Commit | Line | Data |
642e522c |
1 | |
2 | package IO::Compress::Gzip ; |
3 | |
4 | require 5.004 ; |
5 | |
6 | use strict ; |
7 | use warnings; |
8 | |
642e522c |
9 | |
1a6a8453 |
10 | use IO::Compress::RawDeflate; |
642e522c |
11 | |
12 | use Compress::Zlib 2 ; |
1a6a8453 |
13 | use Compress::Zlib::Common qw(:Status createSelfTiedObject); |
642e522c |
14 | use Compress::Gzip::Constants; |
642e522c |
15 | |
16 | BEGIN |
17 | { |
18 | if (defined &utf8::downgrade ) |
19 | { *noUTF8 = \&utf8::downgrade } |
20 | else |
21 | { *noUTF8 = sub {} } |
22 | } |
642e522c |
23 | |
1a6a8453 |
24 | require Exporter ; |
642e522c |
25 | |
1a6a8453 |
26 | our ($VERSION, @ISA, @EXPORT_OK, %EXPORT_TAGS, $GzipError); |
642e522c |
27 | |
1a6a8453 |
28 | $VERSION = '2.000_07'; |
29 | $GzipError = '' ; |
642e522c |
30 | |
1a6a8453 |
31 | @ISA = qw(Exporter IO::Compress::RawDeflate); |
32 | @EXPORT_OK = qw( $GzipError gzip ) ; |
33 | %EXPORT_TAGS = %IO::Compress::RawDeflate::DEFLATE_CONSTANTS ; |
34 | push @{ $EXPORT_TAGS{all} }, @EXPORT_OK ; |
35 | Exporter::export_ok_tags('all'); |
642e522c |
36 | |
1a6a8453 |
37 | sub new |
642e522c |
38 | { |
1a6a8453 |
39 | my $class = shift ; |
642e522c |
40 | |
1a6a8453 |
41 | my $obj = createSelfTiedObject($class, \$GzipError); |
642e522c |
42 | |
1a6a8453 |
43 | $obj->_create(undef, @_); |
642e522c |
44 | } |
45 | |
642e522c |
46 | |
1a6a8453 |
47 | sub gzip |
642e522c |
48 | { |
1a6a8453 |
49 | my $obj = createSelfTiedObject(undef, \$GzipError); |
50 | return $obj->_def(@_); |
642e522c |
51 | } |
52 | |
1a6a8453 |
53 | #sub newHeader |
54 | #{ |
55 | # my $self = shift ; |
56 | # #return GZIP_MINIMUM_HEADER ; |
57 | # return $self->mkHeader(*$self->{Got}); |
58 | #} |
642e522c |
59 | |
1a6a8453 |
60 | sub getExtraParams |
642e522c |
61 | { |
62 | my $self = shift ; |
642e522c |
63 | |
1a6a8453 |
64 | use Compress::Zlib::ParseParameters; |
642e522c |
65 | |
1a6a8453 |
66 | return ( |
642e522c |
67 | # zlib behaviour |
1a6a8453 |
68 | $self->getZlibParams(), |
642e522c |
69 | |
70 | # Gzip header fields |
1a6a8453 |
71 | 'Minimal' => [0, 1, Parse_boolean, 0], |
72 | 'Comment' => [0, 1, Parse_any, undef], |
73 | 'Name' => [0, 1, Parse_any, undef], |
74 | 'Time' => [0, 1, Parse_any, undef], |
75 | 'TextFlag' => [0, 1, Parse_boolean, 0], |
76 | 'HeaderCRC' => [0, 1, Parse_boolean, 0], |
77 | 'OS_Code' => [0, 1, Parse_unsigned, $Compress::Zlib::gzip_os_code], |
78 | 'ExtraField'=> [0, 1, Parse_string, undef], |
79 | 'ExtraFlags'=> [0, 1, Parse_any, undef], |
80 | |
81 | ); |
642e522c |
82 | } |
83 | |
642e522c |
84 | |
1a6a8453 |
85 | sub ckParams |
86 | { |
87 | my $self = shift ; |
88 | my $got = shift ; |
642e522c |
89 | |
1a6a8453 |
90 | # gzip always needs crc32 |
91 | $got->value('CRC32' => 1); |
642e522c |
92 | |
1a6a8453 |
93 | return 1 |
94 | if $got->value('Merge') ; |
642e522c |
95 | |
96 | my $lax = ! $got->value('Strict') ; |
97 | |
642e522c |
98 | |
642e522c |
99 | { |
642e522c |
100 | if (! $got->parsed('Time') ) { |
101 | # Modification time defaults to now. |
102 | $got->value('Time' => time) ; |
103 | } |
104 | |
105 | # Check that the Name & Comment don't have embedded NULLs |
106 | # Also check that they only contain ISO 8859-1 chars. |
107 | if ($got->parsed('Name') && defined $got->value('Name')) { |
108 | my $name = $got->value('Name'); |
109 | |
1a6a8453 |
110 | return $self->saveErrorString(undef, "Null Character found in Name", |
642e522c |
111 | Z_DATA_ERROR) |
112 | if ! $lax && $name =~ /\x00/ ; |
113 | |
1a6a8453 |
114 | return $self->saveErrorString(undef, "Non ISO 8859-1 Character found in Name", |
642e522c |
115 | Z_DATA_ERROR) |
116 | if ! $lax && $name =~ /$GZIP_FNAME_INVALID_CHAR_RE/o ; |
117 | } |
118 | |
119 | if ($got->parsed('Comment') && defined $got->value('Comment')) { |
120 | my $comment = $got->value('Comment'); |
121 | |
1a6a8453 |
122 | return $self->saveErrorString(undef, "Null Character found in Comment", |
642e522c |
123 | Z_DATA_ERROR) |
124 | if ! $lax && $comment =~ /\x00/ ; |
125 | |
1a6a8453 |
126 | return $self->saveErrorString(undef, "Non ISO 8859-1 Character found in Comment", |
642e522c |
127 | Z_DATA_ERROR) |
128 | if ! $lax && $comment =~ /$GZIP_FCOMMENT_INVALID_CHAR_RE/o; |
129 | } |
130 | |
131 | if ($got->parsed('OS_Code') ) { |
132 | my $value = $got->value('OS_Code'); |
133 | |
1a6a8453 |
134 | return $self->saveErrorString(undef, "OS_Code must be between 0 and 255, got '$value'") |
642e522c |
135 | if $value < 0 || $value > 255 ; |
136 | |
137 | } |
138 | |
139 | # gzip only supports Deflate at present |
140 | $got->value('Method' => Z_DEFLATED) ; |
141 | |
142 | if ( ! $got->parsed('ExtraFlags')) { |
143 | $got->value('ExtraFlags' => 2) |
144 | if $got->value('Level') == Z_BEST_SPEED ; |
145 | $got->value('ExtraFlags' => 4) |
146 | if $got->value('Level') == Z_BEST_COMPRESSION ; |
147 | } |
148 | |
149 | if ($got->parsed('ExtraField')) { |
150 | |
1a6a8453 |
151 | my $bad = $self->parseExtraField($got, $lax) ; |
152 | return $self->saveErrorString(undef, $bad, Z_DATA_ERROR) |
642e522c |
153 | if $bad ; |
154 | |
155 | my $len = length $got->value('ExtraField') ; |
1a6a8453 |
156 | return $self->saveErrorString(undef, ExtraFieldError("Too Large"), |
642e522c |
157 | Z_DATA_ERROR) |
158 | if $len > GZIP_FEXTRA_MAX_SIZE; |
159 | } |
160 | } |
161 | |
1a6a8453 |
162 | return 1; |
642e522c |
163 | } |
164 | |
1a6a8453 |
165 | sub mkTrailer |
642e522c |
166 | { |
167 | my $self = shift ; |
1a6a8453 |
168 | return pack("V V", *$self->{Compress}->crc32(), |
169 | *$self->{UnCompSize_32bit}); |
642e522c |
170 | } |
171 | |
1a6a8453 |
172 | sub getInverseClass |
642e522c |
173 | { |
1a6a8453 |
174 | return ('IO::Uncompress::Gunzip', |
175 | \$IO::Uncompress::Gunzip::GunzipError); |
642e522c |
176 | } |
177 | |
1a6a8453 |
178 | sub getFileInfo |
642e522c |
179 | { |
180 | my $self = shift ; |
1a6a8453 |
181 | my $params = shift; |
182 | my $filename = shift ; |
642e522c |
183 | |
1a6a8453 |
184 | my $defaultTime = (stat($filename))[9] ; |
642e522c |
185 | |
1a6a8453 |
186 | $params->value('Name' => $filename) |
187 | if ! $params->parsed('Name') ; |
642e522c |
188 | |
1a6a8453 |
189 | $params->value('Time' => $defaultTime) |
190 | if ! $params->parsed('Time') ; |
191 | } |
642e522c |
192 | |
193 | |
1a6a8453 |
194 | sub mkHeader |
642e522c |
195 | { |
196 | my $self = shift ; |
1a6a8453 |
197 | my $param = shift ; |
642e522c |
198 | |
1a6a8453 |
199 | # stort-circuit if a minimal header is requested. |
200 | return GZIP_MINIMUM_HEADER if $param->value('Minimal') ; |
642e522c |
201 | |
1a6a8453 |
202 | # METHOD |
203 | my $method = $param->valueOrDefault('Method', GZIP_CM_DEFLATED) ; |
642e522c |
204 | |
1a6a8453 |
205 | # FLAGS |
206 | my $flags = GZIP_FLG_DEFAULT ; |
207 | $flags |= GZIP_FLG_FTEXT if $param->value('TextFlag') ; |
208 | $flags |= GZIP_FLG_FHCRC if $param->value('HeaderCRC') ; |
209 | $flags |= GZIP_FLG_FEXTRA if $param->wantValue('ExtraField') ; |
210 | $flags |= GZIP_FLG_FNAME if $param->wantValue('Name') ; |
211 | $flags |= GZIP_FLG_FCOMMENT if $param->wantValue('Comment') ; |
212 | |
213 | # MTIME |
214 | my $time = $param->valueOrDefault('Time', GZIP_MTIME_DEFAULT) ; |
642e522c |
215 | |
1a6a8453 |
216 | # EXTRA FLAGS |
217 | my $extra_flags = $param->valueOrDefault('ExtraFlags', GZIP_XFL_DEFAULT); |
642e522c |
218 | |
1a6a8453 |
219 | # OS CODE |
220 | my $os_code = $param->valueOrDefault('OS_Code', GZIP_OS_DEFAULT) ; |
642e522c |
221 | |
642e522c |
222 | |
1a6a8453 |
223 | my $out = pack("C4 V C C", |
224 | GZIP_ID1, # ID1 |
225 | GZIP_ID2, # ID2 |
226 | $method, # Compression Method |
227 | $flags, # Flags |
228 | $time, # Modification Time |
229 | $extra_flags, # Extra Flags |
230 | $os_code, # Operating System Code |
231 | ) ; |
642e522c |
232 | |
1a6a8453 |
233 | # EXTRA |
234 | if ($flags & GZIP_FLG_FEXTRA) { |
235 | my $extra = $param->value('ExtraField') ; |
236 | $out .= pack("v", length $extra) . $extra ; |
642e522c |
237 | } |
238 | |
1a6a8453 |
239 | # NAME |
240 | if ($flags & GZIP_FLG_FNAME) { |
241 | my $name .= $param->value('Name') ; |
242 | $name =~ s/\x00.*$//; |
243 | $out .= $name ; |
244 | # Terminate the filename with NULL unless it already is |
245 | $out .= GZIP_NULL_BYTE |
246 | if !length $name or |
247 | substr($name, 1, -1) ne GZIP_NULL_BYTE ; |
248 | } |
642e522c |
249 | |
1a6a8453 |
250 | # COMMENT |
251 | if ($flags & GZIP_FLG_FCOMMENT) { |
252 | my $comment .= $param->value('Comment') ; |
253 | $comment =~ s/\x00.*$//; |
254 | $out .= $comment ; |
255 | # Terminate the comment with NULL unless it already is |
256 | $out .= GZIP_NULL_BYTE |
257 | if ! length $comment or |
258 | substr($comment, 1, -1) ne GZIP_NULL_BYTE; |
642e522c |
259 | } |
642e522c |
260 | |
1a6a8453 |
261 | # HEADER CRC |
262 | $out .= pack("v", crc32($out) & 0x00FF ) if $param->value('HeaderCRC') ; |
642e522c |
263 | |
1a6a8453 |
264 | noUTF8($out); |
642e522c |
265 | |
1a6a8453 |
266 | return $out ; |
267 | } |
642e522c |
268 | |
1a6a8453 |
269 | sub ExtraFieldError |
642e522c |
270 | { |
1a6a8453 |
271 | return "Error with ExtraField Parameter: $_[0]" ; |
642e522c |
272 | } |
273 | |
1a6a8453 |
274 | sub validateExtraFieldPair |
642e522c |
275 | { |
1a6a8453 |
276 | my $pair = shift ; |
277 | my $lax = shift ; |
642e522c |
278 | |
1a6a8453 |
279 | return ExtraFieldError("Not an array ref") |
280 | unless ref $pair && ref $pair eq 'ARRAY'; |
642e522c |
281 | |
1a6a8453 |
282 | return ExtraFieldError("SubField must have two parts") |
283 | unless @$pair == 2 ; |
642e522c |
284 | |
1a6a8453 |
285 | return ExtraFieldError("SubField ID is a reference") |
286 | if ref $pair->[0] ; |
642e522c |
287 | |
1a6a8453 |
288 | return ExtraFieldError("SubField Data is a reference") |
289 | if ref $pair->[1] ; |
642e522c |
290 | |
1a6a8453 |
291 | # ID is exactly two chars |
292 | return ExtraFieldError("SubField ID not two chars long") |
293 | unless length $pair->[0] == GZIP_FEXTRA_SUBFIELD_ID_SIZE ; |
642e522c |
294 | |
1a6a8453 |
295 | # Check that the 2nd byte of the ID isn't 0 |
296 | return ExtraFieldError("SubField ID 2nd byte is 0x00") |
297 | if ! $lax && substr($pair->[0], 1, 1) eq "\x00" ; |
642e522c |
298 | |
1a6a8453 |
299 | return ExtraFieldError("SubField Data too long") |
300 | if length $pair->[1] > GZIP_FEXTRA_SUBFIELD_MAX_SIZE ; |
642e522c |
301 | |
642e522c |
302 | |
1a6a8453 |
303 | return undef ; |
642e522c |
304 | } |
305 | |
1a6a8453 |
306 | sub parseExtra |
642e522c |
307 | { |
1a6a8453 |
308 | my $data = shift ; |
309 | my $lax = shift ; |
642e522c |
310 | |
1a6a8453 |
311 | return undef |
312 | if $lax ; |
642e522c |
313 | |
1a6a8453 |
314 | my $XLEN = length $data ; |
642e522c |
315 | |
1a6a8453 |
316 | return ExtraFieldError("Too Large") |
317 | if $XLEN > GZIP_FEXTRA_MAX_SIZE; |
642e522c |
318 | |
1a6a8453 |
319 | my $offset = 0 ; |
320 | while ($offset < $XLEN) { |
642e522c |
321 | |
1a6a8453 |
322 | return ExtraFieldError("FEXTRA Body") |
323 | if $offset + GZIP_FEXTRA_SUBFIELD_HEADER_SIZE > $XLEN ; |
642e522c |
324 | |
1a6a8453 |
325 | my $id = substr($data, $offset, GZIP_FEXTRA_SUBFIELD_ID_SIZE); |
326 | $offset += GZIP_FEXTRA_SUBFIELD_ID_SIZE; |
642e522c |
327 | |
1a6a8453 |
328 | my $subLen = unpack("v", substr($data, $offset, |
329 | GZIP_FEXTRA_SUBFIELD_LEN_SIZE)); |
330 | $offset += GZIP_FEXTRA_SUBFIELD_LEN_SIZE ; |
642e522c |
331 | |
1a6a8453 |
332 | return ExtraFieldError("FEXTRA Body") |
333 | if $offset + $subLen > $XLEN ; |
642e522c |
334 | |
1a6a8453 |
335 | my $bad = validateExtraFieldPair( [$id, |
336 | substr($data, $offset, $subLen)], $lax ); |
337 | return $bad if $bad ; |
642e522c |
338 | |
1a6a8453 |
339 | $offset += $subLen ; |
642e522c |
340 | } |
1a6a8453 |
341 | |
342 | return undef ; |
642e522c |
343 | } |
344 | |
1a6a8453 |
345 | sub parseExtraField |
642e522c |
346 | { |
347 | my $self = shift ; |
1a6a8453 |
348 | my $got = shift ; |
349 | my $lax = shift ; |
642e522c |
350 | |
1a6a8453 |
351 | # ExtraField can be any of |
352 | # |
353 | # -ExtraField => $data |
354 | # -ExtraField => [$id1, $data1, |
355 | # $id2, $data2] |
356 | # ... |
357 | # ] |
358 | # -ExtraField => [ [$id1 => $data1], |
359 | # [$id2 => $data2], |
360 | # ... |
361 | # ] |
362 | # -ExtraField => { $id1 => $data1, |
363 | # $id2 => $data2, |
364 | # ... |
365 | # } |
642e522c |
366 | |
1a6a8453 |
367 | |
368 | return undef |
369 | unless $got->parsed('ExtraField') ; |
642e522c |
370 | |
1a6a8453 |
371 | return parseExtra($got->value('ExtraField'), $lax) |
372 | unless ref $got->value('ExtraField') ; |
642e522c |
373 | |
1a6a8453 |
374 | my $data = $got->value('ExtraField'); |
375 | my $out = '' ; |
642e522c |
376 | |
1a6a8453 |
377 | if (ref $data eq 'ARRAY') { |
378 | if (ref $data->[0]) { |
642e522c |
379 | |
1a6a8453 |
380 | foreach my $pair (@$data) { |
381 | return ExtraFieldError("Not list of lists") |
382 | unless ref $pair eq 'ARRAY' ; |
642e522c |
383 | |
1a6a8453 |
384 | my $bad = validateExtraFieldPair($pair, $lax) ; |
385 | return $bad if $bad ; |
642e522c |
386 | |
1a6a8453 |
387 | $out .= $pair->[0] . pack("v", length $pair->[1]) . |
388 | $pair->[1] ; |
389 | } |
390 | } |
391 | else { |
392 | return ExtraFieldError("Not even number of elements") |
393 | unless @$data % 2 == 0; |
642e522c |
394 | |
1a6a8453 |
395 | for (my $ix = 0; $ix <= length(@$data) -1 ; $ix += 2) { |
396 | my $bad = validateExtraFieldPair([$data->[$ix], $data->[$ix+1]], $lax) ; |
397 | return $bad if $bad ; |
642e522c |
398 | |
1a6a8453 |
399 | $out .= $data->[$ix] . pack("v", length $data->[$ix+1]) . |
400 | $data->[$ix+1] ; |
401 | } |
402 | } |
403 | } |
404 | elsif (ref $data eq 'HASH') { |
405 | while (my ($id, $info) = each %$data) { |
406 | my $bad = validateExtraFieldPair([$id, $info], $lax); |
407 | return $bad if $bad ; |
642e522c |
408 | |
1a6a8453 |
409 | $out .= $id . pack("v", length $info) . $info ; |
410 | } |
411 | } |
642e522c |
412 | else { |
1a6a8453 |
413 | return ExtraFieldError("Not a scalar, array ref or hash ref") ; |
642e522c |
414 | } |
415 | |
1a6a8453 |
416 | $got->value('ExtraField' => $out); |
642e522c |
417 | |
1a6a8453 |
418 | return undef; |
642e522c |
419 | } |
420 | |
1a6a8453 |
421 | sub mkFinalTrailer |
642e522c |
422 | { |
1a6a8453 |
423 | return ''; |
642e522c |
424 | } |
425 | |
642e522c |
426 | 1; |
427 | |
428 | __END__ |
429 | |
430 | =head1 NAME |
431 | |
432 | IO::Compress::Gzip - Perl interface to write RFC 1952 files/buffers |
433 | |
434 | =head1 SYNOPSIS |
435 | |
436 | use IO::Compress::Gzip qw(gzip $GzipError) ; |
437 | |
438 | |
439 | my $status = gzip $input => $output [,OPTS] |
440 | or die "gzip failed: $GzipError\n"; |
441 | |
442 | my $z = new IO::Compress::Gzip $output [,OPTS] |
443 | or die "gzip failed: $GzipError\n"; |
444 | |
445 | $z->print($string); |
446 | $z->printf($format, $string); |
447 | $z->write($string); |
448 | $z->syswrite($string [, $length, $offset]); |
449 | $z->flush(); |
450 | $z->tell(); |
451 | $z->eof(); |
452 | $z->seek($position, $whence); |
453 | $z->binmode(); |
454 | $z->fileno(); |
1a6a8453 |
455 | $z->newStream( [OPTS] ); |
642e522c |
456 | $z->deflateParams(); |
457 | $z->close() ; |
458 | |
459 | $GzipError ; |
460 | |
461 | # IO::File mode |
462 | |
463 | print $z $string; |
464 | printf $z $format, $string; |
465 | syswrite $z, $string [, $length, $offset]; |
466 | flush $z, ; |
467 | tell $z |
468 | eof $z |
469 | seek $z, $position, $whence |
470 | binmode $z |
471 | fileno $z |
472 | close $z ; |
473 | |
474 | |
475 | =head1 DESCRIPTION |
476 | |
477 | |
478 | |
479 | B<WARNING -- This is a Beta release>. |
480 | |
481 | =over 5 |
482 | |
483 | =item * DO NOT use in production code. |
484 | |
485 | =item * The documentation is incomplete in places. |
486 | |
487 | =item * Parts of the interface defined here are tentative. |
488 | |
489 | =item * Please report any problems you find. |
490 | |
491 | =back |
492 | |
493 | |
494 | |
495 | This module provides a Perl interface that allows writing compressed |
496 | data to files or buffer as defined in RFC 1952. |
497 | |
498 | |
499 | All the gzip headers defined in RFC 1952 can be created using |
500 | this module. |
501 | |
502 | |
503 | |
504 | |
505 | For reading RFC 1952 files/buffers, see the companion module |
506 | L<IO::Uncompress::Gunzip|IO::Uncompress::Gunzip>. |
507 | |
508 | |
509 | =head1 Functional Interface |
510 | |
1a6a8453 |
511 | A top-level function, C<gzip>, is provided to carry out |
512 | "one-shot" compression between buffers and/or files. For finer |
513 | control over the compression process, see the L</"OO Interface"> |
514 | section. |
642e522c |
515 | |
516 | use IO::Compress::Gzip qw(gzip $GzipError) ; |
517 | |
518 | gzip $input => $output [,OPTS] |
519 | or die "gzip failed: $GzipError\n"; |
520 | |
1a6a8453 |
521 | |
642e522c |
522 | |
523 | The functional interface needs Perl5.005 or better. |
524 | |
525 | |
526 | =head2 gzip $input => $output [, OPTS] |
527 | |
1a6a8453 |
528 | |
529 | C<gzip> expects at least two parameters, C<$input> and C<$output>. |
642e522c |
530 | |
531 | =head3 The C<$input> parameter |
532 | |
533 | The parameter, C<$input>, is used to define the source of |
534 | the uncompressed data. |
535 | |
536 | It can take one of the following forms: |
537 | |
538 | =over 5 |
539 | |
540 | =item A filename |
541 | |
542 | If the C<$input> parameter is a simple scalar, it is assumed to be a |
543 | filename. This file will be opened for reading and the input data |
544 | will be read from it. |
545 | |
546 | =item A filehandle |
547 | |
548 | If the C<$input> parameter is a filehandle, the input data will be |
549 | read from it. |
550 | The string '-' can be used as an alias for standard input. |
551 | |
552 | =item A scalar reference |
553 | |
554 | If C<$input> is a scalar reference, the input data will be read |
555 | from C<$$input>. |
556 | |
557 | =item An array reference |
558 | |
1a6a8453 |
559 | If C<$input> is an array reference, each element in the array must be a |
560 | filename. |
561 | |
562 | The input data will be read from each file in turn. |
563 | |
642e522c |
564 | The complete array will be walked to ensure that it only |
1a6a8453 |
565 | contains valid filenames before any data is compressed. |
566 | |
567 | |
642e522c |
568 | |
569 | =item An Input FileGlob string |
570 | |
571 | If C<$input> is a string that is delimited by the characters "<" and ">" |
572 | C<gzip> will assume that it is an I<input fileglob string>. The |
573 | input is the list of files that match the fileglob. |
574 | |
575 | If the fileglob does not match any files ... |
576 | |
577 | See L<File::GlobMapper|File::GlobMapper> for more details. |
578 | |
579 | |
580 | =back |
581 | |
582 | If the C<$input> parameter is any other type, C<undef> will be returned. |
583 | |
584 | |
585 | |
586 | In addition, if C<$input> is a simple filename, the default values for |
587 | two of the gzip header fields created by this function will be sourced |
588 | from that file -- the NAME gzip header field will be populated with |
589 | the filename itself, and the MTIME header field will be set to the |
590 | modification time of the file. |
1a6a8453 |
591 | The intention here is to mirror part of the behaviour of the gzip |
642e522c |
592 | executable. |
593 | If you do not want to use these defaults they can be overridden by |
1a6a8453 |
594 | explicitly setting the C<Name> and C<Time> options or by setting the |
595 | C<Minimal> parameter. |
642e522c |
596 | |
597 | |
598 | |
599 | =head3 The C<$output> parameter |
600 | |
601 | The parameter C<$output> is used to control the destination of the |
602 | compressed data. This parameter can take one of these forms. |
603 | |
604 | =over 5 |
605 | |
606 | =item A filename |
607 | |
1a6a8453 |
608 | If the C<$output> parameter is a simple scalar, it is assumed to be a |
609 | filename. This file will be opened for writing and the compressed |
610 | data will be written to it. |
642e522c |
611 | |
612 | =item A filehandle |
613 | |
1a6a8453 |
614 | If the C<$output> parameter is a filehandle, the compressed data |
615 | will be written to it. |
642e522c |
616 | The string '-' can be used as an alias for standard output. |
617 | |
618 | |
619 | =item A scalar reference |
620 | |
1a6a8453 |
621 | If C<$output> is a scalar reference, the compressed data will be |
622 | stored in C<$$output>. |
642e522c |
623 | |
642e522c |
624 | |
625 | |
626 | =item An Array Reference |
627 | |
1a6a8453 |
628 | If C<$output> is an array reference, the compressed data will be |
629 | pushed onto the array. |
642e522c |
630 | |
631 | =item An Output FileGlob |
632 | |
633 | If C<$output> is a string that is delimited by the characters "<" and ">" |
634 | C<gzip> will assume that it is an I<output fileglob string>. The |
635 | output is the list of files that match the fileglob. |
636 | |
637 | When C<$output> is an fileglob string, C<$input> must also be a fileglob |
638 | string. Anything else is an error. |
639 | |
640 | =back |
641 | |
642 | If the C<$output> parameter is any other type, C<undef> will be returned. |
643 | |
642e522c |
644 | |
642e522c |
645 | |
646 | =head2 Notes |
647 | |
648 | When C<$input> maps to multiple files/buffers and C<$output> is a single |
1a6a8453 |
649 | file/buffer the compressed input files/buffers will all be stored |
650 | in C<$output> as a single compressed stream. |
642e522c |
651 | |
652 | |
653 | |
654 | =head2 Optional Parameters |
655 | |
656 | Unless specified below, the optional parameters for C<gzip>, |
657 | C<OPTS>, are the same as those used with the OO interface defined in the |
658 | L</"Constructor Options"> section below. |
659 | |
660 | =over 5 |
661 | |
662 | =item AutoClose =E<gt> 0|1 |
663 | |
1a6a8453 |
664 | This option applies to any input or output data streams to |
665 | C<gzip> that are filehandles. |
642e522c |
666 | |
667 | If C<AutoClose> is specified, and the value is true, it will result in all |
668 | input and/or output filehandles being closed once C<gzip> has |
669 | completed. |
670 | |
671 | This parameter defaults to 0. |
672 | |
673 | |
674 | |
1a6a8453 |
675 | =item BinModeIn =E<gt> 0|1 |
676 | |
677 | When reading from a file or filehandle, set C<binmode> before reading. |
678 | |
679 | Defaults to 0. |
680 | |
681 | |
682 | |
683 | |
684 | |
642e522c |
685 | =item -Append =E<gt> 0|1 |
686 | |
687 | TODO |
688 | |
689 | |
690 | =back |
691 | |
692 | |
693 | |
694 | =head2 Examples |
695 | |
696 | To read the contents of the file C<file1.txt> and write the compressed |
697 | data to the file C<file1.txt.gz>. |
698 | |
699 | use strict ; |
700 | use warnings ; |
701 | use IO::Compress::Gzip qw(gzip $GzipError) ; |
702 | |
703 | my $input = "file1.txt"; |
704 | gzip $input => "$input.gz" |
705 | or die "gzip failed: $GzipError\n"; |
706 | |
707 | |
708 | To read from an existing Perl filehandle, C<$input>, and write the |
709 | compressed data to a buffer, C<$buffer>. |
710 | |
711 | use strict ; |
712 | use warnings ; |
713 | use IO::Compress::Gzip qw(gzip $GzipError) ; |
714 | use IO::File ; |
715 | |
716 | my $input = new IO::File "<file1.txt" |
717 | or die "Cannot open 'file1.txt': $!\n" ; |
718 | my $buffer ; |
719 | gzip $input => \$buffer |
720 | or die "gzip failed: $GzipError\n"; |
721 | |
722 | To compress all files in the directory "/my/home" that match "*.txt" |
723 | and store the compressed data in the same directory |
724 | |
725 | use strict ; |
726 | use warnings ; |
727 | use IO::Compress::Gzip qw(gzip $GzipError) ; |
728 | |
729 | gzip '</my/home/*.txt>' => '<*.gz>' |
730 | or die "gzip failed: $GzipError\n"; |
731 | |
732 | and if you want to compress each file one at a time, this will do the trick |
733 | |
734 | use strict ; |
735 | use warnings ; |
736 | use IO::Compress::Gzip qw(gzip $GzipError) ; |
737 | |
738 | for my $input ( glob "/my/home/*.txt" ) |
739 | { |
740 | my $output = "$input.gz" ; |
741 | gzip $input => $output |
742 | or die "Error compressing '$input': $GzipError\n"; |
743 | } |
744 | |
745 | |
746 | =head1 OO Interface |
747 | |
748 | =head2 Constructor |
749 | |
750 | The format of the constructor for C<IO::Compress::Gzip> is shown below |
751 | |
752 | my $z = new IO::Compress::Gzip $output [,OPTS] |
753 | or die "IO::Compress::Gzip failed: $GzipError\n"; |
754 | |
755 | It returns an C<IO::Compress::Gzip> object on success and undef on failure. |
756 | The variable C<$GzipError> will contain an error message on failure. |
757 | |
758 | If you are running Perl 5.005 or better the object, C<$z>, returned from |
759 | IO::Compress::Gzip can be used exactly like an L<IO::File|IO::File> filehandle. |
760 | This means that all normal output file operations can be carried out |
761 | with C<$z>. |
762 | For example, to write to a compressed file/buffer you can use either of |
763 | these forms |
764 | |
765 | $z->print("hello world\n"); |
766 | print $z "hello world\n"; |
767 | |
768 | The mandatory parameter C<$output> is used to control the destination |
769 | of the compressed data. This parameter can take one of these forms. |
770 | |
771 | =over 5 |
772 | |
773 | =item A filename |
774 | |
775 | If the C<$output> parameter is a simple scalar, it is assumed to be a |
776 | filename. This file will be opened for writing and the compressed data |
777 | will be written to it. |
778 | |
779 | =item A filehandle |
780 | |
781 | If the C<$output> parameter is a filehandle, the compressed data will be |
782 | written to it. |
783 | The string '-' can be used as an alias for standard output. |
784 | |
785 | |
786 | =item A scalar reference |
787 | |
788 | If C<$output> is a scalar reference, the compressed data will be stored |
789 | in C<$$output>. |
790 | |
791 | =back |
792 | |
793 | If the C<$output> parameter is any other type, C<IO::Compress::Gzip>::new will |
794 | return undef. |
795 | |
796 | =head2 Constructor Options |
797 | |
798 | C<OPTS> is any combination of the following options: |
799 | |
800 | =over 5 |
801 | |
802 | =item -AutoClose =E<gt> 0|1 |
803 | |
804 | This option is only valid when the C<$output> parameter is a filehandle. If |
1a6a8453 |
805 | specified, and the value is true, it will result in the C<$output> being |
806 | closed once either the C<close> method is called or the C<IO::Compress::Gzip> |
807 | object is destroyed. |
642e522c |
808 | |
809 | This parameter defaults to 0. |
810 | |
811 | =item -Append =E<gt> 0|1 |
812 | |
813 | Opens C<$output> in append mode. |
814 | |
1a6a8453 |
815 | The behaviour of this option is dependent on the type of C<$output>. |
642e522c |
816 | |
817 | =over 5 |
818 | |
819 | =item * A Buffer |
820 | |
1a6a8453 |
821 | If C<$output> is a buffer and C<Append> is enabled, all compressed data |
822 | will be append to the end if C<$output>. Otherwise C<$output> will be |
823 | cleared before any data is written to it. |
642e522c |
824 | |
825 | =item * A Filename |
826 | |
1a6a8453 |
827 | If C<$output> is a filename and C<Append> is enabled, the file will be |
828 | opened in append mode. Otherwise the contents of the file, if any, will be |
829 | truncated before any compressed data is written to it. |
642e522c |
830 | |
831 | =item * A Filehandle |
832 | |
1a6a8453 |
833 | If C<$output> is a filehandle, the file pointer will be positioned to the |
834 | end of the file via a call to C<seek> before any compressed data is written |
835 | to it. Otherwise the file pointer will not be moved. |
642e522c |
836 | |
837 | =back |
838 | |
839 | This parameter defaults to 0. |
840 | |
841 | =item -Merge =E<gt> 0|1 |
842 | |
843 | This option is used to compress input data and append it to an existing |
844 | compressed data stream in C<$output>. The end result is a single compressed |
845 | data stream stored in C<$output>. |
846 | |
847 | |
848 | |
1a6a8453 |
849 | It is a fatal error to attempt to use this option when C<$output> is not an |
850 | RFC 1952 data stream. |
642e522c |
851 | |
852 | |
853 | |
854 | There are a number of other limitations with the C<Merge> option: |
855 | |
856 | =over 5 |
857 | |
858 | =item 1 |
859 | |
1a6a8453 |
860 | This module needs to have been built with zlib 1.2.1 or better to work. A |
861 | fatal error will be thrown if C<Merge> is used with an older version of |
862 | zlib. |
642e522c |
863 | |
864 | =item 2 |
865 | |
866 | If C<$output> is a file or a filehandle, it must be seekable. |
867 | |
868 | =back |
869 | |
870 | |
871 | This parameter defaults to 0. |
872 | |
873 | =item -Level |
874 | |
875 | Defines the compression level used by zlib. The value should either be |
876 | a number between 0 and 9 (0 means no compression and 9 is maximum |
877 | compression), or one of the symbolic constants defined below. |
878 | |
879 | Z_NO_COMPRESSION |
880 | Z_BEST_SPEED |
881 | Z_BEST_COMPRESSION |
882 | Z_DEFAULT_COMPRESSION |
883 | |
884 | The default is Z_DEFAULT_COMPRESSION. |
885 | |
886 | Note, these constants are not imported by C<IO::Compress::Gzip> by default. |
887 | |
888 | use IO::Compress::Gzip qw(:strategy); |
889 | use IO::Compress::Gzip qw(:constants); |
890 | use IO::Compress::Gzip qw(:all); |
891 | |
892 | =item -Strategy |
893 | |
894 | Defines the strategy used to tune the compression. Use one of the symbolic |
895 | constants defined below. |
896 | |
897 | Z_FILTERED |
898 | Z_HUFFMAN_ONLY |
899 | Z_RLE |
900 | Z_FIXED |
901 | Z_DEFAULT_STRATEGY |
902 | |
903 | The default is Z_DEFAULT_STRATEGY. |
904 | |
905 | |
906 | |
907 | |
908 | |
1a6a8453 |
909 | =item -Minimal =E<gt> 0|1 |
642e522c |
910 | |
911 | If specified, this option will force the creation of the smallest possible |
912 | compliant gzip header (which is exactly 10 bytes long) as defined in |
913 | RFC 1952. |
914 | |
915 | See the section titled "Compliance" in RFC 1952 for a definition |
916 | of the values used for the fields in the gzip header. |
917 | |
918 | All other parameters that control the content of the gzip header will |
919 | be ignored if this parameter is set to 1. |
920 | |
921 | This parameter defaults to 0. |
922 | |
923 | =item -Comment =E<gt> $comment |
924 | |
925 | Stores the contents of C<$comment> in the COMMENT field in |
926 | the gzip header. |
927 | By default, no comment field is written to the gzip file. |
928 | |
929 | If the C<-Strict> option is enabled, the comment can only consist of ISO |
930 | 8859-1 characters plus line feed. |
931 | |
932 | If the C<-Strict> option is disabled, the comment field can contain any |
933 | character except NULL. If any null characters are present, the field |
934 | will be truncated at the first NULL. |
935 | |
936 | =item -Name =E<gt> $string |
937 | |
938 | Stores the contents of C<$string> in the gzip NAME header field. If |
939 | C<Name> is not specified, no gzip NAME field will be created. |
940 | |
941 | If the C<-Strict> option is enabled, C<$string> can only consist of ISO |
942 | 8859-1 characters. |
943 | |
944 | If C<-Strict> is disabled, then C<$string> can contain any character |
945 | except NULL. If any null characters are present, the field will be |
946 | truncated at the first NULL. |
947 | |
948 | =item -Time =E<gt> $number |
949 | |
950 | Sets the MTIME field in the gzip header to $number. |
951 | |
952 | This field defaults to the time the C<IO::Compress::Gzip> object was created |
953 | if this option is not specified. |
954 | |
955 | =item -TextFlag =E<gt> 0|1 |
956 | |
1a6a8453 |
957 | This parameter controls the setting of the FLG.FTEXT bit in the gzip |
958 | header. It is used to signal that the data stored in the gzip file/buffer |
959 | is probably text. |
642e522c |
960 | |
961 | The default is 0. |
962 | |
963 | =item -HeaderCRC =E<gt> 0|1 |
964 | |
1a6a8453 |
965 | When true this parameter will set the FLG.FHCRC bit to 1 in the gzip header |
966 | and set the CRC16 header field to the CRC of the complete gzip header |
967 | except the CRC16 field itself. |
642e522c |
968 | |
1a6a8453 |
969 | B<Note> that gzip files created with the C<HeaderCRC> flag set to 1 cannot |
970 | be read by most, if not all, of the the standard gunzip utilities, most |
971 | notably gzip version 1.2.4. You should therefore avoid using this option if |
972 | you want to maximize the portability of your gzip files. |
642e522c |
973 | |
974 | This parameter defaults to 0. |
975 | |
976 | =item -OS_Code =E<gt> $value |
977 | |
1a6a8453 |
978 | Stores C<$value> in the gzip OS header field. A number between 0 and 255 is |
979 | valid. |
642e522c |
980 | |
981 | If not specified, this parameter defaults to the OS code of the Operating |
982 | System this module was built on. The value 3 is used as a catch-all for all |
983 | Unix variants and unknown Operating Systems. |
984 | |
985 | =item -ExtraField =E<gt> $data |
986 | |
1a6a8453 |
987 | This parameter allows additional metadata to be stored in the ExtraField in |
988 | the gzip header. An RFC1952 compliant ExtraField consists of zero or more |
989 | subfields. Each subfield consists of a two byte header followed by the |
990 | subfield data. |
642e522c |
991 | |
992 | The list of subfields can be supplied in any of the following formats |
993 | |
994 | -ExtraField => [$id1, $data1, |
995 | $id2, $data2, |
996 | ... |
997 | ] |
998 | -ExtraField => [ [$id1 => $data1], |
999 | [$id2 => $data2], |
1000 | ... |
1001 | ] |
1002 | -ExtraField => { $id1 => $data1, |
1003 | $id2 => $data2, |
1004 | ... |
1005 | } |
1006 | |
1007 | Where C<$id1>, C<$id2> are two byte subfield ID's. The second byte of |
1008 | the ID cannot be 0, unless the C<Strict> option has been disabled. |
1009 | |
1010 | If you use the hash syntax, you have no control over the order in which |
1011 | the ExtraSubFields are stored, plus you cannot have SubFields with |
1012 | duplicate ID. |
1013 | |
1014 | Alternatively the list of subfields can by supplied as a scalar, thus |
1015 | |
1016 | -ExtraField => $rawdata |
1017 | |
1018 | If you use the raw format, and the C<Strict> option is enabled, |
1019 | C<IO::Compress::Gzip> will check that C<$rawdata> consists of zero or more |
1020 | conformant sub-fields. When C<Strict> is disabled, C<$rawdata> can |
1021 | consist of any arbitrary byte stream. |
1022 | |
1023 | The maximum size of the Extra Field 65535 bytes. |
1024 | |
1025 | =item -ExtraFlags =E<gt> $value |
1026 | |
1027 | Sets the XFL byte in the gzip header to C<$value>. |
1028 | |
1a6a8453 |
1029 | If this option is not present, the value stored in XFL field will be |
1030 | determined by the setting of the C<Level> option. |
642e522c |
1031 | |
1032 | If C<Level =E<gt> Z_BEST_SPEED> has been specified then XFL is set to 2. |
1033 | If C<Level =E<gt> Z_BEST_COMPRESSION> has been specified then XFL is set to 4. |
1034 | Otherwise XFL is set to 0. |
1035 | |
1036 | |
1037 | |
1038 | =item -Strict =E<gt> 0|1 |
1039 | |
1040 | |
1041 | |
1042 | C<Strict> will optionally police the values supplied with other options |
1043 | to ensure they are compliant with RFC1952. |
1044 | |
1045 | This option is enabled by default. |
1046 | |
1a6a8453 |
1047 | If C<Strict> is enabled the following behaviour will be policed: |
642e522c |
1048 | |
1049 | =over 5 |
1050 | |
1051 | =item * |
1052 | |
1053 | The value supplied with the C<Name> option can only contain ISO 8859-1 |
1054 | characters. |
1055 | |
1056 | =item * |
1057 | |
1058 | The value supplied with the C<Comment> option can only contain ISO 8859-1 |
1059 | characters plus line-feed. |
1060 | |
1061 | =item * |
1062 | |
1063 | The values supplied with the C<-Name> and C<-Comment> options cannot |
1064 | contain multiple embedded nulls. |
1065 | |
1066 | =item * |
1067 | |
1068 | If an C<ExtraField> option is specified and it is a simple scalar, |
1069 | it must conform to the sub-field structure as defined in RFC1952. |
1070 | |
1071 | =item * |
1072 | |
1073 | If an C<ExtraField> option is specified the second byte of the ID will be |
1074 | checked in each subfield to ensure that it does not contain the reserved |
1075 | value 0x00. |
1076 | |
1077 | =back |
1078 | |
1a6a8453 |
1079 | When C<Strict> is disabled the following behaviour will be policed: |
642e522c |
1080 | |
1081 | =over 5 |
1082 | |
1083 | =item * |
1084 | |
1085 | The value supplied with C<-Name> option can contain |
1086 | any character except NULL. |
1087 | |
1088 | =item * |
1089 | |
1090 | The value supplied with C<-Comment> option can contain any character |
1091 | except NULL. |
1092 | |
1093 | =item * |
1094 | |
1095 | The values supplied with the C<-Name> and C<-Comment> options can contain |
1096 | multiple embedded nulls. The string written to the gzip header will |
1097 | consist of the characters up to, but not including, the first embedded |
1098 | NULL. |
1099 | |
1100 | =item * |
1101 | |
1102 | If an C<ExtraField> option is specified and it is a simple scalar, the |
1103 | structure will not be checked. The only error is if the length is too big. |
1104 | |
1105 | =item * |
1106 | |
1107 | The ID header in an C<ExtraField> sub-field can consist of any two bytes. |
1108 | |
1109 | =back |
1110 | |
1111 | |
1112 | |
1113 | =back |
1114 | |
1115 | =head2 Examples |
1116 | |
1117 | TODO |
1118 | |
1119 | =head1 Methods |
1120 | |
1121 | =head2 print |
1122 | |
1123 | Usage is |
1124 | |
1125 | $z->print($data) |
1126 | print $z $data |
1127 | |
1128 | Compresses and outputs the contents of the C<$data> parameter. This |
1a6a8453 |
1129 | has the same behaviour as the C<print> built-in. |
642e522c |
1130 | |
1131 | Returns true if successful. |
1132 | |
1133 | =head2 printf |
1134 | |
1135 | Usage is |
1136 | |
1137 | $z->printf($format, $data) |
1138 | printf $z $format, $data |
1139 | |
1140 | Compresses and outputs the contents of the C<$data> parameter. |
1141 | |
1142 | Returns true if successful. |
1143 | |
1144 | =head2 syswrite |
1145 | |
1146 | Usage is |
1147 | |
1148 | $z->syswrite $data |
1149 | $z->syswrite $data, $length |
1150 | $z->syswrite $data, $length, $offset |
1151 | |
1152 | syswrite $z, $data |
1153 | syswrite $z, $data, $length |
1154 | syswrite $z, $data, $length, $offset |
1155 | |
1156 | Compresses and outputs the contents of the C<$data> parameter. |
1157 | |
1158 | Returns the number of uncompressed bytes written, or C<undef> if |
1159 | unsuccessful. |
1160 | |
1161 | =head2 write |
1162 | |
1163 | Usage is |
1164 | |
1165 | $z->write $data |
1166 | $z->write $data, $length |
1167 | $z->write $data, $length, $offset |
1168 | |
1169 | Compresses and outputs the contents of the C<$data> parameter. |
1170 | |
1171 | Returns the number of uncompressed bytes written, or C<undef> if |
1172 | unsuccessful. |
1173 | |
1174 | =head2 flush |
1175 | |
1176 | Usage is |
1177 | |
1178 | $z->flush; |
1179 | $z->flush($flush_type); |
1180 | flush $z ; |
1181 | flush $z $flush_type; |
1182 | |
1183 | Flushes any pending compressed data to the output file/buffer. |
1184 | |
1185 | This method takes an optional parameter, C<$flush_type>, that controls |
1186 | how the flushing will be carried out. By default the C<$flush_type> |
1187 | used is C<Z_FINISH>. Other valid values for C<$flush_type> are |
1188 | C<Z_NO_FLUSH>, C<Z_SYNC_FLUSH>, C<Z_FULL_FLUSH> and C<Z_BLOCK>. It is |
1189 | strongly recommended that you only set the C<flush_type> parameter if |
1190 | you fully understand the implications of what it does - overuse of C<flush> |
1191 | can seriously degrade the level of compression achieved. See the C<zlib> |
1192 | documentation for details. |
1193 | |
1194 | Returns true on success. |
1195 | |
1196 | |
1197 | =head2 tell |
1198 | |
1199 | Usage is |
1200 | |
1201 | $z->tell() |
1202 | tell $z |
1203 | |
1204 | Returns the uncompressed file offset. |
1205 | |
1206 | =head2 eof |
1207 | |
1208 | Usage is |
1209 | |
1210 | $z->eof(); |
1211 | eof($z); |
1212 | |
1213 | |
1214 | |
1215 | Returns true if the C<close> method has been called. |
1216 | |
1217 | |
1218 | |
1219 | =head2 seek |
1220 | |
1221 | $z->seek($position, $whence); |
1222 | seek($z, $position, $whence); |
1223 | |
1224 | |
1225 | |
1226 | |
1227 | Provides a sub-set of the C<seek> functionality, with the restriction |
1228 | that it is only legal to seek forward in the output file/buffer. |
1229 | It is a fatal error to attempt to seek backward. |
1230 | |
1231 | Empty parts of the file/buffer will have NULL (0x00) bytes written to them. |
1232 | |
1233 | |
1234 | |
1235 | The C<$whence> parameter takes one the usual values, namely SEEK_SET, |
1236 | SEEK_CUR or SEEK_END. |
1237 | |
1238 | Returns 1 on success, 0 on failure. |
1239 | |
1240 | =head2 binmode |
1241 | |
1242 | Usage is |
1243 | |
1244 | $z->binmode |
1245 | binmode $z ; |
1246 | |
1247 | This is a noop provided for completeness. |
1248 | |
1249 | =head2 fileno |
1250 | |
1251 | $z->fileno() |
1252 | fileno($z) |
1253 | |
1254 | If the C<$z> object is associated with a file, this method will return |
1255 | the underlying filehandle. |
1256 | |
1257 | If the C<$z> object is is associated with a buffer, this method will |
1258 | return undef. |
1259 | |
1260 | =head2 close |
1261 | |
1262 | $z->close() ; |
1263 | close $z ; |
1264 | |
1265 | |
1266 | |
1267 | Flushes any pending compressed data and then closes the output file/buffer. |
1268 | |
1269 | |
1270 | |
1271 | For most versions of Perl this method will be automatically invoked if |
1272 | the IO::Compress::Gzip object is destroyed (either explicitly or by the |
1273 | variable with the reference to the object going out of scope). The |
1274 | exceptions are Perl versions 5.005 through 5.00504 and 5.8.0. In |
1275 | these cases, the C<close> method will be called automatically, but |
1276 | not until global destruction of all live objects when the program is |
1277 | terminating. |
1278 | |
1279 | Therefore, if you want your scripts to be able to run on all versions |
1280 | of Perl, you should call C<close> explicitly and not rely on automatic |
1281 | closing. |
1282 | |
1283 | Returns true on success, otherwise 0. |
1284 | |
1285 | If the C<AutoClose> option has been enabled when the IO::Compress::Gzip |
1286 | object was created, and the object is associated with a file, the |
1287 | underlying file will also be closed. |
1288 | |
1289 | |
1290 | |
1291 | |
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1292 | =head2 newStream([OPTS]) |
642e522c |
1293 | |
1294 | Usage is |
1295 | |
1a6a8453 |
1296 | $z->newStream( [OPTS] ) |
642e522c |
1297 | |
1a6a8453 |
1298 | Closes the current compressed data stream and starts a new one. |
1299 | |
1300 | OPTS consists of the following sub-set of the the options that are |
1301 | available when creating the C<$z> object, |
1302 | |
1303 | =over 5 |
1304 | |
1305 | =item * Level |
1306 | |
1307 | =item * TODO |
1308 | |
1309 | =back |
642e522c |
1310 | |
1311 | =head2 deflateParams |
1312 | |
1313 | Usage is |
1314 | |
1315 | $z->deflateParams |
1316 | |
1317 | TODO |
1318 | |
1319 | =head1 Importing |
1320 | |
1321 | A number of symbolic constants are required by some methods in |
1322 | C<IO::Compress::Gzip>. None are imported by default. |
1323 | |
1324 | =over 5 |
1325 | |
1326 | =item :all |
1327 | |
1328 | Imports C<gzip>, C<$GzipError> and all symbolic |
1329 | constants that can be used by C<IO::Compress::Gzip>. Same as doing this |
1330 | |
1331 | use IO::Compress::Gzip qw(gzip $GzipError :constants) ; |
1332 | |
1333 | =item :constants |
1334 | |
1335 | Import all symbolic constants. Same as doing this |
1336 | |
1337 | use IO::Compress::Gzip qw(:flush :level :strategy) ; |
1338 | |
1339 | =item :flush |
1340 | |
1341 | These symbolic constants are used by the C<flush> method. |
1342 | |
1343 | Z_NO_FLUSH |
1344 | Z_PARTIAL_FLUSH |
1345 | Z_SYNC_FLUSH |
1346 | Z_FULL_FLUSH |
1347 | Z_FINISH |
1348 | Z_BLOCK |
1349 | |
1350 | |
1351 | =item :level |
1352 | |
1353 | These symbolic constants are used by the C<Level> option in the constructor. |
1354 | |
1355 | Z_NO_COMPRESSION |
1356 | Z_BEST_SPEED |
1357 | Z_BEST_COMPRESSION |
1358 | Z_DEFAULT_COMPRESSION |
1359 | |
1360 | |
1361 | =item :strategy |
1362 | |
1363 | These symbolic constants are used by the C<Strategy> option in the constructor. |
1364 | |
1365 | Z_FILTERED |
1366 | Z_HUFFMAN_ONLY |
1367 | Z_RLE |
1368 | Z_FIXED |
1369 | Z_DEFAULT_STRATEGY |
1370 | |
1371 | =back |
1372 | |
1373 | For |
1374 | |
1375 | =head1 EXAMPLES |
1376 | |
1377 | TODO |
1378 | |
1379 | |
1380 | |
1381 | |
1382 | |
1383 | |
1384 | =head1 SEE ALSO |
1385 | |
1386 | 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::Uncompress::AnyInflate> |
1387 | |
1388 | L<Compress::Zlib::FAQ|Compress::Zlib::FAQ> |
1389 | |
1390 | L<File::GlobMapper|File::GlobMapper>, L<Archive::Tar|Archive::Zip>, |
1391 | L<IO::Zlib|IO::Zlib> |
1392 | |
1393 | For RFC 1950, 1951 and 1952 see |
1394 | F<http://www.faqs.org/rfcs/rfc1950.html>, |
1395 | F<http://www.faqs.org/rfcs/rfc1951.html> and |
1396 | F<http://www.faqs.org/rfcs/rfc1952.html> |
1397 | |
1398 | The primary site for the gzip program is F<http://www.gzip.org>. |
1399 | |
1400 | =head1 AUTHOR |
1401 | |
1402 | The I<IO::Compress::Gzip> module was written by Paul Marquess, |
1403 | F<pmqs@cpan.org>. The latest copy of the module can be |
1404 | found on CPAN in F<modules/by-module/Compress/Compress-Zlib-x.x.tar.gz>. |
1405 | |
1406 | The I<zlib> compression library was written by Jean-loup Gailly |
1407 | F<gzip@prep.ai.mit.edu> and Mark Adler F<madler@alumni.caltech.edu>. |
1408 | |
1409 | The primary site for the I<zlib> compression library is |
1410 | F<http://www.zlib.org>. |
1411 | |
1412 | =head1 MODIFICATION HISTORY |
1413 | |
1414 | See the Changes file. |
1415 | |
1416 | =head1 COPYRIGHT AND LICENSE |
1417 | |
1418 | |
1a6a8453 |
1419 | Copyright (c) 2005-2006 Paul Marquess. All rights reserved. |
642e522c |
1420 | This program is free software; you can redistribute it and/or |
1421 | modify it under the same terms as Perl itself. |
1422 | |
1423 | |
1424 | |
1425 | |