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1 | =head1 NAME |
2 | |
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3 | perldelta - what's new for perl v5.6 (as of v5.005_58) |
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4 | |
5 | =head1 DESCRIPTION |
6 | |
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7 | This is an unsupported alpha release, meant for intrepid Perl developers |
8 | only. The included sources may not even build correctly on some platforms. |
9 | Subscribing to perl5-porters is the best way to monitor and contribute |
10 | to the progress of development releases (see www.perl.org for info). |
11 | |
ba8251e8 |
12 | This document describes differences between the 5.005 release and this one. |
13 | |
14 | =head1 Incompatible Changes |
15 | |
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16 | =head2 Perl Source Incompatibilities |
17 | |
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18 | TODO |
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19 | |
20 | =head2 C Source Incompatibilities |
21 | |
22 | =over 4 |
23 | |
24 | =item C<PERL_POLLUTE> |
25 | |
26 | Release 5.005 grandfathered old global symbol names by providing preprocessor |
87275199 |
27 | macros for extension source compatibility. As of release 5.6, these |
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28 | preprocessor definitions are not available by default. You need to explicitly |
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29 | compile perl with C<-DPERL_POLLUTE> to get these definitions. For |
30 | extensions still using the old symbols, this option can be |
2aea4d40 |
31 | specified via MakeMaker: |
32 | |
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33 | perl Makefile.PL POLLUTE=1 |
e02fdbd2 |
34 | |
f29c64d6 |
35 | =item C<PERL_IMPLICIT_CONTEXT> |
36 | |
37 | This new build option provides a set of macros for all API functions |
38 | such that an implicit interpreter/thread context argument is passed to |
39 | every API function. As a result of this, something like C<sv_setsv(foo,bar)> |
2c2d71f5 |
40 | amounts to a macro invocation that actually translates to something like |
f29c64d6 |
41 | C<Perl_sv_setsv(my_perl,foo,bar)>. While this is generally expected |
42 | to not have any significant source compatibility issues, the difference |
43 | between a macro and a real function call will need to be considered. |
44 | |
2c2d71f5 |
45 | This means that there B<is> a source compatibility issue as a result of |
46 | this if your extensions attempt to use pointers to any of the Perl API |
47 | functions. |
48 | |
f29c64d6 |
49 | Note that the above issue is not relevant to the default build of |
50 | Perl, whose interfaces continue to match those of prior versions |
51 | (but subject to the other options described here). |
52 | |
53 | For testing purposes, the 5.005_58 release automatically enables |
54 | PERL_IMPLICIT_CONTEXT whenever Perl is built with -Dusethreads or |
55 | -Dusemultiplicity. |
56 | |
2c2d71f5 |
57 | See L<perlguts/"The Perl API"> for detailed information on the |
58 | ramifications of building Perl using this option. |
59 | |
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60 | =item C<PERL_POLLUTE_MALLOC> |
61 | |
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62 | Enabling Perl's malloc in release 5.005 and earlier caused |
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63 | the namespace of system versions of the malloc family of functions to |
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64 | be usurped by the Perl versions, since by default they used the |
65 | same names. |
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66 | |
67 | Besides causing problems on platforms that do not allow these functions to |
68 | be cleanly replaced, this also meant that the system versions could not |
69 | be called in programs that used Perl's malloc. Previous versions of Perl |
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70 | have allowed this behaviour to be suppressed with the HIDEMYMALLOC and |
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71 | EMBEDMYMALLOC preprocessor definitions. |
72 | |
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73 | As of release 5.6, Perl's malloc family of functions have default names |
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74 | distinct from the system versions. You need to explicitly compile perl with |
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75 | C<-DPERL_POLLUTE_MALLOC> to get the older behaviour. HIDEMYMALLOC |
76 | and EMBEDMYMALLOC have no effect, since the behaviour they enabled is now |
86058a2d |
77 | the default. |
78 | |
79 | Note that these functions do B<not> constitute Perl's memory allocation API. |
80 | See L<perlguts/"Memory Allocation"> for further information about that. |
81 | |
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82 | =item C<PL_na> and C<dTHR> Issues |
83 | |
84 | The C<PL_na> global is now thread local, so a C<dTHR> declaration is needed |
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85 | in the scope in which the global appears. XSUBs should handle this automatically, |
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86 | but if you have used C<PL_na> in support functions, you either need to |
87 | change the C<PL_na> to a local variable (which is recommended), or put in |
88 | a C<dTHR>. |
89 | |
90 | =back |
91 | |
cceca5ed |
92 | =head2 Compatible C Source API Changes |
93 | |
94 | =over |
95 | |
96 | =item C<PATCHLEVEL> is now C<PERL_VERSION> |
97 | |
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98 | The cpp macros C<PERL_REVISION>, C<PERL_VERSION>, and C<PERL_SUBVERSION> |
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99 | are now available by default from perl.h, and reflect the base revision, |
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100 | patchlevel, and subversion respectively. C<PERL_REVISION> had no |
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101 | prior equivalent, while C<PERL_VERSION> and C<PERL_SUBVERSION> were |
102 | previously available as C<PATCHLEVEL> and C<SUBVERSION>. |
103 | |
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104 | The new names cause less pollution of the B<cpp> namespace and reflect what |
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105 | the numbers have come to stand for in common practice. For compatibility, |
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106 | the old names are still supported when F<patchlevel.h> is explicitly |
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107 | included (as required before), so there is no source incompatibility |
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108 | from the change. |
cceca5ed |
109 | |
110 | =back |
111 | |
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112 | =head2 Binary Incompatibilities |
113 | |
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114 | The default build of this release is binary compatible with the 5.005 |
115 | release or its maintenance versions. |
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116 | |
117 | The usethreads or usemultiplicity builds are B<not> binary compatible |
118 | with the corresponding builds in 5.005. |
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119 | |
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120 | =head1 Core Changes |
121 | |
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122 | =head2 Unicode and UTF-8 support |
123 | |
124 | Perl can optionally use UTF-8 as its internal representation for character |
125 | strings. The C<use utf8> pragma enables this support in the current lexical |
126 | scope. See L<utf8> for more information. |
127 | |
128 | =head2 Lexically scoped warning categories |
129 | |
130 | You can now control the granularity of warnings emitted by perl at a finer |
0453d815 |
131 | level using the C<use warning> pragma. See L<warning> and L<perllexwarn> |
132 | for details. |
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133 | |
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134 | =head2 Binary numbers supported |
135 | |
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136 | Binary numbers are now supported as literals, in s?printf formats, and |
137 | C<oct()>: |
138 | |
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139 | $answer = 0b101010; |
140 | printf "The answer is: %b\n", oct("0b101010"); |
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141 | |
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142 | =head2 syswrite() ease-of-use |
143 | |
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144 | The length argument of C<syswrite()> is now optional. |
145 | |
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146 | =head2 64-bit support |
147 | |
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148 | All platforms that have 64-bit integers either (a) natively as longs |
149 | or ints (b) via special compiler flags (c) using long long are able to |
150 | use "quads" (64-integers) as follows: |
151 | |
152 | =over 4 |
153 | |
154 | =item constants in the code |
155 | |
156 | =item arguments to oct() and hex() |
157 | |
158 | =item arguments to print(), printf() and sprintf() |
159 | |
160 | =item pack() and unpack() "q" format |
161 | |
162 | =item in basic arithmetics |
163 | |
164 | =back |
165 | |
166 | Note that unless you have the case (a) you will have to configure |
167 | and compile Perl using the -Duse64bits Configure flag. |
168 | |
169 | Unfortunately, bit operations (&, <<, ...) and vec() do not work, |
170 | they are limited to 32 bits. |
171 | |
172 | Last but not least: note that due to Perl's tendency to always use |
173 | floating point numbers the quads are not true integers. They may lose |
174 | their precision due to rounding errors, and when they get large their |
175 | less significant digits will fall off. |
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176 | |
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177 | =head2 Better syntax checks on parenthesized unary operators |
178 | |
179 | Expressions such as: |
180 | |
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181 | print defined(&foo,&bar,&baz); |
182 | print uc("foo","bar","baz"); |
183 | undef($foo,&bar); |
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184 | |
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185 | used to be accidentally allowed in earlier versions, and produced |
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186 | unpredictable behaviour. Some produced ancillary warnings |
187 | when used in this way; others silently did the wrong thing. |
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188 | |
189 | The parenthesized forms of most unary operators that expect a single |
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190 | argument now ensure that they are not called with more than one |
191 | argument, making the cases shown above syntax errors. The usual |
192 | behaviour of: |
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193 | |
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194 | print defined &foo, &bar, &baz; |
195 | print uc "foo", "bar", "baz"; |
196 | undef $foo, &bar; |
62c18ce2 |
197 | |
198 | remains unchanged. See L<perlop>. |
199 | |
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200 | =head2 POSIX character class syntax [: :] supported |
201 | |
202 | For example to match alphabetic characters use /[[:alpha:]]/. |
203 | See L<perlre> for details. |
204 | |
5a929a98 |
205 | =head2 Improved C<qw//> operator |
8127e0e3 |
206 | |
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207 | The C<qw//> operator is now evaluated at compile time into a true list |
208 | instead of being replaced with a run time call to C<split()>. This |
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209 | removes the confusing misbehaviour of C<qw//> in scalar context, which |
210 | had inherited that behaviour from split(). |
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211 | |
212 | Thus: |
213 | |
214 | $foo = ($bar) = qw(a b c); print "$foo|$bar\n"; |
215 | |
216 | now correctly prints "3|a", instead of "2|a". |
8127e0e3 |
217 | |
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218 | =head2 pack() format 'Z' supported |
219 | |
220 | The new format type 'Z' is useful for packing and unpacking null-terminated |
221 | strings. See L<perlfunc/"pack">. |
222 | |
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223 | =head2 pack() format modifier '!' supported |
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224 | |
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225 | The new format type modifier '!' is useful for packing and unpacking |
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226 | native shorts, ints, and longs. See L<perlfunc/"pack">. |
227 | |
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228 | =head2 pack() and unpack() support counted strings |
229 | |
230 | The template character '#' can be used to specify a counted string |
231 | type to be packed or unpacked. See L<perlfunc/"pack">. |
232 | |
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233 | =head2 $^X variables may now have names longer than one character |
234 | |
235 | Formerly, $^X was synonymous with ${"\cX"}, but $^XY was a syntax |
236 | error. Now variable names that begin with a control character may be |
237 | arbitrarily long. However, for compatibility reasons, these variables |
238 | I<must> be written with explicit braces, as C<${^XY}> for example. |
14218588 |
239 | C<${^XYZ}> is synonymous with ${"\cXYZ"}. Variable names with more |
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240 | than one control character, such as C<${^XY^Z}>, are illegal. |
241 | |
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242 | The old syntax has not changed. As before, `^X' may be either a |
243 | literal control-X character or the two-character sequence `caret' plus |
244 | `X'. When braces are omitted, the variable name stops after the |
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245 | control character. Thus C<"$^XYZ"> continues to be synonymous with |
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246 | C<$^X . "YZ"> as before. |
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247 | |
248 | As before, lexical variables may not have names beginning with control |
249 | characters. As before, variables whose names begin with a control |
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250 | character are always forced to be in package `main'. All such variables |
251 | are reserved for future extensions, except those that begin with |
252 | C<^_>, which may be used by user programs and is guaranteed not to |
253 | acquire special meaning in any future version of Perl. |
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254 | |
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255 | =head1 Significant bug fixes |
256 | |
257 | =head2 E<lt>HANDLEE<gt> on empty files |
258 | |
259 | With C<$/> set to C<undef>, slurping an empty file returns a string of |
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260 | zero length (instead of C<undef>, as it used to) the first time the |
261 | HANDLE is read. Further reads yield C<undef>. |
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262 | |
263 | This means that the following will append "foo" to an empty file (it used |
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264 | to do nothing): |
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265 | |
266 | perl -0777 -pi -e 's/^/foo/' empty_file |
267 | |
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268 | The behaviour of: |
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269 | |
270 | perl -pi -e 's/^/foo/' empty_file |
271 | |
272 | is unchanged (it continues to leave the file empty). |
273 | |
0244c3a4 |
274 | =head2 C<eval '...'> improvements |
275 | |
276 | Line numbers (as reflected by caller() and most diagnostics) within |
277 | C<eval '...'> were often incorrect when here documents were involved. |
278 | This has been corrected. |
279 | |
280 | Lexical lookups for variables appearing in C<eval '...'> within |
281 | functions that were themselves called within an C<eval '...'> were |
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282 | searching the wrong place for lexicals. The lexical search now |
283 | correctly ends at the subroutine's block boundary. |
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284 | |
285 | Parsing of here documents used to be flawed when they appeared as |
286 | the replacement expression in C<eval 's/.../.../e'>. This has |
287 | been fixed. |
288 | |
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289 | =head2 Automatic flushing of output buffers |
290 | |
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291 | fork(), exec(), system(), qx//, and pipe open()s now flush buffers |
292 | of all files opened for output when the operation |
293 | was attempted. This mostly eliminates confusing |
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294 | buffering mishaps suffered by users unaware of how Perl internally |
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295 | handles I/O. |
45bc9206 |
296 | |
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297 | =head2 Better diagnostics on meaningless filehandle operations |
298 | |
299 | Constructs such as C<open(E<lt>FHE<gt>)> and C<close(E<lt>FHE<gt>)> |
300 | are compile time errors. Attempting to read from filehandles that |
301 | were opened only for writing will now produce warnings (just as |
302 | writing to read-only filehandles does). |
303 | |
54195c32 |
304 | =head2 Buffered data discarded from input filehandle when dup'ed. |
305 | |
306 | C<open(NEW, "E<lt>&OLD")> now discards any data that was previously |
307 | read and buffered in C<OLD>. The next read operation on C<NEW> will |
308 | return the same data as the corresponding operation on C<OLD>. |
309 | Formerly, it would have returned the data from the start of the |
310 | following disk block instead. |
311 | |
ba8251e8 |
312 | =head1 Supported Platforms |
313 | |
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314 | =over 4 |
315 | |
316 | =item * |
317 | |
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318 | VM/ESA is now supported. |
319 | |
5fdc711f |
320 | =item * |
321 | |
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322 | Siemens BS2000 is now supported under the POSIX Shell. |
323 | |
324 | =item * |
325 | |
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326 | The Mach CThreads (NEXTSTEP, OPENSTEP) are now supported by the Thread |
327 | extension. |
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328 | |
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329 | =item * |
330 | |
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331 | GNU/Hurd is now supported. |
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332 | |
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333 | =item * |
334 | |
335 | Rhapsody is now supported. |
336 | |
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337 | =item * |
338 | |
339 | EPOC is is now supported (on Psion 5). |
340 | |
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341 | =back |
342 | |
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343 | =head1 New tests |
344 | |
345 | =over 4 |
346 | |
347 | =item op/io_const |
348 | |
349 | IO constants (SEEK_*, _IO*). |
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350 | |
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351 | =item op/io_dir |
352 | |
353 | Directory-related IO methods (new, read, close, rewind, tied delete). |
354 | |
355 | =item op/io_multihomed |
356 | |
357 | INET sockets with multi-homed hosts. |
358 | |
359 | =item op/io_poll |
360 | |
361 | IO poll(). |
362 | |
363 | =item op/io_unix |
364 | |
365 | UNIX sockets. |
366 | |
367 | =item op/filetest |
368 | |
369 | File test operators. |
370 | |
371 | =item op/lex_assign |
372 | |
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373 | Verify operations that access pad objects (lexicals and temporaries). |
6c67e1bb |
374 | |
375 | =back |
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376 | |
ba8251e8 |
377 | =head1 Modules and Pragmata |
378 | |
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379 | =head2 Modules |
380 | |
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381 | =over 4 |
382 | |
f29c64d6 |
383 | =item ByteLoader |
384 | |
385 | The ByteLoader is a dedication extension to generate and run |
386 | Perl bytecode. See L<ByteLoader>. |
387 | |
388 | =item B |
389 | |
390 | The Perl Compiler suite has been extensively reworked for this |
391 | release. |
392 | |
393 | =item Devel::DProf |
394 | |
395 | Devel::DProf, a Perl source code profiler has been added. |
396 | |
b7d8191e |
397 | =item Dumpvalue |
398 | |
399 | Added Dumpvalue module provides screen dumps of Perl data. |
400 | |
401 | =item Benchmark |
402 | |
868cb350 |
403 | You can now run tests for I<n> seconds instead of guessing the right |
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404 | number of tests to run: e.g. timethese(-5, ...) will run each |
405 | code for at least 5 CPU seconds. Zero as the "number of repetitions" |
155776c0 |
406 | means "for at least 3 CPU seconds". The output format has also |
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407 | changed. For example: |
155776c0 |
408 | |
409 | use Benchmark;$x=3;timethese(-5,{a=>sub{$x*$x},b=>sub{$x**2}}) |
410 | |
411 | will now output something like this: |
412 | |
413 | Benchmark: running a, b, each for at least 5 CPU seconds... |
414 | a: 5 wallclock secs ( 5.77 usr + 0.00 sys = 5.77 CPU) @ 200551.91/s (n=1156516) |
415 | b: 4 wallclock secs ( 5.00 usr + 0.02 sys = 5.02 CPU) @ 159605.18/s (n=800686) |
416 | |
417 | New features: "each for at least N CPU seconds...", "wallclock secs", |
418 | and the "@ operations/CPU second (n=operations)". |
b7d8191e |
419 | |
f505c983 |
420 | =item Devel::Peek |
421 | |
422 | The Devel::Peek module provides access to the internal representation |
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423 | of Perl variables and data. It is a data debugging tool for the XS programmer. |
f505c983 |
424 | |
b7d8191e |
425 | =item Fcntl |
426 | |
427 | More Fcntl constants added: F_SETLK64, F_SETLKW64, O_LARGEFILE for |
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428 | large (more than 4G) file access (64-bit support is not yet |
b7d8191e |
429 | working, though, so no need to get overly excited), Free/Net/OpenBSD |
430 | locking behaviour flags F_FLOCK, F_POSIX, Linux F_SHLCK, and |
431 | O_ACCMODE: the mask of O_RDONLY, O_WRONLY, and O_RDWR. |
432 | |
f505c983 |
433 | =item File::Spec |
434 | |
435 | New methods have been added to the File::Spec module: devnull() returns |
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436 | the name of the null device (/dev/null on Unix) and tmpdir() the name of |
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437 | the temp directory (normally /tmp on Unix). There are now also methods |
f505c983 |
438 | to convert between absolute and relative filenames: abs2rel() and |
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439 | rel2abs(). For compatibility with operating systems that specify volume |
440 | names in file paths, the splitpath(), splitdir(), and catdir() methods |
f505c983 |
441 | have been added. |
442 | |
443 | =item File::Spec::Functions |
444 | |
445 | The new File::Spec::Functions modules provides a function interface |
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446 | to the File::Spec module. Allows shorthand |
f505c983 |
447 | |
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448 | $fullname = catfile($dir1, $dir2, $file); |
f505c983 |
449 | |
450 | instead of |
451 | |
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452 | $fullname = File::Spec->catfile($dir1, $dir2, $file); |
f505c983 |
453 | |
e16b8f49 |
454 | =item Math::BigInt |
455 | |
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456 | The logical operations C<E<lt>E<lt>>, C<E<gt>E<gt>>, C<&>, C<|>, |
e16b8f49 |
457 | and C<~> are now supported on bigints. |
458 | |
b7d8191e |
459 | =item Math::Complex |
7711098a |
460 | |
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461 | The accessor methods Re, Im, arg, abs, rho, and theta can now also |
868cb350 |
462 | act as mutators (accessor $z->Re(), mutator $z->Re(3)). |
b7d8191e |
463 | |
464 | =item Math::Trig |
465 | |
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466 | A little bit of radial trigonometry (cylindrical and spherical), |
467 | radial coordinate conversions, and the great circle distance were added. |
b7d8191e |
468 | |
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469 | =item SDBM_File |
470 | |
471 | An EXISTS method has been added to this module (and sdbm_exists() has |
472 | been added to the underlying sdbm library), so one can now call exists |
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473 | on an SDBM_File tied hash and get the correct result, rather than a |
f4b9d880 |
474 | runtime error. |
475 | |
06ef4121 |
476 | =item Time::Local |
477 | |
478 | The timelocal() and timegm() functions used to silently return bogus |
479 | results when the date exceeded the machine's integer range. They |
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480 | now consistently croak() if the date falls in an unsupported range. |
06ef4121 |
481 | |
8fe0a5c4 |
482 | =item Win32 |
483 | |
484 | The error return value in list context has been changed for all functions |
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485 | that return a list of values. Previously these functions returned a list |
486 | with a single element C<undef> if an error occurred. Now these functions |
487 | return the empty list in these situations. This applies to the following |
8fe0a5c4 |
488 | functions: |
489 | |
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490 | Win32::FsType |
491 | Win32::GetOSVersion |
8fe0a5c4 |
492 | |
493 | The remaining functions are unchanged and continue to return C<undef> on |
494 | error even in list context. |
495 | |
496 | The Win32::SetLastError(ERROR) function has been added as a complement |
497 | to the Win32::GetLastError() function. |
498 | |
499 | The new Win32::GetFullPathName(FILENAME) returns the full absolute |
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500 | pathname for FILENAME in scalar context. In list context it returns |
501 | a two-element list containing the fully qualified directory name and |
8fe0a5c4 |
502 | the filename. |
503 | |
9fe6733a |
504 | =item DBM Filters |
505 | |
506 | A new feature called "DBM Filters" has been added to all the |
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507 | DBM modules--DB_File, GDBM_File, NDBM_File, ODBM_File, and SDBM_File. |
508 | DBM Filters add four new methods to each DBM module: |
9fe6733a |
509 | |
510 | filter_store_key |
511 | filter_store_value |
512 | filter_fetch_key |
513 | filter_fetch_value |
514 | |
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515 | These can be used to filter key-value pairs before the pairs are |
9fe6733a |
516 | written to the database or just after they are read from the database. |
517 | See L<perldbmfilter> for further information. |
518 | |
b7d8191e |
519 | =back |
3e8c4fa0 |
520 | |
521 | =head2 Pragmata |
522 | |
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523 | C<use utf8> to enable UTF-8 and Unicode support. |
43165c05 |
524 | |
525 | C<use caller 'encoding'> allows modules to inherit pragmatic attributes |
526 | from the caller's context. C<encoding> is currently the only supported |
527 | attribute. |
9d73390d |
528 | |
529 | Lexical warnings pragma, C<use warning;>, to control optional warnings. |
6c67e1bb |
530 | |
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531 | C<use filetest> to control the behaviour of filetests (C<-r> C<-w> ...). |
6c67e1bb |
532 | Currently only one subpragma implemented, "use filetest 'access';", |
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533 | that enables the use of access(2) or equivalent to check |
6c67e1bb |
534 | permissions instead of using stat(2) as usual. This matters |
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535 | in filesystems where there are ACLs (access control lists): the |
536 | stat(2) might lie, but access(2) knows better. |
6c67e1bb |
537 | |
ba8251e8 |
538 | =head1 Utility Changes |
539 | |
e02fdbd2 |
540 | Todo. |
541 | |
ba8251e8 |
542 | =head1 Documentation Changes |
543 | |
5fdc711f |
544 | =over 4 |
545 | |
546 | =item perlopentut.pod |
f8284313 |
547 | |
5fdc711f |
548 | A tutorial on using open() effectively. |
549 | |
550 | =item perlreftut.pod |
551 | |
552 | A tutorial that introduces the essentials of references. |
553 | |
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554 | =item perltootc.pod |
555 | |
556 | A tutorial on managing class data for object modules. |
557 | |
5fdc711f |
558 | =back |
e02fdbd2 |
559 | |
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560 | =head1 New Diagnostics |
561 | |
6b121555 |
562 | =item /%s/: Unrecognized escape \\%c passed through |
563 | |
564 | (W) You used a backslash-character combination which is not recognized |
7711098a |
565 | by Perl. This combination appears in an interpolated variable or a |
6b121555 |
566 | C<'>-delimited regular expression. |
567 | |
af8c498a |
568 | =item Filehandle %s opened only for output |
6b121555 |
569 | |
af8c498a |
570 | (W) You tried to read from a filehandle opened only for writing. If you |
571 | intended it to be a read-write filehandle, you needed to open it with |
572 | "+E<lt>" or "+E<gt>" or "+E<gt>E<gt>" instead of with "E<lt>" or nothing. If |
573 | you intended only to read from the file, use "E<lt>". See |
574 | L<perlfunc/open>. |
e02fdbd2 |
575 | |
06eaf0bc |
576 | =item Missing command in piped open |
577 | |
578 | (W) You used the C<open(FH, "| command")> or C<open(FH, "command |")> |
579 | construction, but the command was missing or blank. |
580 | |
af8c498a |
581 | =item Unrecognized escape \\%c passed through |
582 | |
583 | (W) You used a backslash-character combination which is not recognized |
584 | by Perl. |
585 | |
f10b0346 |
586 | =item defined(@array) is deprecated |
69794302 |
587 | |
588 | (D) defined() is not usually useful on arrays because it checks for an |
589 | undefined I<scalar> value. If you want to see if the array is empty, |
590 | just use C<if (@array) { # not empty }> for example. |
591 | |
f10b0346 |
592 | =item defined(%hash) is deprecated |
69794302 |
593 | |
594 | (D) defined() is not usually useful on hashes because it checks for an |
595 | undefined I<scalar> value. If you want to see if the hash is empty, |
596 | just use C<if (%hash) { # not empty }> for example. |
597 | |
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598 | =head1 Obsolete Diagnostics |
599 | |
e02fdbd2 |
600 | Todo. |
601 | |
04d420f9 |
602 | =head1 Configuration Changes |
603 | |
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604 | =head2 installusrbinperl |
605 | |
04d420f9 |
606 | You can use "Configure -Uinstallusrbinperl" which causes installperl |
607 | to skip installing perl also as /usr/bin/perl. This is useful if you |
608 | prefer not to modify /usr/bin for some reason or another but harmful |
609 | because many scripts assume to find Perl in /usr/bin/perl. |
610 | |
27806c82 |
611 | =head2 SOCKS support |
555834d1 |
612 | |
27806c82 |
613 | You can use "Configure -Dusesocks" which causes Perl to probe |
614 | for the SOCKS proxy protocol library, http://www.socks.nec.com/ |
04d420f9 |
615 | |
ba8251e8 |
616 | =head1 BUGS |
617 | |
618 | If you find what you think is a bug, you might check the headers of |
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619 | articles recently posted to the comp.lang.perl.misc newsgroup. |
ba8251e8 |
620 | There may also be information at http://www.perl.com/perl/, the Perl |
621 | Home Page. |
622 | |
623 | If you believe you have an unreported bug, please run the B<perlbug> |
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624 | program included with your release. Make sure to trim your bug down |
ba8251e8 |
625 | to a tiny but sufficient test case. Your bug report, along with the |
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626 | output of C<perl -V>, will be sent off to perlbug@perl.com to be |
ba8251e8 |
627 | analysed by the Perl porting team. |
628 | |
629 | =head1 SEE ALSO |
630 | |
631 | The F<Changes> file for exhaustive details on what changed. |
632 | |
633 | The F<INSTALL> file for how to build Perl. |
634 | |
635 | The F<README> file for general stuff. |
636 | |
637 | The F<Artistic> and F<Copying> files for copyright information. |
638 | |
639 | =head1 HISTORY |
640 | |
641 | Written by Gurusamy Sarathy <F<gsar@umich.edu>>, with many contributions |
642 | from The Perl Porters. |
643 | |
644 | Send omissions or corrections to <F<perlbug@perl.com>>. |
645 | |
646 | =cut |