IO::Uncompress::Unzip(3pm)

1IO::Uncompress::Unzip(3pPme)rl Programmers Reference GuiIdOe::Uncompress::Unzip(3pm)
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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 => $output [,OPTS]
67               or die "unzip failed: $UnzipError\n";
68
69       The functional interface needs Perl5.005 or better.
70
71   unzip $input => $output [, OPTS]
72       "unzip" expects at least two parameters, $input and $output.
73
74       The $input parameter
75
76       The parameter, $input, is used to define the source of the compressed
77       data.
78
79       It can take one of the following forms:
80
81       A filename
82            If the $input parameter is a simple scalar, it is assumed to be a
83            filename. This file will be opened for reading and the input data
84            will be read from it.
85
86       A filehandle
87            If the $input parameter is a filehandle, the input data will be
88            read from it.  The string '-' can be used as an alias for standard
89            input.
90
91       A scalar reference
92            If $input is a scalar reference, the input data will be read from
93            $$input.
94
95       An array reference
96            If $input is an array reference, each element in the array must be
97            a filename.
98
99            The input data will be read from each file in turn.
100
101            The complete array will be walked to ensure that it only contains
102            valid filenames before any data is uncompressed.
103
104       An Input FileGlob string
105            If $input is a string that is delimited by the characters "<" and
106            ">" "unzip" will assume that it is an input fileglob string. The
107            input is the list of files that match the fileglob.
108
109            If the fileglob does not match any files ...
110
111            See File::GlobMapper for more details.
112
113       If the $input parameter is any other type, "undef" will be returned.
114
115       The $output parameter
116
117       The parameter $output is used to control the destination of the
118       uncompressed data. This parameter can take one of these forms.
119
120       A filename
121            If the $output parameter is a simple scalar, it is assumed to be a
122            filename.  This file will be opened for writing and the
123            uncompressed data will be written to it.
124
125       A filehandle
126            If the $output parameter is a filehandle, the uncompressed data
127            will be written to it.  The string '-' can be used as an alias for
128            standard output.
129
130       A scalar reference
131            If $output is a scalar reference, the uncompressed data will be
132            stored in $$output.
133
134       An Array Reference
135            If $output is an array reference, the uncompressed data will be
136            pushed onto the array.
137
138       An Output FileGlob
139            If $output is a string that is delimited by the characters "<" and
140            ">" "unzip" will assume that it is an output fileglob string. The
141            output is the list of files that match the fileglob.
142
143            When $output is an fileglob string, $input must also be a fileglob
144            string. Anything else is an error.
145
146       If the $output parameter is any other type, "undef" will be returned.
147
148   Notes
149       When $input maps to multiple compressed files/buffers and $output is a
150       single file/buffer, after uncompression $output will contain a
151       concatenation of all the uncompressed data from each of the input
152       files/buffers.
153
154   Optional Parameters
155       Unless specified below, the optional parameters for "unzip", "OPTS",
156       are the same as those used with the OO interface defined in the
157       "Constructor Options" section below.
158
159       "AutoClose => 0|1"
160            This option applies to any input or output data streams to "unzip"
161            that are filehandles.
162
163            If "AutoClose" is specified, and the value is true, it will result
164            in all input and/or output filehandles being closed once "unzip"
165            has completed.
166
167            This parameter defaults to 0.
168
169       "BinModeOut => 0|1"
170            When writing to a file or filehandle, set "binmode" before writing
171            to the file.
172
173            Defaults to 0.
174
175       "Append => 0|1"
176            The behaviour of this option is dependent on the type of output
177            data stream.
178
179            ·    A Buffer
180
181                 If "Append" is enabled, all uncompressed data will be append
182                 to the end of the output buffer. Otherwise the output buffer
183                 will be cleared before any uncompressed data is written to
184                 it.
185
186            ·    A Filename
187
188                 If "Append" is enabled, the file will be opened in append
189                 mode. Otherwise the contents of the file, if any, will be
190                 truncated before any uncompressed data is written to it.
191
192            ·    A Filehandle
193
194                 If "Append" is enabled, the filehandle will be positioned to
195                 the end of the file via a call to "seek" before any
196                 uncompressed data is written to it.  Otherwise the file
197                 pointer will not be moved.
198
199            When "Append" is specified, and set to true, it will append all
200            uncompressed data to the output data stream.
201
202            So when the output is a filehandle it will carry out a seek to the
203            eof before writing any uncompressed data. If the output is a
204            filename, it will be opened for appending. If the output is a
205            buffer, all uncompressed data will be appened to the existing
206            buffer.
207
208            Conversely when "Append" is not specified, or it is present and is
209            set to false, it will operate as follows.
210
211            When the output is a filename, it will truncate the contents of
212            the file before writing any uncompressed data. If the output is a
213            filehandle its position will not be changed. If the output is a
214            buffer, it will be wiped before any uncompressed data is output.
215
216            Defaults to 0.
217
218       "MultiStream => 0|1"
219            If the input file/buffer contains multiple compressed data
220            streams, this option will uncompress the whole lot as a single
221            data stream.
222
223            Defaults to 0.
224
225       "TrailingData => $scalar"
226            Returns the data, if any, that is present immediately after the
227            compressed data stream once uncompression is complete.
228
229            This option can be used when there is useful information
230            immediately following the compressed data stream, and you don't
231            know the length of the compressed data stream.
232
233            If the input is a buffer, "trailingData" will return everything
234            from the end of the compressed data stream to the end of the
235            buffer.
236
237            If the input is a filehandle, "trailingData" will return the data
238            that is left in the filehandle input buffer once the end of the
239            compressed data stream has been reached. You can then use the
240            filehandle to read the rest of the input file.
241
242            Don't bother using "trailingData" if the input is a filename.
243
244            If you know the length of the compressed data stream before you
245            start uncompressing, you can avoid having to use "trailingData" by
246            setting the "InputLength" option.
247
248   Examples
249       To read the contents of the file "file1.txt.zip" and write the
250       uncompressed data to the file "file1.txt".
251
252           use strict ;
253           use warnings ;
254           use IO::Uncompress::Unzip qw(unzip $UnzipError) ;
255
256           my $input = "file1.txt.zip";
257           my $output = "file1.txt";
258           unzip $input => $output
259               or die "unzip failed: $UnzipError\n";
260
261       To read from an existing Perl filehandle, $input, and write the
262       uncompressed data to a buffer, $buffer.
263
264           use strict ;
265           use warnings ;
266           use IO::Uncompress::Unzip qw(unzip $UnzipError) ;
267           use IO::File ;
268
269           my $input = new IO::File "<file1.txt.zip"
270               or die "Cannot open 'file1.txt.zip': $!\n" ;
271           my $buffer ;
272           unzip $input => \$buffer
273               or die "unzip failed: $UnzipError\n";
274
275       To uncompress all files in the directory "/my/home" that match
276       "*.txt.zip" and store the compressed data in the same directory
277
278           use strict ;
279           use warnings ;
280           use IO::Uncompress::Unzip qw(unzip $UnzipError) ;
281
282           unzip '</my/home/*.txt.zip>' => '</my/home/#1.txt>'
283               or die "unzip failed: $UnzipError\n";
284
285       and if you want to compress each file one at a time, this will do the
286       trick
287
288           use strict ;
289           use warnings ;
290           use IO::Uncompress::Unzip qw(unzip $UnzipError) ;
291
292           for my $input ( glob "/my/home/*.txt.zip" )
293           {
294               my $output = $input;
295               $output =~ s/.zip// ;
296               unzip $input => $output
297                   or die "Error compressing '$input': $UnzipError\n";
298           }
299

OO Interface

301   Constructor
302       The format of the constructor for IO::Uncompress::Unzip is shown below
303
304           my $z = new IO::Uncompress::Unzip $input [OPTS]
305               or die "IO::Uncompress::Unzip failed: $UnzipError\n";
306
307       Returns an "IO::Uncompress::Unzip" object on success and undef on
308       failure.  The variable $UnzipError will contain an error message on
309       failure.
310
311       If you are running Perl 5.005 or better the object, $z, returned from
312       IO::Uncompress::Unzip can be used exactly like an IO::File filehandle.
313       This means that all normal input file operations can be carried out
314       with $z.  For example, to read a line from a compressed file/buffer you
315       can use either of these forms
316
317           $line = $z->getline();
318           $line = <$z>;
319
320       The mandatory parameter $input is used to determine the source of the
321       compressed data. This parameter can take one of three forms.
322
323       A filename
324            If the $input parameter is a scalar, it is assumed to be a
325            filename. This file will be opened for reading and the compressed
326            data will be read from it.
327
328       A filehandle
329            If the $input parameter is a filehandle, the compressed data will
330            be read from it.  The string '-' can be used as an alias for
331            standard input.
332
333       A scalar reference
334            If $input is a scalar reference, the compressed data will be read
335            from $$output.
336
337   Constructor Options
338       The option names defined below are case insensitive and can be
339       optionally prefixed by a '-'.  So all of the following are valid
340
341           -AutoClose
342           -autoclose
343           AUTOCLOSE
344           autoclose
345
346       OPTS is a combination of the following options:
347
348       "AutoClose => 0|1"
349            This option is only valid when the $input parameter is a
350            filehandle. If specified, and the value is true, it will result in
351            the file being closed once either the "close" method is called or
352            the IO::Uncompress::Unzip object is destroyed.
353
354            This parameter defaults to 0.
355
356       "MultiStream => 0|1"
357            Treats the complete zip file/buffer as a single compressed data
358            stream. When reading in multi-stream mode each member of the zip
359            file/buffer will be uncompressed in turn until the end of the
360            file/buffer is encountered.
361
362            This parameter defaults to 0.
363
364       "Prime => $string"
365            This option will uncompress the contents of $string before
366            processing the input file/buffer.
367
368            This option can be useful when the compressed data is embedded in
369            another file/data structure and it is not possible to work out
370            where the compressed data begins without having to read the first
371            few bytes. If this is the case, the uncompression can be primed
372            with these bytes using this option.
373
374       "Transparent => 0|1"
375            If this option is set and the input file/buffer is not compressed
376            data, the module will allow reading of it anyway.
377
378            In addition, if the input file/buffer does contain compressed data
379            and there is non-compressed data immediately following it, setting
380            this option will make this module treat the whole file/bufffer as
381            a single data stream.
382
383            This option defaults to 1.
384
385       "BlockSize => $num"
386            When reading the compressed input data, IO::Uncompress::Unzip will
387            read it in blocks of $num bytes.
388
389            This option defaults to 4096.
390
391       "InputLength => $size"
392            When present this option will limit the number of compressed bytes
393            read from the input file/buffer to $size. This option can be used
394            in the situation where there is useful data directly after the
395            compressed data stream and you know beforehand the exact length of
396            the compressed data stream.
397
398            This option is mostly used when reading from a filehandle, in
399            which case the file pointer will be left pointing to the first
400            byte directly after the compressed data stream.
401
402            This option defaults to off.
403
404       "Append => 0|1"
405            This option controls what the "read" method does with uncompressed
406            data.
407
408            If set to 1, all uncompressed data will be appended to the output
409            parameter of the "read" method.
410
411            If set to 0, the contents of the output parameter of the "read"
412            method will be overwritten by the uncompressed data.
413
414            Defaults to 0.
415
416       "Strict => 0|1"
417            This option controls whether the extra checks defined below are
418            used when carrying out the decompression. When Strict is on, the
419            extra tests are carried out, when Strict is off they are not.
420
421            The default for this option is off.
422
423   Examples
424       TODO
425

Methods

427   read
428       Usage is
429
430           $status = $z->read($buffer)
431
432       Reads a block of compressed data (the size the the compressed block is
433       determined by the "Buffer" option in the constructor), uncompresses it
434       and writes any uncompressed data into $buffer. If the "Append"
435       parameter is set in the constructor, the uncompressed data will be
436       appended to the $buffer parameter. Otherwise $buffer will be
437       overwritten.
438
439       Returns the number of uncompressed bytes written to $buffer, zero if
440       eof or a negative number on error.
441
442   read
443       Usage is
444
445           $status = $z->read($buffer, $length)
446           $status = $z->read($buffer, $length, $offset)
447
448           $status = read($z, $buffer, $length)
449           $status = read($z, $buffer, $length, $offset)
450
451       Attempt to read $length bytes of uncompressed data into $buffer.
452
453       The main difference between this form of the "read" method and the
454       previous one, is that this one will attempt to return exactly $length
455       bytes. The only circumstances that this function will not is if end-of-
456       file or an IO error is encountered.
457
458       Returns the number of uncompressed bytes written to $buffer, zero if
459       eof or a negative number on error.
460
461   getline
462       Usage is
463
464           $line = $z->getline()
465           $line = <$z>
466
467       Reads a single line.
468
469       This method fully supports the use of of the variable $/ (or
470       $INPUT_RECORD_SEPARATOR or $RS when "English" is in use) to determine
471       what constitutes an end of line. Paragraph mode, record mode and file
472       slurp mode are all supported.
473
474   getc
475       Usage is
476
477           $char = $z->getc()
478
479       Read a single character.
480
481   ungetc
482       Usage is
483
484           $char = $z->ungetc($string)
485
486   inflateSync
487       Usage is
488
489           $status = $z->inflateSync()
490
491       TODO
492
493   getHeaderInfo
494       Usage is
495
496           $hdr  = $z->getHeaderInfo();
497           @hdrs = $z->getHeaderInfo();
498
499       This method returns either a hash reference (in scalar context) or a
500       list or hash references (in array context) that contains information
501       about each of the header fields in the compressed data stream(s).
502
503   tell
504       Usage is
505
506           $z->tell()
507           tell $z
508
509       Returns the uncompressed file offset.
510
511   eof
512       Usage is
513
514           $z->eof();
515           eof($z);
516
517       Returns true if the end of the compressed input stream has been
518       reached.
519
520   seek
521           $z->seek($position, $whence);
522           seek($z, $position, $whence);
523
524       Provides a sub-set of the "seek" functionality, with the restriction
525       that it is only legal to seek forward in the input file/buffer.  It is
526       a fatal error to attempt to seek backward.
527
528       The $whence parameter takes one the usual values, namely SEEK_SET,
529       SEEK_CUR or SEEK_END.
530
531       Returns 1 on success, 0 on failure.
532
533   binmode
534       Usage is
535
536           $z->binmode
537           binmode $z ;
538
539       This is a noop provided for completeness.
540
541   opened
542           $z->opened()
543
544       Returns true if the object currently refers to a opened file/buffer.
545
546   autoflush
547           my $prev = $z->autoflush()
548           my $prev = $z->autoflush(EXPR)
549
550       If the $z object is associated with a file or a filehandle, this method
551       returns the current autoflush setting for the underlying filehandle. If
552       "EXPR" is present, and is non-zero, it will enable flushing after every
553       write/print operation.
554
555       If $z is associated with a buffer, this method has no effect and always
556       returns "undef".
557
558       Note that the special variable $| cannot be used to set or retrieve the
559       autoflush setting.
560
561   input_line_number
562           $z->input_line_number()
563           $z->input_line_number(EXPR)
564
565       Returns the current uncompressed line number. If "EXPR" is present it
566       has the effect of setting the line number. Note that setting the line
567       number does not change the current position within the file/buffer
568       being read.
569
570       The contents of $/ are used to to determine what constitutes a line
571       terminator.
572
573   fileno
574           $z->fileno()
575           fileno($z)
576
577       If the $z object is associated with a file or a filehandle, "fileno"
578       will return the underlying file descriptor. Once the "close" method is
579       called "fileno" will return "undef".
580
581       If the $z object is is associated with a buffer, this method will
582       return "undef".
583
584   close
585           $z->close() ;
586           close $z ;
587
588       Closes the output file/buffer.
589
590       For most versions of Perl this method will be automatically invoked if
591       the IO::Uncompress::Unzip object is destroyed (either explicitly or by
592       the variable with the reference to the object going out of scope). The
593       exceptions are Perl versions 5.005 through 5.00504 and 5.8.0. In these
594       cases, the "close" method will be called automatically, but not until
595       global destruction of all live objects when the program is terminating.
596
597       Therefore, if you want your scripts to be able to run on all versions
598       of Perl, you should call "close" explicitly and not rely on automatic
599       closing.
600
601       Returns true on success, otherwise 0.
602
603       If the "AutoClose" option has been enabled when the
604       IO::Uncompress::Unzip object was created, and the object is associated
605       with a file, the underlying file will also be closed.
606
607   nextStream
608       Usage is
609
610           my $status = $z->nextStream();
611
612       Skips to the next compressed data stream in the input file/buffer. If a
613       new compressed data stream is found, the eof marker will be cleared and
614       $.  will be reset to 0.
615
616       Returns 1 if a new stream was found, 0 if none was found, and -1 if an
617       error was encountered.
618
619   trailingData
620       Usage is
621
622           my $data = $z->trailingData();
623
624       Returns the data, if any, that is present immediately after the
625       compressed data stream once uncompression is complete. It only makes
626       sense to call this method once the end of the compressed data stream
627       has been encountered.
628
629       This option can be used when there is useful information immediately
630       following the compressed data stream, and you don't know the length of
631       the compressed data stream.
632
633       If the input is a buffer, "trailingData" will return everything from
634       the end of the compressed data stream to the end of the buffer.
635
636       If the input is a filehandle, "trailingData" will return the data that
637       is left in the filehandle input buffer once the end of the compressed
638       data stream has been reached. You can then use the filehandle to read
639       the rest of the input file.
640
641       Don't bother using "trailingData" if the input is a filename.
642
643       If you know the length of the compressed data stream before you start
644       uncompressing, you can avoid having to use "trailingData" by setting
645       the "InputLength" option in the constructor.
646

Importing

648       No symbolic constants are required by this IO::Uncompress::Unzip at
649       present.
650
651       :all Imports "unzip" and $UnzipError.  Same as doing this
652
653                use IO::Uncompress::Unzip qw(unzip $UnzipError) ;
654

EXAMPLES

656   Working with Net::FTP
657       See IO::Uncompress::Unzip::FAQ
658

AUTHOR

686       This module was written by Paul Marquess, pmqs@cpan.org.
687

MODIFICATION HISTORY

689       See the Changes file.
690

COPYRIGHT AND LICENSE

692       Copyright (c) 2005-2010 Paul Marquess. All rights reserved.
693
694       This program is free software; you can redistribute it and/or modify it
695       under the same terms as Perl itself.
696
697
698
699perl v5.12.4                      2011-06-07        IO::Uncompress::Unzip(3pm)