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       "AutoClose => 0|1"
360            This option is only valid when the $input parameter is a
361            filehandle. If specified, and the value is true, it will result in
362            the file being closed once either the "close" method is called or
363            the IO::Uncompress::Unzip object is destroyed.
364
365            This parameter defaults to 0.
366
367       "MultiStream => 0|1"
368            Treats the complete zip file/buffer as a single compressed data
369            stream. When reading in multi-stream mode each member of the zip
370            file/buffer will be uncompressed in turn until the end of the
371            file/buffer is encountered.
372
373            This parameter defaults to 0.
374
375       "Prime => $string"
376            This option will uncompress the contents of $string before
377            processing the input file/buffer.
378
379            This option can be useful when the compressed data is embedded in
380            another file/data structure and it is not possible to work out
381            where the compressed data begins without having to read the first
382            few bytes. If this is the case, the uncompression can be primed
383            with these bytes using this option.
384
385       "Transparent => 0|1"
386            If this option is set and the input file/buffer is not compressed
387            data, the module will allow reading of it anyway.
388
389            In addition, if the input file/buffer does contain compressed data
390            and there is non-compressed data immediately following it, setting
391            this option will make this module treat the whole file/buffer as a
392            single data stream.
393
394            This option defaults to 1.
395
396       "BlockSize => $num"
397            When reading the compressed input data, IO::Uncompress::Unzip will
398            read it in blocks of $num bytes.
399
400            This option defaults to 4096.
401
402       "InputLength => $size"
403            When present this option will limit the number of compressed bytes
404            read from the input file/buffer to $size. This option can be used
405            in the situation where there is useful data directly after the
406            compressed data stream and you know beforehand the exact length of
407            the compressed data stream.
408
409            This option is mostly used when reading from a filehandle, in
410            which case the file pointer will be left pointing to the first
411            byte directly after the compressed data stream.
412
413            This option defaults to off.
414
415       "Append => 0|1"
416            This option controls what the "read" method does with uncompressed
417            data.
418
419            If set to 1, all uncompressed data will be appended to the output
420            parameter of the "read" method.
421
422            If set to 0, the contents of the output parameter of the "read"
423            method will be overwritten by the uncompressed data.
424
425            Defaults to 0.
426
427       "Strict => 0|1"
428            This option controls whether the extra checks defined below are
429            used when carrying out the decompression. When Strict is on, the
430            extra tests are carried out, when Strict is off they are not.
431
432            The default for this option is off.
433
434   Examples
435       TODO
436

Methods

438   read
439       Usage is
440
441           $status = $z->read($buffer)
442
443       Reads a block of compressed data (the size of the compressed block is
444       determined by the "Buffer" option in the constructor), uncompresses it
445       and writes any uncompressed data into $buffer. If the "Append"
446       parameter is set in the constructor, the uncompressed data will be
447       appended to the $buffer parameter. Otherwise $buffer will be
448       overwritten.
449
450       Returns the number of uncompressed bytes written to $buffer, zero if
451       eof or a negative number on error.
452
453   read
454       Usage is
455
456           $status = $z->read($buffer, $length)
457           $status = $z->read($buffer, $length, $offset)
458
459           $status = read($z, $buffer, $length)
460           $status = read($z, $buffer, $length, $offset)
461
462       Attempt to read $length bytes of uncompressed data into $buffer.
463
464       The main difference between this form of the "read" method and the
465       previous one, is that this one will attempt to return exactly $length
466       bytes. The only circumstances that this function will not is if end-of-
467       file or an IO error is encountered.
468
469       Returns the number of uncompressed bytes written to $buffer, zero if
470       eof or a negative number on error.
471
472   getline
473       Usage is
474
475           $line = $z->getline()
476           $line = <$z>
477
478       Reads a single line.
479
480       This method fully supports the use of the variable $/ (or
481       $INPUT_RECORD_SEPARATOR or $RS when "English" is in use) to determine
482       what constitutes an end of line. Paragraph mode, record mode and file
483       slurp mode are all supported.
484
485   getc
486       Usage is
487
488           $char = $z->getc()
489
490       Read a single character.
491
492   ungetc
493       Usage is
494
495           $char = $z->ungetc($string)
496
497   inflateSync
498       Usage is
499
500           $status = $z->inflateSync()
501
502       TODO
503
504   getHeaderInfo
505       Usage is
506
507           $hdr  = $z->getHeaderInfo();
508           @hdrs = $z->getHeaderInfo();
509
510       This method returns either a hash reference (in scalar context) or a
511       list or hash references (in array context) that contains information
512       about each of the header fields in the compressed data stream(s).
513
514   tell
515       Usage is
516
517           $z->tell()
518           tell $z
519
520       Returns the uncompressed file offset.
521
522   eof
523       Usage is
524
525           $z->eof();
526           eof($z);
527
528       Returns true if the end of the compressed input stream has been
529       reached.
530
531   seek
532           $z->seek($position, $whence);
533           seek($z, $position, $whence);
534
535       Provides a sub-set of the "seek" functionality, with the restriction
536       that it is only legal to seek forward in the input file/buffer.  It is
537       a fatal error to attempt to seek backward.
538
539       Note that the implementation of "seek" in this module does not provide
540       true random access to a compressed file/buffer. It  works by
541       uncompressing data from the current offset in the file/buffer until it
542       reaches the uncompressed offset specified in the parameters to "seek".
543       For very small files this may be acceptable behaviour. For large files
544       it may cause an unacceptable delay.
545
546       The $whence parameter takes one the usual values, namely SEEK_SET,
547       SEEK_CUR or SEEK_END.
548
549       Returns 1 on success, 0 on failure.
550
551   binmode
552       Usage is
553
554           $z->binmode
555           binmode $z ;
556
557       This is a noop provided for completeness.
558
559   opened
560           $z->opened()
561
562       Returns true if the object currently refers to a opened file/buffer.
563
564   autoflush
565           my $prev = $z->autoflush()
566           my $prev = $z->autoflush(EXPR)
567
568       If the $z object is associated with a file or a filehandle, this method
569       returns the current autoflush setting for the underlying filehandle. If
570       "EXPR" is present, and is non-zero, it will enable flushing after every
571       write/print operation.
572
573       If $z is associated with a buffer, this method has no effect and always
574       returns "undef".
575
576       Note that the special variable $| cannot be used to set or retrieve the
577       autoflush setting.
578
579   input_line_number
580           $z->input_line_number()
581           $z->input_line_number(EXPR)
582
583       Returns the current uncompressed line number. If "EXPR" is present it
584       has the effect of setting the line number. Note that setting the line
585       number does not change the current position within the file/buffer
586       being read.
587
588       The contents of $/ are used to determine what constitutes a line
589       terminator.
590
591   fileno
592           $z->fileno()
593           fileno($z)
594
595       If the $z object is associated with a file or a filehandle, "fileno"
596       will return the underlying file descriptor. Once the "close" method is
597       called "fileno" will return "undef".
598
599       If the $z object is associated with a buffer, this method will return
600       "undef".
601
602   close
603           $z->close() ;
604           close $z ;
605
606       Closes the output file/buffer.
607
608       For most versions of Perl this method will be automatically invoked if
609       the IO::Uncompress::Unzip object is destroyed (either explicitly or by
610       the variable with the reference to the object going out of scope). The
611       exceptions are Perl versions 5.005 through 5.00504 and 5.8.0. In these
612       cases, the "close" method will be called automatically, but not until
613       global destruction of all live objects when the program is terminating.
614
615       Therefore, if you want your scripts to be able to run on all versions
616       of Perl, you should call "close" explicitly and not rely on automatic
617       closing.
618
619       Returns true on success, otherwise 0.
620
621       If the "AutoClose" option has been enabled when the
622       IO::Uncompress::Unzip object was created, and the object is associated
623       with a file, the underlying file will also be closed.
624
625   nextStream
626       Usage is
627
628           my $status = $z->nextStream();
629
630       Skips to the next compressed data stream in the input file/buffer. If a
631       new compressed data stream is found, the eof marker will be cleared and
632       $.  will be reset to 0.
633
634       Returns 1 if a new stream was found, 0 if none was found, and -1 if an
635       error was encountered.
636
637   trailingData
638       Usage is
639
640           my $data = $z->trailingData();
641
642       Returns the data, if any, that is present immediately after the
643       compressed data stream once uncompression is complete. It only makes
644       sense to call this method once the end of the compressed data stream
645       has been encountered.
646
647       This option can be used when there is useful information immediately
648       following the compressed data stream, and you don't know the length of
649       the compressed data stream.
650
651       If the input is a buffer, "trailingData" will return everything from
652       the end of the compressed data stream to the end of the buffer.
653
654       If the input is a filehandle, "trailingData" will return the data that
655       is left in the filehandle input buffer once the end of the compressed
656       data stream has been reached. You can then use the filehandle to read
657       the rest of the input file.
658
659       Don't bother using "trailingData" if the input is a filename.
660
661       If you know the length of the compressed data stream before you start
662       uncompressing, you can avoid having to use "trailingData" by setting
663       the "InputLength" option in the constructor.
664

Importing

666       No symbolic constants are required by this IO::Uncompress::Unzip at
667       present.
668
669       :all Imports "unzip" and $UnzipError.  Same as doing this
670
671                use IO::Uncompress::Unzip qw(unzip $UnzipError) ;
672

EXAMPLES

674   Working with Net::FTP
675       See IO::Compress::FAQ
676
677   Walking through a zip file
678       The code below can be used to traverse a zip file, one compressed data
679       stream at a time.
680
681           use IO::Uncompress::Unzip qw($UnzipError);
682
683           my $zipfile = "somefile.zip";
684           my $u = new IO::Uncompress::Unzip $zipfile
685               or die "Cannot open $zipfile: $UnzipError";
686
687           my $status;
688           for ($status = 1; $status > 0; $status = $u->nextStream())
689           {
690
691               my $name = $u->getHeaderInfo()->{Name};
692               warn "Processing member $name\n" ;
693
694               my $buff;
695               while (($status = $u->read($buff)) > 0) {
696                   # Do something here
697               }
698
699               last if $status < 0;
700           }
701
702           die "Error processing $zipfile: $!\n"
703               if $status < 0 ;
704
705       Each individual compressed data stream is read until the logical end-
706       of-file is reached. Then "nextStream" is called. This will skip to the
707       start of the next compressed data stream and clear the end-of-file
708       flag.
709
710       It is also worth noting that "nextStream" can be called at any time --
711       you don't have to wait until you have exhausted a compressed data
712       stream before skipping to the next one.
713
714   Unzipping a complete zip file to disk
715       Daniel S. Sterling has written a script that uses
716       "IO::Uncompress::UnZip" to read a zip file and unzip its contents to
717       disk.
718
719       The script is available from <https://gist.github.com/eqhmcow/5389877>
720

AUTHOR

750       This module was written by Paul Marquess, "pmqs@cpan.org".
751

MODIFICATION HISTORY

753       See the Changes file.
754

COPYRIGHT AND LICENSE

756       Copyright (c) 2005-2019 Paul Marquess. All rights reserved.
757
758       This program is free software; you can redistribute it and/or modify it
759       under the same terms as Perl itself.
760
761
762
763perl v5.28.1                      2019-01-05          IO::Uncompress::Unzip(3)