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            This option is now a no-op. All files will be written  in binmode.
181
182       "Append => 0|1"
183            The behaviour of this option is dependent on the type of output
184            data stream.
185
186            ·    A Buffer
187
188                 If "Append" is enabled, all uncompressed data will be append
189                 to the end of the output buffer. Otherwise the output buffer
190                 will be cleared before any uncompressed data is written to
191                 it.
192
193            ·    A Filename
194
195                 If "Append" is enabled, the file will be opened in append
196                 mode. Otherwise the contents of the file, if any, will be
197                 truncated before any uncompressed data is written to it.
198
199            ·    A Filehandle
200
201                 If "Append" is enabled, the filehandle will be positioned to
202                 the end of the file via a call to "seek" before any
203                 uncompressed data is written to it.  Otherwise the file
204                 pointer will not be moved.
205
206            When "Append" is specified, and set to true, it will append all
207            uncompressed data to the output data stream.
208
209            So when the output is a filehandle it will carry out a seek to the
210            eof before writing any uncompressed data. If the output is a
211            filename, it will be opened for appending. If the output is a
212            buffer, all uncompressed data will be appended to the existing
213            buffer.
214
215            Conversely when "Append" is not specified, or it is present and is
216            set to false, it will operate as follows.
217
218            When the output is a filename, it will truncate the contents of
219            the file before writing any uncompressed data. If the output is a
220            filehandle its position will not be changed. If the output is a
221            buffer, it will be wiped before any uncompressed data is output.
222
223            Defaults to 0.
224
225       "MultiStream => 0|1"
226            If the input file/buffer contains multiple compressed data
227            streams, this option will uncompress the whole lot as a single
228            data stream.
229
230            Defaults to 0.
231
232       "TrailingData => $scalar"
233            Returns the data, if any, that is present immediately after the
234            compressed data stream once uncompression is complete.
235
236            This option can be used when there is useful information
237            immediately following the compressed data stream, and you don't
238            know the length of the compressed data stream.
239
240            If the input is a buffer, "trailingData" will return everything
241            from the end of the compressed data stream to the end of the
242            buffer.
243
244            If the input is a filehandle, "trailingData" will return the data
245            that is left in the filehandle input buffer once the end of the
246            compressed data stream has been reached. You can then use the
247            filehandle to read the rest of the input file.
248
249            Don't bother using "trailingData" if the input is a filename.
250
251            If you know the length of the compressed data stream before you
252            start uncompressing, you can avoid having to use "trailingData" by
253            setting the "InputLength" option.
254
255   Examples
256       Say you have a zip file, "file1.zip", that only contains a single
257       member, you can read it and write the uncompressed data to the file
258       "file1.txt" like this.
259
260           use strict ;
261           use warnings ;
262           use IO::Uncompress::Unzip qw(unzip $UnzipError) ;
263
264           my $input = "file1.zip";
265           my $output = "file1.txt";
266           unzip $input => $output
267               or die "unzip failed: $UnzipError\n";
268
269       If you have a zip file that contains multiple members and want to read
270       a specific member from the file, say "data1", use the "Name" option
271
272           use strict ;
273           use warnings ;
274           use IO::Uncompress::Unzip qw(unzip $UnzipError) ;
275
276           my $input = "file1.zip";
277           my $output = "file1.txt";
278           unzip $input => $output, Name => "data1"
279               or die "unzip failed: $UnzipError\n";
280
281       Alternatively, if you want to read the  "data1" member into memory, use
282       a scalar reference for the "output" parameter.
283
284           use strict ;
285           use warnings ;
286           use IO::Uncompress::Unzip qw(unzip $UnzipError) ;
287
288           my $input = "file1.zip";
289           my $output ;
290           unzip $input => \$output, Name => "data1"
291               or die "unzip failed: $UnzipError\n";
292           # $output now contains the uncompressed data
293
294       To read from an existing Perl filehandle, $input, and write the
295       uncompressed data to a buffer, $buffer.
296
297           use strict ;
298           use warnings ;
299           use IO::Uncompress::Unzip qw(unzip $UnzipError) ;
300           use IO::File ;
301
302           my $input = new IO::File "<file1.zip"
303               or die "Cannot open 'file1.zip': $!\n" ;
304           my $buffer ;
305           unzip $input => \$buffer
306               or die "unzip failed: $UnzipError\n";
307

OO Interface

309   Constructor
310       The format of the constructor for IO::Uncompress::Unzip is shown below
311
312           my $z = new IO::Uncompress::Unzip $input [OPTS]
313               or die "IO::Uncompress::Unzip failed: $UnzipError\n";
314
315       Returns an "IO::Uncompress::Unzip" object on success and undef on
316       failure.  The variable $UnzipError will contain an error message on
317       failure.
318
319       If you are running Perl 5.005 or better the object, $z, returned from
320       IO::Uncompress::Unzip can be used exactly like an IO::File filehandle.
321       This means that all normal input file operations can be carried out
322       with $z.  For example, to read a line from a compressed file/buffer you
323       can use either of these forms
324
325           $line = $z->getline();
326           $line = <$z>;
327
328       The mandatory parameter $input is used to determine the source of the
329       compressed data. This parameter can take one of three forms.
330
331       A filename
332            If the $input parameter is a scalar, it is assumed to be a
333            filename. This file will be opened for reading and the compressed
334            data will be read from it.
335
336       A filehandle
337            If the $input parameter is a filehandle, the compressed data will
338            be read from it.  The string '-' can be used as an alias for
339            standard input.
340
341       A scalar reference
342            If $input is a scalar reference, the compressed data will be read
343            from $$input.
344
345   Constructor Options
346       The option names defined below are case insensitive and can be
347       optionally prefixed by a '-'.  So all of the following are valid
348
349           -AutoClose
350           -autoclose
351           AUTOCLOSE
352           autoclose
353
354       OPTS is a combination of the following options:
355
356       "Name => "membername""
357            Open "membername" from the zip file for reading.
358
359       "Efs => 0| 1"
360            When this option is set to true AND the zip archive being read has
361            the "Language Encoding Flag" (EFS) set, the member name is assumed
362            to be encoded in UTF-8.
363
364            If the member name in the zip archive is not valid UTF-8 when this
365            optionn is true, the script will die with an error message.
366
367            Note that this option only works with Perl 5.8.4 or better.
368
369            This option defaults to false.
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::Unzip object is destroyed.
376
377            This parameter defaults to 0.
378
379       "MultiStream => 0|1"
380            Treats the complete zip file/buffer as a single compressed data
381            stream. When reading in multi-stream mode each member of the zip
382            file/buffer will be uncompressed in turn until the end of the
383            file/buffer is encountered.
384
385            This parameter defaults to 0.
386
387       "Prime => $string"
388            This option will uncompress the contents of $string before
389            processing the input file/buffer.
390
391            This option can be useful when the compressed data is embedded in
392            another file/data structure and it is not possible to work out
393            where the compressed data begins without having to read the first
394            few bytes. If this is the case, the uncompression can be primed
395            with these bytes using this option.
396
397       "Transparent => 0|1"
398            If this option is set and the input file/buffer is not compressed
399            data, the module will allow reading of it anyway.
400
401            In addition, if the input file/buffer does contain compressed data
402            and there is non-compressed data immediately following it, setting
403            this option will make this module treat the whole file/buffer as a
404            single data stream.
405
406            This option defaults to 1.
407
408       "BlockSize => $num"
409            When reading the compressed input data, IO::Uncompress::Unzip will
410            read it in blocks of $num bytes.
411
412            This option defaults to 4096.
413
414       "InputLength => $size"
415            When present this option will limit the number of compressed bytes
416            read from the input file/buffer to $size. This option can be used
417            in the situation where there is useful data directly after the
418            compressed data stream and you know beforehand the exact length of
419            the compressed data stream.
420
421            This option is mostly used when reading from a filehandle, in
422            which case the file pointer will be left pointing to the first
423            byte directly after the compressed data stream.
424
425            This option defaults to off.
426
427       "Append => 0|1"
428            This option controls what the "read" method does with uncompressed
429            data.
430
431            If set to 1, all uncompressed data will be appended to the output
432            parameter of the "read" method.
433
434            If set to 0, the contents of the output parameter of the "read"
435            method will be overwritten by the uncompressed data.
436
437            Defaults to 0.
438
439       "Strict => 0|1"
440            This option controls whether the extra checks defined below are
441            used when carrying out the decompression. When Strict is on, the
442            extra tests are carried out, when Strict is off they are not.
443
444            The default for this option is off.
445
446   Examples
447       TODO
448

Methods

450   read
451       Usage is
452
453           $status = $z->read($buffer)
454
455       Reads a block of compressed data (the size of the compressed block is
456       determined by the "Buffer" option in the constructor), uncompresses it
457       and writes any uncompressed data into $buffer. If the "Append"
458       parameter is set in the constructor, the uncompressed data will be
459       appended to the $buffer parameter. Otherwise $buffer will be
460       overwritten.
461
462       Returns the number of uncompressed bytes written to $buffer, zero if
463       eof or a negative number on error.
464
465   read
466       Usage is
467
468           $status = $z->read($buffer, $length)
469           $status = $z->read($buffer, $length, $offset)
470
471           $status = read($z, $buffer, $length)
472           $status = read($z, $buffer, $length, $offset)
473
474       Attempt to read $length bytes of uncompressed data into $buffer.
475
476       The main difference between this form of the "read" method and the
477       previous one, is that this one will attempt to return exactly $length
478       bytes. The only circumstances that this function will not is if end-of-
479       file or an IO error is encountered.
480
481       Returns the number of uncompressed bytes written to $buffer, zero if
482       eof or a negative number on error.
483
484   getline
485       Usage is
486
487           $line = $z->getline()
488           $line = <$z>
489
490       Reads a single line.
491
492       This method fully supports the use of the variable $/ (or
493       $INPUT_RECORD_SEPARATOR or $RS when "English" is in use) to determine
494       what constitutes an end of line. Paragraph mode, record mode and file
495       slurp mode are all supported.
496
497   getc
498       Usage is
499
500           $char = $z->getc()
501
502       Read a single character.
503
504   ungetc
505       Usage is
506
507           $char = $z->ungetc($string)
508
509   inflateSync
510       Usage is
511
512           $status = $z->inflateSync()
513
514       TODO
515
516   getHeaderInfo
517       Usage is
518
519           $hdr  = $z->getHeaderInfo();
520           @hdrs = $z->getHeaderInfo();
521
522       This method returns either a hash reference (in scalar context) or a
523       list or hash references (in array context) that contains information
524       about each of the header fields in the compressed data stream(s).
525
526   tell
527       Usage is
528
529           $z->tell()
530           tell $z
531
532       Returns the uncompressed file offset.
533
534   eof
535       Usage is
536
537           $z->eof();
538           eof($z);
539
540       Returns true if the end of the compressed input stream has been
541       reached.
542
543   seek
544           $z->seek($position, $whence);
545           seek($z, $position, $whence);
546
547       Provides a sub-set of the "seek" functionality, with the restriction
548       that it is only legal to seek forward in the input file/buffer.  It is
549       a fatal error to attempt to seek backward.
550
551       Note that the implementation of "seek" in this module does not provide
552       true random access to a compressed file/buffer. It  works by
553       uncompressing data from the current offset in the file/buffer until it
554       reaches the uncompressed offset specified in the parameters to "seek".
555       For very small files this may be acceptable behaviour. For large files
556       it may cause an unacceptable delay.
557
558       The $whence parameter takes one the usual values, namely SEEK_SET,
559       SEEK_CUR or SEEK_END.
560
561       Returns 1 on success, 0 on failure.
562
563   binmode
564       Usage is
565
566           $z->binmode
567           binmode $z ;
568
569       This is a noop provided for completeness.
570
571   opened
572           $z->opened()
573
574       Returns true if the object currently refers to a opened file/buffer.
575
576   autoflush
577           my $prev = $z->autoflush()
578           my $prev = $z->autoflush(EXPR)
579
580       If the $z object is associated with a file or a filehandle, this method
581       returns the current autoflush setting for the underlying filehandle. If
582       "EXPR" is present, and is non-zero, it will enable flushing after every
583       write/print operation.
584
585       If $z is associated with a buffer, this method has no effect and always
586       returns "undef".
587
588       Note that the special variable $| cannot be used to set or retrieve the
589       autoflush setting.
590
591   input_line_number
592           $z->input_line_number()
593           $z->input_line_number(EXPR)
594
595       Returns the current uncompressed line number. If "EXPR" is present it
596       has the effect of setting the line number. Note that setting the line
597       number does not change the current position within the file/buffer
598       being read.
599
600       The contents of $/ are used to determine what constitutes a line
601       terminator.
602
603   fileno
604           $z->fileno()
605           fileno($z)
606
607       If the $z object is associated with a file or a filehandle, "fileno"
608       will return the underlying file descriptor. Once the "close" method is
609       called "fileno" will return "undef".
610
611       If the $z object is associated with a buffer, this method will return
612       "undef".
613
614   close
615           $z->close() ;
616           close $z ;
617
618       Closes the output file/buffer.
619
620       For most versions of Perl this method will be automatically invoked if
621       the IO::Uncompress::Unzip object is destroyed (either explicitly or by
622       the variable with the reference to the object going out of scope). The
623       exceptions are Perl versions 5.005 through 5.00504 and 5.8.0. In these
624       cases, the "close" method will be called automatically, but not until
625       global destruction of all live objects when the program is terminating.
626
627       Therefore, if you want your scripts to be able to run on all versions
628       of Perl, you should call "close" explicitly and not rely on automatic
629       closing.
630
631       Returns true on success, otherwise 0.
632
633       If the "AutoClose" option has been enabled when the
634       IO::Uncompress::Unzip object was created, and the object is associated
635       with a file, the underlying file will also be closed.
636
637   nextStream
638       Usage is
639
640           my $status = $z->nextStream();
641
642       Skips to the next compressed data stream in the input file/buffer. If a
643       new compressed data stream is found, the eof marker will be cleared and
644       $.  will be reset to 0.
645
646       If trailing data is present immediately after the zip archive and the
647       "Transparent" option is enabled, this method will consider that
648       trailing data to be another member of the zip archive.
649
650       Returns 1 if a new stream was found, 0 if none was found, and -1 if an
651       error was encountered.
652
653   trailingData
654       Usage is
655
656           my $data = $z->trailingData();
657
658       Returns the data, if any, that is present immediately after the
659       compressed data stream once uncompression is complete. It only makes
660       sense to call this method once the end of the compressed data stream
661       has been encountered.
662
663       This option can be used when there is useful information immediately
664       following the compressed data stream, and you don't know the length of
665       the compressed data stream.
666
667       If the input is a buffer, "trailingData" will return everything from
668       the end of the compressed data stream to the end of the buffer.
669
670       If the input is a filehandle, "trailingData" will return the data that
671       is left in the filehandle input buffer once the end of the compressed
672       data stream has been reached. You can then use the filehandle to read
673       the rest of the input file.
674
675       Don't bother using "trailingData" if the input is a filename.
676
677       If you know the length of the compressed data stream before you start
678       uncompressing, you can avoid having to use "trailingData" by setting
679       the "InputLength" option in the constructor.
680

Importing

682       No symbolic constants are required by this IO::Uncompress::Unzip at
683       present.
684
685       :all Imports "unzip" and $UnzipError.  Same as doing this
686
687                use IO::Uncompress::Unzip qw(unzip $UnzipError) ;
688

EXAMPLES

690   Working with Net::FTP
691       See IO::Compress::FAQ
692
693   Walking through a zip file
694       The code below can be used to traverse a zip file, one compressed data
695       stream at a time.
696
697           use IO::Uncompress::Unzip qw($UnzipError);
698
699           my $zipfile = "somefile.zip";
700           my $u = new IO::Uncompress::Unzip $zipfile
701               or die "Cannot open $zipfile: $UnzipError";
702
703           my $status;
704           for ($status = 1; $status > 0; $status = $u->nextStream())
705           {
706
707               my $name = $u->getHeaderInfo()->{Name};
708               warn "Processing member $name\n" ;
709
710               my $buff;
711               while (($status = $u->read($buff)) > 0) {
712                   # Do something here
713               }
714
715               last if $status < 0;
716           }
717
718           die "Error processing $zipfile: $!\n"
719               if $status < 0 ;
720
721       Each individual compressed data stream is read until the logical end-
722       of-file is reached. Then "nextStream" is called. This will skip to the
723       start of the next compressed data stream and clear the end-of-file
724       flag.
725
726       It is also worth noting that "nextStream" can be called at any time --
727       you don't have to wait until you have exhausted a compressed data
728       stream before skipping to the next one.
729
730   Unzipping a complete zip file to disk
731       Daniel S. Sterling has written a script that uses
732       "IO::Uncompress::UnZip" to read a zip file and unzip its contents to
733       disk.
734
735       The script is available from <https://gist.github.com/eqhmcow/5389877>
736

AUTHOR

766       This module was written by Paul Marquess, "pmqs@cpan.org".
767

MODIFICATION HISTORY

769       See the Changes file.
770

COPYRIGHT AND LICENSE

772       Copyright (c) 2005-2019 Paul Marquess. All rights reserved.
773
774       This program is free software; you can redistribute it and/or modify it
775       under the same terms as Perl itself.
776
777
778
779perl v5.30.0                      2019-08-12          IO::Uncompress::Unzip(3)