1IO::Uncompress::UnLzip(U3s)er Contributed Perl DocumentatIiOo:n:Uncompress::UnLzip(3)
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6 IO::Uncompress::UnLzip - Read lzip files/buffers
7
9 use IO::Uncompress::UnLzip qw(unlzip $UnLzipError) ;
10
11 my $status = unlzip $input => $output [,OPTS]
12 or die "unlzip failed: $UnLzipError\n";
13
14 my $z = IO::Uncompress::UnLzip->new( $input [OPTS] )
15 or die "unlzip failed: $UnLzipError\n";
16
17 $status = $z->read($buffer)
18 $status = $z->read($buffer, $length)
19 $status = $z->read($buffer, $length, $offset)
20 $line = $z->getline()
21 $char = $z->getc()
22 $char = $z->ungetc()
23 $char = $z->opened()
24
25 $data = $z->trailingData()
26 $status = $z->nextStream()
27 $data = $z->getHeaderInfo()
28 $z->tell()
29 $z->seek($position, $whence)
30 $z->binmode()
31 $z->fileno()
32 $z->eof()
33 $z->close()
34
35 $UnLzipError ;
36
37 # IO::File mode
38
39 <$z>
40 read($z, $buffer);
41 read($z, $buffer, $length);
42 read($z, $buffer, $length, $offset);
43 tell($z)
44 seek($z, $position, $whence)
45 binmode($z)
46 fileno($z)
47 eof($z)
48 close($z)
49
51 This module provides a Perl interface that allows the reading of lzma
52 files/buffers.
53
54 For writing lzip files/buffers, see the companion module
55 IO::Compress::Lzip.
56
58 A top-level function, "unlzip", is provided to carry out "one-shot"
59 uncompression between buffers and/or files. For finer control over the
60 uncompression process, see the "OO Interface" section.
61
62 use IO::Uncompress::UnLzip qw(unlzip $UnLzipError) ;
63
64 unlzip $input_filename_or_reference => $output_filename_or_reference [,OPTS]
65 or die "unlzip failed: $UnLzipError\n";
66
67 The functional interface needs Perl5.005 or better.
68
69 unlzip $input_filename_or_reference => $output_filename_or_reference [,
70 OPTS]
71 "unlzip" expects at least two parameters, $input_filename_or_reference
72 and $output_filename_or_reference and zero or more optional parameters
73 (see "Optional Parameters")
74
75 The $input_filename_or_reference parameter
76
77 The parameter, $input_filename_or_reference, is used to define the
78 source of the compressed data.
79
80 It can take one of the following forms:
81
82 A filename
83 If the $input_filename_or_reference parameter is a simple scalar,
84 it is assumed to be a filename. This file will be opened for
85 reading and the input data will be read from it.
86
87 A filehandle
88 If the $input_filename_or_reference parameter is a filehandle, the
89 input data will be read from it. The string '-' can be used as an
90 alias for standard input.
91
92 A scalar reference
93 If $input_filename_or_reference is a scalar reference, the input
94 data will be read from $$input_filename_or_reference.
95
96 An array reference
97 If $input_filename_or_reference is an array reference, each
98 element in the array must be a filename.
99
100 The input data will be read from each file in turn.
101
102 The complete array will be walked to ensure that it only contains
103 valid filenames before any data is uncompressed.
104
105 An Input FileGlob string
106 If $input_filename_or_reference is a string that is delimited by
107 the characters "<" and ">" "unlzip" will assume that it is an
108 input fileglob string. The input is the list of files that match
109 the fileglob.
110
111 See File::GlobMapper for more details.
112
113 If the $input_filename_or_reference parameter is any other type,
114 "undef" will be returned.
115
116 The $output_filename_or_reference parameter
117
118 The parameter $output_filename_or_reference is used to control the
119 destination of the uncompressed data. This parameter can take one of
120 these forms.
121
122 A filename
123 If the $output_filename_or_reference parameter is a simple scalar,
124 it is assumed to be a filename. This file will be opened for
125 writing and the uncompressed data will be written to it.
126
127 A filehandle
128 If the $output_filename_or_reference parameter is a filehandle,
129 the uncompressed data will be written to it. The string '-' can
130 be used as an alias for standard output.
131
132 A scalar reference
133 If $output_filename_or_reference is a scalar reference, the
134 uncompressed data will be stored in
135 $$output_filename_or_reference.
136
137 An Array Reference
138 If $output_filename_or_reference is an array reference, the
139 uncompressed data will be pushed onto the array.
140
141 An Output FileGlob
142 If $output_filename_or_reference is a string that is delimited by
143 the characters "<" and ">" "unlzip" will assume that it is an
144 output fileglob string. The output is the list of files that match
145 the fileglob.
146
147 When $output_filename_or_reference is an fileglob string,
148 $input_filename_or_reference must also be a fileglob string.
149 Anything else is an error.
150
151 See File::GlobMapper for more details.
152
153 If the $output_filename_or_reference parameter is any other type,
154 "undef" will be returned.
155
156 Notes
157 When $input_filename_or_reference maps to multiple compressed
158 files/buffers and $output_filename_or_reference is a single
159 file/buffer, after uncompression $output_filename_or_reference will
160 contain a concatenation of all the uncompressed data from each of the
161 input files/buffers.
162
163 Optional Parameters
164 The optional parameters for the one-shot function "unlzip" are (for the
165 most part) identical to those used with the OO interface defined in the
166 "Constructor Options" section. The exceptions are listed below
167
168 "AutoClose => 0|1"
169 This option applies to any input or output data streams to
170 "unlzip" that are filehandles.
171
172 If "AutoClose" is specified, and the value is true, it will result
173 in all input and/or output filehandles being closed once "unlzip"
174 has completed.
175
176 This parameter defaults to 0.
177
178 "BinModeOut => 0|1"
179 This option is now a no-op. All files will be written in binmode.
180
181 "Append => 0|1"
182 The behaviour of this option is dependent on the type of output
183 data stream.
184
185 • A Buffer
186
187 If "Append" is enabled, all uncompressed data will be append
188 to the end of the output buffer. Otherwise the output buffer
189 will be cleared before any uncompressed data is written to
190 it.
191
192 • A Filename
193
194 If "Append" is enabled, the file will be opened in append
195 mode. Otherwise the contents of the file, if any, will be
196 truncated before any uncompressed data is written to it.
197
198 • A Filehandle
199
200 If "Append" is enabled, the filehandle will be positioned to
201 the end of the file via a call to "seek" before any
202 uncompressed data is written to it. Otherwise the file
203 pointer will not be moved.
204
205 When "Append" is specified, and set to true, it will append all
206 uncompressed data to the output data stream.
207
208 So when the output is a filehandle it will carry out a seek to the
209 eof before writing any uncompressed data. If the output is a
210 filename, it will be opened for appending. If the output is a
211 buffer, all uncompressed data will be appended to the existing
212 buffer.
213
214 Conversely when "Append" is not specified, or it is present and is
215 set to false, it will operate as follows.
216
217 When the output is a filename, it will truncate the contents of
218 the file before writing any uncompressed data. If the output is a
219 filehandle its position will not be changed. If the output is a
220 buffer, it will be wiped before any uncompressed data is output.
221
222 Defaults to 0.
223
224 "MultiStream => 0|1"
225 If the input file/buffer contains multiple compressed data
226 streams, this option will uncompress the whole lot as a single
227 data stream.
228
229 Defaults to 0.
230
231 "TrailingData => $scalar"
232 Returns the data, if any, that is present immediately after the
233 compressed data stream once uncompression is complete.
234
235 This option can be used when there is useful information
236 immediately following the compressed data stream, and you don't
237 know the length of the compressed data stream.
238
239 If the input is a buffer, "trailingData" will return everything
240 from the end of the compressed data stream to the end of the
241 buffer.
242
243 If the input is a filehandle, "trailingData" will return the data
244 that is left in the filehandle input buffer once the end of the
245 compressed data stream has been reached. You can then use the
246 filehandle to read the rest of the input file.
247
248 Don't bother using "trailingData" if the input is a filename.
249
250 If you know the length of the compressed data stream before you
251 start uncompressing, you can avoid having to use "trailingData" by
252 setting the "InputLength" option.
253
254 OneShot Examples
255 To read the contents of the file "file1.txt.xz" and write the
256 uncompressed data to the file "file1.txt".
257
258 use strict ;
259 use warnings ;
260 use IO::Uncompress::UnLzip qw(unlzip $UnLzipError) ;
261
262 my $input = "file1.txt.xz";
263 my $output = "file1.txt";
264 unlzip $input => $output
265 or die "unlzip failed: $UnLzipError\n";
266
267 To read from an existing Perl filehandle, $input, and write the
268 uncompressed data to a buffer, $buffer.
269
270 use strict ;
271 use warnings ;
272 use IO::Uncompress::UnLzip qw(unlzip $UnLzipError) ;
273 use IO::File ;
274
275 my $input = IO::File->new( "<file1.txt.xz" )
276 or die "Cannot open 'file1.txt.xz': $!\n" ;
277 my $buffer ;
278 unlzip $input => \$buffer
279 or die "unlzip failed: $UnLzipError\n";
280
281 To uncompress all files in the directory "/my/home" that match
282 "*.txt.xz" and store the compressed data in the same directory
283
284 use strict ;
285 use warnings ;
286 use IO::Uncompress::UnLzip qw(unlzip $UnLzipError) ;
287
288 unlzip '</my/home/*.txt.xz>' => '</my/home/#1.txt>'
289 or die "unlzip failed: $UnLzipError\n";
290
291 and if you want to compress each file one at a time, this will do the
292 trick
293
294 use strict ;
295 use warnings ;
296 use IO::Uncompress::UnLzip qw(unlzip $UnLzipError) ;
297
298 for my $input ( glob "/my/home/*.txt.xz" )
299 {
300 my $output = $input;
301 $output =~ s/.xz// ;
302 unlzip $input => $output
303 or die "Error compressing '$input': $UnLzipError\n";
304 }
305
307 Constructor
308 The format of the constructor for IO::Uncompress::UnLzip is shown below
309
310 my $z = IO::Uncompress::UnLzip->new( $input [OPTS] )
311 or die "IO::Uncompress::UnLzip failed: $UnLzipError\n";
312
313 The constructor takes one mandatory parameter, $input, defined below,
314 and zero or more "OPTS", defined in "Constructor Options".
315
316 Returns an "IO::Uncompress::UnLzip" object on success and undef on
317 failure. The variable $UnLzipError will contain an error message on
318 failure.
319
320 If you are running Perl 5.005 or better the object, $z, returned from
321 IO::Uncompress::UnLzip can be used exactly like an IO::File filehandle.
322 This means that all normal input file operations can be carried out
323 with $z. For example, to read a line from a compressed file/buffer you
324 can use either of these forms
325
326 $line = $z->getline();
327 $line = <$z>;
328
329 Below is a simple exaple of using the OO interface to read the
330 compressed file "myfile.xz" and write its contents to stdout.
331
332 my $filename = "myfile.xz";
333 my $z = IO::Uncompress::UnLzip->new($filename)
334 or die "IO::Uncompress::UnLzip failed: $UnLzipError\n";
335
336 while (<$z>) {
337 print $_;
338 }
339 $z->close();
340
341 See "EXAMPLES" for further examples
342
343 The mandatory parameter $input is used to determine the source of the
344 compressed data. This parameter can take one of three forms.
345
346 A filename
347 If the $input parameter is a scalar, it is assumed to be a
348 filename. This file will be opened for reading and the compressed
349 data will be read from it.
350
351 A filehandle
352 If the $input parameter is a filehandle, the compressed data will
353 be read from it. The string '-' can be used as an alias for
354 standard input.
355
356 A scalar reference
357 If $input is a scalar reference, the compressed data will be read
358 from $$input.
359
360 Constructor Options
361 The option names defined below are case insensitive and can be
362 optionally prefixed by a '-'. So all of the following are valid
363
364 -AutoClose
365 -autoclose
366 AUTOCLOSE
367 autoclose
368
369 OPTS is a combination of the following options:
370
371 "AutoClose => 0|1"
372 This option is only valid when the $input parameter is a
373 filehandle. If specified, and the value is true, it will result in
374 the file being closed once either the "close" method is called or
375 the IO::Uncompress::UnLzip object is destroyed.
376
377 This parameter defaults to 0.
378
379 "MultiStream => 0|1"
380 Allows multiple concatenated compressed streams to be treated as a
381 single compressed stream. Decompression will stop once either the
382 end of the file/buffer is reached, an error is encountered
383 (premature eof, corrupt compressed data) or the end of a stream is
384 not immediately followed by the start of another stream.
385
386 This parameter defaults to 0.
387
388 "Prime => $string"
389 This option will uncompress the contents of $string before
390 processing the input file/buffer.
391
392 This option can be useful when the compressed data is embedded in
393 another file/data structure and it is not possible to work out
394 where the compressed data begins without having to read the first
395 few bytes. If this is the case, the uncompression can be primed
396 with these bytes using this option.
397
398 "Transparent => 0|1"
399 If this option is set and the input file/buffer is not compressed
400 data, the module will allow reading of it anyway.
401
402 In addition, if the input file/buffer does contain compressed data
403 and there is non-compressed data immediately following it, setting
404 this option will make this module treat the whole file/buffer as a
405 single data stream.
406
407 This option defaults to 1.
408
409 "BlockSize => $num"
410 When reading the compressed input data, IO::Uncompress::UnLzip
411 will read it in blocks of $num bytes.
412
413 This option defaults to 4096.
414
415 "InputLength => $size"
416 When present this option will limit the number of compressed bytes
417 read from the input file/buffer to $size. This option can be used
418 in the situation where there is useful data directly after the
419 compressed data stream and you know beforehand the exact length of
420 the compressed data stream.
421
422 This option is mostly used when reading from a filehandle, in
423 which case the file pointer will be left pointing to the first
424 byte directly after the compressed data stream.
425
426 This option defaults to off.
427
428 "Append => 0|1"
429 This option controls what the "read" method does with uncompressed
430 data.
431
432 If set to 1, all uncompressed data will be appended to the output
433 parameter of the "read" method.
434
435 If set to 0, the contents of the output parameter of the "read"
436 method will be overwritten by the uncompressed data.
437
438 Defaults to 0.
439
440 "Strict => 0|1"
441 This option controls whether the extra checks defined below are
442 used when carrying out the decompression. When Strict is on, the
443 extra tests are carried out, when Strict is off they are not.
444
445 The default for this option is off.
446
448 read
449 Usage is
450
451 $status = $z->read($buffer)
452
453 Reads a block of compressed data (the size of the compressed block is
454 determined by the "Buffer" option in the constructor), uncompresses it
455 and writes any uncompressed data into $buffer. If the "Append"
456 parameter is set in the constructor, the uncompressed data will be
457 appended to the $buffer parameter. Otherwise $buffer will be
458 overwritten.
459
460 Returns the number of uncompressed bytes written to $buffer, zero if
461 eof or a negative number on error.
462
463 read
464 Usage is
465
466 $status = $z->read($buffer, $length)
467 $status = $z->read($buffer, $length, $offset)
468
469 $status = read($z, $buffer, $length)
470 $status = read($z, $buffer, $length, $offset)
471
472 Attempt to read $length bytes of uncompressed data into $buffer.
473
474 The main difference between this form of the "read" method and the
475 previous one, is that this one will attempt to return exactly $length
476 bytes. The only circumstances that this function will not is if end-of-
477 file or an IO error is encountered.
478
479 Returns the number of uncompressed bytes written to $buffer, zero if
480 eof or a negative number on error.
481
482 getline
483 Usage is
484
485 $line = $z->getline()
486 $line = <$z>
487
488 Reads a single line.
489
490 This method fully supports the use of the variable $/ (or
491 $INPUT_RECORD_SEPARATOR or $RS when "English" is in use) to determine
492 what constitutes an end of line. Paragraph mode, record mode and file
493 slurp mode are all supported.
494
495 getc
496 Usage is
497
498 $char = $z->getc()
499
500 Read a single character.
501
502 ungetc
503 Usage is
504
505 $char = $z->ungetc($string)
506
507 getHeaderInfo
508 Usage is
509
510 $hdr = $z->getHeaderInfo();
511 @hdrs = $z->getHeaderInfo();
512
513 This method returns either a hash reference (in scalar context) or a
514 list or hash references (in array context) that contains information
515 about each of the header fields in the compressed data stream(s).
516
517 tell
518 Usage is
519
520 $z->tell()
521 tell $z
522
523 Returns the uncompressed file offset.
524
525 eof
526 Usage is
527
528 $z->eof();
529 eof($z);
530
531 Returns true if the end of the compressed input stream has been
532 reached.
533
534 seek
535 $z->seek($position, $whence);
536 seek($z, $position, $whence);
537
538 Provides a sub-set of the "seek" functionality, with the restriction
539 that it is only legal to seek forward in the input file/buffer. It is
540 a fatal error to attempt to seek backward.
541
542 Note that the implementation of "seek" in this module does not provide
543 true random access to a compressed file/buffer. It works by
544 uncompressing data from the current offset in the file/buffer until it
545 reaches the uncompressed offset specified in the parameters to "seek".
546 For very small files this may be acceptable behaviour. For large files
547 it may cause an unacceptable delay.
548
549 The $whence parameter takes one the usual values, namely SEEK_SET,
550 SEEK_CUR or SEEK_END.
551
552 Returns 1 on success, 0 on failure.
553
554 binmode
555 Usage is
556
557 $z->binmode
558 binmode $z ;
559
560 This is a noop provided for completeness.
561
562 opened
563 $z->opened()
564
565 Returns true if the object currently refers to a opened file/buffer.
566
567 autoflush
568 my $prev = $z->autoflush()
569 my $prev = $z->autoflush(EXPR)
570
571 If the $z object is associated with a file or a filehandle, this method
572 returns the current autoflush setting for the underlying filehandle. If
573 "EXPR" is present, and is non-zero, it will enable flushing after every
574 write/print operation.
575
576 If $z is associated with a buffer, this method has no effect and always
577 returns "undef".
578
579 Note that the special variable $| cannot be used to set or retrieve the
580 autoflush setting.
581
582 input_line_number
583 $z->input_line_number()
584 $z->input_line_number(EXPR)
585
586 Returns the current uncompressed line number. If "EXPR" is present it
587 has the effect of setting the line number. Note that setting the line
588 number does not change the current position within the file/buffer
589 being read.
590
591 The contents of $/ are used to determine what constitutes a line
592 terminator.
593
594 fileno
595 $z->fileno()
596 fileno($z)
597
598 If the $z object is associated with a file or a filehandle, "fileno"
599 will return the underlying file descriptor. Once the "close" method is
600 called "fileno" will return "undef".
601
602 If the $z object is associated with a buffer, this method will return
603 "undef".
604
605 close
606 $z->close() ;
607 close $z ;
608
609 Closes the output file/buffer.
610
611 For most versions of Perl this method will be automatically invoked if
612 the IO::Uncompress::UnLzip object is destroyed (either explicitly or by
613 the variable with the reference to the object going out of scope). The
614 exceptions are Perl versions 5.005 through 5.00504 and 5.8.0. In these
615 cases, the "close" method will be called automatically, but not until
616 global destruction of all live objects when the program is terminating.
617
618 Therefore, if you want your scripts to be able to run on all versions
619 of Perl, you should call "close" explicitly and not rely on automatic
620 closing.
621
622 Returns true on success, otherwise 0.
623
624 If the "AutoClose" option has been enabled when the
625 IO::Uncompress::UnLzip object was created, and the object is associated
626 with a file, the underlying file will also be closed.
627
628 nextStream
629 Usage is
630
631 my $status = $z->nextStream();
632
633 Skips to the next compressed data stream in the input file/buffer. If a
634 new compressed data stream is found, the eof marker will be cleared and
635 $. will be reset to 0.
636
637 Returns 1 if a new stream was found, 0 if none was found, and -1 if an
638 error was encountered.
639
640 trailingData
641 Usage is
642
643 my $data = $z->trailingData();
644
645 Returns the data, if any, that is present immediately after the
646 compressed data stream once uncompression is complete. It only makes
647 sense to call this method once the end of the compressed data stream
648 has been encountered.
649
650 This option can be used when there is useful information immediately
651 following the compressed data stream, and you don't know the length of
652 the compressed data stream.
653
654 If the input is a buffer, "trailingData" will return everything from
655 the end of the compressed data stream to the end of the buffer.
656
657 If the input is a filehandle, "trailingData" will return the data that
658 is left in the filehandle input buffer once the end of the compressed
659 data stream has been reached. You can then use the filehandle to read
660 the rest of the input file.
661
662 Don't bother using "trailingData" if the input is a filename.
663
664 If you know the length of the compressed data stream before you start
665 uncompressing, you can avoid having to use "trailingData" by setting
666 the "InputLength" option in the constructor.
667
669 No symbolic constants are required by IO::Uncompress::UnLzip at
670 present.
671
672 :all Imports "unlzip" and $UnLzipError. Same as doing this
673
674 use IO::Uncompress::UnLzip qw(unlzip $UnLzipError) ;
675
678 General feedback/questions/bug reports should be sent to
679 <https://github.com/pmqs/IO-Compress-Lzma/issues> (preferred) or
680 <https://rt.cpan.org/Public/Dist/Display.html?Name=IO-Compress-Lzma>.
681
683 Compress::Zlib, IO::Compress::Gzip, IO::Uncompress::Gunzip,
684 IO::Compress::Deflate, IO::Uncompress::Inflate,
685 IO::Compress::RawDeflate, IO::Uncompress::RawInflate,
686 IO::Compress::Bzip2, IO::Uncompress::Bunzip2, IO::Compress::Lzma,
687 IO::Uncompress::UnLzma, IO::Compress::Xz, IO::Uncompress::UnXz,
688 IO::Compress::Lzip, IO::Compress::Lzop, IO::Uncompress::UnLzop,
689 IO::Compress::Lzf, IO::Uncompress::UnLzf, IO::Compress::Zstd,
690 IO::Uncompress::UnZstd, IO::Uncompress::AnyInflate,
691 IO::Uncompress::AnyUncompress
692
693 IO::Compress::FAQ
694
695 File::GlobMapper, Archive::Zip, Archive::Tar, IO::Zlib
696
698 This module was written by Paul Marquess, "pmqs@cpan.org".
699
701 See the Changes file.
702
704 Copyright (c) 2005-2023 Paul Marquess. All rights reserved.
705
706 This program is free software; you can redistribute it and/or modify it
707 under the same terms as Perl itself.
708
709
710
711perl v5.38.0 2023-07-26 IO::Uncompress::UnLzip(3)