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  13 <big><strong><span class="block">&nbsp;perl571delta - what's new for perl v5.7.1</span></strong></big>
  14 </td></tr>
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  16
  17 <p><a name="__index__"></a></p>
  18 <!-- INDEX BEGIN -->
  19
  20 <ul>
  21
  22         <li><a href="#name">NAME</a></li>
  23         <li><a href="#description">DESCRIPTION</a></li>
  24         <li><a href="#security_vulnerability_closed">Security Vulnerability Closed</a></li>
  25         <li><a href="#incompatible_changes">Incompatible Changes</a></li>
  26         <li><a href="#core_enhancements">Core Enhancements</a></li>
  27         <ul>
  28
  29                 <li><a href="#autoload_is_now_lvaluable">AUTOLOAD Is Now Lvaluable</a></li>
  30                 <li><a href="#perlio_is_now_the_default">PerlIO is Now The Default</a></li>
  31                 <li><a href="#signals_are_now_safe">Signals Are Now Safe</a></li>
  32         </ul>
  33
  34         <li><a href="#modules_and_pragmata">Modules and Pragmata</a></li>
  35         <ul>
  36
  37                 <li><a href="#new_modules">New Modules</a></li>
  38                 <li><a href="#updated_and_improved_modules_and_pragmata">Updated And Improved Modules and Pragmata</a></li>
  39         </ul>
  40
  41         <li><a href="#performance_enhancements">Performance Enhancements</a></li>
  42         <li><a href="#utility_changes">Utility Changes</a></li>
  43         <li><a href="#new_documentation">New Documentation</a></li>
  44         <ul>
  45
  46                 <li><a href="#perlclib">perlclib</a></li>
  47                 <li><a href="#perliol">perliol</a></li>
  48                 <li><a href="#readme_aix">README.aix</a></li>
  49                 <li><a href="#readme_bs2000">README.bs2000</a></li>
  50                 <li><a href="#readme_macos">README.macos</a></li>
  51                 <li><a href="#readme_mpeix">README.mpeix</a></li>
  52                 <li><a href="#readme_solaris">README.solaris</a></li>
  53                 <li><a href="#readme_vos">README.vos</a></li>
  54                 <li><a href="#porting_repository_pod">Porting/repository.pod</a></li>
  55         </ul>
  56
  57         <li><a href="#installation_and_configuration_improvements">Installation and Configuration Improvements</a></li>
  58         <ul>
  59
  60                 <li><a href="#new_or_improved_platforms">New Or Improved Platforms</a></li>
  61                 <li><a href="#generic_improvements">Generic Improvements</a></li>
  62         </ul>
  63
  64         <li><a href="#selected_bug_fixes">Selected Bug Fixes</a></li>
  65         <ul>
  66
  67                 <li><a href="#platform_specific_changes_and_fixes">Platform Specific Changes and Fixes</a></li>
  68         </ul>
  69
  70         <li><a href="#new_or_changed_diagnostics">New or Changed Diagnostics</a></li>
  71         <li><a href="#changed_internals">Changed Internals</a></li>
  72         <li><a href="#new_tests">New Tests</a></li>
  73         <li><a href="#known_problems">Known Problems</a></li>
  74         <ul>
  75
  76                 <li><a href="#aix_vac_5_0_0_0_may_produce_buggy_code_for_perl">AIX vac 5.0.0.0 May Produce Buggy Code For Perl</a></li>
  77                 <li><a href="#lib_ftmpsecurity_tests_warn__system_possibly_insecure_">lib/ftmp-security tests warn 'system possibly insecure'</a></li>
  78                 <li><a href="#lib_io_multihomed_fails_in_lp64configured_hpux">lib/io_multihomed Fails In LP64-Configured HP-UX</a></li>
  79                 <li><a href="#test_lib_posix_subtest_9_fails_in_lp64configured_hpux">Test lib/posix Subtest 9 Fails In LP64-Configured HP-UX</a></li>
  80                 <li><a href="#lib_b_test_19">lib/b test 19</a></li>
  81                 <li><a href="#linux_with_sfio_fails_op_misc_test_48">Linux With Sfio Fails op/misc Test 48</a></li>
  82                 <li><a href="#sigaction_test_13_in_vms">sigaction test 13 in VMS</a></li>
  83                 <li><a href="#sprintf_tests_129_and_130">sprintf tests 129 and 130</a></li>
  84                 <li><a href="#failure_of_thread_tests">Failure of Thread tests</a></li>
  85                 <li><a href="#localising_a_tied_variable_leaks_memory">Localising a Tied Variable Leaks Memory</a></li>
  86                 <li><a href="#selftying_of_arrays_and_hashes_is_forbidden">Self-tying of Arrays and Hashes Is Forbidden</a></li>
  87                 <li><a href="#building_extensions_can_fail_because_of_largefiles">Building Extensions Can Fail Because Of Largefiles</a></li>
  88                 <li><a href="#the_compiler_suite_is_still_experimental">The Compiler Suite Is Still Experimental</a></li>
  89         </ul>
  90
  91         <li><a href="#reporting_bugs">Reporting Bugs</a></li>
  92         <li><a href="#see_also">SEE ALSO</a></li>
  93         <li><a href="#history">HISTORY</a></li>
  94 </ul>
  95 <!-- INDEX END -->
  96
  97 <hr />
  98 <p>
  99 </p>
 100 <h1><a name="name">NAME</a></h1>
 101 <p>perl571delta - what's new for perl v5.7.1</p>
 102 <p>
 103 </p>
 104 <hr />
 105 <h1><a name="description">DESCRIPTION</a></h1>
 106 <p>This document describes differences between the 5.7.0 release and the
 107 5.7.1 release.</p>
 108 <p>(To view the differences between the 5.6.0 release and the 5.7.0
 109 release, see <a href="file://C|\msysgit\mingw\html/pod/perl570delta.html">the perl570delta manpage</a>.)</p>
 110 <p>
 111 </p>
 112 <hr />
 113 <h1><a name="security_vulnerability_closed">Security Vulnerability Closed</a></h1>
 114 <p>(This change was already made in 5.7.0 but bears repeating here.)</p>
 115 <p>A potential security vulnerability in the optional suidperl component
 116 of Perl was identified in August 2000.  suidperl is neither built nor
 117 installed by default.  As of April 2001 the only known vulnerable
 118 platform is Linux, most likely all Linux distributions.  CERT and
 119 various vendors and distributors have been alerted about the vulnerability.
 120 See <a href="http://www.cpan.org/src/5.0/sperl-2000-08-05/sperl-2000-08-05.txt">http://www.cpan.org/src/5.0/sperl-2000-08-05/sperl-2000-08-05.txt</a>
 121 for more information.</p>
 122 <p>The problem was caused by Perl trying to report a suspected security
 123 exploit attempt using an external program, /bin/mail.  On Linux
 124 platforms the /bin/mail program had an undocumented feature which
 125 when combined with suidperl gave access to a root shell, resulting in
 126 a serious compromise instead of reporting the exploit attempt.  If you
 127 don't have /bin/mail, or if you have 'safe setuid scripts', or if
 128 suidperl is not installed, you are safe.</p>
 129 <p>The exploit attempt reporting feature has been completely removed from
 130 all the Perl 5.7 releases (and will be gone also from the maintenance
 131 release 5.6.1), so that particular vulnerability isn't there anymore.
 132 However, further security vulnerabilities are, unfortunately, always
 133 possible.  The suidperl code is being reviewed and if deemed too risky
 134 to continue to be supported, it may be completely removed from future
 135 releases.  In any case, suidperl should only be used by security
 136 experts who know exactly what they are doing and why they are using
 137 suidperl instead of some other solution such as sudo
 138 ( see <a href="http://www.courtesan.com/sudo/">http://www.courtesan.com/sudo/</a> ).</p>
 139 <p>
 140 </p>
 141 <hr />
 142 <h1><a name="incompatible_changes">Incompatible Changes</a></h1>
 143 <ul>
 144 <li>
 145 <p>Although ``you shouldn't do that'', it was possible to write code that
 146 depends on Perl's hashed key order (Data::Dumper does this).  The new
 147 algorithm ``One-at-a-Time'' produces a different hashed key order.
 148 More details are in <a href="#performance_enhancements">Performance Enhancements</a>.</p>
 149 </li>
 150 <li>
 151 <p>The list of filenames from <a href="file://C|\msysgit\mingw\html/pod/perlfunc.html#item_glob"><code>glob()</code></a> (or &lt;...&gt;) is now by default sorted
 152 alphabetically to be csh-compliant.  (bsd_glob() does still sort platform
 153 natively, ASCII or EBCDIC, unless GLOB_ALPHASORT is specified.)</p>
 154 </li>
 155 </ul>
 156 <p>
 157 </p>
 158 <hr />
 159 <h1><a name="core_enhancements">Core Enhancements</a></h1>
 160 <p>
 161 </p>
 162 <h2><a name="autoload_is_now_lvaluable">AUTOLOAD Is Now Lvaluable</a></h2>
 163 <p>AUTOLOAD is now lvaluable, meaning that you can add the :lvalue attribute
 164 to AUTOLOAD subroutines and you can assign to the AUTOLOAD return value.</p>
 165 <p>
 166 </p>
 167 <h2><a name="perlio_is_now_the_default">PerlIO is Now The Default</a></h2>
 168 <ul>
 169 <li>
 170 <p>IO is now by default done via PerlIO rather than system's ``stdio''.
 171 PerlIO allows ``layers'' to be ``pushed'' onto a file handle to alter the
 172 handle's behaviour.  Layers can be specified at open time via 3-arg
 173 form of open:</p>
 174 <pre>
 175    open($fh,'&gt;:crlf :utf8', $path) || ...</pre>
 176 <p>or on already opened handles via extended <a href="file://C|\msysgit\mingw\html/pod/perlfunc.html#item_binmode"><code>binmode</code></a>:</p>
 177 <pre>
 178    binmode($fh,':encoding(iso-8859-7)');</pre>
 179 <p>The built-in layers are: unix (low level read/write), stdio (as in
 180 previous Perls), perlio (re-implementation of stdio buffering in a
 181 portable manner), crlf (does CRLF &lt;=&gt; ``\n'' translation as on Win32,
 182 but available on any platform).  A mmap layer may be available if
 183 platform supports it (mostly UNIXes).</p>
 184 <p>Layers to be applied by default may be specified via the 'open' pragma.</p>
 185 <p>See <a href="#installation_and_configuration_improvements">Installation and Configuration Improvements</a> for the effects
 186 of PerlIO on your architecture name.</p>
 187 </li>
 188 <li>
 189 <p>File handles can be marked as accepting Perl's internal encoding of Unicode
 190 (UTF-8 or UTF-EBCDIC depending on platform) by a pseudo layer ``:utf8'' :</p>
 191 <pre>
 192    open($fh,&quot;&gt;:utf8&quot;,&quot;Uni.txt&quot;);</pre>
 193 <p>Note for EBCDIC users: the pseudo layer ``:utf8'' is erroneously named
 194 for you since it's not UTF-8 what you will be getting but instead
 195 UTF-EBCDIC.  See <a href="file://C|\msysgit\mingw\html/pod/perlunicode.html">the perlunicode manpage</a>, <a href="file://C|\msysgit\mingw\html/lib/utf8.html">the utf8 manpage</a>, and
 196 <a href="http://www.unicode.org/unicode/reports/tr16/">http://www.unicode.org/unicode/reports/tr16/</a> for more information.
 197 In future releases this naming may change.</p>
 198 </li>
 199 <li>
 200 <p>File handles can translate character encodings from/to Perl's internal
 201 Unicode form on read/write via the ``:encoding()'' layer.</p>
 202 </li>
 203 <li>
 204 <p>File handles can be opened to ``in memory'' files held in Perl scalars via:</p>
 205 <pre>
 206    open($fh,'&gt;', \$variable) || ...</pre>
 207 </li>
 208 <li>
 209 <p>Anonymous temporary files are available without need to
 210 'use FileHandle' or other module via</p>
 211 <pre>
 212    open($fh,&quot;+&gt;&quot;, undef) || ...</pre>
 213 <p>That is a literal undef, not an undefined value.</p>
 214 </li>
 215 <li>
 216 <p>The list form of <a href="file://C|\msysgit\mingw\html/pod/perlfunc.html#item_open"><code>open</code></a> is now implemented for pipes (at least on UNIX):</p>
 217 <pre>
 218    open($fh,&quot;-|&quot;, 'cat', '/etc/motd')</pre>
 219 <p>creates a pipe, and runs the equivalent of exec('cat', '/etc/motd') in
 220 the child process.</p>
 221 </li>
 222 <li>
 223 <p>The following builtin functions are now overridable: chop(), chomp(),
 224 each(), keys(), pop(), push(), shift(), splice(), unshift().</p>
 225 </li>
 226 <li>
 227 <p>Formats now support zero-padded decimal fields.</p>
 228 </li>
 229 <li>
 230 <p>Perl now tries internally to use integer values in numeric conversions
 231 and basic arithmetics (+ - * /) if the arguments are integers, and
 232 tries also to keep the results stored internally as integers.
 233 This change leads into often slightly faster and always less lossy
 234 arithmetics. (Previously Perl always preferred floating point numbers
 235 in its math.)</p>
 236 </li>
 237 <li>
 238 <p>The <a href="file://C|\msysgit\mingw\html/pod/perlfunc.html#item_printf"><code>printf()</code></a> and <code>sprintf()</code> now support parameter reordering using the
 239 <code>%\d+\$</code> and <code>*\d+\$</code> syntaxes.  For example</p>
 240 <pre>
 241     print &quot;%2\$s %1\$s\n&quot;, &quot;foo&quot;, &quot;bar&quot;;</pre>
 242 <p>will print ``bar foo\n''; This feature helps in writing
 243 internationalised software.</p>
 244 </li>
 245 <li>
 246 <p>Unicode in general should be now much more usable.  Unicode can be
 247 used in hash keys, Unicode in regular expressions should work now,
 248 Unicode in tr/// should work now (though tr/// seems to be a
 249 particularly tricky to get right, so you have been warned)</p>
 250 </li>
 251 <li>
 252 <p>The Unicode Character Database coming with Perl has been upgraded
 253 to Unicode 3.1.  For more information, see <a href="http://www.unicode.org/">http://www.unicode.org/</a> ,
 254 and <a href="http://www.unicode.org/unicode/reports/tr27/">http://www.unicode.org/unicode/reports/tr27/</a></p>
 255 <p>For developers interested in enhancing Perl's Unicode capabilities:
 256 almost all the UCD files are included with the Perl distribution in
 257 the lib/unicode subdirectory.  The most notable omission, for space
 258 considerations, is the Unihan database.</p>
 259 </li>
 260 <li>
 261 <p>The Unicode character classes \p{Blank} and \p{SpacePerl} have been
 262 added.  ``Blank'' is like C isblank(), that is, it contains only
 263 ``horizontal whitespace'' (the space character is, the newline isn't),
 264 and the ``SpacePerl'' is the Unicode equivalent of <code>\s</code> (\p{Space}
 265 isn't, since that includes the vertical tabulator character, whereas
 266 <code>\s</code> doesn't.)</p>
 267 </li>
 268 </ul>
 269 <p>
 270 </p>
 271 <h2><a name="signals_are_now_safe">Signals Are Now Safe</a></h2>
 272 <p>Perl used to be fragile in that signals arriving at inopportune moments
 273 could corrupt Perl's internal state.</p>
 274 <p>
 275 </p>
 276 <hr />
 277 <h1><a name="modules_and_pragmata">Modules and Pragmata</a></h1>
 278 <p>
 279 </p>
 280 <h2><a name="new_modules">New Modules</a></h2>
 281 <ul>
 282 <li>
 283 <p>B::Concise, by Stephen McCamant, is a new compiler backend for
 284 walking the Perl syntax tree, printing concise info about ops.
 285 The output is highly customisable.</p>
 286 <p>See <a href="file://C|\msysgit\mingw\html/lib/B/Concise.html">the B::Concise manpage</a> for more information.</p>
 287 </li>
 288 <li>
 289 <p>Class::ISA, by Sean Burke, for reporting the search path for a
 290 class's ISA tree, has been added.</p>
 291 <p>See <a href="file://C|\msysgit\mingw\html/lib/Class/ISA.html">the Class::ISA manpage</a> for more information.</p>
 292 </li>
 293 <li>
 294 <p>Cwd has now a split personality: if possible, an extension is used,
 295 (this will hopefully be both faster and more secure and robust) but
 296 if not possible, the familiar Perl library implementation is used.</p>
 297 </li>
 298 <li>
 299 <p>Digest, a frontend module for calculating digests (checksums),
 300 from Gisle Aas, has been added.</p>
 301 <p>See <a href="file://C|\msysgit\mingw\html/lib/Digest.html">the Digest manpage</a> for more information.</p>
 302 </li>
 303 <li>
 304 <p>Digest::MD5 for calculating MD5 digests (checksums), by Gisle Aas,
 305 has been added.</p>
 306 <pre>
 307     use Digest::MD5 'md5_hex';</pre>
 308 <pre>
 309     $digest = md5_hex(&quot;Thirsty Camel&quot;);</pre>
 310 <pre>
 311     print $digest, &quot;\n&quot;; # 01d19d9d2045e005c3f1b80e8b164de1</pre>
 312 <p>NOTE: the MD5 backward compatibility module is deliberately not
 313 included since its use is discouraged.</p>
 314 <p>See <a href="file://C|\msysgit\mingw\html/lib/Digest/MD5.html">the Digest::MD5 manpage</a> for more information.</p>
 315 </li>
 316 <li>
 317 <p>Encode, by Nick Ing-Simmons, provides a mechanism to translate
 318 between different character encodings.  Support for Unicode,
 319 ISO-8859-*, ASCII, CP*, KOI8-R, and three variants of EBCDIC are
 320 compiled in to the module.  Several other encodings (like Japanese,
 321 Chinese, and MacIntosh encodings) are included and will be loaded at
 322 runtime.</p>
 323 <p>Any encoding supported by Encode module is also available to the
 324 ``:encoding()'' layer if PerlIO is used.</p>
 325 <p>See <a href="file://C|\msysgit\mingw\html/lib/Encode.html">the Encode manpage</a> for more information.</p>
 326 </li>
 327 <li>
 328 <p>Filter::Simple is an easy-to-use frontend to Filter::Util::Call,
 329 from Damian Conway.</p>
 330 <pre>
 331     # in MyFilter.pm:</pre>
 332 <pre>
 333     package MyFilter;</pre>
 334 <pre>
 335     use Filter::Simple sub {
 336         while (my ($from, $to) = splice @_, 0, 2) {
 337                 s/$from/$to/g;
 338         }
 339     };</pre>
 340 <pre>
 341     1;</pre>
 342 <pre>
 343     # in user's code:</pre>
 344 <pre>
 345     use MyFilter qr/red/ =&gt; 'green';</pre>
 346 <pre>
 347     print &quot;red\n&quot;;   # this code is filtered, will print &quot;green\n&quot;
 348     print &quot;bored\n&quot;; # this code is filtered, will print &quot;bogreen\n&quot;</pre>
 349 <pre>
 350     no MyFilter;</pre>
 351 <pre>
 352     print &quot;red\n&quot;;   # this code is not filtered, will print &quot;red\n&quot;</pre>
 353 <p>See <a href="file://C|\msysgit\mingw\html/lib/Filter/Simple.html">the Filter::Simple manpage</a> for more information.</p>
 354 </li>
 355 <li>
 356 <p>Filter::Util::Call, by Paul Marquess, provides you with the
 357 framework to write <em>Source Filters</em> in Perl.  For most uses
 358 the frontend Filter::Simple is to be preferred.
 359 See <a href="file://C|\msysgit\mingw\html/lib/Filter/Util/Call.html">the Filter::Util::Call manpage</a> for more information.</p>
 360 </li>
 361 <li>
 362 <p>Locale::Constants, Locale::Country, Locale::Currency, and Locale::Language,
 363 from Neil Bowers, have been added.  They provide the codes for various
 364 locale standards, such as ``fr'' for France, ``usd'' for US Dollar, and
 365 ``jp'' for Japanese.</p>
 366 <pre>
 367     use Locale::Country;</pre>
 368 <pre>
 369     $country = code2country('jp');               # $country gets 'Japan'
 370     $code    = country2code('Norway');           # $code gets 'no'</pre>
 371 <p>See <a href="file://C|\msysgit\mingw\html/lib/Locale/Constants.html">the Locale::Constants manpage</a>, <a href="file://C|\msysgit\mingw\html/lib/Locale/Country.html">the Locale::Country manpage</a>, <a href="file://C|\msysgit\mingw\html/lib/Locale/Currency.html">the Locale::Currency manpage</a>,
 372 and <a href="file://C|\msysgit\mingw\html/lib/Locale/Language.html">the Locale::Language manpage</a> for more information.</p>
 373 </li>
 374 <li>
 375 <p>MIME::Base64, by Gisle Aas, allows you to encode data in base64.</p>
 376 <pre>
 377     use MIME::Base64;</pre>
 378 <pre>
 379     $encoded = encode_base64('Aladdin:open sesame');
 380     $decoded = decode_base64($encoded);</pre>
 381 <pre>
 382     print $encoded, &quot;\n&quot;; # &quot;QWxhZGRpbjpvcGVuIHNlc2FtZQ==&quot;</pre>
 383 <p>See <a href="file://C|\msysgit\mingw\html/lib/MIME/Base64.html">the MIME::Base64 manpage</a> for more information.</p>
 384 </li>
 385 <li>
 386 <p>MIME::QuotedPrint, by Gisle Aas, allows you to encode data in
 387 quoted-printable encoding.</p>
 388 <pre>
 389     use MIME::QuotedPrint;</pre>
 390 <pre>
 391     $encoded = encode_qp(&quot;Smiley in Unicode: \x{263a}&quot;);
 392     $decoded = decode_qp($encoded);</pre>
 393 <pre>
 394     print $encoded, &quot;\n&quot;; # &quot;Smiley in Unicode: =263A&quot;</pre>
 395 <p>MIME::QuotedPrint has been enhanced to provide the basic methods
 396 necessary to use it with PerlIO::Via as in :</p>
 397 <pre>
 398     use MIME::QuotedPrint;
 399     open($fh,&quot;&gt;Via(MIME::QuotedPrint)&quot;,$path)</pre>
 400 <p>See <a href="file://C|\msysgit\mingw\html/lib/MIME/QuotedPrint.html">the MIME::QuotedPrint manpage</a> for more information.</p>
 401 </li>
 402 <li>
 403 <p>PerlIO::Scalar, by Nick Ing-Simmons, provides the implementation of
 404 IO to ``in memory'' Perl scalars as discussed above.  It also serves as
 405 an example of a loadable layer.  Other future possibilities include
 406 PerlIO::Array and PerlIO::Code.  See <a href="file://C|\msysgit\mingw\html/PerlIO/Scalar.html">the PerlIO::Scalar manpage</a> for more
 407 information.</p>
 408 </li>
 409 <li>
 410 <p>PerlIO::Via, by Nick Ing-Simmons, acts as a PerlIO layer and wraps
 411 PerlIO layer functionality provided by a class (typically implemented
 412 in perl code).</p>
 413 <pre>
 414     use MIME::QuotedPrint;
 415     open($fh,&quot;&gt;Via(MIME::QuotedPrint)&quot;,$path)</pre>
 416 <p>This will automatically convert everything output to <code>$fh</code>
 417 to Quoted-Printable.  See <a href="file://C|\msysgit\mingw\html/PerlIO/Via.html">the PerlIO::Via manpage</a> for more information.</p>
 418 </li>
 419 <li>
 420 <p>Pod::Text::Overstrike, by Joe Smith, has been added.
 421 It converts POD data to formatted overstrike text.
 422 See <a href="file://C|\msysgit\mingw\html/lib/Pod/Text/Overstrike.html">the Pod::Text::Overstrike manpage</a> for more information.</p>
 423 </li>
 424 <li>
 425 <p>Switch from Damian Conway has been added.  Just by saying</p>
 426 <pre>
 427     use Switch;</pre>
 428 <p>you have <code>switch</code> and <code>case</code> available in Perl.</p>
 429 <pre>
 430     use Switch;</pre>
 431 <pre>
 432     switch ($val) {</pre>
 433 <pre>
 434                 case 1          { print &quot;number 1&quot; }
 435                 case &quot;a&quot;        { print &quot;string a&quot; }
 436                 case [1..10,42] { print &quot;number in list&quot; }
 437                 case (@array)   { print &quot;number in list&quot; }
 438                 case /\w+/      { print &quot;pattern&quot; }
 439                 case qr/\w+/    { print &quot;pattern&quot; }
 440                 case (%hash)    { print &quot;entry in hash&quot; }
 441                 case (\%hash)   { print &quot;entry in hash&quot; }
 442                 case (\&amp;sub)    { print &quot;arg to subroutine&quot; }
 443                 else            { print &quot;previous case not true&quot; }
 444     }</pre>
 445 <p>See <a href="file://C|\msysgit\mingw\html/lib/Switch.html">the Switch manpage</a> for more information.</p>
 446 </li>
 447 <li>
 448 <p>Text::Balanced from Damian Conway has been added, for
 449 extracting delimited text sequences from strings.</p>
 450 <pre>
 451     use Text::Balanced 'extract_delimited';</pre>
 452 <pre>
 453     ($a, $b) = extract_delimited(&quot;'never say never', he never said&quot;, &quot;'&quot;, '');</pre>
 454 <p>$a will be ``'never say never''', $b will be ', he never said'.</p>
 455 <p>In addition to <code>extract_delimited()</code> there are also extract_bracketed(),
 456 extract_quotelike(), extract_codeblock(), extract_variable(),
 457 extract_tagged(), extract_multiple(), gen_delimited_pat(), and
 458 gen_extract_tagged().  With these you can implement rather advanced
 459 parsing algorithms.  See <a href="file://C|\msysgit\mingw\html/lib/Text/Balanced.html">the Text::Balanced manpage</a> for more information.</p>
 460 </li>
 461 <li>
 462 <p>Tie::RefHash::Nestable, by Edward Avis, allows storing hash references
 463 (unlike the standard Tie::RefHash)  The module is contained within
 464 Tie::RefHash.</p>
 465 </li>
 466 <li>
 467 <p>XS::Typemap, by Tim Jenness, is a test extension that exercises XS
 468 typemaps.  Nothing gets installed but for extension writers the code
 469 is worth studying.</p>
 470 </li>
 471 </ul>
 472 <p>
 473 </p>
 474 <h2><a name="updated_and_improved_modules_and_pragmata">Updated And Improved Modules and Pragmata</a></h2>
 475 <ul>
 476 <li>
 477 <p>B::Deparse should be now more robust.  It still far from providing a full
 478 round trip for any random piece of Perl code, though, and is under active
 479 development: expect more robustness in 5.7.2.</p>
 480 </li>
 481 <li>
 482 <p>Class::Struct can now define the classes in compile time.</p>
 483 </li>
 484 <li>
 485 <p>Math::BigFloat has undergone much fixing, and in addition the <code>fmod()</code>
 486 function now supports modulus operations.</p>
 487 <p>( The fixed Math::BigFloat module is also available in CPAN for those
 488 who can't upgrade their Perl: <a href="http://www.cpan.org/authors/id/J/JP/JPEACOCK/">http://www.cpan.org/authors/id/J/JP/JPEACOCK/</a> )</p>
 489 </li>
 490 <li>
 491 <p>Devel::Peek now has an interface for the Perl memory statistics
 492 (this works only if you are using perl's malloc, and if you have
 493 compiled with debugging).</p>
 494 </li>
 495 <li>
 496 <p>IO::Socket has now <code>atmark()</code> method, which returns true if the socket
 497 is positioned at the out-of-band mark.  The method is also exportable
 498 as a <code>sockatmark()</code> function.</p>
 499 </li>
 500 <li>
 501 <p>IO::Socket::INET has support for ReusePort option (if your platform
 502 supports it).  The Reuse option now has an alias, ReuseAddr.  For clarity
 503 you may want to prefer ReuseAddr.</p>
 504 </li>
 505 <li>
 506 <p>Net::Ping has been enhanced.  There is now ``external'' protocol which
 507 uses Net::Ping::External module which runs external <code>ping(1)</code> and parses
 508 the output.  An alpha version of Net::Ping::External is available in
 509 CPAN and in 5.7.2 the Net::Ping::External may be integrated to Perl.</p>
 510 </li>
 511 <li>
 512 <p>The <a href="file://C|\msysgit\mingw\html/pod/perlfunc.html#item_open"><code>open</code></a> pragma allows layers other than ``:raw'' and ``:crlf'' when
 513 using PerlIO.</p>
 514 </li>
 515 <li>
 516 <p>POSIX::sigaction() is now much more flexible and robust.
 517 You can now install coderef handlers, 'DEFAULT', and 'IGNORE'
 518 handlers, installing new handlers was not atomic.</p>
 519 </li>
 520 <li>
 521 <p>The Test module has been significantly enhanced.  Its use is
 522 greatly recommended for module writers.</p>
 523 </li>
 524 <li>
 525 <p>The utf8:: name space (as in the pragma) provides various
 526 Perl-callable functions to provide low level access to Perl's
 527 internal Unicode representation.  At the moment only <a href="file://C|\msysgit\mingw\html/pod/perlfunc.html#item_length"><code>length()</code></a>
 528 has been implemented.</p>
 529 </li>
 530 </ul>
 531 <p>The following modules have been upgraded from the versions at CPAN:
 532 CPAN, CGI, DB_File, File::Temp, Getopt::Long, Pod::Man, Pod::Text,
 533 Storable, Text-Tabs+Wrap.</p>
 534 <p>
 535 </p>
 536 <hr />
 537 <h1><a name="performance_enhancements">Performance Enhancements</a></h1>
 538 <ul>
 539 <li>
 540 <p>Hashes now use Bob Jenkins ``One-at-a-Time'' hashing key algorithm
 541 ( <a href="http://burtleburtle.net/bob/hash/doobs.html">http://burtleburtle.net/bob/hash/doobs.html</a> ).  This algorithm is
 542 reasonably fast while producing a much better spread of values than
 543 the old hashing algorithm (originally by Chris Torek, later tweaked by
 544 Ilya Zakharevich).  Hash values output from the algorithm on a hash of
 545 all 3-char printable ASCII keys comes much closer to passing the
 546 DIEHARD random number generation tests.  According to perlbench, this
 547 change has not affected the overall speed of Perl.</p>
 548 </li>
 549 <li>
 550 <p><code>unshift()</code> should now be noticeably faster.</p>
 551 </li>
 552 </ul>
 553 <p>
 554 </p>
 555 <hr />
 556 <h1><a name="utility_changes">Utility Changes</a></h1>
 557 <ul>
 558 <li>
 559 <p>h2xs now produces template README.</p>
 560 </li>
 561 <li>
 562 <p>s2p has been completely rewritten in Perl.  (It is in fact a full
 563 implementation of sed in Perl.)</p>
 564 </li>
 565 <li>
 566 <p>xsubpp now supports OUT keyword.</p>
 567 </li>
 568 </ul>
 569 <p>
 570 </p>
 571 <hr />
 572 <h1><a name="new_documentation">New Documentation</a></h1>
 573 <p>
 574 </p>
 575 <h2><a name="perlclib">perlclib</a></h2>
 576 <p>Internal replacements for standard C library functions.
 577 (Interesting only for extension writers and Perl core hackers.)</p>
 578 <p>
 579 </p>
 580 <h2><a name="perliol">perliol</a></h2>
 581 <p>Internals of PerlIO with layers.</p>
 582 <p>
 583 </p>
 584 <h2><a name="readme_aix">README.aix</a></h2>
 585 <p>Documentation on compiling Perl on AIX has been added.  AIX has
 586 several different C compilers and getting the right patch level
 587 is essential.  On install README.aix will be installed as <a href="file://C|\msysgit\mingw\html/pod/perlaix.html">the perlaix manpage</a>.</p>
 588 <p>
 589 </p>
 590 <h2><a name="readme_bs2000">README.bs2000</a></h2>
 591 <p>Documentation on compiling Perl on the POSIX-BC platform (an EBCDIC
 592 mainframe environment) has been added.</p>
 593 <p>This was formerly known as README.posix-bc but the name was considered
 594 to be too confusing (it has nothing to do with the POSIX module or the
 595 POSIX standard).  On install README.bs2000 will be installed as <a href="file://C|\msysgit\mingw\html/pod/perlbs2000.html">the perlbs2000 manpage</a>.</p>
 596 <p>
 597 </p>
 598 <h2><a name="readme_macos">README.macos</a></h2>
 599 <p>In perl 5.7.1 (and in the 5.6.1) the MacPerl sources have been
 600 synchronised with the standard Perl sources.  To compile MacPerl
 601 some additional steps are required, and this file documents those
 602 steps.  On install README.macos will be installed as <a href="file://C|\msysgit\mingw\html/pod/perlmacos.html">the perlmacos manpage</a>.</p>
 603 <p>
 604 </p>
 605 <h2><a name="readme_mpeix">README.mpeix</a></h2>
 606 <p>The README.mpeix has been podified, which means that this information
 607 about compiling and using Perl on the MPE/iX miniframe platform will
 608 be installed as <a href="file://C|\msysgit\mingw\html/pod/perlmpeix.html">the perlmpeix manpage</a>.</p>
 609 <p>
 610 </p>
 611 <h2><a name="readme_solaris">README.solaris</a></h2>
 612 <p>README.solaris has been created and Solaris wisdom from elsewhere
 613 in the Perl documentation has been collected there.  On install
 614 README.solaris will be installed as <a href="file://C|\msysgit\mingw\html/pod/perlsolaris.html">the perlsolaris manpage</a>.</p>
 615 <p>
 616 </p>
 617 <h2><a name="readme_vos">README.vos</a></h2>
 618 <p>The README.vos has been podified, which means that this information
 619 about compiling and using Perl on the Stratus VOS miniframe platform
 620 will be installed as <a href="file://C|\msysgit\mingw\html/pod/perlvos.html">the perlvos manpage</a>.</p>
 621 <p>
 622 </p>
 623 <h2><a name="porting_repository_pod">Porting/repository.pod</a></h2>
 624 <p>Documentation on how to use the Perl source repository has been added.</p>
 625 <p>
 626 </p>
 627 <hr />
 628 <h1><a name="installation_and_configuration_improvements">Installation and Configuration Improvements</a></h1>
 629 <ul>
 630 <li>
 631 <p>Because PerlIO is now the default on most platforms, ``-perlio'' doesn't
 632 get appended to the $Config{archname} (also known as $^O) anymore.
 633 Instead, if you explicitly choose not to use perlio (Configure command
 634 line option -Uuseperlio), you will get ``-stdio'' appended.</p>
 635 </li>
 636 <li>
 637 <p>Another change related to the architecture name is that ``-64all''
 638 (-Duse64bitall, or ``maximally 64-bit'') is appended only if your
 639 pointers are 64 bits wide.  (To be exact, the use64bitall is ignored.)</p>
 640 </li>
 641 <li>
 642 <p>APPLLIB_EXP, a less-know configuration-time definition, has been
 643 documented.  It can be used to prepend site-specific directories
 644 to Perl's default search path (@INC), see INSTALL for information.</p>
 645 </li>
 646 <li>
 647 <p>Building Berkeley DB3 for compatibility modes for DB, NDBM, and ODBM
 648 has been documented in INSTALL.</p>
 649 </li>
 650 <li>
 651 <p>If you are on IRIX or Tru64 platforms, new profiling/debugging options
 652 have been added, see <a href="file://C|\msysgit\mingw\html/pod/perlhack.html">the perlhack manpage</a> for more information about pixie and
 653 Third Degree.</p>
 654 </li>
 655 </ul>
 656 <p>
 657 </p>
 658 <h2><a name="new_or_improved_platforms">New Or Improved Platforms</a></h2>
 659 <p>For the list of platforms known to support Perl,
 660 see <a href="file://C|\msysgit\mingw\html/pod/perlport.html#supported_platforms">Supported Platforms in the perlport manpage</a>.</p>
 661 <ul>
 662 <li>
 663 <p>AIX dynamic loading should be now better supported.</p>
 664 </li>
 665 <li>
 666 <p>After a long pause, AmigaOS has been verified to be happy with Perl.</p>
 667 </li>
 668 <li>
 669 <p>EBCDIC platforms (z/OS, also known as OS/390, POSIX-BC, and VM/ESA)
 670 have been regained.  Many test suite tests still fail and the
 671 co-existence of Unicode and EBCDIC isn't quite settled, but the
 672 situation is much better than with Perl 5.6.  See <a href="file://C|\msysgit\mingw\html/pod/perlos390.html">the perlos390 manpage</a>,
 673 <a href="file://C|\msysgit\mingw\html/pod/perlbs2000.html">the perlbs2000 manpage</a> (for POSIX-BC), and <a href="file://C|\msysgit\mingw\html/pod/perlvmesa.html">the perlvmesa manpage</a> for more information.</p>
 674 </li>
 675 <li>
 676 <p>Building perl with -Duseithreads or -Duse5005threads now works under
 677 HP-UX 10.20 (previously it only worked under 10.30 or later). You will
 678 need a thread library package installed. See README.hpux.</p>
 679 </li>
 680 <li>
 681 <p>Mac OS Classic (MacPerl has of course been available since
 682 perl 5.004 but now the source code bases of standard Perl
 683 and MacPerl have been synchronised)</p>
 684 </li>
 685 <li>
 686 <p>NCR MP-RAS is now supported.</p>
 687 </li>
 688 <li>
 689 <p>NonStop-UX is now supported.</p>
 690 </li>
 691 <li>
 692 <p>Amdahl UTS is now supported.</p>
 693 </li>
 694 <li>
 695 <p>z/OS (formerly known as OS/390, formerly known as MVS OE) has now
 696 support for dynamic loading.  This is not selected by default,
 697 however, you must specify -Dusedl in the arguments of Configure.</p>
 698 </li>
 699 </ul>
 700 <p>
 701 </p>
 702 <h2><a name="generic_improvements">Generic Improvements</a></h2>
 703 <ul>
 704 <li>
 705 <p>Configure no longer includes the DBM libraries (dbm, gdbm, db, ndbm)
 706 when building the Perl binary.  The only exception to this is SunOS 4.x,
 707 which needs them.</p>
 708 </li>
 709 <li>
 710 <p>Some new Configure symbols, useful for extension writers:</p>
 711 <dl>
 712 <dt><strong><a name="item_d_cmsghdr">d_cmsghdr</a></strong>
 713
 714 <dd>
 715 <p>For struct cmsghdr.</p>
 716 </dd>
 717 </li>
 718 <dt><strong><a name="item_d_fcntl_can_lock">d_fcntl_can_lock</a></strong>
 719
 720 <dd>
 721 <p>Whether <code>fcntl()</code> can be used for file locking.</p>
 722 </dd>
 723 </li>
 724 <dt><strong><a name="item_d_fsync">d_fsync</a></strong>
 725
 726 <dt><strong><a name="item_d_getitimer">d_getitimer</a></strong>
 727
 728 <dt><strong><a name="item_d_getpagsz">d_getpagsz</a></strong>
 729
 730 <dd>
 731 <p>For getpagesize(), though you should prefer POSIX::sysconf(_SC_PAGE_SIZE))</p>
 732 </dd>
 733 </li>
 734 <dt><strong><a name="item_d_msghdr_s">d_msghdr_s</a></strong>
 735
 736 <dd>
 737 <p>For struct msghdr.</p>
 738 </dd>
 739 </li>
 740 <dt><strong><a name="item_need_va_copy">need_va_copy</a></strong>
 741
 742 <dd>
 743 <p>Whether one needs to use <code>Perl_va_copy()</code> to copy varargs.</p>
 744 </dd>
 745 </li>
 746 <dt><strong><a name="item_d_readv">d_readv</a></strong>
 747
 748 <dt><strong><a name="item_d_recvmsg">d_recvmsg</a></strong>
 749
 750 <dt><strong><a name="item_d_sendmsg">d_sendmsg</a></strong>
 751
 752 <dt><strong><a name="item_sig_size">sig_size</a></strong>
 753
 754 <dd>
 755 <p>The number of elements in an array needed to hold all the available signals.</p>
 756 </dd>
 757 </li>
 758 <dt><strong><a name="item_d_sockatmark">d_sockatmark</a></strong>
 759
 760 <dt><strong><a name="item_d_strtoq">d_strtoq</a></strong>
 761
 762 <dt><strong><a name="item_d_u32align">d_u32align</a></strong>
 763
 764 <dd>
 765 <p>Whether one needs to access character data aligned by U32 sized pointers.</p>
 766 </dd>
 767 </li>
 768 <dt><strong><a name="item_d_ualarm">d_ualarm</a></strong>
 769
 770 <dt><strong><a name="item_d_usleep">d_usleep</a></strong>
 771
 772 </dl>
 773 <li>
 774 <p>Removed Configure symbols: the PDP-11 memory model settings: huge,
 775 large, medium, models.</p>
 776 </li>
 777 <li>
 778 <p>SOCKS support is now much more robust.</p>
 779 </li>
 780 <li>
 781 <p>If your file system supports symbolic links you can build Perl outside
 782 of the source directory by</p>
 783 <pre>
 784         mkdir perl/build/directory
 785         cd perl/build/directory
 786         sh /path/to/perl/source/Configure -Dmksymlinks ...</pre>
 787 <p>This will create in perl/build/directory a tree of symbolic links
 788 pointing to files in /path/to/perl/source.  The original files are left
 789 unaffected.  After Configure has finished you can just say</p>
 790 <pre>
 791         make all test</pre>
 792 <p>and Perl will be built and tested, all in perl/build/directory.</p>
 793 </li>
 794 </ul>
 795 <p>
 796 </p>
 797 <hr />
 798 <h1><a name="selected_bug_fixes">Selected Bug Fixes</a></h1>
 799 <p>Numerous memory leaks and uninitialized memory accesses have been hunted down.
 800 Most importantly anonymous subs used to leak quite a bit.</p>
 801 <ul>
 802 <li>
 803 <p><a href="file://C|\msysgit\mingw\html/pod/perlfunc.html#item_chop"><code>chop(@list)</code></a> in list context returned the characters chopped in
 804 reverse order.  This has been reversed to be in the right order.</p>
 805 </li>
 806 <li>
 807 <p>The order of DESTROYs has been made more predictable.</p>
 808 </li>
 809 <li>
 810 <p><a href="file://C|\msysgit\mingw\html/pod/perlfunc.html#item_mkdir"><code>mkdir()</code></a> now ignores trailing slashes in the directory name,
 811 as mandated by POSIX.</p>
 812 </li>
 813 <li>
 814 <p>Attributes (like :shared) didn't work with our().</p>
 815 </li>
 816 <li>
 817 <p>The PERL5OPT environment variable (for passing command line arguments
 818 to Perl) didn't work for more than a single group of options.</p>
 819 </li>
 820 <li>
 821 <p>The tainting behaviour of <code>sprintf()</code> has been rationalized.  It does
 822 not taint the result of floating point formats anymore, making the
 823 behaviour consistent with that of string interpolation.</p>
 824 </li>
 825 <li>
 826 <p>All but the first argument of the IO <a href="file://C|\msysgit\mingw\html/pod/perlfunc.html#item_syswrite"><code>syswrite()</code></a> method are now optional.</p>
 827 </li>
 828 <li>
 829 <p>Tie::ARRAY SPLICE method was broken.</p>
 830 </li>
 831 <li>
 832 <p><code>vec()</code> now tries to work with characters &lt;= 255 when possible, but it leaves
 833 higher character values in place.  In that case, if <code>vec()</code> was used to modify
 834 the string, it is no longer considered to be utf8-encoded.</p>
 835 </li>
 836 </ul>
 837 <p>
 838 </p>
 839 <h2><a name="platform_specific_changes_and_fixes">Platform Specific Changes and Fixes</a></h2>
 840 <ul>
 841 <li>
 842 <p>Linux previously had problems related to sockaddrlen when using
 843 accept(), <code>revcfrom()</code> (in Perl: recv()), getpeername(), and getsockname().</p>
 844 </li>
 845 <li>
 846 <p>Previously DYNIX/ptx had problems in its Configure probe for non-blocking I/O.</p>
 847 </li>
 848 <li>
 849 <p>Windows</p>
 850 <ul>
 851 <li>
 852 <p>Borland C++ v5.5 is now a supported compiler that can build Perl.
 853 However, the generated binaries continue to be incompatible with those
 854 generated by the other supported compilers (GCC and Visual C++).</p>
 855 </li>
 856 <li>
 857 <p>Win32::GetCwd() correctly returns C:\ instead of C: when at the drive root.
 858 Other bugs in <a href="file://C|\msysgit\mingw\html/pod/perlfunc.html#item_chdir"><code>chdir()</code></a> and Cwd::cwd() have also been fixed.</p>
 859 </li>
 860 <li>
 861 <p>Duping socket handles with open(F, ``&gt;&amp;MYSOCK'') now works under Windows 9x.</p>
 862 </li>
 863 <li>
 864 <p>HTML files will be installed in c:\perl\html instead of c:\perl\lib\pod\html</p>
 865 </li>
 866 <li>
 867 <p>The makefiles now provide a single switch to bulk-enable all the features
 868 enabled in ActiveState ActivePerl (a popular binary distribution).</p>
 869 </li>
 870 </ul>
 871 </ul>
 872 <p>
 873 </p>
 874 <hr />
 875 <h1><a name="new_or_changed_diagnostics">New or Changed Diagnostics</a></h1>
 876 <p>Two new debugging options have been added: if you have compiled your
 877 Perl with debugging, you can use the -DT and -DR options to trace
 878 tokenising and to add reference counts to displaying variables,
 879 respectively.</p>
 880 <ul>
 881 <li>
 882 <p>If an attempt to use a (non-blessed) reference as an array index
 883 is made, a warning is given.</p>
 884 </li>
 885 <li>
 886 <p><code>push @a;</code> and <code>unshift @a;</code> (with no values to push or unshift)
 887 now give a warning.  This may be a problem for generated and evaled
 888 code.</p>
 889 </li>
 890 </ul>
 891 <p>
 892 </p>
 893 <hr />
 894 <h1><a name="changed_internals">Changed Internals</a></h1>
 895 <ul>
 896 <li>
 897 <p>Some new APIs: ptr_table_clear(), ptr_table_free(), sv_setref_uv().
 898 For the full list of the available APIs see <a href="file://C|\msysgit\mingw\html/pod/perlapi.html">the perlapi manpage</a>.</p>
 899 </li>
 900 <li>
 901 <p>dTHR and djSP have been obsoleted; the former removed (because it's
 902 a no-op) and the latter replaced with dSP.</p>
 903 </li>
 904 <li>
 905 <p>Perl now uses system malloc instead of Perl malloc on all 64-bit
 906 platforms, and even in some not-always-64-bit platforms like AIX,
 907 IRIX, and Solaris.  This change breaks backward compatibility but
 908 Perl's malloc has problems with large address spaces and also the
 909 speed of vendors' malloc is generally better in large address space
 910 machines (Perl's malloc is mostly tuned for space).</p>
 911 </li>
 912 </ul>
 913 <p>
 914 </p>
 915 <hr />
 916 <h1><a name="new_tests">New Tests</a></h1>
 917 <p>Many new tests have been added.  The most notable is probably the
 918 lib/1_compile: it is very notable because running it takes quite a
 919 long time -- it test compiles all the Perl modules in the distribution.
 920 Please be patient.</p>
 921 <p>
 922 </p>
 923 <hr />
 924 <h1><a name="known_problems">Known Problems</a></h1>
 925 <p>Note that unlike other sections in this document (which describe
 926 changes since 5.7.0) this section is cumulative containing known
 927 problems for all the 5.7 releases.</p>
 928 <p>
 929 </p>
 930 <h2><a name="aix_vac_5_0_0_0_may_produce_buggy_code_for_perl">AIX vac 5.0.0.0 May Produce Buggy Code For Perl</a></h2>
 931 <p>The AIX C compiler vac version 5.0.0.0 may produce buggy code,
 932 resulting in few random tests failing, but when the failing tests
 933 are run by hand, they succeed.  We suggest upgrading to at least
 934 vac version 5.0.1.0, that has been known to compile Perl correctly.
 935 ``lslpp -L|grep vac.C'' will tell you the vac version.</p>
 936 <p>
 937 </p>
 938 <h2><a name="lib_ftmpsecurity_tests_warn__system_possibly_insecure_">lib/ftmp-security tests warn 'system possibly insecure'</a></h2>
 939 <p>Don't panic.  Read INSTALL 'make test' section instead.</p>
 940 <p>
 941 </p>
 942 <h2><a name="lib_io_multihomed_fails_in_lp64configured_hpux">lib/io_multihomed Fails In LP64-Configured HP-UX</a></h2>
 943 <p>The lib/io_multihomed test may hang in HP-UX if Perl has been
 944 configured to be 64-bit. Because other 64-bit platforms do not hang in
 945 this test, HP-UX is suspect. All other tests pass in 64-bit HP-UX. The
 946 test attempts to create and connect to ``multihomed'' sockets (sockets
 947 which have multiple IP addresses).</p>
 948 <p>
 949 </p>
 950 <h2><a name="test_lib_posix_subtest_9_fails_in_lp64configured_hpux">Test lib/posix Subtest 9 Fails In LP64-Configured HP-UX</a></h2>
 951 <p>If perl is configured with -Duse64bitall, the successful result of the
 952 subtest 10 of lib/posix may arrive before the successful result of the
 953 subtest 9, which confuses the test harness so much that it thinks the
 954 subtest 9 failed.</p>
 955 <p>
 956 </p>
 957 <h2><a name="lib_b_test_19">lib/b test 19</a></h2>
 958 <p>The test fails on various platforms (PA64 and IA64 are known), but the
 959 exact cause is still being investigated.</p>
 960 <p>
 961 </p>
 962 <h2><a name="linux_with_sfio_fails_op_misc_test_48">Linux With Sfio Fails op/misc Test 48</a></h2>
 963 <p>No known fix.</p>
 964 <p>
 965 </p>
 966 <h2><a name="sigaction_test_13_in_vms">sigaction test 13 in VMS</a></h2>
 967 <p>The test is known to fail; whether it's because of VMS of because
 968 of faulty test is not known.</p>
 969 <p>
 970 </p>
 971 <h2><a name="sprintf_tests_129_and_130">sprintf tests 129 and 130</a></h2>
 972 <p>The op/sprintf tests 129 and 130 are known to fail on some platforms.
 973 Examples include any platform using sfio, and Compaq/Tandem's NonStop-UX.
 974 The failing platforms do not comply with the ANSI C Standard, line
 975 19ff on page 134 of ANSI X3.159 1989 to be exact.  (They produce
 976 something else than ``1'' and ``-1'' when formatting 0.6 and -0.6 using
 977 the printf format ``%.0f'', most often they produce ``0'' and ``-0''.)</p>
 978 <p>
 979 </p>
 980 <h2><a name="failure_of_thread_tests">Failure of Thread tests</a></h2>
 981 <p>The subtests 19 and 20 of lib/thr5005.t test are known to fail due to
 982 fundamental problems in the 5.005 threading implementation. These are
 983 not new failures--Perl 5.005_0x has the same bugs, but didn't have
 984 these tests. (Note that support for 5.005-style threading remains
 985 experimental.)</p>
 986 <p>
 987 </p>
 988 <h2><a name="localising_a_tied_variable_leaks_memory">Localising a Tied Variable Leaks Memory</a></h2>
 989 <pre>
 990     use Tie::Hash;
 991     tie my %tie_hash =&gt; 'Tie::StdHash';</pre>
 992 <pre>
 993     ...</pre>
 994 <pre>
 995     local($tie_hash{Foo}) = 1; # leaks</pre>
 996 <p>Code like the above is known to leak memory every time the <code>local()</code>
 997 is executed.</p>
 998 <p>
 999 </p>
1000 <h2><a name="selftying_of_arrays_and_hashes_is_forbidden">Self-tying of Arrays and Hashes Is Forbidden</a></h2>
1001 <p>Self-tying of arrays and hashes is broken in rather deep and
1002 hard-to-fix ways.  As a stop-gap measure to avoid people from getting
1003 frustrated at the mysterious results (core dumps, most often) it is
1004 for now forbidden (you will get a fatal error even from an attempt).</p>
1005 <p>
1006 </p>
1007 <h2><a name="building_extensions_can_fail_because_of_largefiles">Building Extensions Can Fail Because Of Largefiles</a></h2>
1008 <p>Some extensions like mod_perl are known to have issues with
1009 `largefiles', a change brought by Perl 5.6.0 in which file offsets
1010 default to 64 bits wide, where supported.  Modules may fail to compile
1011 at all or compile and work incorrectly.  Currently there is no good
1012 solution for the problem, but Configure now provides appropriate
1013 non-largefile ccflags, ldflags, libswanted, and libs in the %Config
1014 hash (e.g., $Config{ccflags_nolargefiles}) so the extensions that are
1015 having problems can try configuring themselves without the
1016 largefileness.  This is admittedly not a clean solution, and the
1017 solution may not even work at all.  One potential failure is whether
1018 one can (or, if one can, whether it's a good idea) link together at
1019 all binaries with different ideas about file offsets, all this is
1020 platform-dependent.</p>
1021 <p>
1022 </p>
1023 <h2><a name="the_compiler_suite_is_still_experimental">The Compiler Suite Is Still Experimental</a></h2>
1024 <p>The compiler suite is slowly getting better but is nowhere near
1025 working order yet.</p>
1026 <p>
1027 </p>
1028 <hr />
1029 <h1><a name="reporting_bugs">Reporting Bugs</a></h1>
1030 <p>If you find what you think is a bug, you might check the articles
1031 recently posted to the comp.lang.perl.misc newsgroup and the perl
1032 bug database at <a href="http://bugs.perl.org/">http://bugs.perl.org/</a>  There may also be
1033 information at <a href="http://www.perl.com/perl/">http://www.perl.com/perl/</a> , the Perl Home Page.</p>
1034 <p>If you believe you have an unreported bug, please run the <strong>perlbug</strong>
1035 program included with your release.  Be sure to trim your bug down
1036 to a tiny but sufficient test case.  Your bug report, along with the
1037 output of <code>perl -V</code>, will be sent off to <a href="mailto:perlbug@perl.org">perlbug@perl.org</a> to be
1038 analysed by the Perl porting team.</p>
1039 <p>
1040 </p>
1041 <hr />
1042 <h1><a name="see_also">SEE ALSO</a></h1>
1043 <p>The <em>Changes</em> file for exhaustive details on what changed.</p>
1044 <p>The <em>INSTALL</em> file for how to build Perl.</p>
1045 <p>The <em>README</em> file for general stuff.</p>
1046 <p>The <em>Artistic</em> and <em>Copying</em> files for copyright information.</p>
1047 <p>
1048 </p>
1049 <hr />
1050 <h1><a name="history">HISTORY</a></h1>
1051 <p>Written by Jarkko Hietaniemi &lt;<em><a href="mailto:jhi@iki.fi">jhi@iki.fi</a></em>&gt;, with many contributions
1052 from The Perl Porters and Perl Users submitting feedback and patches.</p>
1053 <p>Send omissions or corrections to &lt;<em><a href="mailto:perlbug@perl.org">perlbug@perl.org</a></em>&gt;.</p>
1054 <table border="0" width="100%" cellspacing="0" cellpadding="3">
1055 <tr><td class="block" style="background-color: #cccccc" valign="middle">
1056 <big><strong><span class="block">&nbsp;perl571delta - what's new for perl v5.7.1</span></strong></big>
1057 </td></tr>
1058 </table>
1059
1060 </body>
1061
1062 </html>