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25f0751f PM |
1 | |
2 | package IO::Compress::Gzip ; | |
3 | ||
4 | require 5.004 ; | |
5 | ||
6 | use strict ; | |
7 | use warnings; | |
8 | use bytes; | |
9 | ||
10 | ||
11 | use IO::Compress::RawDeflate; | |
12 | ||
13 | use Compress::Raw::Zlib ; | |
14 | use IO::Compress::Base::Common qw(:Status :Parse createSelfTiedObject); | |
15 | use IO::Compress::Gzip::Constants; | |
16 | ||
17 | BEGIN | |
18 | { | |
19 | if (defined &utf8::downgrade ) | |
20 | { *noUTF8 = \&utf8::downgrade } | |
21 | else | |
22 | { *noUTF8 = sub {} } | |
23 | } | |
24 | ||
25 | require Exporter ; | |
26 | ||
27 | our ($VERSION, @ISA, @EXPORT_OK, %EXPORT_TAGS, $GzipError); | |
28 | ||
29 | $VERSION = '2.000_08'; | |
30 | $GzipError = '' ; | |
31 | ||
32 | @ISA = qw(Exporter IO::Compress::RawDeflate); | |
33 | @EXPORT_OK = qw( $GzipError gzip ) ; | |
34 | %EXPORT_TAGS = %IO::Compress::RawDeflate::DEFLATE_CONSTANTS ; | |
35 | push @{ $EXPORT_TAGS{all} }, @EXPORT_OK ; | |
36 | Exporter::export_ok_tags('all'); | |
37 | ||
38 | sub new | |
39 | { | |
40 | my $class = shift ; | |
41 | ||
42 | my $obj = createSelfTiedObject($class, \$GzipError); | |
43 | ||
44 | $obj->_create(undef, @_); | |
45 | } | |
46 | ||
47 | ||
48 | sub gzip | |
49 | { | |
50 | my $obj = createSelfTiedObject(undef, \$GzipError); | |
51 | return $obj->_def(@_); | |
52 | } | |
53 | ||
54 | #sub newHeader | |
55 | #{ | |
56 | # my $self = shift ; | |
57 | # #return GZIP_MINIMUM_HEADER ; | |
58 | # return $self->mkHeader(*$self->{Got}); | |
59 | #} | |
60 | ||
61 | sub getExtraParams | |
62 | { | |
63 | my $self = shift ; | |
64 | ||
65 | return ( | |
66 | # zlib behaviour | |
67 | $self->getZlibParams(), | |
68 | ||
69 | # Gzip header fields | |
70 | 'Minimal' => [0, 1, Parse_boolean, 0], | |
71 | 'Comment' => [0, 1, Parse_any, undef], | |
72 | 'Name' => [0, 1, Parse_any, undef], | |
73 | 'Time' => [0, 1, Parse_any, undef], | |
74 | 'TextFlag' => [0, 1, Parse_boolean, 0], | |
75 | 'HeaderCRC' => [0, 1, Parse_boolean, 0], | |
76 | 'OS_Code' => [0, 1, Parse_unsigned, $Compress::Raw::Zlib::gzip_os_code], | |
77 | 'ExtraField'=> [0, 1, Parse_string, undef], | |
78 | 'ExtraFlags'=> [0, 1, Parse_any, undef], | |
79 | ||
80 | ); | |
81 | } | |
82 | ||
83 | ||
84 | sub ckParams | |
85 | { | |
86 | my $self = shift ; | |
87 | my $got = shift ; | |
88 | ||
89 | # gzip always needs crc32 | |
90 | $got->value('CRC32' => 1); | |
91 | ||
92 | return 1 | |
93 | if $got->value('Merge') ; | |
94 | ||
95 | my $lax = ! $got->value('Strict') ; | |
96 | ||
97 | ||
98 | { | |
99 | if (! $got->parsed('Time') ) { | |
100 | # Modification time defaults to now. | |
101 | $got->value('Time' => time) ; | |
102 | } | |
103 | ||
104 | # Check that the Name & Comment don't have embedded NULLs | |
105 | # Also check that they only contain ISO 8859-1 chars. | |
106 | if ($got->parsed('Name') && defined $got->value('Name')) { | |
107 | my $name = $got->value('Name'); | |
108 | ||
109 | return $self->saveErrorString(undef, "Null Character found in Name", | |
110 | Z_DATA_ERROR) | |
111 | if ! $lax && $name =~ /\x00/ ; | |
112 | ||
113 | return $self->saveErrorString(undef, "Non ISO 8859-1 Character found in Name", | |
114 | Z_DATA_ERROR) | |
115 | if ! $lax && $name =~ /$GZIP_FNAME_INVALID_CHAR_RE/o ; | |
116 | } | |
117 | ||
118 | if ($got->parsed('Comment') && defined $got->value('Comment')) { | |
119 | my $comment = $got->value('Comment'); | |
120 | ||
121 | return $self->saveErrorString(undef, "Null Character found in Comment", | |
122 | Z_DATA_ERROR) | |
123 | if ! $lax && $comment =~ /\x00/ ; | |
124 | ||
125 | return $self->saveErrorString(undef, "Non ISO 8859-1 Character found in Comment", | |
126 | Z_DATA_ERROR) | |
127 | if ! $lax && $comment =~ /$GZIP_FCOMMENT_INVALID_CHAR_RE/o; | |
128 | } | |
129 | ||
130 | if ($got->parsed('OS_Code') ) { | |
131 | my $value = $got->value('OS_Code'); | |
132 | ||
133 | return $self->saveErrorString(undef, "OS_Code must be between 0 and 255, got '$value'") | |
134 | if $value < 0 || $value > 255 ; | |
135 | ||
136 | } | |
137 | ||
138 | # gzip only supports Deflate at present | |
139 | $got->value('Method' => Z_DEFLATED) ; | |
140 | ||
141 | if ( ! $got->parsed('ExtraFlags')) { | |
142 | $got->value('ExtraFlags' => 2) | |
143 | if $got->value('Level') == Z_BEST_SPEED ; | |
144 | $got->value('ExtraFlags' => 4) | |
145 | if $got->value('Level') == Z_BEST_COMPRESSION ; | |
146 | } | |
147 | ||
148 | if ($got->parsed('ExtraField')) { | |
149 | ||
150 | my $bad = $self->parseExtraField($got, $lax) ; | |
151 | return $self->saveErrorString(undef, $bad, Z_DATA_ERROR) | |
152 | if $bad ; | |
153 | ||
154 | my $len = length $got->value('ExtraField') ; | |
155 | return $self->saveErrorString(undef, ExtraFieldError("Too Large"), | |
156 | Z_DATA_ERROR) | |
157 | if $len > GZIP_FEXTRA_MAX_SIZE; | |
158 | } | |
159 | } | |
160 | ||
161 | return 1; | |
162 | } | |
163 | ||
164 | sub mkTrailer | |
165 | { | |
166 | my $self = shift ; | |
167 | return pack("V V", *$self->{Compress}->crc32(), | |
168 | *$self->{UnCompSize_32bit}); | |
169 | } | |
170 | ||
171 | sub getInverseClass | |
172 | { | |
173 | return ('IO::Uncompress::Gunzip', | |
174 | \$IO::Uncompress::Gunzip::GunzipError); | |
175 | } | |
176 | ||
177 | sub getFileInfo | |
178 | { | |
179 | my $self = shift ; | |
180 | my $params = shift; | |
181 | my $filename = shift ; | |
182 | ||
183 | my $defaultTime = (stat($filename))[9] ; | |
184 | ||
185 | $params->value('Name' => $filename) | |
186 | if ! $params->parsed('Name') ; | |
187 | ||
188 | $params->value('Time' => $defaultTime) | |
189 | if ! $params->parsed('Time') ; | |
190 | } | |
191 | ||
192 | ||
193 | sub mkHeader | |
194 | { | |
195 | my $self = shift ; | |
196 | my $param = shift ; | |
197 | ||
198 | # stort-circuit if a minimal header is requested. | |
199 | return GZIP_MINIMUM_HEADER if $param->value('Minimal') ; | |
200 | ||
201 | # METHOD | |
202 | my $method = $param->valueOrDefault('Method', GZIP_CM_DEFLATED) ; | |
203 | ||
204 | # FLAGS | |
205 | my $flags = GZIP_FLG_DEFAULT ; | |
206 | $flags |= GZIP_FLG_FTEXT if $param->value('TextFlag') ; | |
207 | $flags |= GZIP_FLG_FHCRC if $param->value('HeaderCRC') ; | |
208 | $flags |= GZIP_FLG_FEXTRA if $param->wantValue('ExtraField') ; | |
209 | $flags |= GZIP_FLG_FNAME if $param->wantValue('Name') ; | |
210 | $flags |= GZIP_FLG_FCOMMENT if $param->wantValue('Comment') ; | |
211 | ||
212 | # MTIME | |
213 | my $time = $param->valueOrDefault('Time', GZIP_MTIME_DEFAULT) ; | |
214 | ||
215 | # EXTRA FLAGS | |
216 | my $extra_flags = $param->valueOrDefault('ExtraFlags', GZIP_XFL_DEFAULT); | |
217 | ||
218 | # OS CODE | |
219 | my $os_code = $param->valueOrDefault('OS_Code', GZIP_OS_DEFAULT) ; | |
220 | ||
221 | ||
222 | my $out = pack("C4 V C C", | |
223 | GZIP_ID1, # ID1 | |
224 | GZIP_ID2, # ID2 | |
225 | $method, # Compression Method | |
226 | $flags, # Flags | |
227 | $time, # Modification Time | |
228 | $extra_flags, # Extra Flags | |
229 | $os_code, # Operating System Code | |
230 | ) ; | |
231 | ||
232 | # EXTRA | |
233 | if ($flags & GZIP_FLG_FEXTRA) { | |
234 | my $extra = $param->value('ExtraField') ; | |
235 | $out .= pack("v", length $extra) . $extra ; | |
236 | } | |
237 | ||
238 | # NAME | |
239 | if ($flags & GZIP_FLG_FNAME) { | |
240 | my $name .= $param->value('Name') ; | |
241 | $name =~ s/\x00.*$//; | |
242 | $out .= $name ; | |
243 | # Terminate the filename with NULL unless it already is | |
244 | $out .= GZIP_NULL_BYTE | |
245 | if !length $name or | |
246 | substr($name, 1, -1) ne GZIP_NULL_BYTE ; | |
247 | } | |
248 | ||
249 | # COMMENT | |
250 | if ($flags & GZIP_FLG_FCOMMENT) { | |
251 | my $comment .= $param->value('Comment') ; | |
252 | $comment =~ s/\x00.*$//; | |
253 | $out .= $comment ; | |
254 | # Terminate the comment with NULL unless it already is | |
255 | $out .= GZIP_NULL_BYTE | |
256 | if ! length $comment or | |
257 | substr($comment, 1, -1) ne GZIP_NULL_BYTE; | |
258 | } | |
259 | ||
260 | # HEADER CRC | |
261 | $out .= pack("v", crc32($out) & 0x00FF ) if $param->value('HeaderCRC') ; | |
262 | ||
263 | noUTF8($out); | |
264 | ||
265 | return $out ; | |
266 | } | |
267 | ||
268 | sub ExtraFieldError | |
269 | { | |
270 | return "Error with ExtraField Parameter: $_[0]" ; | |
271 | } | |
272 | ||
273 | sub validateExtraFieldPair | |
274 | { | |
275 | my $pair = shift ; | |
276 | my $lax = shift ; | |
277 | ||
278 | return ExtraFieldError("Not an array ref") | |
279 | unless ref $pair && ref $pair eq 'ARRAY'; | |
280 | ||
281 | return ExtraFieldError("SubField must have two parts") | |
282 | unless @$pair == 2 ; | |
283 | ||
284 | return ExtraFieldError("SubField ID is a reference") | |
285 | if ref $pair->[0] ; | |
286 | ||
287 | return ExtraFieldError("SubField Data is a reference") | |
288 | if ref $pair->[1] ; | |
289 | ||
290 | # ID is exactly two chars | |
291 | return ExtraFieldError("SubField ID not two chars long") | |
292 | unless length $pair->[0] == GZIP_FEXTRA_SUBFIELD_ID_SIZE ; | |
293 | ||
294 | # Check that the 2nd byte of the ID isn't 0 | |
295 | return ExtraFieldError("SubField ID 2nd byte is 0x00") | |
296 | if ! $lax && substr($pair->[0], 1, 1) eq "\x00" ; | |
297 | ||
298 | return ExtraFieldError("SubField Data too long") | |
299 | if length $pair->[1] > GZIP_FEXTRA_SUBFIELD_MAX_SIZE ; | |
300 | ||
301 | ||
302 | return undef ; | |
303 | } | |
304 | ||
305 | sub parseExtra | |
306 | { | |
307 | my $data = shift ; | |
308 | my $lax = shift ; | |
309 | ||
310 | return undef | |
311 | if $lax ; | |
312 | ||
313 | my $XLEN = length $data ; | |
314 | ||
315 | return ExtraFieldError("Too Large") | |
316 | if $XLEN > GZIP_FEXTRA_MAX_SIZE; | |
317 | ||
318 | my $offset = 0 ; | |
319 | while ($offset < $XLEN) { | |
320 | ||
321 | return ExtraFieldError("FEXTRA Body") | |
322 | if $offset + GZIP_FEXTRA_SUBFIELD_HEADER_SIZE > $XLEN ; | |
323 | ||
324 | my $id = substr($data, $offset, GZIP_FEXTRA_SUBFIELD_ID_SIZE); | |
325 | $offset += GZIP_FEXTRA_SUBFIELD_ID_SIZE; | |
326 | ||
327 | my $subLen = unpack("v", substr($data, $offset, | |
328 | GZIP_FEXTRA_SUBFIELD_LEN_SIZE)); | |
329 | $offset += GZIP_FEXTRA_SUBFIELD_LEN_SIZE ; | |
330 | ||
331 | return ExtraFieldError("FEXTRA Body") | |
332 | if $offset + $subLen > $XLEN ; | |
333 | ||
334 | my $bad = validateExtraFieldPair( [$id, | |
335 | substr($data, $offset, $subLen)], $lax ); | |
336 | return $bad if $bad ; | |
337 | ||
338 | $offset += $subLen ; | |
339 | } | |
340 | ||
341 | return undef ; | |
342 | } | |
343 | ||
344 | sub parseExtraField | |
345 | { | |
346 | my $self = shift ; | |
347 | my $got = shift ; | |
348 | my $lax = shift ; | |
349 | ||
350 | # ExtraField can be any of | |
351 | # | |
352 | # -ExtraField => $data | |
353 | # -ExtraField => [$id1, $data1, | |
354 | # $id2, $data2] | |
355 | # ... | |
356 | # ] | |
357 | # -ExtraField => [ [$id1 => $data1], | |
358 | # [$id2 => $data2], | |
359 | # ... | |
360 | # ] | |
361 | # -ExtraField => { $id1 => $data1, | |
362 | # $id2 => $data2, | |
363 | # ... | |
364 | # } | |
365 | ||
366 | ||
367 | return undef | |
368 | unless $got->parsed('ExtraField') ; | |
369 | ||
370 | return parseExtra($got->value('ExtraField'), $lax) | |
371 | unless ref $got->value('ExtraField') ; | |
372 | ||
373 | my $data = $got->value('ExtraField'); | |
374 | my $out = '' ; | |
375 | ||
376 | if (ref $data eq 'ARRAY') { | |
377 | if (ref $data->[0]) { | |
378 | ||
379 | foreach my $pair (@$data) { | |
380 | return ExtraFieldError("Not list of lists") | |
381 | unless ref $pair eq 'ARRAY' ; | |
382 | ||
383 | my $bad = validateExtraFieldPair($pair, $lax) ; | |
384 | return $bad if $bad ; | |
385 | ||
386 | $out .= $pair->[0] . pack("v", length $pair->[1]) . | |
387 | $pair->[1] ; | |
388 | } | |
389 | } | |
390 | else { | |
391 | return ExtraFieldError("Not even number of elements") | |
392 | unless @$data % 2 == 0; | |
393 | ||
394 | for (my $ix = 0; $ix <= length(@$data) -1 ; $ix += 2) { | |
395 | my $bad = validateExtraFieldPair([$data->[$ix], $data->[$ix+1]], $lax) ; | |
396 | return $bad if $bad ; | |
397 | ||
398 | $out .= $data->[$ix] . pack("v", length $data->[$ix+1]) . | |
399 | $data->[$ix+1] ; | |
400 | } | |
401 | } | |
402 | } | |
403 | elsif (ref $data eq 'HASH') { | |
404 | while (my ($id, $info) = each %$data) { | |
405 | my $bad = validateExtraFieldPair([$id, $info], $lax); | |
406 | return $bad if $bad ; | |
407 | ||
408 | $out .= $id . pack("v", length $info) . $info ; | |
409 | } | |
410 | } | |
411 | else { | |
412 | return ExtraFieldError("Not a scalar, array ref or hash ref") ; | |
413 | } | |
414 | ||
415 | $got->value('ExtraField' => $out); | |
416 | ||
417 | return undef; | |
418 | } | |
419 | ||
420 | sub mkFinalTrailer | |
421 | { | |
422 | return ''; | |
423 | } | |
424 | ||
425 | 1; | |
426 | ||
427 | __END__ | |
428 | ||
429 | =head1 NAME | |
430 | ||
431 | ||
432 | IO::Compress::Gzip - Perl interface to write RFC 1952 files/buffers | |
433 | ||
434 | ||
435 | =head1 SYNOPSIS | |
436 | ||
437 | use IO::Compress::Gzip qw(gzip $GzipError) ; | |
438 | ||
439 | ||
440 | my $status = gzip $input => $output [,OPTS] | |
441 | or die "gzip failed: $GzipError\n"; | |
442 | ||
443 | my $z = new IO::Compress::Gzip $output [,OPTS] | |
444 | or die "gzip failed: $GzipError\n"; | |
445 | ||
446 | $z->print($string); | |
447 | $z->printf($format, $string); | |
448 | $z->write($string); | |
449 | $z->syswrite($string [, $length, $offset]); | |
450 | $z->flush(); | |
451 | $z->tell(); | |
452 | $z->eof(); | |
453 | $z->seek($position, $whence); | |
454 | $z->binmode(); | |
455 | $z->fileno(); | |
456 | $z->opened(); | |
457 | $z->autoflush(); | |
458 | $z->input_line_number(); | |
459 | $z->newStream( [OPTS] ); | |
460 | ||
461 | $z->deflateParams(); | |
462 | ||
463 | $z->close() ; | |
464 | ||
465 | $GzipError ; | |
466 | ||
467 | # IO::File mode | |
468 | ||
469 | print $z $string; | |
470 | printf $z $format, $string; | |
471 | tell $z | |
472 | eof $z | |
473 | seek $z, $position, $whence | |
474 | binmode $z | |
475 | fileno $z | |
476 | close $z ; | |
477 | ||
478 | ||
479 | =head1 DESCRIPTION | |
480 | ||
481 | ||
482 | ||
483 | B<WARNING -- This is a Beta release>. | |
484 | ||
485 | =over 5 | |
486 | ||
487 | =item * DO NOT use in production code. | |
488 | ||
489 | =item * The documentation is incomplete in places. | |
490 | ||
491 | =item * Parts of the interface defined here are tentative. | |
492 | ||
493 | =item * Please report any problems you find. | |
494 | ||
495 | =back | |
496 | ||
497 | ||
498 | ||
499 | ||
500 | This module provides a Perl interface that allows writing compressed | |
501 | data to files or buffer as defined in RFC 1952. | |
502 | ||
503 | ||
504 | ||
505 | All the gzip headers defined in RFC 1952 can be created using | |
506 | this module. | |
507 | ||
508 | ||
509 | ||
510 | ||
511 | ||
512 | ||
513 | ||
514 | For reading RFC 1952 files/buffers, see the companion module | |
515 | L<IO::Uncompress::Gunzip|IO::Uncompress::Gunzip>. | |
516 | ||
517 | ||
518 | =head1 Functional Interface | |
519 | ||
520 | A top-level function, C<gzip>, is provided to carry out | |
521 | "one-shot" compression between buffers and/or files. For finer | |
522 | control over the compression process, see the L</"OO Interface"> | |
523 | section. | |
524 | ||
525 | use IO::Compress::Gzip qw(gzip $GzipError) ; | |
526 | ||
527 | gzip $input => $output [,OPTS] | |
528 | or die "gzip failed: $GzipError\n"; | |
529 | ||
530 | ||
531 | ||
532 | The functional interface needs Perl5.005 or better. | |
533 | ||
534 | ||
535 | =head2 gzip $input => $output [, OPTS] | |
536 | ||
537 | ||
538 | C<gzip> expects at least two parameters, C<$input> and C<$output>. | |
539 | ||
540 | =head3 The C<$input> parameter | |
541 | ||
542 | The parameter, C<$input>, is used to define the source of | |
543 | the uncompressed data. | |
544 | ||
545 | It can take one of the following forms: | |
546 | ||
547 | =over 5 | |
548 | ||
549 | =item A filename | |
550 | ||
551 | If the C<$input> parameter is a simple scalar, it is assumed to be a | |
552 | filename. This file will be opened for reading and the input data | |
553 | will be read from it. | |
554 | ||
555 | =item A filehandle | |
556 | ||
557 | If the C<$input> parameter is a filehandle, the input data will be | |
558 | read from it. | |
559 | The string '-' can be used as an alias for standard input. | |
560 | ||
561 | =item A scalar reference | |
562 | ||
563 | If C<$input> is a scalar reference, the input data will be read | |
564 | from C<$$input>. | |
565 | ||
566 | =item An array reference | |
567 | ||
568 | If C<$input> is an array reference, each element in the array must be a | |
569 | filename. | |
570 | ||
571 | The input data will be read from each file in turn. | |
572 | ||
573 | The complete array will be walked to ensure that it only | |
574 | contains valid filenames before any data is compressed. | |
575 | ||
576 | ||
577 | ||
578 | =item An Input FileGlob string | |
579 | ||
580 | If C<$input> is a string that is delimited by the characters "<" and ">" | |
581 | C<gzip> will assume that it is an I<input fileglob string>. The | |
582 | input is the list of files that match the fileglob. | |
583 | ||
584 | If the fileglob does not match any files ... | |
585 | ||
586 | See L<File::GlobMapper|File::GlobMapper> for more details. | |
587 | ||
588 | ||
589 | =back | |
590 | ||
591 | If the C<$input> parameter is any other type, C<undef> will be returned. | |
592 | ||
593 | ||
594 | ||
595 | In addition, if C<$input> is a simple filename, the default values for | |
596 | a number of the gzip header fields created by this function will | |
597 | be sourced from that file -- | |
598 | ||
599 | the NAME gzip header field will be populated with | |
600 | the filename itself, and the MTIME header field will be set to the | |
601 | modification time of the file. | |
602 | The intention here is to mirror part of the behaviour of the gzip | |
603 | executable. | |
604 | ||
605 | If you do not want to use these defaults they can be overridden by | |
606 | explicitly setting the C<Name> and C<Time> options or by setting the | |
607 | C<Minimal> parameter. | |
608 | ||
609 | ||
610 | ||
611 | =head3 The C<$output> parameter | |
612 | ||
613 | The parameter C<$output> is used to control the destination of the | |
614 | compressed data. This parameter can take one of these forms. | |
615 | ||
616 | =over 5 | |
617 | ||
618 | =item A filename | |
619 | ||
620 | If the C<$output> parameter is a simple scalar, it is assumed to be a | |
621 | filename. This file will be opened for writing and the compressed | |
622 | data will be written to it. | |
623 | ||
624 | =item A filehandle | |
625 | ||
626 | If the C<$output> parameter is a filehandle, the compressed data | |
627 | will be written to it. | |
628 | The string '-' can be used as an alias for standard output. | |
629 | ||
630 | ||
631 | =item A scalar reference | |
632 | ||
633 | If C<$output> is a scalar reference, the compressed data will be | |
634 | stored in C<$$output>. | |
635 | ||
636 | ||
637 | ||
638 | =item An Array Reference | |
639 | ||
640 | If C<$output> is an array reference, the compressed data will be | |
641 | pushed onto the array. | |
642 | ||
643 | =item An Output FileGlob | |
644 | ||
645 | If C<$output> is a string that is delimited by the characters "<" and ">" | |
646 | C<gzip> will assume that it is an I<output fileglob string>. The | |
647 | output is the list of files that match the fileglob. | |
648 | ||
649 | When C<$output> is an fileglob string, C<$input> must also be a fileglob | |
650 | string. Anything else is an error. | |
651 | ||
652 | =back | |
653 | ||
654 | If the C<$output> parameter is any other type, C<undef> will be returned. | |
655 | ||
656 | ||
657 | ||
658 | =head2 Notes | |
659 | ||
660 | When C<$input> maps to multiple files/buffers and C<$output> is a single | |
661 | file/buffer the compressed input files/buffers will all be stored | |
662 | in C<$output> as a single compressed stream. | |
663 | ||
664 | ||
665 | ||
666 | =head2 Optional Parameters | |
667 | ||
668 | Unless specified below, the optional parameters for C<gzip>, | |
669 | C<OPTS>, are the same as those used with the OO interface defined in the | |
670 | L</"Constructor Options"> section below. | |
671 | ||
672 | =over 5 | |
673 | ||
674 | =item AutoClose =E<gt> 0|1 | |
675 | ||
676 | This option applies to any input or output data streams to | |
677 | C<gzip> that are filehandles. | |
678 | ||
679 | If C<AutoClose> is specified, and the value is true, it will result in all | |
680 | input and/or output filehandles being closed once C<gzip> has | |
681 | completed. | |
682 | ||
683 | This parameter defaults to 0. | |
684 | ||
685 | ||
686 | ||
687 | =item BinModeIn =E<gt> 0|1 | |
688 | ||
689 | When reading from a file or filehandle, set C<binmode> before reading. | |
690 | ||
691 | Defaults to 0. | |
692 | ||
693 | ||
694 | ||
695 | ||
696 | ||
697 | =item -Append =E<gt> 0|1 | |
698 | ||
699 | TODO | |
700 | ||
701 | ||
702 | =back | |
703 | ||
704 | ||
705 | ||
706 | =head2 Examples | |
707 | ||
708 | To read the contents of the file C<file1.txt> and write the compressed | |
709 | data to the file C<file1.txt.gz>. | |
710 | ||
711 | use strict ; | |
712 | use warnings ; | |
713 | use IO::Compress::Gzip qw(gzip $GzipError) ; | |
714 | ||
715 | my $input = "file1.txt"; | |
716 | gzip $input => "$input.gz" | |
717 | or die "gzip failed: $GzipError\n"; | |
718 | ||
719 | ||
720 | To read from an existing Perl filehandle, C<$input>, and write the | |
721 | compressed data to a buffer, C<$buffer>. | |
722 | ||
723 | use strict ; | |
724 | use warnings ; | |
725 | use IO::Compress::Gzip qw(gzip $GzipError) ; | |
726 | use IO::File ; | |
727 | ||
728 | my $input = new IO::File "<file1.txt" | |
729 | or die "Cannot open 'file1.txt': $!\n" ; | |
730 | my $buffer ; | |
731 | gzip $input => \$buffer | |
732 | or die "gzip failed: $GzipError\n"; | |
733 | ||
734 | To compress all files in the directory "/my/home" that match "*.txt" | |
735 | and store the compressed data in the same directory | |
736 | ||
737 | use strict ; | |
738 | use warnings ; | |
739 | use IO::Compress::Gzip qw(gzip $GzipError) ; | |
740 | ||
741 | gzip '</my/home/*.txt>' => '<*.gz>' | |
742 | or die "gzip failed: $GzipError\n"; | |
743 | ||
744 | and if you want to compress each file one at a time, this will do the trick | |
745 | ||
746 | use strict ; | |
747 | use warnings ; | |
748 | use IO::Compress::Gzip qw(gzip $GzipError) ; | |
749 | ||
750 | for my $input ( glob "/my/home/*.txt" ) | |
751 | { | |
752 | my $output = "$input.gz" ; | |
753 | gzip $input => $output | |
754 | or die "Error compressing '$input': $GzipError\n"; | |
755 | } | |
756 | ||
757 | ||
758 | =head1 OO Interface | |
759 | ||
760 | =head2 Constructor | |
761 | ||
762 | The format of the constructor for C<IO::Compress::Gzip> is shown below | |
763 | ||
764 | my $z = new IO::Compress::Gzip $output [,OPTS] | |
765 | or die "IO::Compress::Gzip failed: $GzipError\n"; | |
766 | ||
767 | It returns an C<IO::Compress::Gzip> object on success and undef on failure. | |
768 | The variable C<$GzipError> will contain an error message on failure. | |
769 | ||
770 | If you are running Perl 5.005 or better the object, C<$z>, returned from | |
771 | IO::Compress::Gzip can be used exactly like an L<IO::File|IO::File> filehandle. | |
772 | This means that all normal output file operations can be carried out | |
773 | with C<$z>. | |
774 | For example, to write to a compressed file/buffer you can use either of | |
775 | these forms | |
776 | ||
777 | $z->print("hello world\n"); | |
778 | print $z "hello world\n"; | |
779 | ||
780 | The mandatory parameter C<$output> is used to control the destination | |
781 | of the compressed data. This parameter can take one of these forms. | |
782 | ||
783 | =over 5 | |
784 | ||
785 | =item A filename | |
786 | ||
787 | If the C<$output> parameter is a simple scalar, it is assumed to be a | |
788 | filename. This file will be opened for writing and the compressed data | |
789 | will be written to it. | |
790 | ||
791 | =item A filehandle | |
792 | ||
793 | If the C<$output> parameter is a filehandle, the compressed data will be | |
794 | written to it. | |
795 | The string '-' can be used as an alias for standard output. | |
796 | ||
797 | ||
798 | =item A scalar reference | |
799 | ||
800 | If C<$output> is a scalar reference, the compressed data will be stored | |
801 | in C<$$output>. | |
802 | ||
803 | =back | |
804 | ||
805 | If the C<$output> parameter is any other type, C<IO::Compress::Gzip>::new will | |
806 | return undef. | |
807 | ||
808 | =head2 Constructor Options | |
809 | ||
810 | C<OPTS> is any combination of the following options: | |
811 | ||
812 | =over 5 | |
813 | ||
814 | =item AutoClose =E<gt> 0|1 | |
815 | ||
816 | This option is only valid when the C<$output> parameter is a filehandle. If | |
817 | specified, and the value is true, it will result in the C<$output> being | |
818 | closed once either the C<close> method is called or the C<IO::Compress::Gzip> | |
819 | object is destroyed. | |
820 | ||
821 | This parameter defaults to 0. | |
822 | ||
823 | =item Append =E<gt> 0|1 | |
824 | ||
825 | Opens C<$output> in append mode. | |
826 | ||
827 | The behaviour of this option is dependent on the type of C<$output>. | |
828 | ||
829 | =over 5 | |
830 | ||
831 | =item * A Buffer | |
832 | ||
833 | If C<$output> is a buffer and C<Append> is enabled, all compressed data | |
834 | will be append to the end if C<$output>. Otherwise C<$output> will be | |
835 | cleared before any data is written to it. | |
836 | ||
837 | =item * A Filename | |
838 | ||
839 | If C<$output> is a filename and C<Append> is enabled, the file will be | |
840 | opened in append mode. Otherwise the contents of the file, if any, will be | |
841 | truncated before any compressed data is written to it. | |
842 | ||
843 | =item * A Filehandle | |
844 | ||
845 | If C<$output> is a filehandle, the file pointer will be positioned to the | |
846 | end of the file via a call to C<seek> before any compressed data is written | |
847 | to it. Otherwise the file pointer will not be moved. | |
848 | ||
849 | =back | |
850 | ||
851 | This parameter defaults to 0. | |
852 | ||
853 | ||
854 | ||
855 | ||
856 | ||
857 | =item -Merge =E<gt> 0|1 | |
858 | ||
859 | This option is used to compress input data and append it to an existing | |
860 | compressed data stream in C<$output>. The end result is a single compressed | |
861 | data stream stored in C<$output>. | |
862 | ||
863 | ||
864 | ||
865 | It is a fatal error to attempt to use this option when C<$output> is not an | |
866 | RFC 1952 data stream. | |
867 | ||
868 | ||
869 | ||
870 | There are a number of other limitations with the C<Merge> option: | |
871 | ||
872 | =over 5 | |
873 | ||
874 | =item 1 | |
875 | ||
876 | This module needs to have been built with zlib 1.2.1 or better to work. A | |
877 | fatal error will be thrown if C<Merge> is used with an older version of | |
878 | zlib. | |
879 | ||
880 | =item 2 | |
881 | ||
882 | If C<$output> is a file or a filehandle, it must be seekable. | |
883 | ||
884 | =back | |
885 | ||
886 | ||
887 | This parameter defaults to 0. | |
888 | ||
889 | ||
890 | ||
891 | =item -Level | |
892 | ||
893 | Defines the compression level used by zlib. The value should either be | |
894 | a number between 0 and 9 (0 means no compression and 9 is maximum | |
895 | compression), or one of the symbolic constants defined below. | |
896 | ||
897 | Z_NO_COMPRESSION | |
898 | Z_BEST_SPEED | |
899 | Z_BEST_COMPRESSION | |
900 | Z_DEFAULT_COMPRESSION | |
901 | ||
902 | The default is Z_DEFAULT_COMPRESSION. | |
903 | ||
904 | Note, these constants are not imported by C<IO::Compress::Gzip> by default. | |
905 | ||
906 | use IO::Compress::Gzip qw(:strategy); | |
907 | use IO::Compress::Gzip qw(:constants); | |
908 | use IO::Compress::Gzip qw(:all); | |
909 | ||
910 | =item -Strategy | |
911 | ||
912 | Defines the strategy used to tune the compression. Use one of the symbolic | |
913 | constants defined below. | |
914 | ||
915 | Z_FILTERED | |
916 | Z_HUFFMAN_ONLY | |
917 | Z_RLE | |
918 | Z_FIXED | |
919 | Z_DEFAULT_STRATEGY | |
920 | ||
921 | The default is Z_DEFAULT_STRATEGY. | |
922 | ||
923 | ||
924 | ||
925 | ||
926 | ||
927 | ||
928 | =item -Minimal =E<gt> 0|1 | |
929 | ||
930 | If specified, this option will force the creation of the smallest possible | |
931 | compliant gzip header (which is exactly 10 bytes long) as defined in | |
932 | RFC 1952. | |
933 | ||
934 | See the section titled "Compliance" in RFC 1952 for a definition | |
935 | of the values used for the fields in the gzip header. | |
936 | ||
937 | All other parameters that control the content of the gzip header will | |
938 | be ignored if this parameter is set to 1. | |
939 | ||
940 | This parameter defaults to 0. | |
941 | ||
942 | =item -Comment =E<gt> $comment | |
943 | ||
944 | Stores the contents of C<$comment> in the COMMENT field in | |
945 | the gzip header. | |
946 | By default, no comment field is written to the gzip file. | |
947 | ||
948 | If the C<-Strict> option is enabled, the comment can only consist of ISO | |
949 | 8859-1 characters plus line feed. | |
950 | ||
951 | If the C<-Strict> option is disabled, the comment field can contain any | |
952 | character except NULL. If any null characters are present, the field | |
953 | will be truncated at the first NULL. | |
954 | ||
955 | =item -Name =E<gt> $string | |
956 | ||
957 | Stores the contents of C<$string> in the gzip NAME header field. If | |
958 | C<Name> is not specified, no gzip NAME field will be created. | |
959 | ||
960 | If the C<-Strict> option is enabled, C<$string> can only consist of ISO | |
961 | 8859-1 characters. | |
962 | ||
963 | If C<-Strict> is disabled, then C<$string> can contain any character | |
964 | except NULL. If any null characters are present, the field will be | |
965 | truncated at the first NULL. | |
966 | ||
967 | =item -Time =E<gt> $number | |
968 | ||
969 | Sets the MTIME field in the gzip header to $number. | |
970 | ||
971 | This field defaults to the time the C<IO::Compress::Gzip> object was created | |
972 | if this option is not specified. | |
973 | ||
974 | =item -TextFlag =E<gt> 0|1 | |
975 | ||
976 | This parameter controls the setting of the FLG.FTEXT bit in the gzip | |
977 | header. It is used to signal that the data stored in the gzip file/buffer | |
978 | is probably text. | |
979 | ||
980 | The default is 0. | |
981 | ||
982 | =item -HeaderCRC =E<gt> 0|1 | |
983 | ||
984 | When true this parameter will set the FLG.FHCRC bit to 1 in the gzip header | |
985 | and set the CRC16 header field to the CRC of the complete gzip header | |
986 | except the CRC16 field itself. | |
987 | ||
988 | B<Note> that gzip files created with the C<HeaderCRC> flag set to 1 cannot | |
989 | be read by most, if not all, of the the standard gunzip utilities, most | |
990 | notably gzip version 1.2.4. You should therefore avoid using this option if | |
991 | you want to maximize the portability of your gzip files. | |
992 | ||
993 | This parameter defaults to 0. | |
994 | ||
995 | =item -OS_Code =E<gt> $value | |
996 | ||
997 | Stores C<$value> in the gzip OS header field. A number between 0 and 255 is | |
998 | valid. | |
999 | ||
1000 | If not specified, this parameter defaults to the OS code of the Operating | |
1001 | System this module was built on. The value 3 is used as a catch-all for all | |
1002 | Unix variants and unknown Operating Systems. | |
1003 | ||
1004 | =item -ExtraField =E<gt> $data | |
1005 | ||
1006 | This parameter allows additional metadata to be stored in the ExtraField in | |
1007 | the gzip header. An RFC 1952 compliant ExtraField consists of zero or more | |
1008 | subfields. Each subfield consists of a two byte header followed by the | |
1009 | subfield data. | |
1010 | ||
1011 | The list of subfields can be supplied in any of the following formats | |
1012 | ||
1013 | -ExtraField => [$id1, $data1, | |
1014 | $id2, $data2, | |
1015 | ... | |
1016 | ] | |
1017 | -ExtraField => [ [$id1 => $data1], | |
1018 | [$id2 => $data2], | |
1019 | ... | |
1020 | ] | |
1021 | -ExtraField => { $id1 => $data1, | |
1022 | $id2 => $data2, | |
1023 | ... | |
1024 | } | |
1025 | ||
1026 | Where C<$id1>, C<$id2> are two byte subfield ID's. The second byte of | |
1027 | the ID cannot be 0, unless the C<Strict> option has been disabled. | |
1028 | ||
1029 | If you use the hash syntax, you have no control over the order in which | |
1030 | the ExtraSubFields are stored, plus you cannot have SubFields with | |
1031 | duplicate ID. | |
1032 | ||
1033 | Alternatively the list of subfields can by supplied as a scalar, thus | |
1034 | ||
1035 | -ExtraField => $rawdata | |
1036 | ||
1037 | If you use the raw format, and the C<Strict> option is enabled, | |
1038 | C<IO::Compress::Gzip> will check that C<$rawdata> consists of zero or more | |
1039 | conformant sub-fields. When C<Strict> is disabled, C<$rawdata> can | |
1040 | consist of any arbitrary byte stream. | |
1041 | ||
1042 | The maximum size of the Extra Field 65535 bytes. | |
1043 | ||
1044 | =item -ExtraFlags =E<gt> $value | |
1045 | ||
1046 | Sets the XFL byte in the gzip header to C<$value>. | |
1047 | ||
1048 | If this option is not present, the value stored in XFL field will be | |
1049 | determined by the setting of the C<Level> option. | |
1050 | ||
1051 | If C<Level =E<gt> Z_BEST_SPEED> has been specified then XFL is set to 2. | |
1052 | If C<Level =E<gt> Z_BEST_COMPRESSION> has been specified then XFL is set to 4. | |
1053 | Otherwise XFL is set to 0. | |
1054 | ||
1055 | ||
1056 | ||
1057 | =item -Strict =E<gt> 0|1 | |
1058 | ||
1059 | ||
1060 | ||
1061 | C<Strict> will optionally police the values supplied with other options | |
1062 | to ensure they are compliant with RFC1952. | |
1063 | ||
1064 | This option is enabled by default. | |
1065 | ||
1066 | If C<Strict> is enabled the following behaviour will be policed: | |
1067 | ||
1068 | =over 5 | |
1069 | ||
1070 | =item * | |
1071 | ||
1072 | The value supplied with the C<Name> option can only contain ISO 8859-1 | |
1073 | characters. | |
1074 | ||
1075 | =item * | |
1076 | ||
1077 | The value supplied with the C<Comment> option can only contain ISO 8859-1 | |
1078 | characters plus line-feed. | |
1079 | ||
1080 | =item * | |
1081 | ||
1082 | The values supplied with the C<-Name> and C<-Comment> options cannot | |
1083 | contain multiple embedded nulls. | |
1084 | ||
1085 | =item * | |
1086 | ||
1087 | If an C<ExtraField> option is specified and it is a simple scalar, | |
1088 | it must conform to the sub-field structure as defined in RFC 1952. | |
1089 | ||
1090 | =item * | |
1091 | ||
1092 | If an C<ExtraField> option is specified the second byte of the ID will be | |
1093 | checked in each subfield to ensure that it does not contain the reserved | |
1094 | value 0x00. | |
1095 | ||
1096 | =back | |
1097 | ||
1098 | When C<Strict> is disabled the following behaviour will be policed: | |
1099 | ||
1100 | =over 5 | |
1101 | ||
1102 | =item * | |
1103 | ||
1104 | The value supplied with C<-Name> option can contain | |
1105 | any character except NULL. | |
1106 | ||
1107 | =item * | |
1108 | ||
1109 | The value supplied with C<-Comment> option can contain any character | |
1110 | except NULL. | |
1111 | ||
1112 | =item * | |
1113 | ||
1114 | The values supplied with the C<-Name> and C<-Comment> options can contain | |
1115 | multiple embedded nulls. The string written to the gzip header will | |
1116 | consist of the characters up to, but not including, the first embedded | |
1117 | NULL. | |
1118 | ||
1119 | =item * | |
1120 | ||
1121 | If an C<ExtraField> option is specified and it is a simple scalar, the | |
1122 | structure will not be checked. The only error is if the length is too big. | |
1123 | ||
1124 | =item * | |
1125 | ||
1126 | The ID header in an C<ExtraField> sub-field can consist of any two bytes. | |
1127 | ||
1128 | =back | |
1129 | ||
1130 | ||
1131 | ||
1132 | =back | |
1133 | ||
1134 | =head2 Examples | |
1135 | ||
1136 | TODO | |
1137 | ||
1138 | =head1 Methods | |
1139 | ||
1140 | =head2 print | |
1141 | ||
1142 | Usage is | |
1143 | ||
1144 | $z->print($data) | |
1145 | print $z $data | |
1146 | ||
1147 | Compresses and outputs the contents of the C<$data> parameter. This | |
1148 | has the same behaviour as the C<print> built-in. | |
1149 | ||
1150 | Returns true if successful. | |
1151 | ||
1152 | =head2 printf | |
1153 | ||
1154 | Usage is | |
1155 | ||
1156 | $z->printf($format, $data) | |
1157 | printf $z $format, $data | |
1158 | ||
1159 | Compresses and outputs the contents of the C<$data> parameter. | |
1160 | ||
1161 | Returns true if successful. | |
1162 | ||
1163 | =head2 syswrite | |
1164 | ||
1165 | Usage is | |
1166 | ||
1167 | $z->syswrite $data | |
1168 | $z->syswrite $data, $length | |
1169 | $z->syswrite $data, $length, $offset | |
1170 | ||
1171 | Compresses and outputs the contents of the C<$data> parameter. | |
1172 | ||
1173 | Returns the number of uncompressed bytes written, or C<undef> if | |
1174 | unsuccessful. | |
1175 | ||
1176 | =head2 write | |
1177 | ||
1178 | Usage is | |
1179 | ||
1180 | $z->write $data | |
1181 | $z->write $data, $length | |
1182 | $z->write $data, $length, $offset | |
1183 | ||
1184 | Compresses and outputs the contents of the C<$data> parameter. | |
1185 | ||
1186 | Returns the number of uncompressed bytes written, or C<undef> if | |
1187 | unsuccessful. | |
1188 | ||
1189 | =head2 flush | |
1190 | ||
1191 | Usage is | |
1192 | ||
1193 | ||
1194 | $z->flush; | |
1195 | $z->flush($flush_type); | |
1196 | ||
1197 | ||
1198 | Flushes any pending compressed data to the output file/buffer. | |
1199 | ||
1200 | ||
1201 | This method takes an optional parameter, C<$flush_type>, that controls | |
1202 | how the flushing will be carried out. By default the C<$flush_type> | |
1203 | used is C<Z_FINISH>. Other valid values for C<$flush_type> are | |
1204 | C<Z_NO_FLUSH>, C<Z_SYNC_FLUSH>, C<Z_FULL_FLUSH> and C<Z_BLOCK>. It is | |
1205 | strongly recommended that you only set the C<flush_type> parameter if | |
1206 | you fully understand the implications of what it does - overuse of C<flush> | |
1207 | can seriously degrade the level of compression achieved. See the C<zlib> | |
1208 | documentation for details. | |
1209 | ||
1210 | ||
1211 | Returns true on success. | |
1212 | ||
1213 | ||
1214 | =head2 tell | |
1215 | ||
1216 | Usage is | |
1217 | ||
1218 | $z->tell() | |
1219 | tell $z | |
1220 | ||
1221 | Returns the uncompressed file offset. | |
1222 | ||
1223 | =head2 eof | |
1224 | ||
1225 | Usage is | |
1226 | ||
1227 | $z->eof(); | |
1228 | eof($z); | |
1229 | ||
1230 | ||
1231 | ||
1232 | Returns true if the C<close> method has been called. | |
1233 | ||
1234 | ||
1235 | ||
1236 | =head2 seek | |
1237 | ||
1238 | $z->seek($position, $whence); | |
1239 | seek($z, $position, $whence); | |
1240 | ||
1241 | ||
1242 | ||
1243 | ||
1244 | Provides a sub-set of the C<seek> functionality, with the restriction | |
1245 | that it is only legal to seek forward in the output file/buffer. | |
1246 | It is a fatal error to attempt to seek backward. | |
1247 | ||
1248 | Empty parts of the file/buffer will have NULL (0x00) bytes written to them. | |
1249 | ||
1250 | ||
1251 | ||
1252 | The C<$whence> parameter takes one the usual values, namely SEEK_SET, | |
1253 | SEEK_CUR or SEEK_END. | |
1254 | ||
1255 | Returns 1 on success, 0 on failure. | |
1256 | ||
1257 | =head2 binmode | |
1258 | ||
1259 | Usage is | |
1260 | ||
1261 | $z->binmode | |
1262 | binmode $z ; | |
1263 | ||
1264 | This is a noop provided for completeness. | |
1265 | ||
1266 | =head2 opened | |
1267 | ||
1268 | $z->opened() | |
1269 | ||
1270 | Returns true if the object currently refers to a opened file/buffer. | |
1271 | ||
1272 | =head2 autoflush | |
1273 | ||
1274 | my $prev = $z->autoflush() | |
1275 | my $prev = $z->autoflush(EXPR) | |
1276 | ||
1277 | If the C<$z> object is associated with a file or a filehandle, this method | |
1278 | returns the current autoflush setting for the underlying filehandle. If | |
1279 | C<EXPR> is present, and is non-zero, it will enable flushing after every | |
1280 | write/print operation. | |
1281 | ||
1282 | If C<$z> is associated with a buffer, this method has no effect and always | |
1283 | returns C<undef>. | |
1284 | ||
1285 | B<Note> that the special variable C<$|> B<cannot> be used to set or | |
1286 | retrieve the autoflush setting. | |
1287 | ||
1288 | =head2 input_line_number | |
1289 | ||
1290 | $z->input_line_number() | |
1291 | $z->input_line_number(EXPR) | |
1292 | ||
1293 | ||
1294 | This method always returns C<undef> when compressing. | |
1295 | ||
1296 | ||
1297 | ||
1298 | =head2 fileno | |
1299 | ||
1300 | $z->fileno() | |
1301 | fileno($z) | |
1302 | ||
1303 | If the C<$z> object is associated with a file or a filehandle, this method | |
1304 | will return the underlying file descriptor. | |
1305 | ||
1306 | If the C<$z> object is is associated with a buffer, this method will | |
1307 | return undef. | |
1308 | ||
1309 | =head2 close | |
1310 | ||
1311 | $z->close() ; | |
1312 | close $z ; | |
1313 | ||
1314 | ||
1315 | ||
1316 | Flushes any pending compressed data and then closes the output file/buffer. | |
1317 | ||
1318 | ||
1319 | ||
1320 | For most versions of Perl this method will be automatically invoked if | |
1321 | the IO::Compress::Gzip object is destroyed (either explicitly or by the | |
1322 | variable with the reference to the object going out of scope). The | |
1323 | exceptions are Perl versions 5.005 through 5.00504 and 5.8.0. In | |
1324 | these cases, the C<close> method will be called automatically, but | |
1325 | not until global destruction of all live objects when the program is | |
1326 | terminating. | |
1327 | ||
1328 | Therefore, if you want your scripts to be able to run on all versions | |
1329 | of Perl, you should call C<close> explicitly and not rely on automatic | |
1330 | closing. | |
1331 | ||
1332 | Returns true on success, otherwise 0. | |
1333 | ||
1334 | If the C<AutoClose> option has been enabled when the IO::Compress::Gzip | |
1335 | object was created, and the object is associated with a file, the | |
1336 | underlying file will also be closed. | |
1337 | ||
1338 | ||
1339 | ||
1340 | ||
1341 | =head2 newStream([OPTS]) | |
1342 | ||
1343 | Usage is | |
1344 | ||
1345 | $z->newStream( [OPTS] ) | |
1346 | ||
1347 | Closes the current compressed data stream and starts a new one. | |
1348 | ||
1349 | OPTS consists of the following sub-set of the the options that are | |
1350 | available when creating the C<$z> object, | |
1351 | ||
1352 | =over 5 | |
1353 | ||
1354 | ||
1355 | ||
1356 | =item * Level | |
1357 | ||
1358 | ||
1359 | ||
1360 | =back | |
1361 | ||
1362 | ||
1363 | =head2 deflateParams | |
1364 | ||
1365 | Usage is | |
1366 | ||
1367 | $z->deflateParams | |
1368 | ||
1369 | TODO | |
1370 | ||
1371 | ||
1372 | =head1 Importing | |
1373 | ||
1374 | ||
1375 | A number of symbolic constants are required by some methods in | |
1376 | C<IO::Compress::Gzip>. None are imported by default. | |
1377 | ||
1378 | ||
1379 | ||
1380 | =over 5 | |
1381 | ||
1382 | =item :all | |
1383 | ||
1384 | ||
1385 | Imports C<gzip>, C<$GzipError> and all symbolic | |
1386 | constants that can be used by C<IO::Compress::Gzip>. Same as doing this | |
1387 | ||
1388 | use IO::Compress::Gzip qw(gzip $GzipError :constants) ; | |
1389 | ||
1390 | =item :constants | |
1391 | ||
1392 | Import all symbolic constants. Same as doing this | |
1393 | ||
1394 | use IO::Compress::Gzip qw(:flush :level :strategy) ; | |
1395 | ||
1396 | =item :flush | |
1397 | ||
1398 | These symbolic constants are used by the C<flush> method. | |
1399 | ||
1400 | Z_NO_FLUSH | |
1401 | Z_PARTIAL_FLUSH | |
1402 | Z_SYNC_FLUSH | |
1403 | Z_FULL_FLUSH | |
1404 | Z_FINISH | |
1405 | Z_BLOCK | |
1406 | ||
1407 | =item :level | |
1408 | ||
1409 | These symbolic constants are used by the C<Level> option in the constructor. | |
1410 | ||
1411 | Z_NO_COMPRESSION | |
1412 | Z_BEST_SPEED | |
1413 | Z_BEST_COMPRESSION | |
1414 | Z_DEFAULT_COMPRESSION | |
1415 | ||
1416 | ||
1417 | =item :strategy | |
1418 | ||
1419 | These symbolic constants are used by the C<Strategy> option in the constructor. | |
1420 | ||
1421 | Z_FILTERED | |
1422 | Z_HUFFMAN_ONLY | |
1423 | Z_RLE | |
1424 | Z_FIXED | |
1425 | Z_DEFAULT_STRATEGY | |
1426 | ||
1427 | ||
1428 | =back | |
1429 | ||
1430 | For | |
1431 | ||
1432 | =head1 EXAMPLES | |
1433 | ||
1434 | TODO | |
1435 | ||
1436 | ||
1437 | ||
1438 | ||
1439 | ||
1440 | ||
1441 | =head1 SEE ALSO | |
1442 | ||
1443 | L<Compress::Zlib>, L<IO::Uncompress::Gunzip>, L<IO::Compress::Deflate>, L<IO::Uncompress::Inflate>, 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::Uncompress::AnyInflate>, L<IO::Uncompress::AnyUncompress> | |
1444 | ||
1445 | L<Compress::Zlib::FAQ|Compress::Zlib::FAQ> | |
1446 | ||
1447 | L<File::GlobMapper|File::GlobMapper>, L<Archive::Zip|Archive::Zip>, | |
1448 | L<Archive::Tar|Archive::Tar>, | |
1449 | L<IO::Zlib|IO::Zlib> | |
1450 | ||
1451 | ||
1452 | For RFC 1950, 1951 and 1952 see | |
1453 | F<http://www.faqs.org/rfcs/rfc1950.html>, | |
1454 | F<http://www.faqs.org/rfcs/rfc1951.html> and | |
1455 | F<http://www.faqs.org/rfcs/rfc1952.html> | |
1456 | ||
1457 | The I<zlib> compression library was written by Jean-loup Gailly | |
1458 | F<gzip@prep.ai.mit.edu> and Mark Adler F<madler@alumni.caltech.edu>. | |
1459 | ||
1460 | The primary site for the I<zlib> compression library is | |
1461 | F<http://www.zlib.org>. | |
1462 | ||
1463 | The primary site for gzip is F<http://www.gzip.org>. | |
1464 | ||
1465 | ||
1466 | ||
1467 | ||
1468 | ||
1469 | ||
1470 | ||
1471 | =head1 AUTHOR | |
1472 | ||
1473 | The I<IO::Compress::Gzip> module was written by Paul Marquess, | |
1474 | F<pmqs@cpan.org>. | |
1475 | ||
1476 | ||
1477 | ||
1478 | =head1 MODIFICATION HISTORY | |
1479 | ||
1480 | See the Changes file. | |
1481 | ||
1482 | =head1 COPYRIGHT AND LICENSE | |
1483 | ||
1484 | ||
1485 | Copyright (c) 2005-2006 Paul Marquess. All rights reserved. | |
1486 | ||
1487 | This program is free software; you can redistribute it and/or | |
1488 | modify it under the same terms as Perl itself. | |
1489 | ||
1490 |