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

OO Interface

310   Constructor
311       The format of the constructor for IO::Uncompress::Unzip is shown below
312
313           my $z = new IO::Uncompress::Unzip $input [OPTS]
314               or die "IO::Uncompress::Unzip failed: $UnzipError\n";
315
316       Returns an "IO::Uncompress::Unzip" object on success and undef on
317       failure.  The variable $UnzipError 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::Unzip 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       The mandatory parameter $input is used to determine the source of the
330       compressed data. This parameter can take one of three forms.
331
332       A filename
333            If the $input parameter is a scalar, it is assumed to be a
334            filename. This file will be opened for reading and the compressed
335            data will be read from it.
336
337       A filehandle
338            If the $input parameter is a filehandle, the compressed data will
339            be read from it.  The string '-' can be used as an alias for
340            standard input.
341
342       A scalar reference
343            If $input is a scalar reference, the compressed data will be read
344            from $$input.
345
346   Constructor Options
347       The option names defined below are case insensitive and can be
348       optionally prefixed by a '-'.  So all of the following are valid
349
350           -AutoClose
351           -autoclose
352           AUTOCLOSE
353           autoclose
354
355       OPTS is a combination of the following options:
356
357       "Name => "membername""
358            Open "membername" from the zip file for reading.
359
360       "Efs => 0| 1"
361            When this option is set to true AND the zip archive being read has
362            the "Language Encoding Flag" (EFS) set, the member name is assumed
363            to be encoded in UTF-8.
364
365            If the member name in the zip archive is not valid UTF-8 when this
366            optionn is true, the script will die with an error message.
367
368            Note that this option only works with Perl 5.8.4 or better.
369
370            This option defaults to false.
371
372       "AutoClose => 0|1"
373            This option is only valid when the $input parameter is a
374            filehandle. If specified, and the value is true, it will result in
375            the file being closed once either the "close" method is called or
376            the IO::Uncompress::Unzip object is destroyed.
377
378            This parameter defaults to 0.
379
380       "MultiStream => 0|1"
381            Treats the complete zip file/buffer as a single compressed data
382            stream. When reading in multi-stream mode each member of the zip
383            file/buffer will be uncompressed in turn until the end of the
384            file/buffer is encountered.
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::Unzip will
411            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
447   Examples
448       TODO
449

Methods

451   read
452       Usage is
453
454           $status = $z->read($buffer)
455
456       Reads a block of compressed data (the size of the compressed block is
457       determined by the "Buffer" option in the constructor), uncompresses it
458       and writes any uncompressed data into $buffer. If the "Append"
459       parameter is set in the constructor, the uncompressed data will be
460       appended to the $buffer parameter. Otherwise $buffer will be
461       overwritten.
462
463       Returns the number of uncompressed bytes written to $buffer, zero if
464       eof or a negative number on error.
465
466   read
467       Usage is
468
469           $status = $z->read($buffer, $length)
470           $status = $z->read($buffer, $length, $offset)
471
472           $status = read($z, $buffer, $length)
473           $status = read($z, $buffer, $length, $offset)
474
475       Attempt to read $length bytes of uncompressed data into $buffer.
476
477       The main difference between this form of the "read" method and the
478       previous one, is that this one will attempt to return exactly $length
479       bytes. The only circumstances that this function will not is if end-of-
480       file or an IO error is encountered.
481
482       Returns the number of uncompressed bytes written to $buffer, zero if
483       eof or a negative number on error.
484
485   getline
486       Usage is
487
488           $line = $z->getline()
489           $line = <$z>
490
491       Reads a single line.
492
493       This method fully supports the use of the variable $/ (or
494       $INPUT_RECORD_SEPARATOR or $RS when "English" is in use) to determine
495       what constitutes an end of line. Paragraph mode, record mode and file
496       slurp mode are all supported.
497
498   getc
499       Usage is
500
501           $char = $z->getc()
502
503       Read a single character.
504
505   ungetc
506       Usage is
507
508           $char = $z->ungetc($string)
509
510   inflateSync
511       Usage is
512
513           $status = $z->inflateSync()
514
515       TODO
516
517   getHeaderInfo
518       Usage is
519
520           $hdr  = $z->getHeaderInfo();
521           @hdrs = $z->getHeaderInfo();
522
523       This method returns either a hash reference (in scalar context) or a
524       list or hash references (in array context) that contains information
525       about each of the header fields in the compressed data stream(s).
526
527   tell
528       Usage is
529
530           $z->tell()
531           tell $z
532
533       Returns the uncompressed file offset.
534
535   eof
536       Usage is
537
538           $z->eof();
539           eof($z);
540
541       Returns true if the end of the compressed input stream has been
542       reached.
543
544   seek
545           $z->seek($position, $whence);
546           seek($z, $position, $whence);
547
548       Provides a sub-set of the "seek" functionality, with the restriction
549       that it is only legal to seek forward in the input file/buffer.  It is
550       a fatal error to attempt to seek backward.
551
552       Note that the implementation of "seek" in this module does not provide
553       true random access to a compressed file/buffer. It  works by
554       uncompressing data from the current offset in the file/buffer until it
555       reaches the uncompressed offset specified in the parameters to "seek".
556       For very small files this may be acceptable behaviour. For large files
557       it may cause an unacceptable delay.
558
559       The $whence parameter takes one the usual values, namely SEEK_SET,
560       SEEK_CUR or SEEK_END.
561
562       Returns 1 on success, 0 on failure.
563
564   binmode
565       Usage is
566
567           $z->binmode
568           binmode $z ;
569
570       This is a noop provided for completeness.
571
572   opened
573           $z->opened()
574
575       Returns true if the object currently refers to a opened file/buffer.
576
577   autoflush
578           my $prev = $z->autoflush()
579           my $prev = $z->autoflush(EXPR)
580
581       If the $z object is associated with a file or a filehandle, this method
582       returns the current autoflush setting for the underlying filehandle. If
583       "EXPR" is present, and is non-zero, it will enable flushing after every
584       write/print operation.
585
586       If $z is associated with a buffer, this method has no effect and always
587       returns "undef".
588
589       Note that the special variable $| cannot be used to set or retrieve the
590       autoflush setting.
591
592   input_line_number
593           $z->input_line_number()
594           $z->input_line_number(EXPR)
595
596       Returns the current uncompressed line number. If "EXPR" is present it
597       has the effect of setting the line number. Note that setting the line
598       number does not change the current position within the file/buffer
599       being read.
600
601       The contents of $/ are used to determine what constitutes a line
602       terminator.
603
604   fileno
605           $z->fileno()
606           fileno($z)
607
608       If the $z object is associated with a file or a filehandle, "fileno"
609       will return the underlying file descriptor. Once the "close" method is
610       called "fileno" will return "undef".
611
612       If the $z object is associated with a buffer, this method will return
613       "undef".
614
615   close
616           $z->close() ;
617           close $z ;
618
619       Closes the output file/buffer.
620
621       For most versions of Perl this method will be automatically invoked if
622       the IO::Uncompress::Unzip object is destroyed (either explicitly or by
623       the variable with the reference to the object going out of scope). The
624       exceptions are Perl versions 5.005 through 5.00504 and 5.8.0. In these
625       cases, the "close" method will be called automatically, but not until
626       global destruction of all live objects when the program is terminating.
627
628       Therefore, if you want your scripts to be able to run on all versions
629       of Perl, you should call "close" explicitly and not rely on automatic
630       closing.
631
632       Returns true on success, otherwise 0.
633
634       If the "AutoClose" option has been enabled when the
635       IO::Uncompress::Unzip object was created, and the object is associated
636       with a file, the underlying file will also be closed.
637
638   nextStream
639       Usage is
640
641           my $status = $z->nextStream();
642
643       Skips to the next compressed data stream in the input file/buffer. If a
644       new compressed data stream is found, the eof marker will be cleared and
645       $.  will be reset to 0.
646
647       If trailing data is present immediately after the zip archive and the
648       "Transparent" option is enabled, this method will consider that
649       trailing data to be another member of the zip archive.
650
651       Returns 1 if a new stream was found, 0 if none was found, and -1 if an
652       error was encountered.
653
654   trailingData
655       Usage is
656
657           my $data = $z->trailingData();
658
659       Returns the data, if any, that is present immediately after the
660       compressed data stream once uncompression is complete. It only makes
661       sense to call this method once the end of the compressed data stream
662       has been encountered.
663
664       This option can be used when there is useful information immediately
665       following the compressed data stream, and you don't know the length of
666       the compressed data stream.
667
668       If the input is a buffer, "trailingData" will return everything from
669       the end of the compressed data stream to the end of the buffer.
670
671       If the input is a filehandle, "trailingData" will return the data that
672       is left in the filehandle input buffer once the end of the compressed
673       data stream has been reached. You can then use the filehandle to read
674       the rest of the input file.
675
676       Don't bother using "trailingData" if the input is a filename.
677
678       If you know the length of the compressed data stream before you start
679       uncompressing, you can avoid having to use "trailingData" by setting
680       the "InputLength" option in the constructor.
681

Importing

683       No symbolic constants are required by this IO::Uncompress::Unzip at
684       present.
685
686       :all Imports "unzip" and $UnzipError.  Same as doing this
687
688                use IO::Uncompress::Unzip qw(unzip $UnzipError) ;
689

EXAMPLES

691   Working with Net::FTP
692       See IO::Compress::FAQ
693
694   Walking through a zip file
695       The code below can be used to traverse a zip file, one compressed data
696       stream at a time.
697
698           use IO::Uncompress::Unzip qw($UnzipError);
699
700           my $zipfile = "somefile.zip";
701           my $u = new IO::Uncompress::Unzip $zipfile
702               or die "Cannot open $zipfile: $UnzipError";
703
704           my $status;
705           for ($status = 1; $status > 0; $status = $u->nextStream())
706           {
707
708               my $name = $u->getHeaderInfo()->{Name};
709               warn "Processing member $name\n" ;
710
711               my $buff;
712               while (($status = $u->read($buff)) > 0) {
713                   # Do something here
714               }
715
716               last if $status < 0;
717           }
718
719           die "Error processing $zipfile: $!\n"
720               if $status < 0 ;
721
722       Each individual compressed data stream is read until the logical end-
723       of-file is reached. Then "nextStream" is called. This will skip to the
724       start of the next compressed data stream and clear the end-of-file
725       flag.
726
727       It is also worth noting that "nextStream" can be called at any time --
728       you don't have to wait until you have exhausted a compressed data
729       stream before skipping to the next one.
730
731   Unzipping a complete zip file to disk
732       Daniel S. Sterling has written a script that uses
733       "IO::Uncompress::UnZip" to read a zip file and unzip its contents to
734       disk.
735
736       The script is available from <https://gist.github.com/eqhmcow/5389877>
737

SUPPORT

739       General feedback/questions/bug reports should be sent to
740       <https://github.com/pmqs/IO-Compress/issues> (preferred) or
741       <https://rt.cpan.org/Public/Dist/Display.html?Name=IO-Compress>.
742

AUTHOR

772       This module was written by Paul Marquess, "pmqs@cpan.org".
773

MODIFICATION HISTORY

775       See the Changes file.
776

COPYRIGHT AND LICENSE

778       Copyright (c) 2005-2019 Paul Marquess. All rights reserved.
779
780       This program is free software; you can redistribute it and/or modify it
781       under the same terms as Perl itself.
782
783
784
785perl v5.30.1                      2020-01-30          IO::Uncompress::Unzip(3)