IO::Uncompress::Unzip(3pm)

1IO::Uncompress::Unzip(3U)ser Contributed Perl DocumentatiIoOn::Uncompress::Unzip(3)
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NAME

6       IO::Uncompress::Unzip - Read zip files/buffers
7

SYNOPSIS

9           use IO::Uncompress::Unzip qw(unzip $UnzipError) ;
10
11           my $status = unzip $input => $output [,OPTS]
12               or die "unzip failed: $UnzipError\n";
13
14           my $z = new IO::Uncompress::Unzip $input [OPTS]
15               or die "unzip failed: $UnzipError\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           $status = $z->inflateSync()
26
27           $data = $z->trailingData()
28           $status = $z->nextStream()
29           $data = $z->getHeaderInfo()
30           $z->tell()
31           $z->seek($position, $whence)
32           $z->binmode()
33           $z->fileno()
34           $z->eof()
35           $z->close()
36
37           $UnzipError ;
38
39           # IO::File mode
40
41           <$z>
42           read($z, $buffer);
43           read($z, $buffer, $length);
44           read($z, $buffer, $length, $offset);
45           tell($z)
46           seek($z, $position, $whence)
47           binmode($z)
48           fileno($z)
49           eof($z)
50           close($z)
51

DESCRIPTION

53       This module provides a Perl interface that allows the reading of zlib
54       files/buffers.
55
56       For writing zip files/buffers, see the companion module
57       IO::Compress::Zip.
58

Functional Interface

60       A top-level function, "unzip", is provided to carry out "one-shot"
61       uncompression between buffers and/or files. For finer control over the
62       uncompression process, see the "OO Interface" section.
63
64           use IO::Uncompress::Unzip qw(unzip $UnzipError) ;
65
66           unzip $input_filename_or_reference => $output_filename_or_reference [,OPTS]
67               or die "unzip failed: $UnzipError\n";
68
69       The functional interface needs Perl5.005 or better.
70
71   unzip $input_filename_or_reference => $output_filename_or_reference [,
72       OPTS]
73       "unzip" expects at least two parameters, $input_filename_or_reference
74       and $output_filename_or_reference.
75
76       The $input_filename_or_reference parameter
77
78       The parameter, $input_filename_or_reference, is used to define the
79       source of the compressed data.
80
81       It can take one of the following forms:
82
83       A filename
84            If the <$input_filename_or_reference> parameter is a simple
85            scalar, it is assumed to be a filename. This file will be opened
86            for reading and the input data will be read from it.
87
88       A filehandle
89            If the $input_filename_or_reference parameter is a filehandle, the
90            input data will be read from it.  The string '-' can be used as an
91            alias for standard input.
92
93       A scalar reference
94            If $input_filename_or_reference is a scalar reference, the input
95            data will be read from $$input_filename_or_reference.
96
97       An array reference
98            If $input_filename_or_reference is an array reference, each
99            element in the array must be a filename.
100
101            The input data will be read from each file in turn.
102
103            The complete array will be walked to ensure that it only contains
104            valid filenames before any data is uncompressed.
105
106       An Input FileGlob string
107            If $input_filename_or_reference is a string that is delimited by
108            the characters "<" and ">" "unzip" will assume that it is an input
109            fileglob string. The input is the list of files that match the
110            fileglob.
111
112            See File::GlobMapper for more details.
113
114       If the $input_filename_or_reference parameter is any other type,
115       "undef" will be returned.
116
117       The $output_filename_or_reference parameter
118
119       The parameter $output_filename_or_reference is used to control the
120       destination of the uncompressed data. This parameter can take one of
121       these forms.
122
123       A filename
124            If the $output_filename_or_reference parameter is a simple scalar,
125            it is assumed to be a filename.  This file will be opened for
126            writing and the uncompressed data will be written to it.
127
128       A filehandle
129            If the $output_filename_or_reference parameter is a filehandle,
130            the uncompressed data will be written to it.  The string '-' can
131            be used as an alias for standard output.
132
133       A scalar reference
134            If $output_filename_or_reference is a scalar reference, the
135            uncompressed data will be stored in
136            $$output_filename_or_reference.
137
138       An Array Reference
139            If $output_filename_or_reference is an array reference, the
140            uncompressed data will be pushed onto the array.
141
142       An Output FileGlob
143            If $output_filename_or_reference is a string that is delimited by
144            the characters "<" and ">" "unzip" will assume that it is an
145            output fileglob string. The output is the list of files that match
146            the fileglob.
147
148            When $output_filename_or_reference is an fileglob string,
149            $input_filename_or_reference must also be a fileglob string.
150            Anything else is an error.
151
152            See File::GlobMapper for more details.
153
154       If the $output_filename_or_reference parameter is any other type,
155       "undef" will be returned.
156
157   Notes
158       When $input_filename_or_reference maps to multiple compressed
159       files/buffers and $output_filename_or_reference is a single
160       file/buffer, after uncompression $output_filename_or_reference will
161       contain a concatenation of all the uncompressed data from each of the
162       input files/buffers.
163
164   Optional Parameters
165       Unless specified below, the optional parameters for "unzip", "OPTS",
166       are the same as those used with the OO interface defined in the
167       "Constructor Options" section below.
168
169       "AutoClose => 0|1"
170            This option applies to any input or output data streams to "unzip"
171            that are filehandles.
172
173            If "AutoClose" is specified, and the value is true, it will result
174            in all input and/or output filehandles being closed once "unzip"
175            has completed.
176
177            This parameter defaults to 0.
178
179       "BinModeOut => 0|1"
180            When writing to a file or filehandle, set "binmode" before writing
181            to the file.
182
183            Defaults to 0.
184
185       "Append => 0|1"
186            The behaviour of this option is dependent on the type of output
187            data stream.
188
189            ·    A Buffer
190
191                 If "Append" is enabled, all uncompressed data will be append
192                 to the end of the output buffer. Otherwise the output buffer
193                 will be cleared before any uncompressed data is written to
194                 it.
195
196            ·    A Filename
197
198                 If "Append" is enabled, the file will be opened in append
199                 mode. Otherwise the contents of the file, if any, will be
200                 truncated before any uncompressed data is written to it.
201
202            ·    A Filehandle
203
204                 If "Append" is enabled, the filehandle will be positioned to
205                 the end of the file via a call to "seek" before any
206                 uncompressed data is written to it.  Otherwise the file
207                 pointer will not be moved.
208
209            When "Append" is specified, and set to true, it will append all
210            uncompressed data to the output data stream.
211
212            So when the output is a filehandle it will carry out a seek to the
213            eof before writing any uncompressed data. If the output is a
214            filename, it will be opened for appending. If the output is a
215            buffer, all uncompressed data will be appended to the existing
216            buffer.
217
218            Conversely when "Append" is not specified, or it is present and is
219            set to false, it will operate as follows.
220
221            When the output is a filename, it will truncate the contents of
222            the file before writing any uncompressed data. If the output is a
223            filehandle its position will not be changed. If the output is a
224            buffer, it will be wiped before any uncompressed data is output.
225
226            Defaults to 0.
227
228       "MultiStream => 0|1"
229            If the input file/buffer contains multiple compressed data
230            streams, this option will uncompress the whole lot as a single
231            data stream.
232
233            Defaults to 0.
234
235       "TrailingData => $scalar"
236            Returns the data, if any, that is present immediately after the
237            compressed data stream once uncompression is complete.
238
239            This option can be used when there is useful information
240            immediately following the compressed data stream, and you don't
241            know the length of the compressed data stream.
242
243            If the input is a buffer, "trailingData" will return everything
244            from the end of the compressed data stream to the end of the
245            buffer.
246
247            If the input is a filehandle, "trailingData" will return the data
248            that is left in the filehandle input buffer once the end of the
249            compressed data stream has been reached. You can then use the
250            filehandle to read the rest of the input file.
251
252            Don't bother using "trailingData" if the input is a filename.
253
254            If you know the length of the compressed data stream before you
255            start uncompressing, you can avoid having to use "trailingData" by
256            setting the "InputLength" option.
257
258   Examples
259       Say you have a zip file, "file1.zip", that only contains a single
260       member, you can read it and write the uncompressed data to the file
261       "file1.txt" like this.
262
263           use strict ;
264           use warnings ;
265           use IO::Uncompress::Unzip qw(unzip $UnzipError) ;
266
267           my $input = "file1.zip";
268           my $output = "file1.txt";
269           unzip $input => $output
270               or die "unzip failed: $UnzipError\n";
271
272       If you have a zip file that contains multiple members and want to read
273       a specific member from the file, say "data1", use the "Name" option
274
275           use strict ;
276           use warnings ;
277           use IO::Uncompress::Unzip qw(unzip $UnzipError) ;
278
279           my $input = "file1.zip";
280           my $output = "file1.txt";
281           unzip $input => $output, Name => "data1"
282               or die "unzip failed: $UnzipError\n";
283
284       Alternatively, if you want to read the  "data1" member into memory, use
285       a scalar reference for the "output" parameter.
286
287           use strict ;
288           use warnings ;
289           use IO::Uncompress::Unzip qw(unzip $UnzipError) ;
290
291           my $input = "file1.zip";
292           my $output ;
293           unzip $input => \$output, Name => "data1"
294               or die "unzip failed: $UnzipError\n";
295           # $output now contains the uncompressed data
296
297       To read from an existing Perl filehandle, $input, and write the
298       uncompressed data to a buffer, $buffer.
299
300           use strict ;
301           use warnings ;
302           use IO::Uncompress::Unzip qw(unzip $UnzipError) ;
303           use IO::File ;
304
305           my $input = new IO::File "<file1.zip"
306               or die "Cannot open 'file1.zip': $!\n" ;
307           my $buffer ;
308           unzip $input => \$buffer
309               or die "unzip failed: $UnzipError\n";
310

OO Interface

312   Constructor
313       The format of the constructor for IO::Uncompress::Unzip is shown below
314
315           my $z = new IO::Uncompress::Unzip $input [OPTS]
316               or die "IO::Uncompress::Unzip failed: $UnzipError\n";
317
318       Returns an "IO::Uncompress::Unzip" object on success and undef on
319       failure.  The variable $UnzipError will contain an error message on
320       failure.
321
322       If you are running Perl 5.005 or better the object, $z, returned from
323       IO::Uncompress::Unzip can be used exactly like an IO::File filehandle.
324       This means that all normal input file operations can be carried out
325       with $z.  For example, to read a line from a compressed file/buffer you
326       can use either of these forms
327
328           $line = $z->getline();
329           $line = <$z>;
330
331       The mandatory parameter $input is used to determine the source of the
332       compressed data. This parameter can take one of three forms.
333
334       A filename
335            If the $input parameter is a scalar, it is assumed to be a
336            filename. This file will be opened for reading and the compressed
337            data will be read from it.
338
339       A filehandle
340            If the $input parameter is a filehandle, the compressed data will
341            be read from it.  The string '-' can be used as an alias for
342            standard input.
343
344       A scalar reference
345            If $input is a scalar reference, the compressed data will be read
346            from $$input.
347
348   Constructor Options
349       The option names defined below are case insensitive and can be
350       optionally prefixed by a '-'.  So all of the following are valid
351
352           -AutoClose
353           -autoclose
354           AUTOCLOSE
355           autoclose
356
357       OPTS is a combination of the following options:
358
359       "Name => "membername""
360            Open "membername" from the zip file for reading.
361
362       "AutoClose => 0|1"
363            This option is only valid when the $input parameter is a
364            filehandle. If specified, and the value is true, it will result in
365            the file being closed once either the "close" method is called or
366            the IO::Uncompress::Unzip object is destroyed.
367
368            This parameter defaults to 0.
369
370       "MultiStream => 0|1"
371            Treats the complete zip file/buffer as a single compressed data
372            stream. When reading in multi-stream mode each member of the zip
373            file/buffer will be uncompressed in turn until the end of the
374            file/buffer is encountered.
375
376            This parameter defaults to 0.
377
378       "Prime => $string"
379            This option will uncompress the contents of $string before
380            processing the input file/buffer.
381
382            This option can be useful when the compressed data is embedded in
383            another file/data structure and it is not possible to work out
384            where the compressed data begins without having to read the first
385            few bytes. If this is the case, the uncompression can be primed
386            with these bytes using this option.
387
388       "Transparent => 0|1"
389            If this option is set and the input file/buffer is not compressed
390            data, the module will allow reading of it anyway.
391
392            In addition, if the input file/buffer does contain compressed data
393            and there is non-compressed data immediately following it, setting
394            this option will make this module treat the whole file/buffer as a
395            single data stream.
396
397            This option defaults to 1.
398
399       "BlockSize => $num"
400            When reading the compressed input data, IO::Uncompress::Unzip will
401            read it in blocks of $num bytes.
402
403            This option defaults to 4096.
404
405       "InputLength => $size"
406            When present this option will limit the number of compressed bytes
407            read from the input file/buffer to $size. This option can be used
408            in the situation where there is useful data directly after the
409            compressed data stream and you know beforehand the exact length of
410            the compressed data stream.
411
412            This option is mostly used when reading from a filehandle, in
413            which case the file pointer will be left pointing to the first
414            byte directly after the compressed data stream.
415
416            This option defaults to off.
417
418       "Append => 0|1"
419            This option controls what the "read" method does with uncompressed
420            data.
421
422            If set to 1, all uncompressed data will be appended to the output
423            parameter of the "read" method.
424
425            If set to 0, the contents of the output parameter of the "read"
426            method will be overwritten by the uncompressed data.
427
428            Defaults to 0.
429
430       "Strict => 0|1"
431            This option controls whether the extra checks defined below are
432            used when carrying out the decompression. When Strict is on, the
433            extra tests are carried out, when Strict is off they are not.
434
435            The default for this option is off.
436
437   Examples
438       TODO
439

Methods

441   read
442       Usage is
443
444           $status = $z->read($buffer)
445
446       Reads a block of compressed data (the size of the compressed block is
447       determined by the "Buffer" option in the constructor), uncompresses it
448       and writes any uncompressed data into $buffer. If the "Append"
449       parameter is set in the constructor, the uncompressed data will be
450       appended to the $buffer parameter. Otherwise $buffer will be
451       overwritten.
452
453       Returns the number of uncompressed bytes written to $buffer, zero if
454       eof or a negative number on error.
455
456   read
457       Usage is
458
459           $status = $z->read($buffer, $length)
460           $status = $z->read($buffer, $length, $offset)
461
462           $status = read($z, $buffer, $length)
463           $status = read($z, $buffer, $length, $offset)
464
465       Attempt to read $length bytes of uncompressed data into $buffer.
466
467       The main difference between this form of the "read" method and the
468       previous one, is that this one will attempt to return exactly $length
469       bytes. The only circumstances that this function will not is if end-of-
470       file or an IO error is encountered.
471
472       Returns the number of uncompressed bytes written to $buffer, zero if
473       eof or a negative number on error.
474
475   getline
476       Usage is
477
478           $line = $z->getline()
479           $line = <$z>
480
481       Reads a single line.
482
483       This method fully supports the use of the variable $/ (or
484       $INPUT_RECORD_SEPARATOR or $RS when "English" is in use) to determine
485       what constitutes an end of line. Paragraph mode, record mode and file
486       slurp mode are all supported.
487
488   getc
489       Usage is
490
491           $char = $z->getc()
492
493       Read a single character.
494
495   ungetc
496       Usage is
497
498           $char = $z->ungetc($string)
499
500   inflateSync
501       Usage is
502
503           $status = $z->inflateSync()
504
505       TODO
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::Unzip 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::Unzip 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

Importing

669       No symbolic constants are required by this IO::Uncompress::Unzip at
670       present.
671
672       :all Imports "unzip" and $UnzipError.  Same as doing this
673
674                use IO::Uncompress::Unzip qw(unzip $UnzipError) ;
675

EXAMPLES

677   Working with Net::FTP
678       See IO::Compress::FAQ
679
680   Walking through a zip file
681       The code below can be used to traverse a zip file, one compressed data
682       stream at a time.
683
684           use IO::Uncompress::Unzip qw($UnzipError);
685
686           my $zipfile = "somefile.zip";
687           my $u = new IO::Uncompress::Unzip $zipfile
688               or die "Cannot open $zipfile: $UnzipError";
689
690           my $status;
691           for ($status = 1; $status > 0; $status = $u->nextStream())
692           {
693
694               my $name = $u->getHeaderInfo()->{Name};
695               warn "Processing member $name\n" ;
696
697               my $buff;
698               while (($status = $u->read($buff)) > 0) {
699                   # Do something here
700               }
701
702               last if $status < 0;
703           }
704
705           die "Error processing $zipfile: $!\n"
706               if $status < 0 ;
707
708       Each individual compressed data stream is read until the logical end-
709       of-file is reached. Then "nextStream" is called. This will skip to the
710       start of the next compressed data stream and clear the end-of-file
711       flag.
712
713       It is also worth noting that "nextStream" can be called at any time --
714       you don't have to wait until you have exhausted a compressed data
715       stream before skipping to the next one.
716
717   Unzipping a complete zip file to disk
718       Daniel S. Sterling has written a script that uses
719       "IO::Uncompress::UnZip" to read a zip file and unzip its contents to
720       disk.
721
722       The script is available from <https://gist.github.com/eqhmcow/5389877>
723

AUTHOR

752       This module was written by Paul Marquess, "pmqs@cpan.org".
753

MODIFICATION HISTORY

755       See the Changes file.
756

COPYRIGHT AND LICENSE

758       Copyright (c) 2005-2018 Paul Marquess. All rights reserved.
759
760       This program is free software; you can redistribute it and/or modify it
761       under the same terms as Perl itself.
762
763
764
765perl v5.26.3                      2018-04-05          IO::Uncompress::Unzip(3)