, please run the 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 "perl -V", will be sent off to <> to
       be analysed by the Perl porting team.


       The Changes file for exhaustive details on what changed.

       The INSTALL file for how to build Perl.

       The README file for general stuff.

       The Artistic and Copying files for copyright information.


       Written by Gurusamy Sarathy <>, with many contributions from The Perl

       Send omissions or corrections to <>.