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1 | =head1 NAME |
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2 | |
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3 | perldelta - what is new for perl v5.8.0 |
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4 | |
5 | =head1 DESCRIPTION |
6 | |
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7 | This document describes differences between the 5.6.0 release |
8 | and the 5.8.0 release. |
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9 | |
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10 | Many of the bug fixes in 5.8.0 were already seen in the 5.6.1 |
11 | maintenance release since the two releases were kept closely |
12 | coordinated. |
13 | |
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14 | If you are upgrading from Perl 5.005_03, you might also want |
15 | to read L<perl56delta>. |
16 | |
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17 | =head1 Highlights In 5.8.0 |
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18 | |
19 | =over 4 |
20 | |
21 | =item * |
22 | |
23 | Better Unicode support |
24 | |
25 | =item * |
26 | |
27 | New Thread Implementation |
28 | |
29 | =item * |
30 | |
31 | Many New Modules |
32 | |
33 | =item * |
34 | |
35 | Better Numeric Accuracy |
36 | |
37 | =item * |
38 | |
39 | Safe Signals |
40 | |
41 | =item * |
42 | |
43 | More Extensive Regression Testing |
44 | |
45 | =back |
46 | |
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47 | =head1 Incompatible Changes |
48 | |
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49 | =head2 64-bit platforms and malloc |
50 | |
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51 | If your pointers are 64 bits wide, the Perl malloc is no longer being |
c2e23569 |
52 | used because it does not work well with 8-byte pointers. Also, |
61947107 |
53 | usually the system mallocs on such platforms are much better optimized |
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54 | for such large memory models than the Perl malloc. Some memory-hungry |
55 | Perl applications like the PDL don't work well with Perl's malloc. |
56 | Finally, other applications than Perl (like modperl) tend to prefer |
57 | the system malloc. Such platforms include Alpha and 64-bit HPPA, |
58 | MIPS, PPC, and Sparc. |
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59 | |
60 | =head2 AIX Dynaloading |
61 | |
62 | The AIX dynaloading now uses in AIX releases 4.3 and newer the native |
63 | dlopen interface of AIX instead of the old emulated interface. This |
64 | change will probably break backward compatibility with compiled |
65 | modules. The change was made to make Perl more compliant with other |
66 | applications like modperl which are using the AIX native interface. |
67 | |
68 | =head2 Socket Extension Dynamic in VMS |
69 | |
70 | The Socket extension is now dynamically loaded instead of being |
71 | statically built in. This may or may not be a problem with ancient |
72 | TCP/IP stacks of VMS: we do not know since we weren't able to test |
73 | Perl in such configurations. |
74 | |
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75 | =head2 IEEE-format Floating Point Default on OpenVMS Alpha |
76 | |
77 | Perl now uses IEEE format (T_FLOAT) as the default internal floating |
78 | point format on OpenVMS Alpha, potentially breaking binary compatibility |
79 | with external libraries or existing data. G_FLOAT is still available as |
80 | a configuration option. The default on VAX (D_FLOAT) has not changed. |
81 | |
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82 | =head2 Different Definition of the Unicode Character Classes \p{In...} |
83 | |
84 | As suggested by the Unicode consortium, the Unicode character classes |
85 | now prefer I<scripts> as opposed to I<blocks> (as defined by Unicode); |
86 | in Perl, when the C<\p{In....}> and the C<\p{In....}> regular expression |
87 | constructs are used. This has changed the definition of some of those |
88 | character classes. |
89 | |
90 | The difference between scripts and blocks is that scripts are the |
91 | glyphs used by a language or a group of languages, while the blocks |
92 | are more artificial groupings of 256 characters based on the Unicode |
93 | numbering. |
94 | |
95 | In general this change results in more inclusive Unicode character |
96 | classes, but changes to the other direction also do take place: |
97 | for example while the script C<Latin> includes all the Latin |
98 | characters and their various diacritic-adorned versions, it |
99 | does not include the various punctuation or digits (since they |
100 | are not solely C<Latin>). |
101 | |
102 | Changes in the character class semantics may have happened if a script |
103 | and a block happen to have the same name, for example C<Hebrew>. |
104 | In such cases the script wins and C<\p{InHebrew}> now means the script |
105 | definition of Hebrew. The block definition in still available, |
106 | though, by appending C<Block> to the name: C<\p{InHebrewBlock}> means |
107 | what C<\p{InHebrew}> meant in perl 5.6.0. For the full list |
108 | of affected character classes, see L<perlunicode/Blocks>. |
109 | |
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110 | =head2 Perl Parser Stress Tested |
111 | |
112 | The Perl parser has been stress tested using both random input and |
113 | Markov chain input and the few found crashes and lockups have been |
114 | fixed. |
115 | |
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116 | =head2 REF(...) Instead Of SCALAR(...) |
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117 | |
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118 | A reference to a reference now stringifies as "REF(0x81485ec)" instead |
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119 | of "SCALAR(0x81485ec)" in order to be more consistent with the return |
120 | value of ref(). |
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121 | |
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122 | =head2 Deprecations |
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123 | |
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124 | =over 4 |
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125 | |
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126 | =item * |
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127 | |
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128 | The semantics of bless(REF, REF) were unclear and until someone proves |
129 | it to make some sense, it is forbidden. |
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130 | |
131 | =item * |
132 | |
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133 | The obsolete chat2 library that should never have been allowed |
134 | to escape the laboratory has been decommissioned. |
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135 | |
136 | =item * |
137 | |
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138 | The very dusty examples in the eg/ directory have been removed. |
139 | Suggestions for new shiny examples welcome but the main issue is that |
140 | the examples need to be documented, tested and (most importantly) |
141 | maintained. |
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142 | |
143 | =item * |
144 | |
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145 | The (bogus) escape sequences \8 and \9 now give an optional warning |
146 | ("Unrecognized escape passed through"). There is no need to \-escape |
147 | any C<\w> character. |
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148 | |
149 | =item * |
150 | |
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151 | The list of filenames from glob() (or <...>) is now by default sorted |
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152 | alphabetically to be csh-compliant (which is what happened before |
153 | in most UNIX platforms). (bsd_glob() does still sort platform |
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154 | natively, ASCII or EBCDIC, unless GLOB_ALPHASORT is specified.) |
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155 | |
156 | =item * |
157 | |
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158 | Spurious syntax errors generated in certain situations, when glob() |
159 | caused File::Glob to be loaded for the first time, have been fixed. |
160 | |
161 | =item * |
162 | |
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163 | Although "you shouldn't do that", it was possible to write code that |
164 | depends on Perl's hashed key order (Data::Dumper does this). The new |
165 | algorithm "One-at-a-Time" produces a different hashed key order. |
166 | More details are in L</"Performance Enhancements">. |
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167 | |
168 | =item * |
169 | |
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170 | lstat(FILEHANDLE) now gives a warning because the operation makes no sense. |
171 | In future releases this may become a fatal error. |
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172 | |
173 | =item * |
174 | |
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175 | The C<package;> syntax (C<package> without an argument) has been |
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176 | deprecated. Its semantics were never that clear and its |
177 | implementation even less so. If you have used that feature to |
178 | disallow all but fully qualified variables, C<use strict;> instead. |
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179 | |
180 | =item * |
181 | |
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182 | The unimplemented POSIX regex features [[.cc.]] and [[=c=]] are still |
183 | recognised but now cause fatal errors. The previous behaviour of |
184 | ignoring them by default and warning if requested was unacceptable |
185 | since it, in a way, falsely promised that the features could be used. |
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186 | |
187 | =item * |
188 | |
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189 | The current user-visible implementation of pseudo-hashes (the weird |
190 | use of the first array element) is deprecated starting from Perl 5.8.0 |
191 | and will be removed in Perl 5.10.0, and the feature will be |
192 | implemented differently. Not only is the current interface rather |
193 | ugly, but the current implementation slows down normal array and hash |
194 | use quite noticeably. The C<fields> pragma interface will remain |
195 | available. |
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196 | |
197 | =item * |
198 | |
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199 | The syntaxes C<< @a->[...] >> and C<< %h->{...} >> have now been deprecated. |
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200 | |
201 | =item * |
202 | |
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203 | After years of trying the suidperl is considered to be too complex to |
204 | ever be considered truly secure. The suidperl functionality is likely |
205 | to be removed in a future release. |
206 | |
207 | =item * |
208 | |
209 | The long deprecated uppercase aliases for the string comparison |
210 | operators (EQ, NE, LT, LE, GE, GT) have now been removed. |
211 | |
212 | =item * |
213 | |
214 | The tr///C and tr///U features have been removed and will not return; |
215 | the interface was a mistake. Sorry about that. For similar |
216 | functionality, see pack('U0', ...) and pack('C0', ...). |
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217 | |
218 | =back |
219 | |
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220 | =head1 Core Enhancements |
221 | |
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222 | =head2 PerlIO is Now The Default |
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223 | |
224 | =over 4 |
225 | |
226 | =item * |
227 | |
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228 | IO is now by default done via PerlIO rather than system's "stdio". |
229 | PerlIO allows "layers" to be "pushed" onto a file handle to alter the |
230 | handle's behaviour. Layers can be specified at open time via 3-arg |
231 | form of open: |
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232 | |
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233 | open($fh,'>:crlf :utf8', $path) || ... |
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234 | |
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235 | or on already opened handles via extended C<binmode>: |
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236 | |
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237 | binmode($fh,':encoding(iso-8859-7)'); |
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238 | |
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239 | The built-in layers are: unix (low level read/write), stdio (as in |
240 | previous Perls), perlio (re-implementation of stdio buffering in a |
241 | portable manner), crlf (does CRLF <=> "\n" translation as on Win32, |
242 | but available on any platform). A mmap layer may be available if |
243 | platform supports it (mostly UNIXes). |
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244 | |
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245 | Layers to be applied by default may be specified via the 'open' pragma. |
246 | |
247 | See L</"Installation and Configuration Improvements"> for the effects |
248 | of PerlIO on your architecture name. |
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249 | |
250 | =item * |
251 | |
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252 | File handles can be marked as accepting Perl's internal encoding of Unicode |
253 | (UTF-8 or UTF-EBCDIC depending on platform) by a pseudo layer ":utf8" : |
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254 | |
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255 | open($fh,">:utf8","Uni.txt"); |
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256 | |
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257 | Note for EBCDIC users: the pseudo layer ":utf8" is erroneously named |
258 | for you since it's not UTF-8 what you will be getting but instead |
259 | UTF-EBCDIC. See L<perlunicode>, L<utf8>, and |
260 | http://www.unicode.org/unicode/reports/tr16/ for more information. |
261 | In future releases this naming may change. |
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262 | |
263 | =item * |
264 | |
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265 | File handles can translate character encodings from/to Perl's internal |
266 | Unicode form on read/write via the ":encoding()" layer. |
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267 | |
268 | =item * |
269 | |
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270 | File handles can be opened to "in memory" files held in Perl scalars via: |
271 | |
272 | open($fh,'>', \$variable) || ... |
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273 | |
274 | =item * |
275 | |
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276 | Anonymous temporary files are available without need to |
277 | 'use FileHandle' or other module via |
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278 | |
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279 | open($fh,"+>", undef) || ... |
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280 | |
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281 | That is a literal undef, not an undefined value. |
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282 | |
283 | =item * |
284 | |
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285 | The list form of C<open> is now implemented for pipes (at least on UNIX): |
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286 | |
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287 | open($fh,"-|", 'cat', '/etc/motd') |
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288 | |
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289 | creates a pipe, and runs the equivalent of exec('cat', '/etc/motd') in |
290 | the child process. |
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291 | |
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292 | =back |
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293 | |
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294 | =head2 Signals Are Now Safe |
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295 | |
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296 | Perl used to be fragile in that signals arriving at inopportune moments |
297 | could corrupt Perl's internal state. Now Perl postpones handling of |
298 | signals until it's safe. |
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299 | |
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300 | =head2 Unicode Overhaul |
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301 | |
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302 | Unicode in general should be now much more usable than in Perl 5.6.0 |
303 | (or even in 5.6.1). Unicode can be used in hash keys, Unicode in |
304 | regular expressions should work now, Unicode in tr/// should work now, |
305 | Unicode in I/O should work now. |
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306 | |
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307 | =over 4 |
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308 | |
309 | =item * |
310 | |
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311 | The Unicode Character Database coming with Perl has been upgraded |
312 | to Unicode 3.1.1. For more information, see http://www.unicode.org/. |
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313 | |
314 | =item * |
315 | |
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316 | For developers interested in enhancing Perl's Unicode capabilities: |
317 | almost all the UCD files are included with the Perl distribution in |
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318 | the lib/unicore subdirectory. The most notable omission, for space |
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319 | considerations, is the Unihan database. |
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320 | |
321 | =item * |
322 | |
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323 | The Unicode character classes \p{Blank} and \p{SpacePerl} have been |
324 | added. "Blank" is like C isblank(), that is, it contains only |
325 | "horizontal whitespace" (the space character is, the newline isn't), |
326 | and the "SpacePerl" is the Unicode equivalent of C<\s> (\p{Space} |
327 | isn't, since that includes the vertical tabulator character, whereas |
328 | C<\s> doesn't.) |
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329 | |
330 | =back |
331 | |
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332 | =head2 Understanding of Numbers |
333 | |
334 | In general a lot of fixing has happened in the area of Perl's |
335 | understanding of numbers, both integer and floating point. Since in |
336 | many systems the standard number parsing functions like C<strtoul()> |
337 | and C<atof()> seem to have bugs, Perl tries to work around their |
338 | deficiencies. This results hopefully in more accurate numbers. |
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339 | |
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340 | Perl now tries internally to use integer values in numeric conversions |
341 | and basic arithmetics (+ - * /) if the arguments are integers, and |
342 | tries also to keep the results stored internally as integers. |
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343 | This change leads to often slightly faster and always less lossy |
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344 | arithmetics. (Previously Perl always preferred floating point numbers |
345 | in its math.) |
346 | |
347 | =head2 Miscellaneous Enhancements |
348 | |
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349 | =over 4 |
350 | |
351 | =item * |
352 | |
e1f170bd |
353 | AUTOLOAD is now lvaluable, meaning that you can add the :lvalue attribute |
354 | to AUTOLOAD subroutines and you can assign to the AUTOLOAD return value. |
355 | |
356 | =item * |
357 | |
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358 | C<perl -d:Module=arg,arg,arg> now works (previously one couldn't pass |
359 | in multiple arguments.) |
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360 | |
361 | =item * |
362 | |
61947107 |
363 | END blocks are now run even if you exit/die in a BEGIN block. |
364 | Internally, the execution of END blocks is now controlled by |
365 | PL_exit_flags & PERL_EXIT_DESTRUCT_END. This enables the new |
366 | behaviour for Perl embedders. This will default in 5.10. See |
367 | L<perlembed>. |
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368 | |
369 | =item * |
370 | |
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371 | Formats now support zero-padded decimal fields. |
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372 | |
373 | =item * |
374 | |
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375 | Lvalue subroutines can now return C<undef> in list context. |
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376 | However, the lvalue subroutine feature still remains experimental. |
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377 | |
378 | =item * |
379 | |
61947107 |
380 | A new special regular expression variable has been introduced: |
381 | C<$^N>, which contains the most-recently closed group (submatch). |
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382 | |
383 | =item * |
384 | |
61947107 |
385 | C<no Module;> now works even if there is no "sub unimport" in the Module. |
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386 | |
387 | =item * |
388 | |
61947107 |
389 | The numerical comparison operators return C<undef> if either operand |
390 | is a NaN. Previously the behaviour was unspecified. |
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391 | |
392 | =item * |
393 | |
e1f170bd |
394 | The following builtin functions are now overridable: each(), keys(), |
395 | pop(), push(), shift(), splice(), unshift(). |
396 | |
397 | =item * |
398 | |
61947107 |
399 | C<pack('U0a*', ...)> can now be used to force a string to UTF8. |
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400 | |
401 | =item * |
402 | |
61947107 |
403 | my __PACKAGE__ $obj now works. |
f39f21d8 |
404 | |
405 | =item * |
406 | |
e1f170bd |
407 | The printf() and sprintf() now support parameter reordering using the |
408 | C<%\d+\$> and C<*\d+\$> syntaxes. For example |
409 | |
410 | print "%2\$s %1\$s\n", "foo", "bar"; |
411 | |
da6838c8 |
412 | will print "bar foo\n". This feature helps in writing |
413 | internationalised software, and in general when the order |
414 | of the parameters can vary. |
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415 | |
416 | =item * |
417 | |
e1f170bd |
418 | prototype(\&) is now available. |
61947107 |
419 | |
420 | =item * |
421 | |
e1f170bd |
422 | prototype(\[$@%&]) is now available to implicitly create references |
423 | (useful for example if you want to emulate the tie() interface). |
61947107 |
424 | |
425 | =item * |
426 | |
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427 | untie() will now call an UNTIE() hook if it exists. See L<perltie> |
428 | for details. |
61947107 |
429 | |
430 | =item * |
431 | |
432 | L<utime> now supports C<utime undef, undef, @files> to change the |
433 | file timestamps to the current time. |
434 | |
435 | =item * |
436 | |
e1f170bd |
437 | The rules for allowing underscores (underbars) in numeric constants |
438 | have been relaxed and simplified: now you can have an underscore |
439 | simply B<between digits>. |
f39f21d8 |
440 | |
441 | =back |
442 | |
77c8cf41 |
443 | =head1 Modules and Pragmata |
f39f21d8 |
444 | |
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445 | =head2 New Modules and Pragmata |
f39f21d8 |
446 | |
447 | =over 4 |
448 | |
449 | =item * |
450 | |
61947107 |
451 | C<Attribute::Handlers> allows a class to define attribute handlers. |
f39f21d8 |
452 | |
61947107 |
453 | package MyPack; |
454 | use Attribute::Handlers; |
455 | sub Wolf :ATTR(SCALAR) { print "howl!\n" } |
f39f21d8 |
456 | |
61947107 |
457 | # later, in some package using or inheriting from MyPack... |
f39f21d8 |
458 | |
61947107 |
459 | my MyPack $Fluffy : Wolf; # the attribute handler Wolf will be called |
ba370e9b |
460 | |
61947107 |
461 | Both variables and routines can have attribute handlers. Handlers can |
462 | be specific to type (SCALAR, ARRAY, HASH, or CODE), or specific to the |
463 | exact compilation phase (BEGIN, CHECK, INIT, or END). |
f39f21d8 |
464 | |
61947107 |
465 | =item * |
f39f21d8 |
466 | |
61947107 |
467 | B<B::Concise> is a new compiler backend for walking the Perl syntax |
468 | tree, printing concise info about ops, from Stephen McCamant. The |
469 | output is highly customisable. See L<B::Concise>. |
f39f21d8 |
470 | |
471 | =item * |
472 | |
61947107 |
473 | C<Class::ISA> for reporting the search path for a class's ISA tree, |
474 | by Sean Burke, has been added. See L<Class::ISA>. |
f39f21d8 |
475 | |
476 | =item * |
477 | |
61947107 |
478 | C<Cwd> has now a split personality: if possible, an XS extension is |
479 | used, (this will hopefully be faster, more secure, and more robust) |
480 | but if not possible, the familiar Perl implementation is used. |
f39f21d8 |
481 | |
482 | =item * |
483 | |
e1f170bd |
484 | C<Devel::PPPort>, originally from Kenneth Albanowski and now |
485 | maintained by Paul Marquess, has been added. It is primarily used |
486 | by C<h2xs> to enhance portability of of XS modules between different |
487 | versions of Perl. |
1e13d81f |
488 | |
489 | =item * |
490 | |
61947107 |
491 | C<Digest>, frontend module for calculating digests (checksums), from |
492 | Gisle Aas, has been added. See L<Digest>. |
f39f21d8 |
493 | |
494 | =item * |
495 | |
61947107 |
496 | C<Digest::MD5> for calculating MD5 digests (checksums) as defined in |
497 | RFC 1321, from Gisle Aas, has been added. See L<Digest::MD5>. |
f39f21d8 |
498 | |
499 | use Digest::MD5 'md5_hex'; |
500 | |
501 | $digest = md5_hex("Thirsty Camel"); |
502 | |
503 | print $digest, "\n"; # 01d19d9d2045e005c3f1b80e8b164de1 |
504 | |
61947107 |
505 | NOTE: the C<MD5> backward compatibility module is deliberately not |
e1f170bd |
506 | included since its further use is discouraged. |
f39f21d8 |
507 | |
f39f21d8 |
508 | =item * |
509 | |
61947107 |
510 | C<Encode>, by Nick Ing-Simmons, provides a mechanism to translate |
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511 | between different character encodings. Support for Unicode, |
512 | ISO-8859-*, ASCII, CP*, KOI8-R, and three variants of EBCDIC are |
513 | compiled in to the module. Several other encodings (like Japanese, |
514 | Chinese, and MacIntosh encodings) are included and will be loaded at |
61947107 |
515 | runtime. See L<Encode>. |
f39f21d8 |
516 | |
517 | Any encoding supported by Encode module is also available to the |
518 | ":encoding()" layer if PerlIO is used. |
519 | |
61947107 |
520 | =item * |
521 | |
522 | C<I18N::Langinfo> can be use to query locale information. |
523 | See L<I18N::Langinfo>. |
f39f21d8 |
524 | |
525 | =item * |
526 | |
61947107 |
527 | C<I18N::LangTags> has functions for dealing with RFC3066-style |
bea4d472 |
528 | language tags, by Sean Burke. See L<I18N::LangTags>. |
61947107 |
529 | |
530 | =item * |
531 | |
532 | C<ExtUtils::Constant> is a new tool for extension writers for |
533 | generating XS code to import C header constants, by Nicholas Clark. |
534 | See L<ExtUtils::Constant>. |
535 | |
536 | =item * |
537 | |
538 | C<Filter::Simple> is an easy-to-use frontend to Filter::Util::Call, |
539 | from Damian Conway. See L<Filter::Simple>. |
f39f21d8 |
540 | |
541 | # in MyFilter.pm: |
542 | |
543 | package MyFilter; |
544 | |
545 | use Filter::Simple sub { |
546 | while (my ($from, $to) = splice @_, 0, 2) { |
547 | s/$from/$to/g; |
548 | } |
549 | }; |
550 | |
551 | 1; |
552 | |
553 | # in user's code: |
554 | |
555 | use MyFilter qr/red/ => 'green'; |
556 | |
557 | print "red\n"; # this code is filtered, will print "green\n" |
558 | print "bored\n"; # this code is filtered, will print "bogreen\n" |
559 | |
560 | no MyFilter; |
561 | |
562 | print "red\n"; # this code is not filtered, will print "red\n" |
563 | |
61947107 |
564 | =item * |
565 | |
566 | C<File::Temp> allows one to create temporary files and directories in |
567 | an easy, portable, and secure way, by Tim Jenness. See L<File::Temp>. |
568 | |
569 | =item * |
570 | |
571 | C<Filter::Util::Call> provides you with the framework to write |
572 | I<Source Filters> in Perl, from Paul Marquess. For most uses the |
573 | frontend Filter::Simple is to be preferred. See L<Filter::Util::Call>. |
574 | |
575 | =item * |
576 | |
577 | L<libnet> is a collection of perl5 modules related to network |
578 | programming, from Graham Barr. See L<Net::FTP>, L<Net::NNTP>, |
579 | L<Net::Ping>, L<Net::POP3>, L<Net::SMTP>, and L<Net::Time>. |
580 | |
581 | Perl installation leaves libnet unconfigured, use F<libnetcfg> to configure. |
f39f21d8 |
582 | |
583 | =item * |
584 | |
61947107 |
585 | C<List::Util> is a selection of general-utility list subroutines, like |
bea4d472 |
586 | sum(), min(), first(), and shuffle(), by Graham Barr. See L<List::Util>. |
f39f21d8 |
587 | |
588 | =item * |
589 | |
61947107 |
590 | C<Locale::Constants>, C<Locale::Country>, C<Locale::Currency>, and |
591 | C<Locale::Language>, from Neil Bowers, have been added. They provide the |
592 | codes for various locale standards, such as "fr" for France, "usd" for |
593 | US Dollar, and "jp" for Japanese. |
f39f21d8 |
594 | |
595 | use Locale::Country; |
596 | |
597 | $country = code2country('jp'); # $country gets 'Japan' |
598 | $code = country2code('Norway'); # $code gets 'no' |
599 | |
600 | See L<Locale::Constants>, L<Locale::Country>, L<Locale::Currency>, |
61947107 |
601 | and L<Locale::Language>. |
602 | |
603 | =item * |
604 | |
605 | C<Locale::Maketext> is localization framework from Sean Burke. See |
606 | L<Locale::Maketext>, and L<Locale::Maketext::TPJ13>. The latter is an |
607 | article about software localization, originally published in The Perl |
608 | Journal #13, republished here with kind permission. |
609 | |
610 | =item * |
611 | |
612 | C<Memoize> can make your functions faster by trading space for time, |
613 | from Mark-Jason Dominus. See L<Memoize>. |
f39f21d8 |
614 | |
615 | =item * |
616 | |
61947107 |
617 | C<MIME::Base64> allows you to encode data in base64, from Gisle Aas, |
618 | as defined in RFC 2045 - I<MIME (Multipurpose Internet Mail |
619 | Extensions)>. |
f39f21d8 |
620 | |
621 | use MIME::Base64; |
622 | |
623 | $encoded = encode_base64('Aladdin:open sesame'); |
624 | $decoded = decode_base64($encoded); |
625 | |
626 | print $encoded, "\n"; # "QWxhZGRpbjpvcGVuIHNlc2FtZQ==" |
627 | |
61947107 |
628 | See L<MIME::Base64>. |
f39f21d8 |
629 | |
630 | =item * |
631 | |
61947107 |
632 | C<MIME::QuotedPrint> allows you to encode data in quoted-printable |
633 | encoding, as defined in RFC 2045 - I<MIME (Multipurpose Internet Mail |
634 | Extensions)>, from Gisle Aas. |
f39f21d8 |
635 | |
636 | use MIME::QuotedPrint; |
637 | |
638 | $encoded = encode_qp("Smiley in Unicode: \x{263a}"); |
639 | $decoded = decode_qp($encoded); |
640 | |
641 | print $encoded, "\n"; # "Smiley in Unicode: =263A" |
642 | |
643 | MIME::QuotedPrint has been enhanced to provide the basic methods |
644 | necessary to use it with PerlIO::Via as in : |
645 | |
646 | use MIME::QuotedPrint; |
057b7f2b |
647 | open($fh,">Via(MIME::QuotedPrint)",$path); |
f39f21d8 |
648 | |
61947107 |
649 | See L<MIME::QuotedPrint>. |
f39f21d8 |
650 | |
651 | =item * |
652 | |
61947107 |
653 | C<NEXT> is pseudo-class for method redispatch, from Damian Conway. |
654 | See L<NEXT>. |
f39f21d8 |
655 | |
656 | =item * |
657 | |
1e13d81f |
658 | C<open> is a new pragma for setting the default I/O disciplines |
659 | for open(). |
660 | |
661 | =item * |
662 | |
61947107 |
663 | C<PerlIO::Scalar> provides the implementation of IO to "in memory" |
664 | Perl scalars as discussed above, from Nick Ing-Simmons. It also |
665 | serves as an example of a loadable PerlIO layer. Other future |
666 | possibilities include PerlIO::Array and PerlIO::Code. |
667 | See L<PerlIO::Scalar>. |
668 | |
669 | =item * |
670 | |
671 | C<PerlIO::Via> acts as a PerlIO layer and wraps PerlIO layer |
672 | functionality provided by a class (typically implemented in perl |
673 | code), from Nick Ing-Simmons. |
f39f21d8 |
674 | |
675 | use MIME::QuotedPrint; |
057b7f2b |
676 | open($fh,">Via(MIME::QuotedPrint)",$path); |
f39f21d8 |
677 | |
678 | This will automatically convert everything output to C<$fh> |
61947107 |
679 | to Quoted-Printable. See L<PerlIO::Via>. |
f39f21d8 |
680 | |
681 | =item * |
682 | |
1e13d81f |
683 | C<Pod::ParseLink>, by Russ Allbery, has been added, |
e1f170bd |
684 | to parse L<> links in pods as described in the new |
1e13d81f |
685 | perlpodspec. |
686 | |
687 | =item * |
688 | |
61947107 |
689 | C<Pod::Text::Overstrike>, by Joe Smith, has been added. |
f39f21d8 |
690 | It converts POD data to formatted overstrike text. |
61947107 |
691 | See L<Pod::Text::Overstrike>. |
f39f21d8 |
692 | |
693 | =item * |
694 | |
61947107 |
695 | C<Scalar::Util> is a selection of general-utility scalar subroutines, |
696 | like blessed(), reftype(), and tainted(). See L<Scalar::Util>. |
697 | |
698 | =item * |
699 | |
1e13d81f |
700 | C<sort> is a new pragma for controlling the behaviour of sort(). |
701 | |
702 | =item * |
703 | |
61947107 |
704 | C<Storable> gives persistence to Perl data structures by allowing the |
705 | storage and retrieval of Perl data to and from files in a fast and |
706 | compact binary format, from Raphael Manfredi. See L<Storable>. |
707 | |
708 | =item * |
709 | |
710 | C<Switch>, from Damian Conway, has been added. Just by saying |
f39f21d8 |
711 | |
712 | use Switch; |
713 | |
714 | you have C<switch> and C<case> available in Perl. |
715 | |
716 | use Switch; |
717 | |
718 | switch ($val) { |
719 | |
720 | case 1 { print "number 1" } |
721 | case "a" { print "string a" } |
722 | case [1..10,42] { print "number in list" } |
723 | case (@array) { print "number in list" } |
724 | case /\w+/ { print "pattern" } |
725 | case qr/\w+/ { print "pattern" } |
726 | case (%hash) { print "entry in hash" } |
727 | case (\%hash) { print "entry in hash" } |
728 | case (\&sub) { print "arg to subroutine" } |
729 | else { print "previous case not true" } |
730 | } |
731 | |
61947107 |
732 | See L<Switch>. |
733 | |
734 | =item * |
735 | |
736 | C<Test::More> is yet another framework for writing test scripts, |
737 | more extensive than Test::Simple, by Michael Schwern. See L<Test::More>. |
738 | |
739 | =item * |
740 | |
aecce728 |
741 | C<Test::Simple> has basic utilities for writing tests, by Michael |
61947107 |
742 | Schwern. See L<Test::Simple>. |
77c8cf41 |
743 | |
744 | =item * |
745 | |
61947107 |
746 | C<Text::Balanced> has been added, for extracting delimited text |
747 | sequences from strings, from Damian Conway. |
77c8cf41 |
748 | |
749 | use Text::Balanced 'extract_delimited'; |
750 | |
751 | ($a, $b) = extract_delimited("'never say never', he never said", "'", ''); |
752 | |
753 | $a will be "'never say never'", $b will be ', he never said'. |
754 | |
755 | In addition to extract_delimited() there are also extract_bracketed(), |
756 | extract_quotelike(), extract_codeblock(), extract_variable(), |
757 | extract_tagged(), extract_multiple(), gen_delimited_pat(), and |
758 | gen_extract_tagged(). With these you can implement rather advanced |
61947107 |
759 | parsing algorithms. See L<Text::Balanced>. |
77c8cf41 |
760 | |
761 | =item * |
762 | |
c2e23569 |
763 | C<threads> is an interface to interpreter threads, by Arthur Bergman. |
61947107 |
764 | Interpreter threads (ithreads) is the new thread model introduced in |
c2e23569 |
765 | Perl 5.6 but only available as an internal interface for extension |
766 | writers (and for Win32 Perl for C<fork()> emulation). See L<threads>. |
77c8cf41 |
767 | |
768 | =item * |
769 | |
61947107 |
770 | C<threads::shared> allows data sharing for interpreter threads, from |
771 | Arthur Bergman. In the ithreads model any data sharing between |
772 | threads must be explicit, as opposed to the old 5.005 thread model |
773 | where data sharing was implicit. See L<threads::shared>. |
77c8cf41 |
774 | |
775 | =item * |
776 | |
61947107 |
777 | C<Tie::RefHash::Nestable>, by Edward Avis, allows storing hash |
ba370e9b |
778 | references (unlike the standard Tie::RefHash) The module is contained |
779 | within Tie::RefHash, see L<Tie::RefHash>. |
77c8cf41 |
780 | |
781 | =item * |
782 | |
61947107 |
783 | C<Time::HiRes> provides high resolution timing (ualarm, usleep, |
784 | and gettimeofday), from Douglas E. Wegscheid. See L<Time::HiRes>. |
77c8cf41 |
785 | |
786 | =item * |
787 | |
61947107 |
788 | C<Unicode::UCD> offers a querying interface to the Unicode Character |
789 | Database. See L<Unicode::UCD>. |
77c8cf41 |
790 | |
791 | =item * |
792 | |
61947107 |
793 | C<Unicode::Collate> implements the UCA (Unicode Collation Algorithm) |
794 | for sorting Unicode strings, by SADAHIRO Tomoyuki. See L<Unicode::Collate>. |
77c8cf41 |
795 | |
796 | =item * |
797 | |
61947107 |
798 | C<Unicode::Normalize> implements the various Unicode normalization |
799 | forms, by SADAHIRO Tomoyuki. See L<Unicode::Normalize>. |
77c8cf41 |
800 | |
801 | =item * |
802 | |
61947107 |
803 | C<XS::Typemap>, by Tim Jenness, is a test extension that exercises XS |
804 | typemaps. Nothing gets installed but for extension writers the code |
805 | is worth studying. |
77c8cf41 |
806 | |
807 | =back |
808 | |
809 | =head2 Updated And Improved Modules and Pragmata |
810 | |
811 | =over 4 |
812 | |
813 | =item * |
814 | |
61947107 |
815 | The following independently supported modules have been updated to the |
816 | newest versions from CPAN: CGI, CPAN, DB_File, File::Spec, File::Temp, |
817 | Getopt::Long, Math::BigFloat, Math::BigInt, the podlators bundle |
818 | (Pod::Man, Pod::Text), Pod::LaTeX, Pod::Parser, Storable, |
819 | Term::ANSIColor, Test, Text-Tabs+Wrap. |
77c8cf41 |
820 | |
821 | =item * |
822 | |
61947107 |
823 | The attributes::reftype() now works on tied arguments. |
77c8cf41 |
824 | |
825 | =item * |
826 | |
057b7f2b |
827 | AutoLoader can now be disabled with C<no AutoLoader;>. |
77c8cf41 |
828 | |
829 | =item * |
830 | |
1e13d81f |
831 | B::Deparse has been significantly enhanced. It now can deparse almost |
832 | all of the standard test suite (so that the tests still succeed). |
833 | There is a make target "test.deparse" for trying this out. |
77c8cf41 |
834 | |
835 | =item * |
836 | |
1e13d81f |
837 | Class::Struct can now define the classes in compile time. |
77c8cf41 |
838 | |
839 | =item * |
840 | |
1e13d81f |
841 | Class::Struct now assigns the array/hash element if the accessor |
842 | is called with an array/hash element as the B<sole> argument. |
77c8cf41 |
843 | |
844 | =item * |
845 | |
1e13d81f |
846 | Data::Dumper has now an option to sort hashes. |
77c8cf41 |
847 | |
848 | =item * |
849 | |
1e13d81f |
850 | Data::Dumper has now an option to dump code references |
851 | using B::Deparse. |
77c8cf41 |
852 | |
853 | =item * |
854 | |
44da0e71 |
855 | DB_File now supports newer Berkeley DB versions, among |
856 | other improvements. |
857 | |
858 | =item * |
859 | |
1e13d81f |
860 | The English module can now be used without the infamous performance |
861 | hit by saying |
77c8cf41 |
862 | |
1e13d81f |
863 | use English '-no_performance_hit'; |
77c8cf41 |
864 | |
1e13d81f |
865 | (Assuming, of course, that one doesn't need the troublesome variables |
866 | C<$`>, C<$&>, or C<$'>.) Also, introduced C<@LAST_MATCH_START> and |
867 | C<@LAST_MATCH_END> English aliases for C<@-> and C<@+>. |
77c8cf41 |
868 | |
869 | =item * |
870 | |
1e13d81f |
871 | Fcntl, Socket, and Sys::Syslog have been rewritten to use the |
872 | new-style constant dispatch section (see L<ExtUtils::Constant>). |
873 | This means that they will be more robust and hopefully faster. |
77c8cf41 |
874 | |
875 | =item * |
876 | |
44da0e71 |
877 | File::Find now chdir()s correctly when chasing symbolic links. |
878 | |
879 | =item * |
880 | |
1e13d81f |
881 | File::Find now has pre- and post-processing callbacks. It also |
882 | correctly changes directories when chasing symbolic links. Callbacks |
883 | (naughtily) exiting with "next;" instead of "return;" now work. |
61947107 |
884 | |
885 | =item * |
886 | |
1e13d81f |
887 | File::Find is now (again) reentrant. It also has been made |
888 | more portable. |
77c8cf41 |
889 | |
61947107 |
890 | =item * |
891 | |
1e13d81f |
892 | File::Glob::glob() renamed to File::Glob::bsd_glob() to avoid |
893 | prototype mismatch with CORE::glob(). |
61947107 |
894 | |
895 | =item * |
896 | |
897 | File::Glob now supports C<GLOB_LIMIT> constant to limit the size of |
898 | the returned list of filenames. |
77c8cf41 |
899 | |
900 | =item * |
901 | |
902 | Devel::Peek now has an interface for the Perl memory statistics |
903 | (this works only if you are using perl's malloc, and if you have |
904 | compiled with debugging). |
905 | |
906 | =item * |
907 | |
1e13d81f |
908 | IPC::Open3 now allows the use of numeric file descriptors. |
909 | |
910 | =item * |
911 | |
77c8cf41 |
912 | IO::Socket has now atmark() method, which returns true if the socket |
913 | is positioned at the out-of-band mark. The method is also exportable |
914 | as a sockatmark() function. |
915 | |
916 | =item * |
917 | |
918 | IO::Socket::INET has support for ReusePort option (if your platform |
919 | supports it). The Reuse option now has an alias, ReuseAddr. For clarity |
920 | you may want to prefer ReuseAddr. |
921 | |
922 | =item * |
923 | |
61947107 |
924 | IO::Socket::INET now supports C<LocalPort> of zero (usually meaning |
925 | that the operating system will make one up.) |
77c8cf41 |
926 | |
927 | =item * |
928 | |
1e13d81f |
929 | use lib now works identically to @INC. Removing directories |
930 | with 'no lib' now works. |
931 | |
932 | =item * |
933 | |
934 | Math::BigFloat and Math::BigInt have undergone a full rewrite. |
935 | They are now magnitudes faster, and they support various |
61947107 |
936 | bignum libraries such as GMP and PARI as their backends. |
f39f21d8 |
937 | |
938 | =item * |
939 | |
44da0e71 |
940 | Math::Complex handles inf, NaN etc., better. |
941 | |
942 | =item * |
943 | |
61947107 |
944 | Net::Ping has been enhanced. There is now "external" protocol which |
945 | uses Net::Ping::External module which runs external ping(1) and parses |
44da0e71 |
946 | the output. A version of Net::Ping::External is available in CPAN. |
f39f21d8 |
947 | |
77c8cf41 |
948 | =item * |
f39f21d8 |
949 | |
da6838c8 |
950 | POSIX::sigaction() is now much more flexible and robust. |
61947107 |
951 | You can now install coderef handlers, 'DEFAULT', and 'IGNORE' |
952 | handlers, installing new handlers was not atomic. |
f39f21d8 |
953 | |
954 | =item * |
955 | |
da6838c8 |
956 | In Safe the C<%INC> now localised in a Safe compartment so that |
76663d67 |
957 | use/require work. |
958 | |
959 | =item * |
960 | |
44da0e71 |
961 | In SDBM_File on dosish platforms, some keys went missing because of |
962 | lack of support for files with "holes". A workaround for the problem |
963 | has been added. |
964 | |
965 | =item * |
966 | |
da6838c8 |
967 | In Search::Dict one can now have a pre-processing hook for the |
76663d67 |
968 | lines being searched. |
1e13d81f |
969 | |
970 | =item * |
971 | |
972 | The Shell module now has an OO interface. |
973 | |
974 | =item * |
975 | |
61947107 |
976 | The Test module has been significantly enhanced. |
f39f21d8 |
977 | |
978 | =item * |
979 | |
da6838c8 |
980 | The vars pragma now supports declaring fully qualified variables. |
77c8cf41 |
981 | (Something that C<our()> does not and will not support.) |
f39f21d8 |
982 | |
888aee59 |
983 | =item * |
984 | |
61947107 |
985 | The utf8:: name space (as in the pragma) provides various |
986 | Perl-callable functions to provide low level access to Perl's |
987 | internal Unicode representation. At the moment only length() |
988 | has been implemented. |
888aee59 |
989 | |
f39f21d8 |
990 | =back |
991 | |
77c8cf41 |
992 | =head1 Utility Changes |
f39f21d8 |
993 | |
994 | =over 4 |
995 | |
996 | =item * |
997 | |
61947107 |
998 | Emacs perl mode (emacs/cperl-mode.el) has been updated to version |
77c8cf41 |
999 | 4.31. |
f39f21d8 |
1000 | |
1001 | =item * |
1002 | |
61947107 |
1003 | F<emacs/e2ctags.pl> is now much faster. |
f39f21d8 |
1004 | |
1005 | =item * |
1006 | |
1e13d81f |
1007 | C<h2ph> now supports C trigraphs. |
1008 | |
1009 | =item * |
1010 | |
1011 | C<h2xs> now produces a template README. |
f39f21d8 |
1012 | |
77c8cf41 |
1013 | =item * |
1014 | |
1e13d81f |
1015 | C<h2xs> now uses C<Devel::PPort> for better portability between |
1016 | different versions of Perl. |
f39f21d8 |
1017 | |
1018 | =item * |
1019 | |
1e13d81f |
1020 | C<h2xs> uses the new L<ExtUtils::Constant> module which will affect |
61947107 |
1021 | newly created extensions that define constants. Since the new code is |
1022 | more correct (if you have two constants where the first one is a |
1023 | prefix of the second one, the first constant B<never> gets defined), |
1024 | less lossy (it uses integers for integer constant, as opposed to the |
1025 | old code that used floating point numbers even for integer constants), |
1026 | and slightly faster, you might want to consider regenerating your |
1027 | extension code (the new scheme makes regenerating easy). |
1028 | L<h2xs> now also supports C trigraphs. |
f39f21d8 |
1029 | |
1030 | =item * |
1031 | |
1e13d81f |
1032 | C<libnetcfg> has been added to configure the libnet. |
f39f21d8 |
1033 | |
1034 | =item * |
1035 | |
1e13d81f |
1036 | C<perlbug> is now much more robust. It also sends the bug report to |
61947107 |
1037 | perl.org, not perl.com. |
f39f21d8 |
1038 | |
1039 | =item * |
1040 | |
1e13d81f |
1041 | C<perlcc> has been rewritten and its user interface (that is, |
61947107 |
1042 | command line) is much more like that of the UNIX C compiler, cc. |
44da0e71 |
1043 | (The perlbc tools has been removed. Use C<perlcc -B> instead.) |
f39f21d8 |
1044 | |
1045 | =item * |
1046 | |
aecce728 |
1047 | C<perlivp> is a new Installation Verification Procedure utility |
1048 | for running any time after installing Perl. |
f39f21d8 |
1049 | |
1050 | =item * |
1051 | |
1e13d81f |
1052 | C<pod2html> now allows specifying a cache directory. |
f39f21d8 |
1053 | |
1054 | =item * |
1055 | |
1e13d81f |
1056 | C<s2p> has been completely rewritten in Perl. (It is in fact a full |
1057 | implementation of sed in Perl: you can use the sed functionality by |
1058 | using the C<psed> utility.) |
61947107 |
1059 | |
1060 | =item * |
1061 | |
1e13d81f |
1062 | C<xsubpp> now understands POD documentation embedded in the *.xs files. |
f39f21d8 |
1063 | |
1064 | =item * |
1065 | |
1e13d81f |
1066 | C<xsubpp> now supports OUT keyword. |
f39f21d8 |
1067 | |
1068 | =back |
1069 | |
77c8cf41 |
1070 | =head1 New Documentation |
f39f21d8 |
1071 | |
1072 | =over 4 |
1073 | |
1074 | =item * |
1075 | |
77c8cf41 |
1076 | perl56delta details the changes between the 5.005 release and the |
1077 | 5.6.0 release. |
f39f21d8 |
1078 | |
1079 | =item * |
1080 | |
61947107 |
1081 | perlclib documents the internal replacements for standard C library |
1082 | functions. (Interesting only for extension writers and Perl core |
1083 | hackers.) |
1084 | |
1085 | =item * |
1086 | |
77c8cf41 |
1087 | perldebtut is a Perl debugging tutorial. |
f39f21d8 |
1088 | |
77c8cf41 |
1089 | =item * |
f39f21d8 |
1090 | |
77c8cf41 |
1091 | perlebcdic contains considerations for running Perl on EBCDIC platforms. |
f39f21d8 |
1092 | |
77c8cf41 |
1093 | =item * |
1094 | |
888aee59 |
1095 | perlintro is a gentle introduction to Perl. |
1096 | |
1097 | =item * |
1098 | |
61947107 |
1099 | perliol documents the internals of PerlIO with layers. |
1100 | |
1101 | =item * |
1102 | |
888aee59 |
1103 | perlmodstyle is a style guide for writing modules. |
1104 | |
1105 | =item * |
1106 | |
77c8cf41 |
1107 | perlnewmod tells about writing and submitting a new module. |
f39f21d8 |
1108 | |
1109 | =item * |
1110 | |
34babc16 |
1111 | perlpacktut is a pack() tutorial. |
1112 | |
1113 | =item * |
1114 | |
888aee59 |
1115 | perlpod has been rewritten to be clearer and to record the best |
1116 | practices gathered over the years. |
1117 | |
1118 | =item * |
1119 | |
057b7f2b |
1120 | perlpodspec is a more formal specification of the pod format, |
888aee59 |
1121 | mainly of interest for writers of pod applications, not to |
1122 | people writing in pod. |
1123 | |
1124 | =item * |
1125 | |
77c8cf41 |
1126 | perlretut is a regular expression tutorial. |
f39f21d8 |
1127 | |
1128 | =item * |
1129 | |
77c8cf41 |
1130 | perlrequick is a regular expressions quick-start guide. |
1131 | Yes, much quicker than perlretut. |
f39f21d8 |
1132 | |
77c8cf41 |
1133 | =item * |
f39f21d8 |
1134 | |
61947107 |
1135 | perltodo has been updated. |
1136 | |
1137 | =item * |
1138 | |
888aee59 |
1139 | perltootc has been renamed as perltooc (to not to conflict |
61947107 |
1140 | with perltoot in filesystems restricted to "8.3" names) |
888aee59 |
1141 | |
1142 | =item * |
1143 | |
1144 | perluniintro is an introduction to using Unicode in Perl |
1145 | (perlunicode is more of a reference) |
1146 | |
1147 | =item * |
1148 | |
77c8cf41 |
1149 | perlutil explains the command line utilities packaged with the Perl |
1150 | distribution. |
1151 | |
1152 | =back |
f39f21d8 |
1153 | |
61947107 |
1154 | The following platform-specific documents are available before |
1155 | the installation as README.I<platform>, and after the installation |
1156 | as perlI<platform>: |
f39f21d8 |
1157 | |
61947107 |
1158 | perlaix perlamiga perlapollo perlbeos perlbs2000 |
1159 | perlce perlcygwin perldgux perldos perlepoc perlhpux |
1160 | perlhurd perlmachten perlmacos perlmint perlmpeix |
1161 | perlnetware perlos2 perlos390 perlplan9 perlqnx perlsolaris |
1162 | perltru64 perluts perlvmesa perlvms perlvos perlwin32 |
77c8cf41 |
1163 | |
1164 | =over 4 |
1165 | |
1166 | =item * |
1167 | |
61947107 |
1168 | The documentation for the POSIX-BC platform is called "BS2000", to avoid |
1169 | confusion with the Perl POSIX module. |
77c8cf41 |
1170 | |
1171 | =item * |
1172 | |
61947107 |
1173 | The documentation for the WinCE platform is called "CE", to avoid |
1174 | confusion with the perlwin32 documentation on 8.3-restricted filesystems. |
77c8cf41 |
1175 | |
1176 | =back |
1177 | |
1178 | =head1 Performance Enhancements |
1179 | |
1180 | =over 4 |
1181 | |
1182 | =item * |
1183 | |
44da0e71 |
1184 | map() could get pathologically slow when the result list it generates |
1185 | is larger than the source list. The performance has been improved for |
1186 | common scenarios. |
77c8cf41 |
1187 | |
1188 | =item * |
1189 | |
e1f170bd |
1190 | sort() has been changed to use primarily mergesort internally as |
1191 | opposed to the earlier quicksort. For very small lists this may |
1192 | result in slightly slower sorting times, but in general the speedup |
1193 | should be at least 20%. Additional bonuses are that the worst case |
1194 | behaviour of sort() is now better (in computer science terms it now |
1195 | runs in time O(N log N), as opposed to quicksort's Theta(N**2) |
1196 | worst-case run time behaviour), and that sort() is now stable |
1197 | (meaning that elements with identical keys will stay ordered as they |
1198 | were before the sort). See the C<sort> pragma for information. |
77c8cf41 |
1199 | |
05e25c75 |
1200 | The story in more detail: suppose you want to serve yourself a little |
1201 | slice of Pi. |
1202 | |
1203 | @digits = ( 3,1,4,1,5,9 ); |
1204 | |
1205 | A numerical sort of the digits will yield (1,1,3,4,5,9), as expected. |
1206 | Which C<1> comes first is hard to know, since one C<1> looks pretty |
1207 | much like any other. You can regard this as totally trivial, |
1208 | or somewhat profound. However, if you just want to sort the even |
1209 | digits ahead of the odd ones, then what will |
1210 | |
1211 | sort { ($a % 2) <=> ($b % 2) } @digits; |
1212 | |
1213 | yield? The only even digit, C<4>, will come first. But how about |
1214 | the odd numbers, which all compare equal? With the quicksort algorithm |
1215 | used to implement Perl 5.6 and earlier, the order of ties is left up |
1216 | to the sort. So, as you add more and more digits of Pi, the order |
1217 | in which the sorted even and odd digits appear will change. |
1218 | and, for sufficiently large slices of Pi, the quicksort algorithm |
1219 | in Perl 5.8 won't return the same results even if reinvoked with the |
1220 | same input. The justification for this rests with quicksort's |
1221 | worst case behavior. If you run |
1222 | |
1223 | sort { $a <=> $b } ( 1 .. $N , 1 .. $N ); |
1224 | |
1225 | (something you might approximate if you wanted to merge two sorted |
1226 | arrays using sort), doubling $N doesn't just double the quicksort time, |
1227 | it I<quadruples> it. Quicksort has a worst case run time that can |
1228 | grow like N**2, so-called I<quadratic> behaviour, and it can happen |
1229 | on patterns that may well arise in normal use. You won't notice this |
1230 | for small arrays, but you I<will> notice it with larger arrays, |
1231 | and you may not live long enough for the sort to complete on arrays |
1232 | of a million elements. So the 5.8 quicksort scrambles large arrays |
1233 | before sorting them, as a statistical defence against quadratic behaviour. |
1234 | But that means if you sort the same large array twice, ties may be |
1235 | broken in different ways. |
1236 | |
1237 | Because of the unpredictability of tie-breaking order, and the quadratic |
1238 | worst-case behaviour, quicksort was I<almost> replaced completely with |
1239 | a stable mergesort. I<Stable> means that ties are broken to preserve |
1240 | the original order of appearance in the input array. So |
1241 | |
1242 | sort { ($a % 2) <=> ($b % 2) } (3,1,4,1,5,9); |
1243 | |
1244 | will yield (4,3,1,1,5,9), guaranteed. The even and odd numbers |
1245 | appear in the output in the same order they appeared in the input. |
1246 | Mergesort has worst case O(NlogN) behaviour, the best value |
1247 | attainable. And, ironically, this mergesort does particularly |
1248 | well where quicksort goes quadratic: mergesort sorts (1..$N, 1..$N) |
1249 | in O(N) time. But quicksort was rescued at the last moment because |
1250 | it is faster than mergesort on certain inputs and platforms. |
1251 | For example, if you really I<don't> care about the order of even |
1252 | and odd digits, quicksort will run in O(N) time; it's very good |
1253 | at sorting many repetitions of a small number of distinct elements. |
1254 | The quicksort divide and conquer strategy works well on platforms |
1255 | with relatively small, very fast, caches. Eventually, the problem gets |
1256 | whittled down to one that fits in the cache, from which point it |
1257 | benefits from the increased memory speed. |
1258 | |
1259 | Quicksort was rescued by implementing a sort pragma to control aspects |
1260 | of the sort. The B<stable> subpragma forces stable behaviour, |
1261 | regardless of algorithm. The B<_quicksort> and B<_mergesort> |
1262 | subpragmas are heavy-handed ways to select the underlying implementation. |
1263 | The leading C<_> is a reminder that these subpragmas may not survive |
1264 | beyond 5.8. More appropriate mechanisms for selecting the implementation |
1265 | exist, but they wouldn't have arrived in time to save quicksort. |
1266 | |
77c8cf41 |
1267 | =item * |
1268 | |
1269 | Hashes now use Bob Jenkins "One-at-a-Time" hashing key algorithm |
1270 | (http://burtleburtle.net/bob/hash/doobs.html). This algorithm is |
1271 | reasonably fast while producing a much better spread of values than |
1272 | the old hashing algorithm (originally by Chris Torek, later tweaked by |
1273 | Ilya Zakharevich). Hash values output from the algorithm on a hash of |
1274 | all 3-char printable ASCII keys comes much closer to passing the |
1275 | DIEHARD random number generation tests. According to perlbench, this |
1276 | change has not affected the overall speed of Perl. |
1277 | |
1278 | =item * |
1279 | |
1280 | unshift() should now be noticeably faster. |
1281 | |
1282 | =back |
1283 | |
1284 | =head1 Installation and Configuration Improvements |
1285 | |
1286 | =head2 Generic Improvements |
1287 | |
1288 | =over 4 |
1289 | |
1290 | =item * |
1291 | |
1292 | INSTALL now explains how you can configure Perl to use 64-bit |
1293 | integers even on non-64-bit platforms. |
1294 | |
1295 | =item * |
1296 | |
1297 | Policy.sh policy change: if you are reusing a Policy.sh file |
1298 | (see INSTALL) and you use Configure -Dprefix=/foo/bar and in the old |
1299 | Policy $prefix eq $siteprefix and $prefix eq $vendorprefix, all of |
1300 | them will now be changed to the new prefix, /foo/bar. (Previously |
1301 | only $prefix changed.) If you do not like this new behaviour, |
1302 | specify prefix, siteprefix, and vendorprefix explicitly. |
1303 | |
1304 | =item * |
1305 | |
1306 | A new optional location for Perl libraries, otherlibdirs, is available. |
1307 | It can be used for example for vendor add-ons without disturbing Perl's |
1308 | own library directories. |
1309 | |
1310 | =item * |
1311 | |
1312 | In many platforms the vendor-supplied 'cc' is too stripped-down to |
1313 | build Perl (basically, 'cc' doesn't do ANSI C). If this seems |
1314 | to be the case and 'cc' does not seem to be the GNU C compiler |
1315 | 'gcc', an automatic attempt is made to find and use 'gcc' instead. |
1316 | |
1317 | =item * |
1318 | |
1319 | gcc needs to closely track the operating system release to avoid |
1320 | build problems. If Configure finds that gcc was built for a different |
1321 | operating system release than is running, it now gives a clearly visible |
1322 | warning that there may be trouble ahead. |
1323 | |
1324 | =item * |
1325 | |
1326 | If binary compatibility with the 5.005 release is not wanted, Configure |
1327 | no longer suggests including the 5.005 modules in @INC. |
1328 | |
1329 | =item * |
1330 | |
1331 | Configure C<-S> can now run non-interactively. |
1332 | |
1333 | =item * |
1334 | |
44da0e71 |
1335 | Configure support for pdp11-style memory models has been removed due |
1336 | to obsolescence. |
1337 | |
1338 | =item * |
1339 | |
77c8cf41 |
1340 | configure.gnu now works with options with whitespace in them. |
f39f21d8 |
1341 | |
77c8cf41 |
1342 | =item * |
f39f21d8 |
1343 | |
77c8cf41 |
1344 | installperl now outputs everything to STDERR. |
f39f21d8 |
1345 | |
77c8cf41 |
1346 | =item * |
1347 | |
1348 | $Config{byteorder} is now computed dynamically (this is more robust |
1349 | with "fat binaries" where an executable image contains binaries for |
1350 | more than one binary platform.) |
f39f21d8 |
1351 | |
1352 | =item * |
1353 | |
1354 | Because PerlIO is now the default on most platforms, "-perlio" doesn't |
1355 | get appended to the $Config{archname} (also known as $^O) anymore. |
1356 | Instead, if you explicitly choose not to use perlio (Configure command |
1357 | line option -Uuseperlio), you will get "-stdio" appended. |
1358 | |
1359 | =item * |
1360 | |
1361 | Another change related to the architecture name is that "-64all" |
1362 | (-Duse64bitall, or "maximally 64-bit") is appended only if your |
1363 | pointers are 64 bits wide. (To be exact, the use64bitall is ignored.) |
1364 | |
1365 | =item * |
1366 | |
77c8cf41 |
1367 | In AFS installations one can configure the root of the AFS to be |
1368 | somewhere else than the default F</afs> by using the Configure |
1369 | parameter C<-Dafsroot=/some/where/else>. |
1370 | |
1371 | =item * |
1372 | |
61947107 |
1373 | APPLLIB_EXP, a less-know configuration-time definition, has been |
1374 | documented. It can be used to prepend site-specific directories |
1375 | to Perl's default search path (@INC), see INSTALL for information. |
1376 | |
1377 | =item * |
1378 | |
77c8cf41 |
1379 | The version of Berkeley DB used when the Perl (and, presumably, the |
1380 | DB_File extension) was built is now available as |
1381 | C<@Config{qw(db_version_major db_version_minor db_version_patch)}> |
1382 | from Perl and as C<DB_VERSION_MAJOR_CFG DB_VERSION_MINOR_CFG |
1383 | DB_VERSION_PATCH_CFG> from C. |
1384 | |
1385 | =item * |
1386 | |
61947107 |
1387 | Building Berkeley DB3 for compatibility modes for DB, NDBM, and ODBM |
1388 | has been documented in INSTALL. |
77c8cf41 |
1389 | |
1390 | =item * |
1391 | |
61947107 |
1392 | If you have CPAN access (either network or a local copy such as a |
1393 | CD-ROM) you can during specify extra modules to Configure to build and |
1394 | install with Perl using the -Dextras=... option. See INSTALL for |
1395 | more details. |
f39f21d8 |
1396 | |
61947107 |
1397 | =item * |
f39f21d8 |
1398 | |
61947107 |
1399 | In addition to config.over a new override file, config.arch, is |
1400 | available. That is supposed to be used by hints file writers for |
1401 | architecture-wide changes (as opposed to config.over which is for |
1402 | site-wide changes). |
f39f21d8 |
1403 | |
1404 | =item * |
1405 | |
e1f170bd |
1406 | If your file system supports symbolic links you can build Perl outside |
1407 | of the source directory by |
1408 | |
1409 | mkdir /tmp/perl/build/directory |
1410 | cd /tmp/perl/build/directory |
1411 | sh /path/to/perl/source/Configure -Dmksymlinks ... |
1412 | |
1413 | This will create in /tmp/perl/build/directory a tree of symbolic links |
1414 | pointing to files in /path/to/perl/source. The original files are left |
1415 | unaffected. After Configure has finished you can just say |
1416 | |
1417 | make all test |
1418 | |
1419 | and Perl will be built and tested, all in /tmp/perl/build/directory. |
1420 | |
1421 | =item * |
1422 | |
61947107 |
1423 | For Perl developers several new make targets for profiling |
1424 | and debugging have been added, see L<perlhack>. |
1425 | |
1426 | =over 8 |
f39f21d8 |
1427 | |
1428 | =item * |
1429 | |
61947107 |
1430 | Use of the F<gprof> tool to profile Perl has been documented in |
1431 | L<perlhack>. There is a make target called "perl.gprof" for |
1432 | generating a gprofiled Perl executable. |
f39f21d8 |
1433 | |
1434 | =item * |
1435 | |
61947107 |
1436 | If you have GCC 3, there is a make target called "perl.gcov" for |
1437 | creating a gcoved Perl executable for coverage analysis. See |
1438 | L<perlhack>. |
f39f21d8 |
1439 | |
1440 | =item * |
1441 | |
61947107 |
1442 | If you are on IRIX or Tru64 platforms, new profiling/debugging options |
1443 | have been added, see L<perlhack> for more information about pixie and |
1444 | Third Degree. |
1445 | |
1446 | =back |
f39f21d8 |
1447 | |
1448 | =item * |
1449 | |
61947107 |
1450 | Guidelines of how to construct minimal Perl installations have |
1451 | been added to INSTALL. |
f39f21d8 |
1452 | |
1453 | =item * |
1454 | |
61947107 |
1455 | The Thread extension is now not built at all under ithreads |
1456 | (C<Configure -Duseithreads>) because it wouldn't work anyway (the |
1457 | Thread extension requires being Configured with C<-Duse5005threads>). |
f39f21d8 |
1458 | |
61947107 |
1459 | But note that the Thread.pm interface is now shared by both |
1460 | thread models. |
f39f21d8 |
1461 | |
61947107 |
1462 | =back |
f39f21d8 |
1463 | |
61947107 |
1464 | =head2 New Or Improved Platforms |
f39f21d8 |
1465 | |
61947107 |
1466 | For the list of platforms known to support Perl, |
1467 | see L<perlport/"Supported Platforms">. |
1468 | |
1469 | =over 4 |
f39f21d8 |
1470 | |
1471 | =item * |
1472 | |
61947107 |
1473 | AIX dynamic loading should be now better supported. |
f39f21d8 |
1474 | |
f39f21d8 |
1475 | =item * |
1476 | |
77c8cf41 |
1477 | AIX should now work better with gcc, threads, and 64-bitness. Also the |
1478 | long doubles support in AIX should be better now. See L<perlaix>. |
f39f21d8 |
1479 | |
1480 | =item * |
1481 | |
61947107 |
1482 | After a long pause, AmigaOS has been verified to be happy with Perl. |
1483 | |
1484 | =item * |
1485 | |
77c8cf41 |
1486 | AtheOS (http://www.atheos.cx/) is a new platform. |
f39f21d8 |
1487 | |
77c8cf41 |
1488 | =item * |
f39f21d8 |
1489 | |
77c8cf41 |
1490 | DG/UX platform now supports the 5.005-style threads. See L<perldgux>. |
f39f21d8 |
1491 | |
1492 | =item * |
1493 | |
77c8cf41 |
1494 | DYNIX/ptx platform (a.k.a. dynixptx) is supported at or near osvers 4.5.2. |
f39f21d8 |
1495 | |
1496 | =item * |
1497 | |
61947107 |
1498 | EBCDIC platforms (z/OS, also known as OS/390, POSIX-BC, and VM/ESA) |
1499 | have been regained. Many test suite tests still fail and the |
1500 | co-existence of Unicode and EBCDIC isn't quite settled, but the |
1501 | situation is much better than with Perl 5.6. See L<perlos390>, |
1502 | L<perlbs2000> (for POSIX-BC), and L<perlvmesa> for more information. |
f39f21d8 |
1503 | |
1504 | =item * |
1505 | |
61947107 |
1506 | Building perl with -Duseithreads or -Duse5005threads now works under |
1507 | HP-UX 10.20 (previously it only worked under 10.30 or later). You will |
1508 | need a thread library package installed. See README.hpux. |
f39f21d8 |
1509 | |
77c8cf41 |
1510 | =item * |
f39f21d8 |
1511 | |
61947107 |
1512 | MacOS Classic (MacPerl has of course been available since |
1513 | perl 5.004 but now the source code bases of standard Perl |
1514 | and MacPerl have been synchronised) |
f39f21d8 |
1515 | |
77c8cf41 |
1516 | =item * |
f39f21d8 |
1517 | |
61947107 |
1518 | MacOS X (or Darwin) should now be able to build Perl even on HFS+ |
1519 | filesystems. (The case-insensitivity confused the Perl build process.) |
f39f21d8 |
1520 | |
888aee59 |
1521 | =item * |
1522 | |
61947107 |
1523 | NCR MP-RAS is now supported. |
888aee59 |
1524 | |
1525 | =item * |
1526 | |
61947107 |
1527 | NetWare from Novell is now supported. See L<perlnetware>. |
888aee59 |
1528 | |
1529 | =item * |
1530 | |
61947107 |
1531 | NonStop-UX is now supported. |
888aee59 |
1532 | |
1533 | =item * |
1534 | |
44da0e71 |
1535 | NEC SUPER-UX is now supported. |
1536 | |
1537 | =item * |
1538 | |
61947107 |
1539 | Amdahl UTS UNIX mainframe platform is now supported. |
888aee59 |
1540 | |
1541 | =item * |
1542 | |
61947107 |
1543 | WinCE is now supported. See L<perlce>. |
1544 | |
1545 | =item * |
1546 | |
1547 | z/OS (formerly known as OS/390, formerly known as MVS OE) has now |
1548 | support for dynamic loading. This is not selected by default, |
1549 | however, you must specify -Dusedl in the arguments of Configure. |
888aee59 |
1550 | |
f39f21d8 |
1551 | =back |
1552 | |
1553 | =head1 Selected Bug Fixes |
1554 | |
e1f170bd |
1555 | Numerous memory leaks and uninitialized memory accesses have been |
1556 | hunted down. Most importantly anonymous subs used to leak quite |
1557 | a bit. |
ba370e9b |
1558 | |
f39f21d8 |
1559 | =over 4 |
1560 | |
1561 | =item * |
1562 | |
e1f170bd |
1563 | The autouse pragma didn't work for Multi::Part::Function::Names. |
f39f21d8 |
1564 | |
1565 | =item * |
1566 | |
44da0e71 |
1567 | caller() could cause core dumps in certain situations. Carp was sometimes |
1568 | affected by this problem. |
1569 | |
1570 | =item * |
1571 | |
e1f170bd |
1572 | chop(@list) in list context returned the characters chopped in |
1573 | reverse order. This has been reversed to be in the right order. |
f39f21d8 |
1574 | |
1575 | =item * |
1576 | |
e1f170bd |
1577 | Configure no longer includes the DBM libraries (dbm, gdbm, db, ndbm) |
1578 | when building the Perl binary. The only exception to this is SunOS 4.x, |
1579 | which needs them. |
f39f21d8 |
1580 | |
1581 | =item * |
1582 | |
e1f170bd |
1583 | The behaviour of non-decimal but numeric string constants such as |
1584 | "0x23" was platform-dependent: in some platforms that was seen as 35, |
1585 | in some as 0, in some as a floating point number (don't ask). This |
1586 | was caused by Perl using the operating system libraries in a situation |
1587 | where the result of the string to number conversion is undefined: now |
1588 | Perl consistently handles such strings as zero in numeric contexts. |
f39f21d8 |
1589 | |
1590 | =item * |
1591 | |
e1f170bd |
1592 | The order of DESTROYs has been made more predictable. |
f39f21d8 |
1593 | |
1594 | =item * |
1595 | |
e1f170bd |
1596 | Several debugger fixes: exit code now reflects the script exit code, |
1597 | condition C<"0"> now treated correctly, the C<d> command now checks |
44da0e71 |
1598 | line number, the C<$.> no longer gets corrupted, all debugger output |
1599 | now goes correctly to the socket if RemotePort is set. |
1600 | |
1601 | =item * |
1602 | |
1603 | Perl 5.6.0 could emit spurious warnings about redefinition of dl_error() |
1604 | when statically building extensions into perl. This has been corrected. |
f39f21d8 |
1605 | |
1606 | =item * |
1607 | |
e1f170bd |
1608 | L<dprofpp> -R didn't work. |
f39f21d8 |
1609 | |
1610 | =item * |
1611 | |
e1f170bd |
1612 | C<*foo{FORMAT}> now works. |
44da0e71 |
1613 | =item * |
1614 | |
1615 | Infinity is now recognized as a number. |
f39f21d8 |
1616 | |
1617 | =item * |
1618 | |
e1f170bd |
1619 | UNIVERSAL::isa no longer caches methods incorrectly. (This broke |
1620 | the Tk extension with 5.6.0.) |
f39f21d8 |
1621 | |
1622 | =item * |
1623 | |
e1f170bd |
1624 | Lexicals I: lexicals outside an eval "" weren't resolved |
1625 | correctly inside a subroutine definition inside the eval "" if they |
1626 | were not already referenced in the top level of the eval""ed code. |
f39f21d8 |
1627 | |
1628 | =item * |
1629 | |
e1f170bd |
1630 | Lexicals II: lexicals leaked at file scope into subroutines that |
1631 | were declared before the lexicals. |
f39f21d8 |
1632 | |
1633 | =item * |
1634 | |
44da0e71 |
1635 | Lexical warnings now propagating correctly between scopes |
1636 | and into C<eval "...">. |
1637 | |
1638 | =item * |
1639 | |
1640 | C<use warnings qw(FATAL all)> did not work as intended. This has been |
1641 | corrected. |
1642 | |
1643 | =item * |
1644 | |
1645 | warnings::enabled() now reports the state of $^W correctly if the caller |
1646 | isn't using lexical warnings. |
f39f21d8 |
1647 | |
1648 | =item * |
1649 | |
e1f170bd |
1650 | Line renumbering with eval and C<#line> now works. |
f39f21d8 |
1651 | |
1652 | =item * |
1653 | |
e1f170bd |
1654 | Fixed numerous memory leaks, especially in eval "". |
f39f21d8 |
1655 | |
1656 | =item * |
1657 | |
e1f170bd |
1658 | mkdir() now ignores trailing slashes in the directory name, |
1659 | as mandated by POSIX. |
f39f21d8 |
1660 | |
1661 | =item * |
1662 | |
e1f170bd |
1663 | Some versions of glibc have a broken modfl(). This affects builds |
1664 | with C<-Duselongdouble>. This version of Perl detects this brokenness |
1665 | and has a workaround for it. The glibc release 2.2.2 is known to have |
1666 | fixed the modfl() bug. |
f39f21d8 |
1667 | |
1668 | =item * |
1669 | |
e1f170bd |
1670 | Modulus of unsigned numbers now works (4063328477 % 65535 used to |
1671 | return 27406, instead of 27047). |
f39f21d8 |
1672 | |
1673 | =item * |
1674 | |
e1f170bd |
1675 | Some "not a number" warnings introduced in 5.6.0 eliminated to be |
1676 | more compatible with 5.005. Infinity is now recognised as a number. |
f39f21d8 |
1677 | |
77c8cf41 |
1678 | =item * |
f39f21d8 |
1679 | |
44da0e71 |
1680 | Numeric conversions did not recognize changes in the string value |
1681 | properly in certain circumstances. |
1682 | |
1683 | =item * |
1684 | |
e1f170bd |
1685 | Attributes (like :shared) didn't work with our(). |
f39f21d8 |
1686 | |
1687 | =item * |
1688 | |
e1f170bd |
1689 | our() variables will not cause "will not stay shared" warnings. |
f39f21d8 |
1690 | |
1691 | =item * |
1692 | |
44da0e71 |
1693 | "our" variables of the same name declared in two sibling blocks |
1694 | resulted in bogus warnings about "redeclaration" of the variables. |
1695 | The problem has been corrected. |
1696 | |
1697 | =item * |
1698 | |
e1f170bd |
1699 | pack "Z" now correctly terminates the string with "\0". |
f39f21d8 |
1700 | |
1701 | =item * |
1702 | |
e1f170bd |
1703 | Fix password routines which in some shadow password platforms |
1704 | (e.g. HP-UX) caused getpwent() to return every other entry. |
f39f21d8 |
1705 | |
77c8cf41 |
1706 | =item * |
f39f21d8 |
1707 | |
e1f170bd |
1708 | The PERL5OPT environment variable (for passing command line arguments |
1709 | to Perl) didn't work for more than a single group of options. |
f39f21d8 |
1710 | |
77c8cf41 |
1711 | =item * |
f39f21d8 |
1712 | |
e1f170bd |
1713 | PERL5OPT with embedded spaces didn't work. |
f39f21d8 |
1714 | |
77c8cf41 |
1715 | =item * |
f39f21d8 |
1716 | |
e1f170bd |
1717 | printf() no longer resets the numeric locale to "C". |
f39f21d8 |
1718 | |
77c8cf41 |
1719 | =item * |
f39f21d8 |
1720 | |
44da0e71 |
1721 | C<qw(a\\b)> now parses correctly as C<'a\\b'>. |
1722 | |
1723 | =item * |
1724 | |
1725 | pos() did not return the correct value within s///ge in earlier |
1726 | versions. This is now handled correctly. |
f39f21d8 |
1727 | |
77c8cf41 |
1728 | =item * |
f39f21d8 |
1729 | |
e1f170bd |
1730 | Printing quads (64-bit integers) with printf/sprintf now works |
1731 | without the q L ll prefixes (assuming you are on a quad-capable platform). |
f39f21d8 |
1732 | |
77c8cf41 |
1733 | =item * |
f39f21d8 |
1734 | |
e1f170bd |
1735 | Regular expressions on references and overloaded scalars now work. |
f39f21d8 |
1736 | |
ba370e9b |
1737 | =item * |
1738 | |
e1f170bd |
1739 | Right-hand side magic (GMAGIC) could in many cases such as string |
1740 | concatenation be invoked too many times. |
ba370e9b |
1741 | |
1742 | =item * |
1743 | |
e1f170bd |
1744 | scalar() now forces scalar context even when used in void context. |
ba370e9b |
1745 | |
1746 | =item * |
1747 | |
e1f170bd |
1748 | SOCKS support is now much more robust. |
ba370e9b |
1749 | |
1750 | =item * |
1751 | |
e1f170bd |
1752 | sort() arguments are now compiled in the right wantarray context |
1753 | (they were accidentally using the context of the sort() itself). |
44da0e71 |
1754 | The comparison block is now run in scalar context, and the arguments |
1755 | to be sorted are always provided list context. |
ba370e9b |
1756 | |
1757 | =item * |
1758 | |
e1f170bd |
1759 | Changed the POSIX character class C<[[:space:]]> to include the (very |
c2e23569 |
1760 | rarely used) vertical tab character. Added a new POSIX-ish character |
1761 | class C<[[:blank:]]> which stands for horizontal whitespace |
1762 | (currently, the space and the tab). |
ba370e9b |
1763 | |
1764 | =item * |
1765 | |
1766 | The tainting behaviour of sprintf() has been rationalized. It does |
1767 | not taint the result of floating point formats anymore, making the |
1768 | behaviour consistent with that of string interpolation. |
1769 | |
1770 | =item * |
1771 | |
44da0e71 |
1772 | Some cases of inconsistent taint propagation (such as within hash |
1773 | values) have been fixed. |
1774 | |
1775 | =item * |
1776 | |
1777 | The RE engine found in Perl 5.6.0 accidentally pessimised certain kinds |
1778 | of simple pattern matches. These are now handled better. |
1779 | |
1780 | =item * |
1781 | |
1782 | Regular expression debug output (whether through C<use re 'debug'> |
1783 | or via C<-Dr>) now looks better. |
1784 | |
1785 | =item * |
1786 | |
1787 | Multi-line matches like C<"a\nxb\n" =~ /(?!\A)x/m> were flawed. The |
1788 | bug has been fixed. |
1789 | |
1790 | =item * |
1791 | |
1792 | Use of $& could trigger a core dump under some situations. This |
1793 | is now avoided. |
1794 | |
1795 | =item * |
1796 | |
c2e23569 |
1797 | The regular expression captured submatches ($1, $2, ...) are now |
1798 | more consistently unset if the match fails, instead of leaving false |
1799 | data lying around in them. |
1800 | |
1801 | =item * |
1802 | |
44da0e71 |
1803 | readline() on files opened in "slurp" mode could return an extra "" at |
1804 | the end in certain situations. This has been corrected. |
1805 | |
1806 | =item * |
1807 | |
1808 | Autovivification of symbolic references of special variables described |
1809 | in L<perlvar> (as in C<${$num}>) was accidentally disabled. This works |
1810 | again now. |
1811 | |
1812 | =item * |
1813 | |
da6838c8 |
1814 | Sys::Syslog ignored the C<LOG_AUTH> constant. |
ba370e9b |
1815 | |
1816 | =item * |
1817 | |
e1f170bd |
1818 | All but the first argument of the IO syswrite() method are now optional. |
ba370e9b |
1819 | |
1820 | =item * |
1821 | |
e1f170bd |
1822 | $AUTOLOAD, sort(), lock(), and spawning subprocesses |
1823 | in multiple threads simultaneously are now thread-safe. |
ba370e9b |
1824 | |
1825 | =item * |
1826 | |
e1f170bd |
1827 | Tie::ARRAY SPLICE method was broken. |
ba370e9b |
1828 | |
1829 | =item * |
1830 | |
e1f170bd |
1831 | Allow read-only string on left hand side of non-modifying tr///. |
ba370e9b |
1832 | |
1833 | =item * |
1834 | |
e1f170bd |
1835 | Several Unicode fixes. |
ba370e9b |
1836 | |
1837 | =over 8 |
1838 | |
1839 | =item * |
1840 | |
e1f170bd |
1841 | BOMs (byte order marks) in the beginning of Perl files |
1842 | (scripts, modules) should now be transparently skipped. |
1843 | UTF-16 (UCS-2) encoded Perl files should now be read correctly. |
ba370e9b |
1844 | |
1845 | =item * |
1846 | |
e1f170bd |
1847 | The character tables have been updated to Unicode 3.1.1. |
ba370e9b |
1848 | |
1849 | =item * |
1850 | |
e1f170bd |
1851 | Comparing with utf8 data does not magically upgrade non-utf8 data |
1852 | into utf8. |
ba370e9b |
1853 | |
1854 | =item * |
1855 | |
e1f170bd |
1856 | C<IsAlnum>, C<IsAlpha>, and C<IsWord> now match titlecase. |
f39f21d8 |
1857 | |
77c8cf41 |
1858 | =item * |
f39f21d8 |
1859 | |
e1f170bd |
1860 | Concatenation with the C<.> operator or via variable interpolation, |
1861 | C<eq>, C<substr>, C<reverse>, C<quotemeta>, the C<x> operator, |
1862 | substitution with C<s///>, single-quoted UTF8, should now work. |
f39f21d8 |
1863 | |
77c8cf41 |
1864 | =item * |
f39f21d8 |
1865 | |
e1f170bd |
1866 | The C<tr///> operator now works. Note that the C<tr///CU> |
1867 | functionality has been removed (but see pack('U0', ...)). |
f39f21d8 |
1868 | |
77c8cf41 |
1869 | =item * |
f39f21d8 |
1870 | |
e1f170bd |
1871 | C<eval "v200"> now works. |
f39f21d8 |
1872 | |
77c8cf41 |
1873 | =item * |
f39f21d8 |
1874 | |
44da0e71 |
1875 | Perl 5.6.0 parsed m/\x{ab}/ incorrectly, leading to spurious warnings. |
1876 | This has been corrected. |
1877 | |
1878 | =item * |
1879 | |
e1f170bd |
1880 | Zero entries were missing from the Unicode classes like C<IsDigit>. |
f39f21d8 |
1881 | |
e1f170bd |
1882 | =back |
f39f21d8 |
1883 | |
44da0e71 |
1884 | =item * |
1885 | |
1886 | Large unsigned numbers (those above 2**31) could sometimes lose their |
1887 | unsignedness, causing bogus results in arithmetic operations. |
1888 | |
77c8cf41 |
1889 | =back |
f39f21d8 |
1890 | |
77c8cf41 |
1891 | =head2 Platform Specific Changes and Fixes |
f39f21d8 |
1892 | |
1893 | =over 4 |
1894 | |
1895 | =item * |
1896 | |
77c8cf41 |
1897 | BSDI 4.* |
f39f21d8 |
1898 | |
77c8cf41 |
1899 | Perl now works on post-4.0 BSD/OSes. |
f39f21d8 |
1900 | |
1901 | =item * |
1902 | |
77c8cf41 |
1903 | All BSDs |
f39f21d8 |
1904 | |
057b7f2b |
1905 | Setting C<$0> now works (as much as possible; see L<perlvar> for details). |
f39f21d8 |
1906 | |
1907 | =item * |
1908 | |
77c8cf41 |
1909 | Cygwin |
f39f21d8 |
1910 | |
77c8cf41 |
1911 | Numerous updates; currently synchronised with Cygwin 1.1.4. |
f39f21d8 |
1912 | |
1913 | =item * |
1914 | |
e1f170bd |
1915 | Previously DYNIX/ptx had problems in its Configure probe for non-blocking I/O. |
1916 | |
1917 | =item * |
1918 | |
77c8cf41 |
1919 | EPOC |
f39f21d8 |
1920 | |
77c8cf41 |
1921 | EPOC update after Perl 5.6.0. See README.epoc. |
f39f21d8 |
1922 | |
1923 | =item * |
1924 | |
77c8cf41 |
1925 | FreeBSD 3.* |
f39f21d8 |
1926 | |
77c8cf41 |
1927 | Perl now works on post-3.0 FreeBSDs. |
f39f21d8 |
1928 | |
1929 | =item * |
1930 | |
77c8cf41 |
1931 | HP-UX |
1932 | |
1933 | README.hpux updated; C<Configure -Duse64bitall> now almost works. |
f39f21d8 |
1934 | |
1935 | =item * |
1936 | |
77c8cf41 |
1937 | IRIX |
f39f21d8 |
1938 | |
77c8cf41 |
1939 | Numerous compilation flag and hint enhancements; accidental mixing |
1940 | of 32-bit and 64-bit libraries (a doomed attempt) made much harder. |
f39f21d8 |
1941 | |
77c8cf41 |
1942 | =item * |
f39f21d8 |
1943 | |
77c8cf41 |
1944 | Linux |
f39f21d8 |
1945 | |
e1f170bd |
1946 | =over 8 |
1947 | |
1948 | =item * |
1949 | |
77c8cf41 |
1950 | Long doubles should now work (see INSTALL). |
f39f21d8 |
1951 | |
1952 | =item * |
1953 | |
e1f170bd |
1954 | Linux previously had problems related to sockaddrlen when using |
1955 | accept(), revcfrom() (in Perl: recv()), getpeername(), and getsockname(). |
1956 | |
1957 | =back |
1958 | |
1959 | =item * |
1960 | |
77c8cf41 |
1961 | MacOS Classic |
f39f21d8 |
1962 | |
77c8cf41 |
1963 | Compilation of the standard Perl distribution in MacOS Classic should |
1964 | now work if you have the Metrowerks development environment and |
1965 | the missing Mac-specific toolkit bits. Contact the macperl mailing |
1966 | list for details. |
f39f21d8 |
1967 | |
1968 | =item * |
1969 | |
77c8cf41 |
1970 | MPE/iX |
f39f21d8 |
1971 | |
77c8cf41 |
1972 | MPE/iX update after Perl 5.6.0. See README.mpeix. |
f39f21d8 |
1973 | |
1974 | =item * |
1975 | |
77c8cf41 |
1976 | NetBSD/sparc |
f39f21d8 |
1977 | |
77c8cf41 |
1978 | Perl now works on NetBSD/sparc. |
f39f21d8 |
1979 | |
1980 | =item * |
1981 | |
77c8cf41 |
1982 | OS/2 |
f39f21d8 |
1983 | |
77c8cf41 |
1984 | Now works with usethreads (see INSTALL). |
f39f21d8 |
1985 | |
1986 | =item * |
1987 | |
77c8cf41 |
1988 | Solaris |
f39f21d8 |
1989 | |
77c8cf41 |
1990 | 64-bitness using the Sun Workshop compiler now works. |
f39f21d8 |
1991 | |
1992 | =item * |
1993 | |
77c8cf41 |
1994 | Tru64 (aka Digital UNIX, aka DEC OSF/1) |
f39f21d8 |
1995 | |
77c8cf41 |
1996 | The operating system version letter now recorded in $Config{osvers}. |
1997 | Allow compiling with gcc (previously explicitly forbidden). Compiling |
1998 | with gcc still not recommended because buggy code results, even with |
1999 | gcc 2.95.2. |
f39f21d8 |
2000 | |
2001 | =item * |
2002 | |
77c8cf41 |
2003 | Unicos |
2004 | |
2005 | Fixed various alignment problems that lead into core dumps either |
2006 | during build or later; no longer dies on math errors at runtime; |
2007 | now using full quad integers (64 bits), previously was using |
2008 | only 46 bit integers for speed. |
f39f21d8 |
2009 | |
2010 | =item * |
2011 | |
77c8cf41 |
2012 | VMS |
2013 | |
2014 | chdir() now works better despite a CRT bug; now works with MULTIPLICITY |
2015 | (see INSTALL); now works with Perl's malloc. |
f39f21d8 |
2016 | |
00bb525a |
2017 | The tainting of C<%ENV> elements via C<keys> or C<values> was previously |
2018 | unimplemented. It now works as documented. |
2019 | |
2020 | The C<waitpid> emulation has been improved. The worst bug (now fixed) |
2021 | was that a pid of -1 would cause a wildcard search of all processes on |
2022 | the system. The most significant enhancement is that we can now |
2023 | usually get the completion status of a terminated process. |
2024 | |
2025 | POSIX-style signals are now emulated much better on VMS versions prior |
2026 | to 7.0. |
2027 | |
2028 | The C<system> function and backticks operator have improved |
2029 | functionality and better error handling. |
2030 | |
f39f21d8 |
2031 | =item * |
2032 | |
77c8cf41 |
2033 | Windows |
f39f21d8 |
2034 | |
77c8cf41 |
2035 | =over 8 |
f39f21d8 |
2036 | |
2037 | =item * |
2038 | |
77c8cf41 |
2039 | accept() no longer leaks memory. |
f39f21d8 |
2040 | |
2041 | =item * |
2042 | |
e1f170bd |
2043 | Borland C++ v5.5 is now a supported compiler that can build Perl. |
2044 | However, the generated binaries continue to be incompatible with those |
2045 | generated by the other supported compilers (GCC and Visual C++). |
2046 | |
2047 | =item * |
2048 | |
77c8cf41 |
2049 | Better chdir() return value for a non-existent directory. |
f39f21d8 |
2050 | |
77c8cf41 |
2051 | =item * |
f39f21d8 |
2052 | |
e1f170bd |
2053 | Duping socket handles with open(F, ">&MYSOCK") now works under Windows 9x. |
2054 | |
2055 | =item * |
2056 | |
77c8cf41 |
2057 | New %ENV entries now propagate to subprocesses. |
f39f21d8 |
2058 | |
2059 | =item * |
2060 | |
44da0e71 |
2061 | Current directory entries in %ENV are now correctly propagated to child |
2062 | processes. |
2063 | |
2064 | =item * |
2065 | |
77c8cf41 |
2066 | $ENV{LIB} now used to search for libs under Visual C. |
2067 | |
2068 | =item * |
2069 | |
44da0e71 |
2070 | fork() emulation has been improved in various ways, but still continues |
2071 | to be experimental. See L<perlfork> for known bugs and caveats. |
e1f170bd |
2072 | |
2073 | =item * |
2074 | |
77c8cf41 |
2075 | A failed (pseudo)fork now returns undef and sets errno to EAGAIN. |
f39f21d8 |
2076 | |
2077 | =item * |
2078 | |
44da0e71 |
2079 | Win32::GetCwd() correctly returns C:\ instead of C: when at the drive root. |
2080 | Other bugs in chdir() and Cwd::cwd() have also been fixed. |
2081 | |
2082 | =item * |
2083 | |
e1f170bd |
2084 | HTML files will be installed in c:\perl\html instead of c:\perl\lib\pod\html |
2085 | |
2086 | =item * |
2087 | |
2088 | The makefiles now provide a single switch to bulk-enable all the features |
2089 | enabled in ActiveState ActivePerl (a popular Win32 binary distribution). |
2090 | |
2091 | =item * |
2092 | |
77c8cf41 |
2093 | Allow REG_EXPAND_SZ keys in the registry. |
f39f21d8 |
2094 | |
2095 | =item * |
2096 | |
77c8cf41 |
2097 | Can now send() from all threads, not just the first one. |
f39f21d8 |
2098 | |
2099 | =item * |
2100 | |
77c8cf41 |
2101 | Fake signal handling reenabled, bugs and all. |
f39f21d8 |
2102 | |
2103 | =item * |
2104 | |
44da0e71 |
2105 | %SIG has been enabled under USE_ITHREADS, but its use is completely |
2106 | unsupported under all configurations. |
2107 | |
2108 | =item * |
2109 | |
77c8cf41 |
2110 | Less stack reserved per thread so that more threads can run |
2111 | concurrently. (Still 16M per thread.) |
f39f21d8 |
2112 | |
2113 | =item * |
2114 | |
c2e23569 |
2115 | C<File::Spec->tmpdir()> now prefers C:/temp over /tmp |
77c8cf41 |
2116 | (works better when perl is running as service). |
f39f21d8 |
2117 | |
2118 | =item * |
2119 | |
77c8cf41 |
2120 | Better UNC path handling under ithreads. |
f39f21d8 |
2121 | |
2122 | =item * |
2123 | |
44da0e71 |
2124 | wait(), waitpid() and backticks now return the correct exit status under |
2125 | Windows 9x. |
f39f21d8 |
2126 | |
2127 | =item * |
2128 | |
77c8cf41 |
2129 | winsock handle leak fixed. |
f39f21d8 |
2130 | |
2131 | =back |
2132 | |
77c8cf41 |
2133 | =back |
f39f21d8 |
2134 | |
77c8cf41 |
2135 | =head1 New or Changed Diagnostics |
f39f21d8 |
2136 | |
ba370e9b |
2137 | =over 4 |
2138 | |
2139 | =item * |
2140 | |
77c8cf41 |
2141 | All regular expression compilation error messages are now hopefully |
2142 | easier to understand both because the error message now comes before |
2143 | the failed regex and because the point of failure is now clearly |
ba370e9b |
2144 | marked by a C<E<lt>-- HERE> marker. |
2145 | |
2146 | =item * |
f39f21d8 |
2147 | |
77c8cf41 |
2148 | The various "opened only for", "on closed", "never opened" warnings |
2149 | drop the C<main::> prefix for filehandles in the C<main> package, |
bea4d472 |
2150 | for example C<STDIN> instead of C<main::STDIN>. |
f39f21d8 |
2151 | |
ba370e9b |
2152 | =item * |
2153 | |
77c8cf41 |
2154 | The "Unrecognized escape" warning has been extended to include C<\8>, |
2155 | C<\9>, and C<\_>. There is no need to escape any of the C<\w> characters. |
f39f21d8 |
2156 | |
ba370e9b |
2157 | =item * |
f39f21d8 |
2158 | |
77c8cf41 |
2159 | Two new debugging options have been added: if you have compiled your |
2160 | Perl with debugging, you can use the -DT and -DR options to trace |
2161 | tokenising and to add reference counts to displaying variables, |
2162 | respectively. |
f39f21d8 |
2163 | |
2164 | =item * |
2165 | |
77c8cf41 |
2166 | If an attempt to use a (non-blessed) reference as an array index |
2167 | is made, a warning is given. |
f39f21d8 |
2168 | |
2169 | =item * |
2170 | |
77c8cf41 |
2171 | C<push @a;> and C<unshift @a;> (with no values to push or unshift) |
2172 | now give a warning. This may be a problem for generated and evaled |
2173 | code. |
f39f21d8 |
2174 | |
ba370e9b |
2175 | =item * |
2176 | |
2177 | If you try to L<perlfunc/pack> a number less than 0 or larger than 255 |
2178 | using the C<"C"> format you will get an optional warning. Similarly |
2179 | for the C<"c"> format and a number less than -128 or more than 127. |
2180 | |
2181 | =item * |
2182 | |
2183 | Certain regex modifiers such as C<(?o)> make sense only if applied to |
2184 | the entire regex. You will an optional warning if you try to do otherwise. |
2185 | |
2186 | =item * |
2187 | |
c2e23569 |
2188 | Using arrays or hashes as references (e.g. C<< %foo->{bar} >> |
2189 | has been deprecated for a while. Now you will get an optional warning. |
ba370e9b |
2190 | |
f39f21d8 |
2191 | =back |
2192 | |
77c8cf41 |
2193 | =head1 Changed Internals |
f39f21d8 |
2194 | |
2195 | =over 4 |
2196 | |
2197 | =item * |
2198 | |
77c8cf41 |
2199 | perlapi.pod (a companion to perlguts) now attempts to document the |
2200 | internal API. |
f39f21d8 |
2201 | |
2202 | =item * |
2203 | |
77c8cf41 |
2204 | You can now build a really minimal perl called microperl. |
2205 | Building microperl does not require even running Configure; |
2206 | C<make -f Makefile.micro> should be enough. Beware: microperl makes |
2207 | many assumptions, some of which may be too bold; the resulting |
2208 | executable may crash or otherwise misbehave in wondrous ways. |
2209 | For careful hackers only. |
f39f21d8 |
2210 | |
2211 | =item * |
2212 | |
c2e23569 |
2213 | Added rsignal(), whichsig(), do_join(), op_clear, op_null, |
2214 | ptr_table_clear(), ptr_table_free(), sv_setref_uv(), and several UTF-8 |
2215 | interfaces to the publicised API. For the full list of the available |
2216 | APIs see L<perlapi>. |
f39f21d8 |
2217 | |
2218 | =item * |
2219 | |
77c8cf41 |
2220 | Made possible to propagate customised exceptions via croak()ing. |
f39f21d8 |
2221 | |
77c8cf41 |
2222 | =item * |
f39f21d8 |
2223 | |
77c8cf41 |
2224 | Now xsubs can have attributes just like subs. |
f39f21d8 |
2225 | |
2226 | =item * |
2227 | |
77c8cf41 |
2228 | dTHR and djSP have been obsoleted; the former removed (because it's |
2229 | a no-op) and the latter replaced with dSP. |
f39f21d8 |
2230 | |
2231 | =item * |
2232 | |
61947107 |
2233 | PERL_OBJECT has been completely removed. |
2234 | |
2235 | =item * |
2236 | |
ba370e9b |
2237 | The MAGIC constants (e.g. C<'P'>) have been macrofied |
2238 | (e.g. C<PERL_MAGIC_TIED>) for better source code readability |
2239 | and maintainability. |
2240 | |
2241 | =item * |
2242 | |
2243 | The regex compiler now maintains a structure that identifies nodes in |
2244 | the compiled bytecode with the corresponding syntactic features of the |
2245 | original regex expression. The information is attached to the new |
2246 | C<offsets> member of the C<struct regexp>. See L<perldebguts> for more |
2247 | complete information. |
2248 | |
2249 | =item * |
2250 | |
2251 | The C code has been made much more C<gcc -Wall> clean. Some warning |
2252 | messages still remain in some platforms, so if you are compiling with |
2253 | gcc you may see some warnings about dubious practices. The warnings |
2254 | are being worked on. |
2255 | |
2256 | =item * |
2257 | |
2258 | F<perly.c>, F<sv.c>, and F<sv.h> have now been extensively commented. |
2259 | |
2260 | =item * |
2261 | |
61947107 |
2262 | Documentation on how to use the Perl source repository has been added |
2263 | to F<Porting/repository.pod>. |
f39f21d8 |
2264 | |
888aee59 |
2265 | =item * |
2266 | |
c2e23569 |
2267 | There are now several profiling make targets. |
888aee59 |
2268 | |
77c8cf41 |
2269 | =back |
f39f21d8 |
2270 | |
77c8cf41 |
2271 | =head1 Security Vulnerability Closed |
f39f21d8 |
2272 | |
77c8cf41 |
2273 | (This change was already made in 5.7.0 but bears repeating here.) |
f39f21d8 |
2274 | |
77c8cf41 |
2275 | A potential security vulnerability in the optional suidperl component |
2276 | of Perl was identified in August 2000. suidperl is neither built nor |
2277 | installed by default. As of November 2001 the only known vulnerable |
2278 | platform is Linux, most likely all Linux distributions. CERT and |
2279 | various vendors and distributors have been alerted about the vulnerability. |
2280 | See http://www.cpan.org/src/5.0/sperl-2000-08-05/sperl-2000-08-05.txt |
2281 | for more information. |
f39f21d8 |
2282 | |
77c8cf41 |
2283 | The problem was caused by Perl trying to report a suspected security |
2284 | exploit attempt using an external program, /bin/mail. On Linux |
2285 | platforms the /bin/mail program had an undocumented feature which |
2286 | when combined with suidperl gave access to a root shell, resulting in |
2287 | a serious compromise instead of reporting the exploit attempt. If you |
2288 | don't have /bin/mail, or if you have 'safe setuid scripts', or if |
2289 | suidperl is not installed, you are safe. |
f39f21d8 |
2290 | |
77c8cf41 |
2291 | The exploit attempt reporting feature has been completely removed from |
2292 | Perl 5.8.0 (and the maintenance release 5.6.1, and it was removed also |
2293 | from all the Perl 5.7 releases), so that particular vulnerability |
2294 | isn't there anymore. However, further security vulnerabilities are, |
ba370e9b |
2295 | unfortunately, always possible. The suidperl functionality is most |
2296 | probably going to be removed in Perl 5.10. In any case, suidperl |
2297 | should only be used by security experts who know exactly what they are |
2298 | doing and why they are using suidperl instead of some other solution |
2299 | such as sudo (see http://www.courtesan.com/sudo/). |
77c8cf41 |
2300 | |
2301 | =head1 New Tests |
2302 | |
76663d67 |
2303 | Several new tests have been added, especially for the F<lib> |
2304 | subsection. There are now about 34 000 individual tests (spread over |
2305 | about 530 test scripts), in the regression suite (5.6.1 has about |
2306 | 11700 tests, in 258 test scripts) Many of the new tests are introduced |
2307 | by the new modules, but still in general Perl is now more thoroughly |
2308 | tested. |
2309 | |
2310 | Because of the large number of tests, running the regression suite |
2311 | will take considerably longer time than it used to: expect the suite |
2312 | to take up to 4-5 times longer to run than in perl 5.6. In a really |
2313 | fast machine you can hope to finish the suite in about 5 minutes |
2314 | (wallclock time). |
77c8cf41 |
2315 | |
2316 | The tests are now reported in a different order than in earlier Perls. |
2317 | (This happens because the test scripts from under t/lib have been moved |
2318 | to be closer to the library/extension they are testing.) |
2319 | |
f39f21d8 |
2320 | =head1 Known Problems |
2321 | |
f39f21d8 |
2322 | =head2 AIX |
2323 | |
2324 | =over 4 |
2325 | |
2326 | =item * |
2327 | |
2328 | In AIX 4.2 Perl extensions that use C++ functions that use statics |
2329 | may have problems in that the statics are not getting initialized. |
2330 | In newer AIX releases this has been solved by linking Perl with |
2331 | the libC_r library, but unfortunately in AIX 4.2 the said library |
2332 | has an obscure bug where the various functions related to time |
2333 | (such as time() and gettimeofday()) return broken values, and |
2334 | therefore in AIX 4.2 Perl is not linked against the libC_r. |
2335 | |
2336 | =item * |
2337 | |
2338 | vac 5.0.0.0 May Produce Buggy Code For Perl |
2339 | |
2340 | The AIX C compiler vac version 5.0.0.0 may produce buggy code, |
2341 | resulting in few random tests failing, but when the failing tests |
2342 | are run by hand, they succeed. We suggest upgrading to at least |
2343 | vac version 5.0.1.0, that has been known to compile Perl correctly. |
2344 | "lslpp -L|grep vac.C" will tell you the vac version. |
2345 | |
2346 | =back |
2347 | |
2348 | =head2 Amiga Perl Invoking Mystery |
2349 | |
2350 | One cannot call Perl using the C<volume:> syntax, that is, C<perl -v> |
057b7f2b |
2351 | works, but for example C<bin:perl -v> doesn't. The exact reason isn't |
f39f21d8 |
2352 | known but the current suspect is the F<ixemul> library. |
2353 | |
2354 | =head2 lib/ftmp-security tests warn 'system possibly insecure' |
2355 | |
2356 | Don't panic. Read INSTALL 'make test' section instead. |
2357 | |
2358 | =head2 Cygwin intermittent failures of lib/Memoize/t/expire_file 11 and 12 |
2359 | |
2360 | The subtests 11 and 12 sometimes fail and sometimes work. |
2361 | |
2362 | =head2 HP-UX lib/io_multihomed Fails When LP64-Configured |
2363 | |
2364 | The lib/io_multihomed test may hang in HP-UX if Perl has been |
2365 | configured to be 64-bit. Because other 64-bit platforms do not hang in |
2366 | this test, HP-UX is suspect. All other tests pass in 64-bit HP-UX. The |
2367 | test attempts to create and connect to "multihomed" sockets (sockets |
2368 | which have multiple IP addresses). |
2369 | |
2370 | =head2 HP-UX lib/posix Subtest 9 Fails When LP64-Configured |
2371 | |
2372 | If perl is configured with -Duse64bitall, the successful result of the |
2373 | subtest 10 of lib/posix may arrive before the successful result of the |
2374 | subtest 9, which confuses the test harness so much that it thinks the |
2375 | subtest 9 failed. |
2376 | |
2377 | =head2 Linux With Sfio Fails op/misc Test 48 |
2378 | |
2379 | No known fix. |
2380 | |
a0aae13b |
2381 | =head2 Mac OS X |
2382 | |
2383 | The following tests are known to fail: |
2384 | |
2385 | Failed Test Stat Wstat Total Fail Failed List of Failed |
2386 | ------------------------------------------------------------------------- |
2387 | ../ext/DB_File/t/db-btree.t 0 11 ?? ?? % ?? |
2388 | ../ext/DB_File/t/db-recno.t 149 3 2.01% 61 63 65 |
2389 | ../ext/POSIX/t/posix.t 31 1 3.23% 10 |
2390 | ../lib/warnings.t 450 1 0.22% 316 |
2391 | |
f39f21d8 |
2392 | =head2 OS/390 |
2393 | |
2394 | OS/390 has rather many test failures but the situation is actually |
2395 | better than it was in 5.6.0, it's just that so many new modules and |
2396 | tests have been added. |
2397 | |
2398 | Failed Test Stat Wstat Total Fail Failed List of Failed |
2399 | ----------------------------------------------------------------------------- |
2400 | ../ext/B/Deparse.t 14 1 7.14% 14 |
2401 | ../ext/B/Showlex.t 1 1 100.00% 1 |
2402 | ../ext/Encode/Encode/Tcl.t 610 13 2.13% 592 594 596 598 |
2403 | 600 602 604-610 |
2404 | ../ext/IO/lib/IO/t/io_unix.t 113 28928 5 3 60.00% 3-5 |
2405 | ../ext/POSIX/POSIX.t 29 1 3.45% 14 |
2406 | ../ext/Storable/t/lock.t 255 65280 5 3 60.00% 3-5 |
2407 | ../lib/locale.t 129 33024 117 19 16.24% 99-117 |
2408 | ../lib/warnings.t 434 1 0.23% 75 |
2409 | ../lib/ExtUtils.t 27 1 3.70% 25 |
2410 | ../lib/Math/BigInt/t/bigintpm.t 1190 1 0.08% 1145 |
2411 | ../lib/Unicode/UCD.t 81 48 59.26% 1-16 49-64 66-81 |
2412 | ../lib/User/pwent.t 9 1 11.11% 4 |
2413 | op/pat.t 660 6 0.91% 242-243 424-425 |
2414 | 626-627 |
2415 | op/split.t 0 9 ?? ?? % ?? |
2416 | op/taint.t 174 3 1.72% 156 162 168 |
2417 | op/tr.t 70 3 4.29% 50 58-59 |
2418 | Failed 16/422 test scripts, 96.21% okay. 105/23251 subtests failed, 99.55% okay. |
2419 | |
2420 | =head2 op/sprintf tests 129 and 130 |
2421 | |
2422 | The op/sprintf tests 129 and 130 are known to fail on some platforms. |
2423 | Examples include any platform using sfio, and Compaq/Tandem's NonStop-UX. |
2424 | The failing platforms do not comply with the ANSI C Standard, line |
2425 | 19ff on page 134 of ANSI X3.159 1989 to be exact. (They produce |
2426 | something other than "1" and "-1" when formatting 0.6 and -0.6 using |
2427 | the printf format "%.0f", most often they produce "0" and "-0".) |
2428 | |
2429 | =head2 Failure of Thread tests |
2430 | |
fedd8cf1 |
2431 | B<Note that support for 5.005-style threading remains experimental |
2432 | and practically unsupported.> |
f39f21d8 |
2433 | |
2434 | The following tests are known to fail due to fundamental problems in |
2435 | the 5.005 threading implementation. These are not new failures--Perl |
2436 | 5.005_0x has the same bugs, but didn't have these tests. |
2437 | |
fedd8cf1 |
2438 | ext/List/Util/t/first 2 |
2439 | lib/autouse 4 |
2440 | ext/Thread/thr5005 19-20 |
2441 | |
2442 | These failures are unlikely to get fixed. |
f39f21d8 |
2443 | |
2444 | =head2 UNICOS |
2445 | |
2446 | =over 4 |
2447 | |
2448 | =item * |
2449 | |
2450 | ext/POSIX/sigaction subtests 6 and 13 may fail. |
2451 | |
2452 | =item * |
2453 | |
2454 | lib/ExtUtils may spuriously claim that subtest 28 failed, |
2455 | which is interesting since the test only has 27 tests. |
2456 | |
2457 | =item * |
2458 | |
2459 | Numerous numerical test failures |
2460 | |
2461 | op/numconvert 209,210,217,218 |
2462 | op/override 7 |
2463 | ext/Time/HiRes/HiRes 9 |
2464 | lib/Math/BigInt/t/bigintpm 1145 |
2465 | lib/Math/Trig 25 |
2466 | |
2467 | These tests fail because of yet unresolved floating point inaccuracies. |
2468 | |
2469 | =back |
2470 | |
2471 | =head2 UTS |
2472 | |
2473 | There are a few known test failures, see L<perluts>. |
2474 | |
2475 | =head2 VMS |
2476 | |
00bb525a |
2477 | There is one known test failure with a default configuration: |
aecce728 |
2478 | |
2479 | [.run]switches..........................FAILED on test 1 |
aecce728 |
2480 | |
f39f21d8 |
2481 | =head2 Win32 |
2482 | |
2483 | In multi-CPU boxes there are some problems with the I/O buffering: |
2484 | some output may appear twice. |
2485 | |
2486 | =head2 Localising a Tied Variable Leaks Memory |
2487 | |
2488 | use Tie::Hash; |
2489 | tie my %tie_hash => 'Tie::StdHash'; |
2490 | |
2491 | ... |
2492 | |
2493 | local($tie_hash{Foo}) = 1; # leaks |
2494 | |
2495 | Code like the above is known to leak memory every time the local() |
2496 | is executed. |
2497 | |
aecce728 |
2498 | =head2 Localising Tied Arrays and Hashes Is Broken |
2499 | |
2500 | local %tied_array; |
2501 | |
2502 | doesn't work as one would expect: the old value is restored |
2503 | incorrectly. |
2504 | |
f39f21d8 |
2505 | =head2 Self-tying of Arrays and Hashes Is Forbidden |
2506 | |
2507 | Self-tying of arrays and hashes is broken in rather deep and |
2508 | hard-to-fix ways. As a stop-gap measure to avoid people from getting |
2509 | frustrated at the mysterious results (core dumps, most often) it is |
2510 | for now forbidden (you will get a fatal error even from an attempt). |
2511 | |
2512 | =head2 Variable Attributes are not Currently Usable for Tieing |
2513 | |
2514 | This limitation will hopefully be fixed in future. (Subroutine |
2515 | attributes work fine for tieing, see L<Attribute::Handlers>). |
2516 | |
aecce728 |
2517 | One way to run into this limitation is to have a loop variable with |
2518 | attributes within a loop: the tie is called only once, not for each |
2519 | iteration of the loop. |
2520 | |
f39f21d8 |
2521 | =head2 Building Extensions Can Fail Because Of Largefiles |
2522 | |
2523 | Some extensions like mod_perl are known to have issues with |
2524 | `largefiles', a change brought by Perl 5.6.0 in which file offsets |
2525 | default to 64 bits wide, where supported. Modules may fail to compile |
2526 | at all or compile and work incorrectly. Currently there is no good |
2527 | solution for the problem, but Configure now provides appropriate |
2528 | non-largefile ccflags, ldflags, libswanted, and libs in the %Config |
2529 | hash (e.g., $Config{ccflags_nolargefiles}) so the extensions that are |
2530 | having problems can try configuring themselves without the |
2531 | largefileness. This is admittedly not a clean solution, and the |
2532 | solution may not even work at all. One potential failure is whether |
2533 | one can (or, if one can, whether it's a good idea) link together at |
2534 | all binaries with different ideas about file offsets, all this is |
2535 | platform-dependent. |
2536 | |
aecce728 |
2537 | =head2 Unicode Support on EBCDIC Still Spotty |
2538 | |
2539 | Though mostly working, Unicode support still has problem spots on |
2540 | EBCDIC platforms. One such known spot are the C<\p{}> and C<\P{}> |
2541 | regular expression constructs for code points less than 256: the |
2542 | pP are testing for Unicode code points, not knowing about EBCDIC. |
2543 | |
f39f21d8 |
2544 | =head2 The Compiler Suite Is Still Experimental |
2545 | |
44da0e71 |
2546 | The compiler suite is slowly getting better but it continues to be |
2547 | highly experimental. Use in production environments is discouraged. |
f39f21d8 |
2548 | |
2549 | =head2 The Long Double Support is Still Experimental |
2550 | |
2551 | The ability to configure Perl's numbers to use "long doubles", |
2552 | floating point numbers of hopefully better accuracy, is still |
2553 | experimental. The implementations of long doubles are not yet |
2554 | widespread and the existing implementations are not quite mature |
2555 | or standardised, therefore trying to support them is a rare |
2556 | and moving target. The gain of more precision may also be offset |
2557 | by slowdown in computations (more bits to move around, and the |
2558 | operations are more likely to be executed by less optimised |
2559 | libraries). |
33a87e58 |
2560 | |
cc0fca54 |
2561 | =head1 Reporting Bugs |
2562 | |
d4ad863d |
2563 | If you find what you think is a bug, you might check the articles |
2564 | recently posted to the comp.lang.perl.misc newsgroup and the perl |
2565 | bug database at http://bugs.perl.org. There may also be |
2566 | information at http://www.perl.com/perl/, the Perl Home Page. |
cc0fca54 |
2567 | |
2568 | If you believe you have an unreported bug, please run the B<perlbug> |
2569 | program included with your release. Be sure to trim your bug down |
2570 | to a tiny but sufficient test case. Your bug report, along with the |
d4ad863d |
2571 | output of C<perl -V>, will be sent off to perlbug@perl.org to be |
cc0fca54 |
2572 | analysed by the Perl porting team. |
2573 | |
2574 | =head1 SEE ALSO |
2575 | |
2576 | The F<Changes> file for exhaustive details on what changed. |
2577 | |
2578 | The F<INSTALL> file for how to build Perl. |
2579 | |
2580 | The F<README> file for general stuff. |
2581 | |
2582 | The F<Artistic> and F<Copying> files for copyright information. |
2583 | |
2584 | =head1 HISTORY |
2585 | |
d468ca04 |
2586 | Written by Jarkko Hietaniemi <F<jhi@iki.fi>>. |
cc0fca54 |
2587 | |
2588 | =cut |