PERL5005DELTA(1) Perl Programmers Reference GuidePERL5005DELTA(1)NAME
perldelta - what's new for perl5.005
DESCRIPTION
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 ver
sions 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 exten
sions to use them 5.005. See INSTALL for detailed
instructions on how to upgrade.
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 gener
ally expected to have very little impact on compatibility.
See the New "INIT" keyword entry elsewhere in this docu
ment, the New "lock" keyword entry elsewhere in this docu
ment, and the section on "/" operator" in the New "qr man
page.
Certain barewords are now reserved. Use of these will
provoke a warning if you have asked for them with the "-w"
switch. See the section on ""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 unquali
fied 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 with
out the "Perl_" prefix are supported with macros, but
this support may cease in a future release.
See the API LISTING entry in the perlguts manpage.
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("@",FALSE)" 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 the section on "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 bina
ries built with threads enabled are incompatible with
binaries built without. This should largely be transpar
ent 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 direc
tory 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 the New Diagnostics entry elsewhere in this document.
Licensing
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 the perl manpage
and the individual perl man pages listed therein.
Core Changes
Threads
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.
Compiler
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 transforma
tions 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 opti
mized 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 elimi
nates 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 constructs.
"B::Xref" generates cross reference reports of all defini
tion and use of variables, subroutines and formats in a
program.
"B::Showlex" show the lexical variables used by a subrou
tine or file at a glance.
"perlcc" is a simple frontend for compiling perl.
See "ext/B/README", the B manpage, and the respective com
piler modules.
Regular Expressions
Perl's regular expression engine has been seriously over
hauled, 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:
(?<=RE)
(?<!RE)
(?{ CODE })
(?i-x)
(?i:RE)
(?(COND)YES_RE|NO_RE)
(?>RE)
\z
New operator for precompiled regular expressions
See the section on "/" operator" in the New "qr man
page.
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 the perlre manpage and the perlop manpage.
Improved malloc()
See banner at the beginning of "malloc.c" for details.
Quicksort is internally implemented
Perl now contains its own highly optimized qsort() rou
tine. The new qsort() is resistant to inconsistent com
parison functions, so Perl's "sort()" will not provoke
coredumps any more when given poorly written sort subrou
tines. (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()" implementa
tions.
See "perlfunc/sort".
Reliable signals
Perl's signal handling is susceptible to random crashes,
because signals arrive asynchronously, and the Perl run
time is not reentrant at arbitrary times.
However, one experimental implementation of reliable sig
nals is available when threads are enabled. See
"Thread::Signal". Also see INSTALL for how to build a
Perl capable of threads.
Reliable stack pointers
The internals now reallocate the perl stack only at pre
dictable 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 inter
nals 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 com
piler 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 "PerlIn
terp" extension on CPAN.
Behavior of local() on array and hash elements is now
well-defined
See the Temporary Values via local() entry in the perlsub
manpage.
"%!" is transparently tied to the the Errno manpage module
See the perlvar manpage, and the Errno manpage.
Pseudo-hashes are supported
See the perlref manpage.
"EXPR foreach EXPR" is supported
See the perlsyn manpage.
Keywords can be globally overridden
See the perlsub manpage.
"$^E" is meaningful on Win32
See the perlvar manpage.
"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
$Foo::{Bar::}" can be used to test if the "Foo::Bar"
namespace has been created.
Better locale support
See the perllocale manpage.
Experimental support for 64-bit platforms
Perl5 has always had 64-bit support on systems with 64-bit
longs. Starting with 5.005, the beginnings of experimen
tal support for systems with 32-bit long and 64-bit 'long
long' integers has been added. If you add -DUSE_LONG_LONG
to your ccflags in config.sh (or manually define it in
perl.h) then perl will be built with 'long long' support.
There will be many compiler warnings, and the resultant
perl may not work on all systems. There are many other
issues related to third-party extensions and libraries.
This option exists to allow people to work on those
issues.
prototype() returns useful results on builtins
See the prototype entry in the perlfunc manpage.
Extended support for exception handling
"die()" now accepts a reference value, and "$@" 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 the Destructors entry in the perlobj manpage.
All "printf" format conversions are handled internally
See the printf entry in the perlfunc manpage.
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 the perlop manpage.
"our" is now a reserved word
Calling a subroutine with the name "our" will now provoke
a warning when using the "-w" switch.
Tied arrays are now fully supported
See the Tie::Array manpage.
Tied handles support is better
Several missing hooks have been added. There is also a
new base class for TIEARRAY implementations. See the
Tie::Array manpage.
4th argument to substr
substr() can now both return and replace in one operation.
The optional 4th argument is the replacement string. See
the substr entry in the perlfunc manpage.
Negative LENGTH argument to splice
splice() with a negative LENGTH argument now work similar
to what the LENGTH did for substr(). Previously a nega
tive LENGTH was treated as 0. See the splice entry in the
perlfunc manpage.
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 modi
fications to it affect $x. (This is called a 'magic
lvalue' because an 'lvalue' is something on the left side
of an assignment.) Normally, this is exactly what you
would expect to happen, but Perl uses the same magic if
you use substr(), pos(), or vec() in a context where they
might be modified, like taking a reference with "\" or as
an argument to a sub that modifies "@_". In previous ver
sions, this 'magic' only went one way, but now changes to
the scalar the magic refers to ($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 "$/" is a reference to an integer, or a scalar that
holds an integer, <> will read in records instead of
lines. For more info, see the section on "$/" in the perl
var manpage.
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 argu
ments used in config.sh.
New Platforms
BeOS is now supported. See README.beos.
DOS is now supported under the DJGPP tools. See
README.dos (installed as the perldos manpage on some sys
tems).
MiNT is now supported. See README.mint.
MPE/iX is now supported. See README.mpeix.
MVS (aka OS390, aka Open Edition) is now supported. See
README.os390 (installed as the perlos390 manpage 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 the perlwin32
manpage.
VMS configuration system has been rewritten. See
README.vms (installed as the README_vms manpage on some
systems).
The hints files for most Unix platforms have seen incre
mental improvements.
Modules and Pragmata
New Modules
B Perl compiler and tools. See the B manpage.
Data::Dumper
A module to pretty print Perl data. See the
Data::Dumper manpage.
Dumpvalue
A module to dump perl values to the screen. See the
Dumpvalue manpage.
Errno
A module to look up errors more conveniently. See the
Errno manpage.
File::Spec
A portable API for file operations.
ExtUtils::Installed
Query and manage installed modules.
ExtUtils::Packlist
Manipulate .packlist files.
Fatal
Make functions/builtins succeed or die.
IPC::SysV
Constants and other support infrastructure for System
V IPC operations in perl.
Test
A framework for writing testsuites.
Tie::Array
Base class for tied arrays.
Tie::Handle
Base class for tied handles.
Thread
Perl thread creation, manipulation, and support.
attrs
Set subroutine attributes.
fields
Compile-time class fields.
re Various pragmata to control behavior of regular
expressions.
Changes in existing modules
Benchmark
You can now run tests for x seconds instead of guess
ing the right number of tests to run.
Keeps better time.
Carp
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.
Fcntl
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.
Math::Complex
The accessors methods Re, Im, arg, abs, rho, theta,
methods can ($z->Re()) now also act as mutators
($z->Re(3)).
Math::Trig
A little bit of radial trigonometry (cylindrical and
spherical) added, for example the great circle dis
tance.
POSIX
POSIX now has its own platform-specific hints files.
DB_File
DB_File supports version 2.x of Berkeley DB. See
"ext/DB_File/Changes".
MakeMaker
MakeMaker now supports writing empty makefiles, pro
vides a way to specify that site umask() policy should
be honored. There is also better support for manipu
lation 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 ver
sions and were therefore liable to be overwritten with
newer versions that might have subtle incompatibili
ties.
CPAN
See <perlmodinstall> and the CPAN manpage.
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 "config
ure.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
Config.pm now has a glossary of variables.
Porting/patching.pod has detailed instructions on how to
create and submit patches for perl.
the perlport manpage specifies guidelines on how to write
portably.
the perlmodinstall manpage describes how to fetch and
install modules from "CPAN" sites.
Some more Perl traps are documented now. See the perltrap
manpage.
the perlopentut manpage gives a tutorial on using open().
the perlreftut manpage gives a tutorial on references.
the perlthrtut manpage 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 qual
ify 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 the attrs manpage).
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 the perlref manpage.
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 con
tains an undefined value. Something like this will
reproduce the error:
$BADREF = 42;
process $BADREF 1,2,3;
$BADREF->process(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 Errno.pm is not available
(F) The first time the %! hash is used, perl automati
cally loads the Errno.pm module. The Errno module is
expected to tie the %! hash to provide symbolic names
for "$!" errno values.
Cannot find an opnumber for ""%s""
(F) A string of a form "CORE::word" was given to pro_
totype(), but there is no builtin with the name
"word".
Character class syntax [. .] is reserved for future exten
sions
(W) Within regular expression character classes ([])
the syntax beginning with "[." and ending with ".]" is
reserved for future extensions. If you need to repre
sent 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 exten
sions
(W) Within regular expression character classes ([])
the syntax beginning with "[:" and ending with ":]" is
reserved for future extensions. If you need to repre
sent 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 exten
sions
(W) Within regular expression character classes ([])
the syntax beginning with "[=" and ending with "=]" is
reserved for future extensions. If you need to repre
sent 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 the sec
tion on "(?{ code })" in the perlre manpage, and the
perlsec manpage.
%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 the section on "(?{ code })" in the perlre man
page.
%s: Eval-group not allowed at run time
(F) Perl tried to compile a regular expression con
taining the "(?{ ... })" zero-width assertion at run
time, as it would when the pattern contains interpo
lated 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
the section on "(?{ code })" in the perlre manpage.
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, $p || 'MyPackage');
Illegal hex digit ignored
(W) You may have tried to use a character other than 0
- 9 or A - F in a hexadecimal number. Interpretation
of the hexadecimal number stopped before the illegal
character.
No such array field
(F) You tried to access an array as a hash, but the
field name used is not defined. The hash at index 0
should map all valid field names to array indices for
that to work.
No such field ""%s"" in variable %s of type %s
(F) You tried to access a field of a typed variable
where the type does not know about the field name.
The field names are looked up in the %FIELDS hash in
the type package at compile time. The %FIELDS hash is
usually set up with the 'fields' pragma.
Out of memory during ridiculously large request
(F) You can't allocate more than 2^31+"small amount"
bytes. This error is most likely to be caused by a
typo in the Perl program. e.g., "$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 encoun
tered 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 expect
ing 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 pairs.
%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 sup
pressed 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 admin
istrator 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
the LOCALE PROBLEMS entry in the perllocale manpage.
Obsolete Diagnostics
Can't mktemp()
(F) The mktemp() routine failed for some reason while
trying to process a -e switch. Maybe your /tmp parti
tion 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 parti
tion 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 parti
tion 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 expres
sion 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 state
ments. See the perlre manpage.
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.
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 informa
tion at http://www.perl.com/perl/, 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 <perlbug@perl.com> to be analysed by the
Perl porting team.
SEE ALSO
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.
HISTORY
Written by Gurusamy Sarathy <gsar@activestate.com>, with
many contributions from The Perl Porters.
Send omissions or corrections to <perlbug@perl.com>.
2001-04-07 perl v5.6.1 PERL5005DELTA(1)
