perl588delta - what is new for perl v5.8.8


   This document describes differences between the 5.8.7 release and the
   5.8.8 release.

Incompatible Changes

   There are no changes intentionally incompatible with 5.8.7. If any
   exist, they are bugs and reports are welcome.

Core Enhancements

   *   "chdir", "chmod" and "chown" can now work on filehandles as well as
       filenames, if the system supports respectively "fchdir", "fchmod"
       and "fchown", thanks to a patch provided by Gisle Aas.

Modules and Pragmata

   *   "Attribute::Handlers" upgraded to version 0.78_02

       *   Documentation typo fix

   *   "attrs" upgraded to version 1.02

       *   Internal cleanup only

   *   "autouse" upgraded to version 1.05

       *   Simplified implementation

   *   "B" upgraded to version 1.09_01

       *   The inheritance hierarchy of the "B::" modules has been
           corrected; "B::NV" now inherits from "B::SV" (instead of

   *   "blib" upgraded to version 1.03

       *   Documentation typo fix

   *   "ByteLoader" upgraded to version 0.06

       *   Internal cleanup

   *   "CGI" upgraded to version 3.15

       *   Extraneous "?" from "self_url()" removed

       *   "scrolling_list()" select attribute fixed

       *   "virtual_port" now works properly with the https protocol

       *   "upload_hook()" and "append()" now works in function-oriented

       *   "POST_MAX" doesn't cause the client to hang any more

       *   Automatic tab indexes are now disabled and new "-tabindex"
           pragma has been added to turn automatic indexes back on

       *   "end_form()" doesn't emit empty (and non-validating) "<div>"

       *   "CGI::Carp" works better in certain mod_perl configurations

       *   Setting $CGI::TMPDIRECTORY is now effective

       *   Enhanced documentation

   *   "charnames" upgraded to version 1.05

       *   "viacode()" now accept hex strings and has been optimized.

   *   "CPAN" upgraded to version 1.76_02

       *   1 minor bug fix for Win32

   *   "Cwd" upgraded to version 3.12

       *   "canonpath()" on Win32 now collapses foo\.. sections correctly.

       *   Improved behaviour on Symbian OS.

       *   Enhanced documentation and typo fixes

       *   Internal cleanup

   *   "Data::Dumper" upgraded to version 2.121_08

       *   A problem where "Data::Dumper" would sometimes update the
           iterator state of hashes has been fixed

       *   Numeric labels now work

       *   Internal cleanup

   *   "DB" upgraded to version 1.01

       *   A problem where the state of the regexp engine would sometimes
           get clobbered when running under the debugger has been fixed.

   *   "DB_File" upgraded to version 1.814

       *   Adds support for Berkeley DB 4.4.

   *   "Devel::DProf" upgraded to version 20050603.00

       *   Internal cleanup

   *   "Devel::Peek" upgraded to version 1.03

       *   Internal cleanup

   *   "Devel::PPPort" upgraded to version 3.06_01

       *   "--compat-version" argument checking has been improved

       *   Files passed on the command line are filtered by default

       *   "--nofilter" option to override the filtering has been added

       *   Enhanced documentation

   *   "diagnostics" upgraded to version 1.15

       *   Documentation typo fix

   *   "Digest" upgraded to version 1.14

       *   The constructor now knows which module implements SHA-224

       *   Documentation tweaks and typo fixes

   *   "Digest::MD5" upgraded to version 2.36

       *   "XSLoader" is now used for faster loading

       *   Enhanced documentation including MD5 weaknesses discovered

   *   "Dumpvalue" upgraded to version 1.12

       *   Documentation fix

   *   "DynaLoader" upgraded but unfortunately we're not able to increment
       its version number :-(

       *   Implements "dl_unload_file" on Win32

       *   Internal cleanup

       *   "XSLoader" 0.06 incorporated; small optimisation for calling
           "bootstrap_inherit()" and documentation enhancements.

   *   "Encode" upgraded to version 2.12

       *   A coderef is now acceptable for "CHECK"!

       *   3 new characters added to the ISO-8859-7 encoding

       *   New encoding "MIME-Header-ISO_2022_JP" added

       *   Problem with partial characters and "encoding(utf-8-strict)"

       *   Documentation enhancements and typo fixes

   *   "English" upgraded to version 1.02

       *   the $COMPILING variable has been added

   *   "ExtUtils::Constant" upgraded to version 0.17

       *   Improved compatibility with older versions of perl

   *   "ExtUtils::MakeMaker" upgraded to version 6.30 (was 6.17)

       *   Too much to list here;  see

   *   "File::Basename" upgraded to version 2.74, with changes contributed
       by Michael Schwern.

       *   Documentation clarified and errors corrected.

       *   "basename" now strips trailing path separators before
           processing the name.

       *   "basename" now returns "/" for parameter "/", to make
           "basename" consistent with the shell utility of the same name.

       *   The suffix is no longer stripped if it is identical to the
           remaining characters in the name, again for consistency with
           the shell utility.

       *   Some internal code cleanup.

   *   "File::Copy" upgraded to version 2.09

       *   Copying a file onto itself used to fail.

       *   Moving a file between file systems now preserves the access and
           modification time stamps

   *   "File::Find" upgraded to version 1.10

       *   Win32 portability fixes

       *   Enhanced documentation

   *   "File::Glob" upgraded to version 1.05

       *   Internal cleanup

   *   "File::Path" upgraded to version 1.08

       *   "mkpath" now preserves "errno" when "mkdir" fails

   *   "File::Spec" upgraded to version 3.12

       *   "File::Spec-"rootdir()> now returns "\" on Win32, instead of

       *   $^O could sometimes become tainted. This has been fixed.

       *   "canonpath" on Win32 now collapses "foo/.." (or "foo\..")
           sections correctly, rather than doing the "misguided" work it
           was previously doing.  Note that "canonpath" on Unix still does
           not collapse these sections, as doing so would be incorrect.

       *   Some documentation improvements

       *   Some internal code cleanup

   *   "FileCache" upgraded to version 1.06

       *   POD formatting errors in the documentation fixed

   *   "Filter::Simple" upgraded to version 0.82

   *   "FindBin" upgraded to version 1.47

       *   Now works better with directories where access rights are more
           restrictive than usual.

   *   "GDBM_File" upgraded to version 1.08

       *   Internal cleanup

   *   "Getopt::Long" upgraded to version 2.35

       *   "prefix_pattern" has now been complemented by a new
           configuration option "long_prefix_pattern" that allows the user
           to specify what prefix patterns should have long option style
           semantics applied.

       *   Options can now take multiple values at once (experimental)

       *   Various bug fixes

   *   "if" upgraded to version 0.05

       *   Give more meaningful error messages from "if" when invoked with
           a condition in list context.

       *   Restore backwards compatibility with earlier versions of perl

   *   "IO" upgraded to version 1.22

       *   Enhanced documentation

       *   Internal cleanup

   *   "IPC::Open2" upgraded to version 1.02

       *   Enhanced documentation

   *   "IPC::Open3" upgraded to version 1.02

       *   Enhanced documentation

   *   "List::Util" upgraded to version 1.18 (was 1.14)

       *   Fix pure-perl version of "refaddr" to avoid blessing an un-
           blessed reference

       *   Use "XSLoader" for faster loading

       *   Fixed various memory leaks

       *   Internal cleanup and portability fixes

   *   "Math::Complex" upgraded to version 1.35

       *   "atan2(0, i)" now works, as do all the (computable) complex
           argument cases

       *   Fixes for certain bugs in "make" and "emake"

       *   Support returning the kth root directly

       *   Support "[2,-3pi/8]" in "emake"

       *   Support "inf" for "make"/"emake"

       *   Document "make"/"emake" more visibly

   *   "Math::Trig" upgraded to version 1.03

       *   Add more great circle routines: "great_circle_waypoint" and

   *   "MIME::Base64" upgraded to version 3.07

       *   Use "XSLoader" for faster loading

       *   Enhanced documentation

       *   Internal cleanup

   *   "NDBM_File" upgraded to version 1.06

       *   Enhanced documentation

   *   "ODBM_File" upgraded to version 1.06

       *   Documentation typo fixed

       *   Internal cleanup

   *   "Opcode" upgraded to version 1.06

       *   Enhanced documentation

       *   Internal cleanup

   *   "open" upgraded to version 1.05

       *   Enhanced documentation

   *   "overload" upgraded to version 1.04

       *   Enhanced documentation

   *   "PerlIO" upgraded to version 1.04

       *   "PerlIO::via" iterate over layers properly now

       *   "PerlIO::scalar" understands "$/ = """ now

       *   "encoding(utf-8-strict)" with partial characters now works

       *   Enhanced documentation

       *   Internal cleanup

   *   "Pod::Functions" upgraded to version 1.03

       *   Documentation typos fixed

   *   "Pod::Html" upgraded to version 1.0504

       *   HTML output will now correctly link to "=item"s on the same
           page, and should be valid XHTML.

       *   Variable names are recognized as intended

       *   Documentation typos fixed

   *   "Pod::Parser" upgraded to version 1.32

       *   Allow files that start with "=head" on the first line

       *   Win32 portability fix

       *   Exit status of "pod2usage" fixed

       *   New "-noperldoc" switch for "pod2usage"

       *   Arbitrary URL schemes now allowed

       *   Documentation typos fixed

   *   "POSIX" upgraded to version 1.09

       *   Documentation typos fixed

       *   Internal cleanup

   *   "re" upgraded to version 0.05

       *   Documentation typo fixed

   *   "Safe" upgraded to version 2.12

       *   Minor documentation enhancement

   *   "SDBM_File" upgraded to version 1.05

       *   Documentation typo fixed

       *   Internal cleanup

   *   "Socket" upgraded to version 1.78

       *   Internal cleanup

   *   "Storable" upgraded to version 2.15

       *   This includes the "STORABLE_attach" hook functionality added by
           Adam Kennedy, and more frugal memory requirements when storing
           under "ithreads", by using the "ithreads" cloning tracking

   *   "Switch" upgraded to version 2.10_01

       *   Documentation typos fixed

   *   "Sys::Syslog" upgraded to version 0.13

       *   Now provides numeric macros and meaningful "Exporter" tags.

       *   No longer uses "Sys::Hostname" as it may provide useless values
           in unconfigured network environments, so instead uses
           "INADDR_LOOPBACK" directly.

       *   "syslog()" now uses local timestamp.

       *   "setlogmask()" now behaves like its C counterpart.

       *   "setlogsock()" will now "croak()" as documented.

       *   Improved error and warnings messages.

       *   Improved documentation.

   *   "Term::ANSIColor" upgraded to version 1.10

       *   Fixes a bug in "colored" when $EACHLINE is set that caused it
           to not color lines consisting solely of 0 (literal zero).

       *   Improved tests.

   *   "Term::ReadLine" upgraded to version 1.02

       *   Documentation tweaks

   *   "Test::Harness" upgraded to version 2.56 (was 2.48)

       *   The "Test::Harness" timer is now off by default.

       *   Now shows elapsed time in milliseconds.

       *   Various bug fixes

   *   "Test::Simple" upgraded to version 0.62 (was 0.54)

       *   "is_deeply()" no longer fails to work for many cases

       *   Various minor bug fixes

       *   Documentation enhancements

   *   "Text::Tabs" upgraded to version 2005.0824

       *   Provides a faster implementation of "expand"

   *   "Text::Wrap" upgraded to version 2005.082401

       *   Adds $Text::Wrap::separator2, which allows you to preserve
           existing newlines but add line-breaks with some other string.

   *   "threads" upgraded to version 1.07

       *   "threads" will now honour "no warnings 'threads'"

       *   A thread's interpreter is now freed after "$t->join()" rather
           than after "undef $t", which should fix some "ithreads" memory
           leaks. (Fixed by Dave Mitchell)

       *   Some documentation typo fixes.

   *   "threads::shared" upgraded to version 0.94

       *   Documentation changes only

       *   Note: An improved implementation of "threads::shared" is
           available on CPAN - this will be merged into 5.8.9 if it proves

   *   "Tie::Hash" upgraded to version 1.02

       *   Documentation typo fixed

   *   "Time::HiRes" upgraded to version 1.86 (was 1.66)

       *   "clock_nanosleep()" and "clock()" functions added

       *   Support for the POSIX "clock_gettime()" and "clock_getres()"
           has been added

       *   Return "undef" or an empty list if the C "gettimeofday()"
           function fails

       *   Improved "nanosleep" detection

       *   Internal cleanup

       *   Enhanced documentation

   *   "Unicode::Collate" upgraded to version 0.52

       *   Now implements UCA Revision 14 (based on Unicode 4.1.0).

       *   "Unicode::Collate-"new> method no longer overwrites user's $_

       *   Enhanced documentation

   *   "Unicode::UCD" upgraded to version 0.24

       *   Documentation typos fixed

   *   "User::grent" upgraded to version 1.01

       *   Documentation typo fixed

   *   "utf8" upgraded to version 1.06

       *   Documentation typos fixed

   *   "vmsish" upgraded to version 1.02

       *   Documentation typos fixed

   *   "warnings" upgraded to version 1.05

       *   Gentler messing with "Carp::" internals

       *   Internal cleanup

       *   Documentation update

   *   "Win32" upgraded to version 0.2601

       *   Provides Windows Vista support to "Win32::GetOSName"

       *   Documentation enhancements

   *   "XS::Typemap" upgraded to version 0.02

       *   Internal cleanup

Utility Changes

   "h2xs" enhancements
   "h2xs" implements new option "--use-xsloader" to force use of
   "XSLoader" even in backwards compatible modules.

   The handling of authors' names that had apostrophes has been fixed.

   Any enums with negative values are now skipped.

   "perlivp" enhancements
   "perlivp" implements new option "-a" and will not check for *.ph files
   by default any more.  Use the "-a" option to run all tests.

New Documentation

   The perlglossary manpage is a glossary of terms used in the Perl
   documentation, technical and otherwise, kindly provided by O'Reilly
   Media, inc.

Performance Enhancements

   *   Weak reference creation is now O(1) rather than O(n), courtesy of
       Nicholas Clark. Weak reference deletion remains O(n), but if
       deletion only happens at program exit, it may be skipped

   *   Salvador Fandio provided improvements to reduce the memory usage
       of "sort" and to speed up some cases.

   *   Jarkko Hietaniemi and Andy Lester worked to mark as much data as
       possible in the C source files as "static", to increase the
       proportion of the executable file that the operating system can
       share between process, and thus reduce real memory usage on multi-
       user systems.

Installation and Configuration Improvements

   Parallel makes should work properly now, although there may still be
   problems if "make test" is instructed to run in parallel.

   Building with Borland's compilers on Win32 should work more smoothly.
   In particular Steve Hay has worked to side step many warnings emitted
   by their compilers and at least one C compiler internal error.

   "Configure" will now detect "clearenv" and "unsetenv", thanks to a
   patch from Alan Burlison. It will also probe for "futimes" and whether
   "sprintf" correctly returns the length of the formatted string, which
   will both be used in perl 5.8.9.

   There are improved hints for next-3.0, vmesa, IX, Darwin, Solaris,
   Linux, DEC/OSF, HP-UX and MPE/iX

   Perl extensions on Windows now can be statically built into the Perl
   DLL, thanks to a work by Vadim Konovalov. (This improvement was
   actually in 5.8.7, but was accidentally omitted from perl587delta).

Selected Bug Fixes

   no warnings 'category' works correctly with -w
   Previously when running with warnings enabled globally via "-w",
   selective disabling of specific warning categories would actually turn
   off all warnings.  This is now fixed; now "no warnings 'io';" will only
   turn off warnings in the "io" class. Previously it would erroneously
   turn off all warnings.

   This bug fix may cause some programs to start correctly issuing

   Remove over-optimisation
   Perl 5.8.4 introduced a change so that assignments of "undef" to a
   scalar, or of an empty list to an array or a hash, were optimised away.
   As this could cause problems when "goto" jumps were involved, this
   change has been backed out.

   sprintf() fixes
   Using the sprintf() function with some formats could lead to a buffer
   overflow in some specific cases. This has been fixed, along with
   several other bugs, notably in bounds checking.

   In related fixes, it was possible for badly written code that did not
   follow the documentation of "Sys::Syslog" to have formatting
   vulnerabilities.  "Sys::Syslog" has been changed to protect people from
   poor quality third party code.

   Debugger and Unicode slowdown
   It had been reported that running under perl's debugger when processing
   Unicode data could cause unexpectedly large slowdowns. The most likely
   cause of this was identified and fixed by Nicholas Clark.

   Smaller fixes
   *   "FindBin" now works better with directories where access rights are
       more restrictive than usual.

   *   Several memory leaks in ithreads were closed. An improved
       implementation of "threads::shared" is available on CPAN - this
       will be merged into 5.8.9 if it proves stable.

   *   Trailing spaces are now trimmed from $! and $^E.

   *   Operations that require perl to read a process's list of groups,
       such as reads of $( and $), now dynamically allocate memory rather
       than using a fixed sized array. The fixed size array could cause C
       stack exhaustion on systems configured to use large numbers of

   *   "PerlIO::scalar" now works better with non-default $/ settings.

   *   You can now use the "x" operator to repeat a "qw//" list. This used
       to raise a syntax error.

   *   The debugger now traces correctly execution in eval("")uated code
       that contains #line directives.

   *   The value of the "open" pragma is no longer ignored for three-
       argument opens.

   *   The optimisation of "for (reverse @a)" introduced in perl 5.8.6
       could misbehave when the array had undefined elements and was used
       in LVALUE context. Dave Mitchell provided a fix.

   *   Some case insensitive matches between UTF-8 encoded data and 8 bit
       regexps, and vice versa, could give malformed character warnings.
       These have been fixed by Dave Mitchell and Yves Orton.

   *   "lcfirst" and "ucfirst" could corrupt the string for certain cases
       where the length UTF-8 encoding of the string in lower case, upper
       case or title case differed. This was fixed by Nicholas Clark.

   *   Perl will now use the C library calls "unsetenv" and "clearenv" if
       present to delete keys from %ENV and delete %ENV entirely, thanks
       to a patch from Alan Burlison.

New or Changed Diagnostics

   Attempt to set length of freed array
   This is a new warning, produced in situations such as this:

       $r = do {my @a; \$#a};
       $$r = 503;

   Non-string passed as bitmask
   This is a new warning, produced when number has been passed as a
   argument to select(), instead of a bitmask.

       # Wrong, will now warn
       $rin = fileno(STDIN);
       ($nfound,$timeleft) = select($rout=$rin, undef, undef, $timeout);

       # Should be
       $rin = '';
       vec($rin,fileno(STDIN),1) = 1;
       ($nfound,$timeleft) = select($rout=$rin, undef, undef, $timeout);

   Search pattern not terminated or ternary operator parsed as search pattern
   This syntax error indicates that the lexer couldn't find the final
   delimiter of a "?PATTERN?" construct. Mentioning the ternary operator
   in this error message makes it easier to diagnose syntax errors.

Changed Internals

   There has been a fair amount of refactoring of the "C" source code,
   partly to make it tidier and more maintainable. The resulting object
   code and the "perl" binary may well be smaller than 5.8.7, in
   particular due to a change contributed by Dave Mitchell which reworked
   the warnings code to be significantly smaller. Apart from being smaller
   and possibly faster, there should be no user-detectable changes.

   Andy Lester supplied many improvements to determine which function
   parameters and local variables could actually be declared "const" to
   the C compiler. Steve Peters provided new *_set macros and reworked the
   core to use these rather than assigning to macros in LVALUE context.

   Dave Mitchell improved the lexer debugging output under "-DT"

   Nicholas Clark changed the string buffer allocation so that it is now
   rounded up to the next multiple of 4 (or 8 on platforms with 64 bit
   pointers). This should reduce the number of calls to "realloc" without
   actually using any extra memory.

   The "HV"'s array of "HE*"s is now allocated at the correct (minimal)
   size, thanks to another change by Nicholas Clark. Compile with
   "-DPERL_USE_LARGE_HV_ALLOC" to use the old, sloppier, default.

   For XS or embedding debugging purposes, if perl is compiled with
   "-DDEBUG_LEAKING_SCALARS" then a child process is "fork"ed just before
   global destruction, which is used to display the values of any scalars
   found to have leaked at the end of global destruction. Without this,
   the scalars have already been freed sufficiently at the point of
   detection that it is impossible to produce any meaningful dump of their
   contents.  This feature was implemented by the indefatigable Nicholas
   Clark, based on an idea by Mike Giroux.

Platform Specific Problems

   The optimiser on HP-UX 11.23 (Itanium 2) is currently partly disabled
   (scaled down to +O1) when using HP C-ANSI-C; the cause of problems at
   higher optimisation levels is still unclear.

   There are a handful of remaining test failures on VMS, mostly due to
   test fixes and minor module tweaks with too many dependencies to
   integrate into this release from the development stream, where they
   have all been corrected.  The following is a list of expected failures
   with the patch number of the fix where that is known:

       ext/Devel/PPPort/t/ppphtest.t  #26913
       ext/List/Util/t/p_tainted.t    #26912
       lib/ExtUtils/t/PL_FILES.t      #26813
       lib/ExtUtils/t/basic.t         #26813

Reporting Bugs

   If you find what you think is a bug, you might check the articles
   recently posted to the comp.lang.perl.misc newsgroup and the perl bug
   database at  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.  Be sure to 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.  You can browse and search the Perl 5 bugs at


   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.


Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.

Free Software

Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.

Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.

Free Books

The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.

Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.


Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.

Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.