Commit | Line | Data |
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1 | package IO::Uncompress::Inflate ; |
2 | # for RFC1950 |
3 | |
4 | use strict ; |
5 | use warnings; |
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6 | use bytes; |
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7 | |
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8 | use IO::Compress::Base::Common qw(:Status createSelfTiedObject); |
9 | use IO::Compress::Zlib::Constants; |
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10 | |
11 | use IO::Uncompress::RawInflate ; |
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12 | |
13 | require Exporter ; |
14 | our ($VERSION, @ISA, @EXPORT_OK, %EXPORT_TAGS, $InflateError); |
15 | |
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16 | $VERSION = '2.001'; |
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17 | $InflateError = ''; |
18 | |
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19 | @ISA = qw( Exporter IO::Uncompress::RawInflate ); |
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20 | @EXPORT_OK = qw( $InflateError inflate ) ; |
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21 | %EXPORT_TAGS = %IO::Uncompress::RawInflate::DEFLATE_CONSTANTS ; |
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22 | push @{ $EXPORT_TAGS{all} }, @EXPORT_OK ; |
23 | Exporter::export_ok_tags('all'); |
24 | |
25 | |
26 | sub new |
27 | { |
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28 | my $class = shift ; |
29 | my $obj = createSelfTiedObject($class, \$InflateError); |
30 | |
31 | $obj->_create(undef, 0, @_); |
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32 | } |
33 | |
34 | sub inflate |
35 | { |
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36 | my $obj = createSelfTiedObject(undef, \$InflateError); |
37 | return $obj->_inf(@_); |
38 | } |
39 | |
40 | sub getExtraParams |
41 | { |
42 | return (); |
43 | } |
44 | |
45 | sub ckParams |
46 | { |
47 | my $self = shift ; |
48 | my $got = shift ; |
49 | |
50 | # gunzip always needs adler32 |
51 | $got->value('ADLER32' => 1); |
52 | |
53 | return 1; |
54 | } |
55 | |
56 | sub ckMagic |
57 | { |
58 | my $self = shift; |
59 | |
60 | my $magic ; |
61 | $self->smartReadExact(\$magic, ZLIB_HEADER_SIZE); |
62 | |
63 | *$self->{HeaderPending} = $magic ; |
64 | |
65 | return $self->HeaderError("Header size is " . |
66 | ZLIB_HEADER_SIZE . " bytes") |
67 | if length $magic != ZLIB_HEADER_SIZE; |
68 | |
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69 | #return $self->HeaderError("CRC mismatch.") |
70 | return undef |
71 | if ! $self->isZlibMagic($magic) ; |
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72 | |
73 | *$self->{Type} = 'rfc1950'; |
74 | return $magic; |
75 | } |
76 | |
77 | sub readHeader |
78 | { |
79 | my $self = shift; |
80 | my $magic = shift ; |
81 | |
82 | return $self->_readDeflateHeader($magic) ; |
83 | } |
84 | |
85 | sub chkTrailer |
86 | { |
87 | my $self = shift; |
88 | my $trailer = shift; |
89 | |
90 | my $ADLER32 = unpack("N", $trailer) ; |
91 | *$self->{Info}{ADLER32} = $ADLER32; |
92 | return $self->TrailerError("CRC mismatch") |
93 | if *$self->{Strict} && $ADLER32 != *$self->{Uncomp}->adler32() ; |
94 | |
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95 | return STATUS_OK; |
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96 | } |
97 | |
98 | |
99 | |
100 | sub isZlibMagic |
101 | { |
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102 | my $self = shift; |
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103 | my $buffer = shift ; |
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104 | |
105 | return 0 |
106 | if length $buffer < ZLIB_HEADER_SIZE ; |
107 | |
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108 | my $hdr = unpack("n", $buffer) ; |
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109 | #return 0 if $hdr % 31 != 0 ; |
110 | return $self->HeaderError("CRC mismatch.") |
111 | if $hdr % 31 != 0 ; |
112 | |
113 | my ($CMF, $FLG) = unpack "C C", $buffer; |
114 | my $cm = bits($CMF, ZLIB_CMF_CM_OFFSET, ZLIB_CMF_CM_BITS) ; |
115 | |
116 | # Only Deflate supported |
117 | return $self->HeaderError("Not Deflate (CM is $cm)") |
118 | if $cm != ZLIB_CMF_CM_DEFLATED ; |
119 | |
120 | # Max window value is 7 for Deflate. |
121 | my $cinfo = bits($CMF, ZLIB_CMF_CINFO_OFFSET, ZLIB_CMF_CINFO_BITS) ; |
122 | return $self->HeaderError("CINFO > " . ZLIB_CMF_CINFO_MAX . |
123 | " (CINFO is $cinfo)") |
124 | if $cinfo > ZLIB_CMF_CINFO_MAX ; |
125 | |
126 | return 1; |
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127 | } |
128 | |
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129 | sub bits |
130 | { |
131 | my $data = shift ; |
132 | my $offset = shift ; |
133 | my $mask = shift ; |
134 | |
135 | ($data >> $offset ) & $mask & 0xFF ; |
136 | } |
137 | |
138 | |
139 | sub _readDeflateHeader |
140 | { |
141 | my ($self, $buffer) = @_ ; |
142 | |
143 | # if (! $buffer) { |
144 | # $self->smartReadExact(\$buffer, ZLIB_HEADER_SIZE); |
145 | # |
146 | # *$self->{HeaderPending} = $buffer ; |
147 | # |
148 | # return $self->HeaderError("Header size is " . |
149 | # ZLIB_HEADER_SIZE . " bytes") |
150 | # if length $buffer != ZLIB_HEADER_SIZE; |
151 | # |
152 | # return $self->HeaderError("CRC mismatch.") |
153 | # if ! isZlibMagic($buffer) ; |
154 | # } |
155 | |
156 | my ($CMF, $FLG) = unpack "C C", $buffer; |
157 | my $FDICT = bits($FLG, ZLIB_FLG_FDICT_OFFSET, ZLIB_FLG_FDICT_BITS ), |
158 | |
159 | my $cm = bits($CMF, ZLIB_CMF_CM_OFFSET, ZLIB_CMF_CM_BITS) ; |
160 | $cm == ZLIB_CMF_CM_DEFLATED |
161 | or return $self->HeaderError("Not Deflate (CM is $cm)") ; |
162 | |
163 | my $DICTID; |
164 | if ($FDICT) { |
165 | $self->smartReadExact(\$buffer, ZLIB_FDICT_SIZE) |
166 | or return $self->TruncatedHeader("FDICT"); |
167 | |
168 | $DICTID = unpack("N", $buffer) ; |
169 | } |
170 | |
171 | *$self->{Type} = 'rfc1950'; |
172 | |
173 | return { |
174 | 'Type' => 'rfc1950', |
175 | 'FingerprintLength' => ZLIB_HEADER_SIZE, |
176 | 'HeaderLength' => ZLIB_HEADER_SIZE, |
177 | 'TrailerLength' => ZLIB_TRAILER_SIZE, |
178 | 'Header' => $buffer, |
179 | |
180 | CMF => $CMF , |
181 | CM => bits($CMF, ZLIB_CMF_CM_OFFSET, ZLIB_CMF_CM_BITS ), |
182 | CINFO => bits($CMF, ZLIB_CMF_CINFO_OFFSET, ZLIB_CMF_CINFO_BITS ), |
183 | FLG => $FLG , |
184 | FCHECK => bits($FLG, ZLIB_FLG_FCHECK_OFFSET, ZLIB_FLG_FCHECK_BITS), |
185 | FDICT => bits($FLG, ZLIB_FLG_FDICT_OFFSET, ZLIB_FLG_FDICT_BITS ), |
186 | FLEVEL => bits($FLG, ZLIB_FLG_LEVEL_OFFSET, ZLIB_FLG_LEVEL_BITS ), |
187 | DICTID => $DICTID , |
188 | |
189 | }; |
190 | } |
191 | |
192 | |
193 | |
194 | |
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195 | 1 ; |
196 | |
197 | __END__ |
198 | |
199 | |
200 | =head1 NAME |
201 | |
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202 | |
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203 | |
204 | IO::Uncompress::Inflate - Read RFC 1950 files/buffers |
205 | |
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206 | |
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207 | |
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208 | =head1 SYNOPSIS |
209 | |
210 | use IO::Uncompress::Inflate qw(inflate $InflateError) ; |
211 | |
212 | my $status = inflate $input => $output [,OPTS] |
213 | or die "inflate failed: $InflateError\n"; |
214 | |
215 | my $z = new IO::Uncompress::Inflate $input [OPTS] |
216 | or die "inflate failed: $InflateError\n"; |
217 | |
218 | $status = $z->read($buffer) |
219 | $status = $z->read($buffer, $length) |
220 | $status = $z->read($buffer, $length, $offset) |
221 | $line = $z->getline() |
222 | $char = $z->getc() |
223 | $char = $z->ungetc() |
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224 | $char = $z->opened() |
225 | |
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226 | $status = $z->inflateSync() |
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227 | |
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228 | $data = $z->trailingData() |
229 | $status = $z->nextStream() |
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230 | $data = $z->getHeaderInfo() |
231 | $z->tell() |
232 | $z->seek($position, $whence) |
233 | $z->binmode() |
234 | $z->fileno() |
235 | $z->eof() |
236 | $z->close() |
237 | |
238 | $InflateError ; |
239 | |
240 | # IO::File mode |
241 | |
242 | <$z> |
243 | read($z, $buffer); |
244 | read($z, $buffer, $length); |
245 | read($z, $buffer, $length, $offset); |
246 | tell($z) |
247 | seek($z, $position, $whence) |
248 | binmode($z) |
249 | fileno($z) |
250 | eof($z) |
251 | close($z) |
252 | |
253 | |
254 | =head1 DESCRIPTION |
255 | |
256 | |
257 | |
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258 | This module provides a Perl interface that allows the reading of |
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259 | files/buffers that conform to RFC 1950. |
260 | |
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261 | For writing RFC 1950 files/buffers, see the companion module IO::Compress::Deflate. |
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262 | |
263 | |
264 | |
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265 | |
266 | |
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267 | =head1 Functional Interface |
268 | |
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269 | A top-level function, C<inflate>, is provided to carry out |
270 | "one-shot" uncompression between buffers and/or files. For finer |
271 | control over the uncompression process, see the L</"OO Interface"> |
272 | section. |
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273 | |
274 | use IO::Uncompress::Inflate qw(inflate $InflateError) ; |
275 | |
276 | inflate $input => $output [,OPTS] |
277 | or die "inflate failed: $InflateError\n"; |
278 | |
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279 | |
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280 | |
281 | The functional interface needs Perl5.005 or better. |
282 | |
283 | |
284 | =head2 inflate $input => $output [, OPTS] |
285 | |
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286 | |
287 | C<inflate> expects at least two parameters, C<$input> and C<$output>. |
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288 | |
289 | =head3 The C<$input> parameter |
290 | |
291 | The parameter, C<$input>, is used to define the source of |
292 | the compressed data. |
293 | |
294 | It can take one of the following forms: |
295 | |
296 | =over 5 |
297 | |
298 | =item A filename |
299 | |
300 | If the C<$input> parameter is a simple scalar, it is assumed to be a |
301 | filename. This file will be opened for reading and the input data |
302 | will be read from it. |
303 | |
304 | =item A filehandle |
305 | |
306 | If the C<$input> parameter is a filehandle, the input data will be |
307 | read from it. |
308 | The string '-' can be used as an alias for standard input. |
309 | |
310 | =item A scalar reference |
311 | |
312 | If C<$input> is a scalar reference, the input data will be read |
313 | from C<$$input>. |
314 | |
315 | =item An array reference |
316 | |
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317 | If C<$input> is an array reference, each element in the array must be a |
318 | filename. |
319 | |
320 | The input data will be read from each file in turn. |
321 | |
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322 | The complete array will be walked to ensure that it only |
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323 | contains valid filenames before any data is uncompressed. |
324 | |
325 | |
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326 | |
327 | =item An Input FileGlob string |
328 | |
329 | If C<$input> is a string that is delimited by the characters "<" and ">" |
330 | C<inflate> will assume that it is an I<input fileglob string>. The |
331 | input is the list of files that match the fileglob. |
332 | |
333 | If the fileglob does not match any files ... |
334 | |
335 | See L<File::GlobMapper|File::GlobMapper> for more details. |
336 | |
337 | |
338 | =back |
339 | |
340 | If the C<$input> parameter is any other type, C<undef> will be returned. |
341 | |
342 | |
343 | |
344 | =head3 The C<$output> parameter |
345 | |
346 | The parameter C<$output> is used to control the destination of the |
347 | uncompressed data. This parameter can take one of these forms. |
348 | |
349 | =over 5 |
350 | |
351 | =item A filename |
352 | |
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353 | If the C<$output> parameter is a simple scalar, it is assumed to be a |
354 | filename. This file will be opened for writing and the uncompressed |
355 | data will be written to it. |
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356 | |
357 | =item A filehandle |
358 | |
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359 | If the C<$output> parameter is a filehandle, the uncompressed data |
360 | will be written to it. |
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361 | The string '-' can be used as an alias for standard output. |
362 | |
363 | |
364 | =item A scalar reference |
365 | |
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366 | If C<$output> is a scalar reference, the uncompressed data will be |
367 | stored in C<$$output>. |
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368 | |
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369 | |
370 | |
371 | =item An Array Reference |
372 | |
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373 | If C<$output> is an array reference, the uncompressed data will be |
374 | pushed onto the array. |
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375 | |
376 | =item An Output FileGlob |
377 | |
378 | If C<$output> is a string that is delimited by the characters "<" and ">" |
379 | C<inflate> will assume that it is an I<output fileglob string>. The |
380 | output is the list of files that match the fileglob. |
381 | |
382 | When C<$output> is an fileglob string, C<$input> must also be a fileglob |
383 | string. Anything else is an error. |
384 | |
385 | =back |
386 | |
387 | If the C<$output> parameter is any other type, C<undef> will be returned. |
388 | |
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389 | |
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390 | |
391 | =head2 Notes |
392 | |
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393 | |
394 | When C<$input> maps to multiple compressed files/buffers and C<$output> is |
395 | a single file/buffer, after uncompression C<$output> will contain a |
396 | concatenation of all the uncompressed data from each of the input |
397 | files/buffers. |
398 | |
399 | |
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400 | |
401 | |
402 | |
403 | =head2 Optional Parameters |
404 | |
405 | Unless specified below, the optional parameters for C<inflate>, |
406 | C<OPTS>, are the same as those used with the OO interface defined in the |
407 | L</"Constructor Options"> section below. |
408 | |
409 | =over 5 |
410 | |
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411 | =item C<< AutoClose => 0|1 >> |
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412 | |
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413 | This option applies to any input or output data streams to |
414 | C<inflate> that are filehandles. |
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415 | |
416 | If C<AutoClose> is specified, and the value is true, it will result in all |
417 | input and/or output filehandles being closed once C<inflate> has |
418 | completed. |
419 | |
420 | This parameter defaults to 0. |
421 | |
422 | |
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423 | =item C<< BinModeOut => 0|1 >> |
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424 | |
425 | When writing to a file or filehandle, set C<binmode> before writing to the |
426 | file. |
427 | |
428 | Defaults to 0. |
429 | |
430 | |
431 | |
432 | |
433 | |
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434 | =item C<< Append => 0|1 >> |
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435 | |
436 | TODO |
437 | |
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438 | =item C<< MultiStream => 0|1 >> |
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439 | |
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440 | |
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441 | If the input file/buffer contains multiple compressed data streams, this |
442 | option will uncompress the whole lot as a single data stream. |
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443 | |
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444 | Defaults to 0. |
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445 | |
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446 | |
447 | |
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448 | |
449 | |
450 | =item C<< TrailingData => $scalar >> |
451 | |
452 | Returns the data, if any, that is present immediately after the compressed |
453 | data stream once uncompression is complete. |
454 | |
455 | This option can be used when there is useful information immediately |
456 | following the compressed data stream, and you don't know the length of the |
457 | compressed data stream. |
458 | |
459 | If the input is a buffer, C<trailingData> will return everything from the |
460 | end of the compressed data stream to the end of the buffer. |
461 | |
462 | If the input is a filehandle, C<trailingData> will return the data that is |
463 | left in the filehandle input buffer once the end of the compressed data |
464 | stream has been reached. You can then use the filehandle to read the rest |
465 | of the input file. |
466 | |
467 | Don't bother using C<trailingData> if the input is a filename. |
468 | |
469 | |
470 | |
471 | If you know the length of the compressed data stream before you start |
472 | uncompressing, you can avoid having to use C<trailingData> by setting the |
473 | C<InputLength> option. |
474 | |
475 | |
476 | |
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477 | =back |
478 | |
479 | |
480 | |
481 | |
482 | =head2 Examples |
483 | |
484 | To read the contents of the file C<file1.txt.1950> and write the |
485 | compressed data to the file C<file1.txt>. |
486 | |
487 | use strict ; |
488 | use warnings ; |
489 | use IO::Uncompress::Inflate qw(inflate $InflateError) ; |
490 | |
491 | my $input = "file1.txt.1950"; |
492 | my $output = "file1.txt"; |
493 | inflate $input => $output |
494 | or die "inflate failed: $InflateError\n"; |
495 | |
496 | |
497 | To read from an existing Perl filehandle, C<$input>, and write the |
498 | uncompressed data to a buffer, C<$buffer>. |
499 | |
500 | use strict ; |
501 | use warnings ; |
502 | use IO::Uncompress::Inflate qw(inflate $InflateError) ; |
503 | use IO::File ; |
504 | |
505 | my $input = new IO::File "<file1.txt.1950" |
506 | or die "Cannot open 'file1.txt.1950': $!\n" ; |
507 | my $buffer ; |
508 | inflate $input => \$buffer |
509 | or die "inflate failed: $InflateError\n"; |
510 | |
511 | To uncompress all files in the directory "/my/home" that match "*.txt.1950" and store the compressed data in the same directory |
512 | |
513 | use strict ; |
514 | use warnings ; |
515 | use IO::Uncompress::Inflate qw(inflate $InflateError) ; |
516 | |
517 | inflate '</my/home/*.txt.1950>' => '</my/home/#1.txt>' |
518 | or die "inflate failed: $InflateError\n"; |
519 | |
520 | and if you want to compress each file one at a time, this will do the trick |
521 | |
522 | use strict ; |
523 | use warnings ; |
524 | use IO::Uncompress::Inflate qw(inflate $InflateError) ; |
525 | |
526 | for my $input ( glob "/my/home/*.txt.1950" ) |
527 | { |
528 | my $output = $input; |
529 | $output =~ s/.1950// ; |
530 | inflate $input => $output |
531 | or die "Error compressing '$input': $InflateError\n"; |
532 | } |
533 | |
534 | =head1 OO Interface |
535 | |
536 | =head2 Constructor |
537 | |
538 | The format of the constructor for IO::Uncompress::Inflate is shown below |
539 | |
540 | |
541 | my $z = new IO::Uncompress::Inflate $input [OPTS] |
542 | or die "IO::Uncompress::Inflate failed: $InflateError\n"; |
543 | |
544 | Returns an C<IO::Uncompress::Inflate> object on success and undef on failure. |
545 | The variable C<$InflateError> will contain an error message on failure. |
546 | |
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547 | If you are running Perl 5.005 or better the object, C<$z>, returned from |
548 | IO::Uncompress::Inflate can be used exactly like an L<IO::File|IO::File> filehandle. |
549 | This means that all normal input file operations can be carried out with |
550 | C<$z>. For example, to read a line from a compressed file/buffer you can |
551 | use either of these forms |
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552 | |
553 | $line = $z->getline(); |
554 | $line = <$z>; |
555 | |
556 | The mandatory parameter C<$input> is used to determine the source of the |
557 | compressed data. This parameter can take one of three forms. |
558 | |
559 | =over 5 |
560 | |
561 | =item A filename |
562 | |
563 | If the C<$input> parameter is a scalar, it is assumed to be a filename. This |
564 | file will be opened for reading and the compressed data will be read from it. |
565 | |
566 | =item A filehandle |
567 | |
568 | If the C<$input> parameter is a filehandle, the compressed data will be |
569 | read from it. |
570 | The string '-' can be used as an alias for standard input. |
571 | |
572 | |
573 | =item A scalar reference |
574 | |
575 | If C<$input> is a scalar reference, the compressed data will be read from |
576 | C<$$output>. |
577 | |
578 | =back |
579 | |
580 | =head2 Constructor Options |
581 | |
582 | |
583 | The option names defined below are case insensitive and can be optionally |
584 | prefixed by a '-'. So all of the following are valid |
585 | |
586 | -AutoClose |
587 | -autoclose |
588 | AUTOCLOSE |
589 | autoclose |
590 | |
591 | OPTS is a combination of the following options: |
592 | |
593 | =over 5 |
594 | |
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595 | =item C<< AutoClose => 0|1 >> |
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596 | |
597 | This option is only valid when the C<$input> parameter is a filehandle. If |
598 | specified, and the value is true, it will result in the file being closed once |
599 | either the C<close> method is called or the IO::Uncompress::Inflate object is |
600 | destroyed. |
601 | |
602 | This parameter defaults to 0. |
603 | |
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604 | =item C<< MultiStream => 0|1 >> |
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605 | |
606 | |
607 | |
608 | Allows multiple concatenated compressed streams to be treated as a single |
609 | compressed stream. Decompression will stop once either the end of the |
610 | file/buffer is reached, an error is encountered (premature eof, corrupt |
611 | compressed data) or the end of a stream is not immediately followed by the |
612 | start of another stream. |
613 | |
614 | This parameter defaults to 0. |
615 | |
616 | |
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617 | =item C<< Prime => $string >> |
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618 | |
619 | This option will uncompress the contents of C<$string> before processing the |
620 | input file/buffer. |
621 | |
622 | This option can be useful when the compressed data is embedded in another |
623 | file/data structure and it is not possible to work out where the compressed |
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624 | data begins without having to read the first few bytes. If this is the |
625 | case, the uncompression can be I<primed> with these bytes using this |
626 | option. |
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627 | |
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628 | =item C<< Transparent => 0|1 >> |
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629 | |
630 | If this option is set and the input file or buffer is not compressed data, |
631 | the module will allow reading of it anyway. |
632 | |
633 | This option defaults to 1. |
634 | |
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635 | =item C<< BlockSize => $num >> |
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636 | |
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637 | When reading the compressed input data, IO::Uncompress::Inflate will read it in |
638 | blocks of C<$num> bytes. |
642e522c |
639 | |
640 | This option defaults to 4096. |
641 | |
e7d45986 |
642 | =item C<< InputLength => $size >> |
642e522c |
643 | |
1a6a8453 |
644 | When present this option will limit the number of compressed bytes read |
645 | from the input file/buffer to C<$size>. This option can be used in the |
646 | situation where there is useful data directly after the compressed data |
647 | stream and you know beforehand the exact length of the compressed data |
648 | stream. |
642e522c |
649 | |
1a6a8453 |
650 | This option is mostly used when reading from a filehandle, in which case |
651 | the file pointer will be left pointing to the first byte directly after the |
642e522c |
652 | compressed data stream. |
653 | |
654 | |
655 | |
656 | This option defaults to off. |
657 | |
e7d45986 |
658 | =item C<< Append => 0|1 >> |
642e522c |
659 | |
660 | This option controls what the C<read> method does with uncompressed data. |
661 | |
1a6a8453 |
662 | If set to 1, all uncompressed data will be appended to the output parameter |
663 | of the C<read> method. |
642e522c |
664 | |
1a6a8453 |
665 | If set to 0, the contents of the output parameter of the C<read> method |
666 | will be overwritten by the uncompressed data. |
642e522c |
667 | |
668 | Defaults to 0. |
669 | |
e7d45986 |
670 | =item C<< Strict => 0|1 >> |
642e522c |
671 | |
672 | |
673 | |
674 | This option controls whether the extra checks defined below are used when |
1a6a8453 |
675 | carrying out the decompression. When Strict is on, the extra tests are |
676 | carried out, when Strict is off they are not. |
642e522c |
677 | |
678 | The default for this option is off. |
679 | |
680 | |
681 | |
682 | |
683 | |
684 | =over 5 |
685 | |
686 | =item 1 |
687 | |
688 | The ADLER32 checksum field must be present. |
689 | |
690 | =item 2 |
691 | |
692 | The value of the ADLER32 field read must match the adler32 value of the |
693 | uncompressed data actually contained in the file. |
694 | |
695 | =back |
696 | |
697 | |
698 | |
699 | |
700 | |
701 | |
702 | |
703 | |
704 | |
a02d0f6f |
705 | |
706 | |
258133d1 |
707 | |
642e522c |
708 | =back |
709 | |
710 | =head2 Examples |
711 | |
712 | TODO |
713 | |
714 | =head1 Methods |
715 | |
716 | =head2 read |
717 | |
718 | Usage is |
719 | |
720 | $status = $z->read($buffer) |
721 | |
722 | Reads a block of compressed data (the size the the compressed block is |
723 | determined by the C<Buffer> option in the constructor), uncompresses it and |
1a6a8453 |
724 | writes any uncompressed data into C<$buffer>. If the C<Append> parameter is |
725 | set in the constructor, the uncompressed data will be appended to the |
726 | C<$buffer> parameter. Otherwise C<$buffer> will be overwritten. |
642e522c |
727 | |
1a6a8453 |
728 | Returns the number of uncompressed bytes written to C<$buffer>, zero if eof |
729 | or a negative number on error. |
642e522c |
730 | |
731 | =head2 read |
732 | |
733 | Usage is |
734 | |
735 | $status = $z->read($buffer, $length) |
736 | $status = $z->read($buffer, $length, $offset) |
737 | |
738 | $status = read($z, $buffer, $length) |
739 | $status = read($z, $buffer, $length, $offset) |
740 | |
741 | Attempt to read C<$length> bytes of uncompressed data into C<$buffer>. |
742 | |
1a6a8453 |
743 | The main difference between this form of the C<read> method and the |
744 | previous one, is that this one will attempt to return I<exactly> C<$length> |
745 | bytes. The only circumstances that this function will not is if end-of-file |
746 | or an IO error is encountered. |
642e522c |
747 | |
1a6a8453 |
748 | Returns the number of uncompressed bytes written to C<$buffer>, zero if eof |
749 | or a negative number on error. |
642e522c |
750 | |
751 | |
752 | =head2 getline |
753 | |
754 | Usage is |
755 | |
756 | $line = $z->getline() |
757 | $line = <$z> |
758 | |
759 | Reads a single line. |
760 | |
258133d1 |
761 | This method fully supports the use of of the variable C<$/> (or |
762 | C<$INPUT_RECORD_SEPARATOR> or C<$RS> when C<English> is in use) to |
763 | determine what constitutes an end of line. Paragraph mode, record mode and |
764 | file slurp mode are all supported. |
642e522c |
765 | |
766 | |
767 | =head2 getc |
768 | |
769 | Usage is |
770 | |
771 | $char = $z->getc() |
772 | |
773 | Read a single character. |
774 | |
775 | =head2 ungetc |
776 | |
777 | Usage is |
778 | |
779 | $char = $z->ungetc($string) |
780 | |
781 | |
a02d0f6f |
782 | |
642e522c |
783 | =head2 inflateSync |
784 | |
785 | Usage is |
786 | |
787 | $status = $z->inflateSync() |
788 | |
789 | TODO |
790 | |
a02d0f6f |
791 | |
642e522c |
792 | =head2 getHeaderInfo |
793 | |
794 | Usage is |
795 | |
1a6a8453 |
796 | $hdr = $z->getHeaderInfo(); |
797 | @hdrs = $z->getHeaderInfo(); |
642e522c |
798 | |
1a6a8453 |
799 | This method returns either a hash reference (in scalar context) or a list |
800 | or hash references (in array context) that contains information about each |
801 | of the header fields in the compressed data stream(s). |
642e522c |
802 | |
803 | |
804 | |
805 | |
806 | =head2 tell |
807 | |
808 | Usage is |
809 | |
810 | $z->tell() |
811 | tell $z |
812 | |
813 | Returns the uncompressed file offset. |
814 | |
815 | =head2 eof |
816 | |
817 | Usage is |
818 | |
819 | $z->eof(); |
820 | eof($z); |
821 | |
822 | |
823 | |
824 | Returns true if the end of the compressed input stream has been reached. |
825 | |
826 | |
827 | |
828 | =head2 seek |
829 | |
830 | $z->seek($position, $whence); |
831 | seek($z, $position, $whence); |
832 | |
833 | |
834 | |
835 | |
836 | Provides a sub-set of the C<seek> functionality, with the restriction |
837 | that it is only legal to seek forward in the input file/buffer. |
838 | It is a fatal error to attempt to seek backward. |
839 | |
840 | |
841 | |
842 | The C<$whence> parameter takes one the usual values, namely SEEK_SET, |
843 | SEEK_CUR or SEEK_END. |
844 | |
845 | Returns 1 on success, 0 on failure. |
846 | |
847 | =head2 binmode |
848 | |
849 | Usage is |
850 | |
851 | $z->binmode |
852 | binmode $z ; |
853 | |
854 | This is a noop provided for completeness. |
855 | |
a02d0f6f |
856 | =head2 opened |
857 | |
858 | $z->opened() |
859 | |
860 | Returns true if the object currently refers to a opened file/buffer. |
861 | |
862 | =head2 autoflush |
863 | |
864 | my $prev = $z->autoflush() |
865 | my $prev = $z->autoflush(EXPR) |
866 | |
867 | If the C<$z> object is associated with a file or a filehandle, this method |
868 | returns the current autoflush setting for the underlying filehandle. If |
869 | C<EXPR> is present, and is non-zero, it will enable flushing after every |
870 | write/print operation. |
871 | |
872 | If C<$z> is associated with a buffer, this method has no effect and always |
873 | returns C<undef>. |
874 | |
875 | B<Note> that the special variable C<$|> B<cannot> be used to set or |
876 | retrieve the autoflush setting. |
877 | |
878 | =head2 input_line_number |
879 | |
880 | $z->input_line_number() |
881 | $z->input_line_number(EXPR) |
882 | |
883 | |
884 | |
885 | Returns the current uncompressed line number. If C<EXPR> is present it has |
886 | the effect of setting the line number. Note that setting the line number |
887 | does not change the current position within the file/buffer being read. |
888 | |
889 | The contents of C<$/> are used to to determine what constitutes a line |
890 | terminator. |
891 | |
892 | |
893 | |
642e522c |
894 | =head2 fileno |
895 | |
896 | $z->fileno() |
897 | fileno($z) |
898 | |
a02d0f6f |
899 | If the C<$z> object is associated with a file or a filehandle, this method |
900 | will return the underlying file descriptor. |
642e522c |
901 | |
902 | If the C<$z> object is is associated with a buffer, this method will |
903 | return undef. |
904 | |
905 | =head2 close |
906 | |
907 | $z->close() ; |
908 | close $z ; |
909 | |
910 | |
911 | |
912 | Closes the output file/buffer. |
913 | |
914 | |
915 | |
916 | For most versions of Perl this method will be automatically invoked if |
917 | the IO::Uncompress::Inflate object is destroyed (either explicitly or by the |
918 | variable with the reference to the object going out of scope). The |
919 | exceptions are Perl versions 5.005 through 5.00504 and 5.8.0. In |
920 | these cases, the C<close> method will be called automatically, but |
921 | not until global destruction of all live objects when the program is |
922 | terminating. |
923 | |
924 | Therefore, if you want your scripts to be able to run on all versions |
925 | of Perl, you should call C<close> explicitly and not rely on automatic |
926 | closing. |
927 | |
928 | Returns true on success, otherwise 0. |
929 | |
930 | If the C<AutoClose> option has been enabled when the IO::Uncompress::Inflate |
931 | object was created, and the object is associated with a file, the |
932 | underlying file will also be closed. |
933 | |
934 | |
935 | |
936 | |
e7d45986 |
937 | =head2 nextStream |
938 | |
939 | Usage is |
940 | |
941 | my $status = $z->nextStream(); |
942 | |
943 | Skips to the next compressed data stream in the input file/buffer. If a new |
258133d1 |
944 | compressed data stream is found, the eof marker will be cleared and C<$.> |
945 | will be reset to 0. |
e7d45986 |
946 | |
947 | Returns 1 if a new stream was found, 0 if none was found, and -1 if an |
948 | error was encountered. |
949 | |
950 | =head2 trailingData |
951 | |
952 | Usage is |
953 | |
954 | my $data = $z->trailingData(); |
955 | |
258133d1 |
956 | Returns the data, if any, that is present immediately after the compressed |
957 | data stream once uncompression is complete. It only makes sense to call |
958 | this method once the end of the compressed data stream has been |
959 | encountered. |
960 | |
961 | This option can be used when there is useful information immediately |
962 | following the compressed data stream, and you don't know the length of the |
963 | compressed data stream. |
964 | |
965 | If the input is a buffer, C<trailingData> will return everything from the |
966 | end of the compressed data stream to the end of the buffer. |
967 | |
968 | If the input is a filehandle, C<trailingData> will return the data that is |
969 | left in the filehandle input buffer once the end of the compressed data |
970 | stream has been reached. You can then use the filehandle to read the rest |
971 | of the input file. |
972 | |
973 | Don't bother using C<trailingData> if the input is a filename. |
974 | |
975 | |
976 | |
977 | If you know the length of the compressed data stream before you start |
978 | uncompressing, you can avoid having to use C<trailingData> by setting the |
979 | C<InputLength> option in the constructor. |
e7d45986 |
980 | |
642e522c |
981 | =head1 Importing |
982 | |
983 | No symbolic constants are required by this IO::Uncompress::Inflate at present. |
984 | |
985 | =over 5 |
986 | |
987 | =item :all |
988 | |
989 | Imports C<inflate> and C<$InflateError>. |
990 | Same as doing this |
991 | |
992 | use IO::Uncompress::Inflate qw(inflate $InflateError) ; |
993 | |
994 | =back |
995 | |
996 | =head1 EXAMPLES |
997 | |
998 | |
999 | |
1000 | |
1001 | =head1 SEE ALSO |
1002 | |
258133d1 |
1003 | L<Compress::Zlib>, L<IO::Compress::Gzip>, L<IO::Uncompress::Gunzip>, L<IO::Compress::Deflate>, L<IO::Compress::RawDeflate>, L<IO::Uncompress::RawInflate>, L<IO::Compress::Bzip2>, L<IO::Uncompress::Bunzip2>, L<IO::Compress::Lzop>, L<IO::Uncompress::UnLzop>, L<IO::Compress::Lzf>, L<IO::Uncompress::UnLzf>, L<IO::Uncompress::AnyInflate>, L<IO::Uncompress::AnyUncompress> |
642e522c |
1004 | |
1005 | L<Compress::Zlib::FAQ|Compress::Zlib::FAQ> |
1006 | |
a02d0f6f |
1007 | L<File::GlobMapper|File::GlobMapper>, L<Archive::Zip|Archive::Zip>, |
1008 | L<Archive::Tar|Archive::Tar>, |
642e522c |
1009 | L<IO::Zlib|IO::Zlib> |
1010 | |
a02d0f6f |
1011 | |
642e522c |
1012 | For RFC 1950, 1951 and 1952 see |
1013 | F<http://www.faqs.org/rfcs/rfc1950.html>, |
1014 | F<http://www.faqs.org/rfcs/rfc1951.html> and |
1015 | F<http://www.faqs.org/rfcs/rfc1952.html> |
1016 | |
a02d0f6f |
1017 | The I<zlib> compression library was written by Jean-loup Gailly |
1018 | F<gzip@prep.ai.mit.edu> and Mark Adler F<madler@alumni.caltech.edu>. |
1019 | |
1020 | The primary site for the I<zlib> compression library is |
1021 | F<http://www.zlib.org>. |
1022 | |
1023 | The primary site for gzip is F<http://www.gzip.org>. |
1024 | |
1025 | |
1026 | |
1027 | |
642e522c |
1028 | =head1 AUTHOR |
1029 | |
cb7abd7f |
1030 | This module was written by Paul Marquess, F<pmqs@cpan.org>. |
642e522c |
1031 | |
642e522c |
1032 | |
642e522c |
1033 | |
1034 | =head1 MODIFICATION HISTORY |
1035 | |
1036 | See the Changes file. |
1037 | |
1038 | =head1 COPYRIGHT AND LICENSE |
642e522c |
1039 | |
1a6a8453 |
1040 | Copyright (c) 2005-2006 Paul Marquess. All rights reserved. |
a02d0f6f |
1041 | |
642e522c |
1042 | This program is free software; you can redistribute it and/or |
1043 | modify it under the same terms as Perl itself. |
1044 | |