1IO::Uncompress::AnyUncoUmsperresCso(n3t)ributed Perl DocIuOm:e:nUtnactoimopnress::AnyUncompress(3)
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NAME

6       IO::Uncompress::AnyUncompress - Uncompress gzip, zip, bzip2, zstd, xz,
7       lzma, lzip, lzf or lzop file/buffer
8

SYNOPSIS

10           use IO::Uncompress::AnyUncompress qw(anyuncompress $AnyUncompressError) ;
11
12           my $status = anyuncompress $input => $output [,OPTS]
13               or die "anyuncompress failed: $AnyUncompressError\n";
14
15           my $z = IO::Uncompress::AnyUncompress->new( $input [OPTS] )
16               or die "anyuncompress failed: $AnyUncompressError\n";
17
18           $status = $z->read($buffer)
19           $status = $z->read($buffer, $length)
20           $status = $z->read($buffer, $length, $offset)
21           $line = $z->getline()
22           $char = $z->getc()
23           $char = $z->ungetc()
24           $char = $z->opened()
25
26           $data = $z->trailingData()
27           $status = $z->nextStream()
28           $data = $z->getHeaderInfo()
29           $z->tell()
30           $z->seek($position, $whence)
31           $z->binmode()
32           $z->fileno()
33           $z->eof()
34           $z->close()
35
36           $AnyUncompressError ;
37
38           # IO::File mode
39
40           <$z>
41           read($z, $buffer);
42           read($z, $buffer, $length);
43           read($z, $buffer, $length, $offset);
44           tell($z)
45           seek($z, $position, $whence)
46           binmode($z)
47           fileno($z)
48           eof($z)
49           close($z)
50

DESCRIPTION

52       This module provides a Perl interface that allows the reading of
53       files/buffers that have been compressed with a variety of compression
54       libraries.
55
56       The formats supported are:
57
58       RFC 1950
59       RFC 1951 (optionally)
60       gzip (RFC 1952)
61       zip
62       zstd (Zstandard)
63       bzip2
64       lzop
65       lzf
66       lzma
67       lzip
68       xz
69
70       The module will auto-detect which, if any, of the supported compression
71       formats is being used.
72

Functional Interface

74       A top-level function, "anyuncompress", is provided to carry out "one-
75       shot" uncompression between buffers and/or files. For finer control
76       over the uncompression process, see the "OO Interface" section.
77
78           use IO::Uncompress::AnyUncompress qw(anyuncompress $AnyUncompressError) ;
79
80           anyuncompress $input_filename_or_reference => $output_filename_or_reference [,OPTS]
81               or die "anyuncompress failed: $AnyUncompressError\n";
82
83       The functional interface needs Perl5.005 or better.
84
85   anyuncompress $input_filename_or_reference => $output_filename_or_reference
86       [, OPTS]
87       "anyuncompress" expects at least two parameters,
88       $input_filename_or_reference and $output_filename_or_reference and zero
89       or more optional parameters (see "Optional Parameters")
90
91       The $input_filename_or_reference parameter
92
93       The parameter, $input_filename_or_reference, is used to define the
94       source of the compressed data.
95
96       It can take one of the following forms:
97
98       A filename
99            If the $input_filename_or_reference parameter is a simple scalar,
100            it is assumed to be a filename. This file will be opened for
101            reading and the input data will be read from it.
102
103       A filehandle
104            If the $input_filename_or_reference parameter is a filehandle, the
105            input data will be read from it.  The string '-' can be used as an
106            alias for standard input.
107
108       A scalar reference
109            If $input_filename_or_reference is a scalar reference, the input
110            data will be read from $$input_filename_or_reference.
111
112       An array reference
113            If $input_filename_or_reference is an array reference, each
114            element in the array must be a filename.
115
116            The input data will be read from each file in turn.
117
118            The complete array will be walked to ensure that it only contains
119            valid filenames before any data is uncompressed.
120
121       An Input FileGlob string
122            If $input_filename_or_reference is a string that is delimited by
123            the characters "<" and ">" "anyuncompress" will assume that it is
124            an input fileglob string. The input is the list of files that
125            match the fileglob.
126
127            See File::GlobMapper for more details.
128
129       If the $input_filename_or_reference parameter is any other type,
130       "undef" will be returned.
131
132       The $output_filename_or_reference parameter
133
134       The parameter $output_filename_or_reference is used to control the
135       destination of the uncompressed data. This parameter can take one of
136       these forms.
137
138       A filename
139            If the $output_filename_or_reference parameter is a simple scalar,
140            it is assumed to be a filename.  This file will be opened for
141            writing and the uncompressed data will be written to it.
142
143       A filehandle
144            If the $output_filename_or_reference parameter is a filehandle,
145            the uncompressed data will be written to it.  The string '-' can
146            be used as an alias for standard output.
147
148       A scalar reference
149            If $output_filename_or_reference is a scalar reference, the
150            uncompressed data will be stored in
151            $$output_filename_or_reference.
152
153       An Array Reference
154            If $output_filename_or_reference is an array reference, the
155            uncompressed data will be pushed onto the array.
156
157       An Output FileGlob
158            If $output_filename_or_reference is a string that is delimited by
159            the characters "<" and ">" "anyuncompress" will assume that it is
160            an output fileglob string. The output is the list of files that
161            match the fileglob.
162
163            When $output_filename_or_reference is an fileglob string,
164            $input_filename_or_reference must also be a fileglob string.
165            Anything else is an error.
166
167            See File::GlobMapper for more details.
168
169       If the $output_filename_or_reference parameter is any other type,
170       "undef" will be returned.
171
172   Notes
173       When $input_filename_or_reference maps to multiple compressed
174       files/buffers and $output_filename_or_reference is a single
175       file/buffer, after uncompression $output_filename_or_reference will
176       contain a concatenation of all the uncompressed data from each of the
177       input files/buffers.
178
179   Optional Parameters
180       The optional parameters for the one-shot function "anyuncompress" are
181       (for the most part) identical to those used with the OO interface
182       defined in the "Constructor Options" section. The exceptions are listed
183       below
184
185       "AutoClose => 0|1"
186            This option applies to any input or output data streams to
187            "anyuncompress" that are filehandles.
188
189            If "AutoClose" is specified, and the value is true, it will result
190            in all input and/or output filehandles being closed once
191            "anyuncompress" has completed.
192
193            This parameter defaults to 0.
194
195       "BinModeOut => 0|1"
196            This option is now a no-op. All files will be written  in binmode.
197
198       "Append => 0|1"
199            The behaviour of this option is dependent on the type of output
200            data stream.
201
202            •    A Buffer
203
204                 If "Append" is enabled, all uncompressed data will be append
205                 to the end of the output buffer. Otherwise the output buffer
206                 will be cleared before any uncompressed data is written to
207                 it.
208
209            •    A Filename
210
211                 If "Append" is enabled, the file will be opened in append
212                 mode. Otherwise the contents of the file, if any, will be
213                 truncated before any uncompressed data is written to it.
214
215            •    A Filehandle
216
217                 If "Append" is enabled, the filehandle will be positioned to
218                 the end of the file via a call to "seek" before any
219                 uncompressed data is written to it.  Otherwise the file
220                 pointer will not be moved.
221
222            When "Append" is specified, and set to true, it will append all
223            uncompressed data to the output data stream.
224
225            So when the output is a filehandle it will carry out a seek to the
226            eof before writing any uncompressed data. If the output is a
227            filename, it will be opened for appending. If the output is a
228            buffer, all uncompressed data will be appended to the existing
229            buffer.
230
231            Conversely when "Append" is not specified, or it is present and is
232            set to false, it will operate as follows.
233
234            When the output is a filename, it will truncate the contents of
235            the file before writing any uncompressed data. If the output is a
236            filehandle its position will not be changed. If the output is a
237            buffer, it will be wiped before any uncompressed data is output.
238
239            Defaults to 0.
240
241       "MultiStream => 0|1"
242            If the input file/buffer contains multiple compressed data
243            streams, this option will uncompress the whole lot as a single
244            data stream.
245
246            Defaults to 0.
247
248       "TrailingData => $scalar"
249            Returns the data, if any, that is present immediately after the
250            compressed data stream once uncompression is complete.
251
252            This option can be used when there is useful information
253            immediately following the compressed data stream, and you don't
254            know the length of the compressed data stream.
255
256            If the input is a buffer, "trailingData" will return everything
257            from the end of the compressed data stream to the end of the
258            buffer.
259
260            If the input is a filehandle, "trailingData" will return the data
261            that is left in the filehandle input buffer once the end of the
262            compressed data stream has been reached. You can then use the
263            filehandle to read the rest of the input file.
264
265            Don't bother using "trailingData" if the input is a filename.
266
267            If you know the length of the compressed data stream before you
268            start uncompressing, you can avoid having to use "trailingData" by
269            setting the "InputLength" option.
270
271   Examples
272       To read the contents of the file "file1.txt.Compressed" and write the
273       uncompressed data to the file "file1.txt".
274
275           use strict ;
276           use warnings ;
277           use IO::Uncompress::AnyUncompress qw(anyuncompress $AnyUncompressError) ;
278
279           my $input = "file1.txt.Compressed";
280           my $output = "file1.txt";
281           anyuncompress $input => $output
282               or die "anyuncompress failed: $AnyUncompressError\n";
283
284       To read from an existing Perl filehandle, $input, and write the
285       uncompressed data to a buffer, $buffer.
286
287           use strict ;
288           use warnings ;
289           use IO::Uncompress::AnyUncompress qw(anyuncompress $AnyUncompressError) ;
290           use IO::File ;
291
292           my $input = IO::File->new( "<file1.txt.Compressed" )
293               or die "Cannot open 'file1.txt.Compressed': $!\n" ;
294           my $buffer ;
295           anyuncompress $input => \$buffer
296               or die "anyuncompress failed: $AnyUncompressError\n";
297
298       To uncompress all files in the directory "/my/home" that match
299       "*.txt.Compressed" and store the compressed data in the same directory
300
301           use strict ;
302           use warnings ;
303           use IO::Uncompress::AnyUncompress qw(anyuncompress $AnyUncompressError) ;
304
305           anyuncompress '</my/home/*.txt.Compressed>' => '</my/home/#1.txt>'
306               or die "anyuncompress failed: $AnyUncompressError\n";
307
308       and if you want to compress each file one at a time, this will do the
309       trick
310
311           use strict ;
312           use warnings ;
313           use IO::Uncompress::AnyUncompress qw(anyuncompress $AnyUncompressError) ;
314
315           for my $input ( glob "/my/home/*.txt.Compressed" )
316           {
317               my $output = $input;
318               $output =~ s/.Compressed// ;
319               anyuncompress $input => $output
320                   or die "Error compressing '$input': $AnyUncompressError\n";
321           }
322

OO Interface

324   Constructor
325       The format of the constructor for IO::Uncompress::AnyUncompress is
326       shown below
327
328           my $z = IO::Uncompress::AnyUncompress->new( $input [OPTS] )
329               or die "IO::Uncompress::AnyUncompress failed: $AnyUncompressError\n";
330
331       Returns an "IO::Uncompress::AnyUncompress" object on success and undef
332       on failure.  The variable $AnyUncompressError will contain an error
333       message on failure.
334
335       If you are running Perl 5.005 or better the object, $z, returned from
336       IO::Uncompress::AnyUncompress can be used exactly like an IO::File
337       filehandle.  This means that all normal input file operations can be
338       carried out with $z.  For example, to read a line from a compressed
339       file/buffer you can use either of these forms
340
341           $line = $z->getline();
342           $line = <$z>;
343
344       The mandatory parameter $input is used to determine the source of the
345       compressed data. This parameter can take one of three forms.
346
347       A filename
348            If the $input parameter is a scalar, it is assumed to be a
349            filename. This file will be opened for reading and the compressed
350            data will be read from it.
351
352       A filehandle
353            If the $input parameter is a filehandle, the compressed data will
354            be read from it.  The string '-' can be used as an alias for
355            standard input.
356
357       A scalar reference
358            If $input is a scalar reference, the compressed data will be read
359            from $$input.
360
361   Constructor Options
362       The option names defined below are case insensitive and can be
363       optionally prefixed by a '-'.  So all of the following are valid
364
365           -AutoClose
366           -autoclose
367           AUTOCLOSE
368           autoclose
369
370       OPTS is a combination of the following options:
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::AnyUncompress object is destroyed.
377
378            This parameter defaults to 0.
379
380       "MultiStream => 0|1"
381            Allows multiple concatenated compressed streams to be treated as a
382            single compressed stream. Decompression will stop once either the
383            end of the file/buffer is reached, an error is encountered
384            (premature eof, corrupt compressed data) or the end of a stream is
385            not immediately followed by the start of another stream.
386
387            This parameter defaults to 0.
388
389       "Prime => $string"
390            This option will uncompress the contents of $string before
391            processing the input file/buffer.
392
393            This option can be useful when the compressed data is embedded in
394            another file/data structure and it is not possible to work out
395            where the compressed data begins without having to read the first
396            few bytes. If this is the case, the uncompression can be primed
397            with these bytes using this option.
398
399       "Transparent => 0|1"
400            If this option is set and the input file/buffer is not compressed
401            data, the module will allow reading of it anyway.
402
403            In addition, if the input file/buffer does contain compressed data
404            and there is non-compressed data immediately following it, setting
405            this option will make this module treat the whole file/buffer as a
406            single data stream.
407
408            This option defaults to 1.
409
410       "BlockSize => $num"
411            When reading the compressed input data,
412            IO::Uncompress::AnyUncompress will read it in blocks of $num
413            bytes.
414
415            This option defaults to 4096.
416
417       "InputLength => $size"
418            When present this option will limit the number of compressed bytes
419            read from the input file/buffer to $size. This option can be used
420            in the situation where there is useful data directly after the
421            compressed data stream and you know beforehand the exact length of
422            the compressed data stream.
423
424            This option is mostly used when reading from a filehandle, in
425            which case the file pointer will be left pointing to the first
426            byte directly after the compressed data stream.
427
428            This option defaults to off.
429
430       "Append => 0|1"
431            This option controls what the "read" method does with uncompressed
432            data.
433
434            If set to 1, all uncompressed data will be appended to the output
435            parameter of the "read" method.
436
437            If set to 0, the contents of the output parameter of the "read"
438            method will be overwritten by the uncompressed data.
439
440            Defaults to 0.
441
442       "Strict => 0|1"
443            This option controls whether the extra checks defined below are
444            used when carrying out the decompression. When Strict is on, the
445            extra tests are carried out, when Strict is off they are not.
446
447            The default for this option is off.
448
449       "RawInflate => 0|1"
450            When auto-detecting the compressed format, try to test for raw-
451            deflate (RFC 1951) content using the "IO::Uncompress::RawInflate"
452            module.
453
454            The reason this is not default behaviour is because RFC 1951
455            content can only be detected by attempting to uncompress it. This
456            process is error prone and can result is false positives.
457
458            Defaults to 0.
459
460       "UnLzma => 0|1"
461            When auto-detecting the compressed format, try to test for
462            lzma_alone content using the "IO::Uncompress::UnLzma" module.
463
464            The reason this is not default behaviour is because lzma_alone
465            content can only be detected by attempting to uncompress it. This
466            process is error prone and can result is false positives.
467
468            Defaults to 0.
469
470   Examples
471       TODO
472

Methods

474   read
475       Usage is
476
477           $status = $z->read($buffer)
478
479       Reads a block of compressed data (the size of the compressed block is
480       determined by the "Buffer" option in the constructor), uncompresses it
481       and writes any uncompressed data into $buffer. If the "Append"
482       parameter is set in the constructor, the uncompressed data will be
483       appended to the $buffer parameter. Otherwise $buffer will be
484       overwritten.
485
486       Returns the number of uncompressed bytes written to $buffer, zero if
487       eof or a negative number on error.
488
489   read
490       Usage is
491
492           $status = $z->read($buffer, $length)
493           $status = $z->read($buffer, $length, $offset)
494
495           $status = read($z, $buffer, $length)
496           $status = read($z, $buffer, $length, $offset)
497
498       Attempt to read $length bytes of uncompressed data into $buffer.
499
500       The main difference between this form of the "read" method and the
501       previous one, is that this one will attempt to return exactly $length
502       bytes. The only circumstances that this function will not is if end-of-
503       file or an IO error is encountered.
504
505       Returns the number of uncompressed bytes written to $buffer, zero if
506       eof or a negative number on error.
507
508   getline
509       Usage is
510
511           $line = $z->getline()
512           $line = <$z>
513
514       Reads a single line.
515
516       This method fully supports the use of the variable $/ (or
517       $INPUT_RECORD_SEPARATOR or $RS when "English" is in use) to determine
518       what constitutes an end of line. Paragraph mode, record mode and file
519       slurp mode are all supported.
520
521   getc
522       Usage is
523
524           $char = $z->getc()
525
526       Read a single character.
527
528   ungetc
529       Usage is
530
531           $char = $z->ungetc($string)
532
533   getHeaderInfo
534       Usage is
535
536           $hdr  = $z->getHeaderInfo();
537           @hdrs = $z->getHeaderInfo();
538
539       This method returns either a hash reference (in scalar context) or a
540       list or hash references (in array context) that contains information
541       about each of the header fields in the compressed data stream(s).
542
543   tell
544       Usage is
545
546           $z->tell()
547           tell $z
548
549       Returns the uncompressed file offset.
550
551   eof
552       Usage is
553
554           $z->eof();
555           eof($z);
556
557       Returns true if the end of the compressed input stream has been
558       reached.
559
560   seek
561           $z->seek($position, $whence);
562           seek($z, $position, $whence);
563
564       Provides a sub-set of the "seek" functionality, with the restriction
565       that it is only legal to seek forward in the input file/buffer.  It is
566       a fatal error to attempt to seek backward.
567
568       Note that the implementation of "seek" in this module does not provide
569       true random access to a compressed file/buffer. It  works by
570       uncompressing data from the current offset in the file/buffer until it
571       reaches the uncompressed offset specified in the parameters to "seek".
572       For very small files this may be acceptable behaviour. For large files
573       it may cause an unacceptable delay.
574
575       The $whence parameter takes one the usual values, namely SEEK_SET,
576       SEEK_CUR or SEEK_END.
577
578       Returns 1 on success, 0 on failure.
579
580   binmode
581       Usage is
582
583           $z->binmode
584           binmode $z ;
585
586       This is a noop provided for completeness.
587
588   opened
589           $z->opened()
590
591       Returns true if the object currently refers to a opened file/buffer.
592
593   autoflush
594           my $prev = $z->autoflush()
595           my $prev = $z->autoflush(EXPR)
596
597       If the $z object is associated with a file or a filehandle, this method
598       returns the current autoflush setting for the underlying filehandle. If
599       "EXPR" is present, and is non-zero, it will enable flushing after every
600       write/print operation.
601
602       If $z is associated with a buffer, this method has no effect and always
603       returns "undef".
604
605       Note that the special variable $| cannot be used to set or retrieve the
606       autoflush setting.
607
608   input_line_number
609           $z->input_line_number()
610           $z->input_line_number(EXPR)
611
612       Returns the current uncompressed line number. If "EXPR" is present it
613       has the effect of setting the line number. Note that setting the line
614       number does not change the current position within the file/buffer
615       being read.
616
617       The contents of $/ are used to determine what constitutes a line
618       terminator.
619
620   fileno
621           $z->fileno()
622           fileno($z)
623
624       If the $z object is associated with a file or a filehandle, "fileno"
625       will return the underlying file descriptor. Once the "close" method is
626       called "fileno" will return "undef".
627
628       If the $z object is associated with a buffer, this method will return
629       "undef".
630
631   close
632           $z->close() ;
633           close $z ;
634
635       Closes the output file/buffer.
636
637       For most versions of Perl this method will be automatically invoked if
638       the IO::Uncompress::AnyUncompress object is destroyed (either
639       explicitly or by the variable with the reference to the object going
640       out of scope). The exceptions are Perl versions 5.005 through 5.00504
641       and 5.8.0. In these cases, the "close" method will be called
642       automatically, but not until global destruction of all live objects
643       when the program is terminating.
644
645       Therefore, if you want your scripts to be able to run on all versions
646       of Perl, you should call "close" explicitly and not rely on automatic
647       closing.
648
649       Returns true on success, otherwise 0.
650
651       If the "AutoClose" option has been enabled when the
652       IO::Uncompress::AnyUncompress object was created, and the object is
653       associated with a file, the underlying file will also be closed.
654
655   nextStream
656       Usage is
657
658           my $status = $z->nextStream();
659
660       Skips to the next compressed data stream in the input file/buffer. If a
661       new compressed data stream is found, the eof marker will be cleared and
662       $.  will be reset to 0.
663
664       Returns 1 if a new stream was found, 0 if none was found, and -1 if an
665       error was encountered.
666
667   trailingData
668       Usage is
669
670           my $data = $z->trailingData();
671
672       Returns the data, if any, that is present immediately after the
673       compressed data stream once uncompression is complete. It only makes
674       sense to call this method once the end of the compressed data stream
675       has been encountered.
676
677       This option can be used when there is useful information immediately
678       following the compressed data stream, and you don't know the length of
679       the compressed data stream.
680
681       If the input is a buffer, "trailingData" will return everything from
682       the end of the compressed data stream to the end of the buffer.
683
684       If the input is a filehandle, "trailingData" will return the data that
685       is left in the filehandle input buffer once the end of the compressed
686       data stream has been reached. You can then use the filehandle to read
687       the rest of the input file.
688
689       Don't bother using "trailingData" if the input is a filename.
690
691       If you know the length of the compressed data stream before you start
692       uncompressing, you can avoid having to use "trailingData" by setting
693       the "InputLength" option in the constructor.
694

Importing

696       No symbolic constants are required by IO::Uncompress::AnyUncompress at
697       present.
698
699       :all Imports "anyuncompress" and $AnyUncompressError.  Same as doing
700            this
701
702                use IO::Uncompress::AnyUncompress qw(anyuncompress $AnyUncompressError) ;
703

EXAMPLES

SUPPORT

706       General feedback/questions/bug reports should be sent to
707       <https://github.com/pmqs/IO-Compress/issues> (preferred) or
708       <https://rt.cpan.org/Public/Dist/Display.html?Name=IO-Compress>.
709

SEE ALSO

711       Compress::Zlib, IO::Compress::Gzip, IO::Uncompress::Gunzip,
712       IO::Compress::Deflate, IO::Uncompress::Inflate,
713       IO::Compress::RawDeflate, IO::Uncompress::RawInflate,
714       IO::Compress::Bzip2, IO::Uncompress::Bunzip2, IO::Compress::Lzma,
715       IO::Uncompress::UnLzma, IO::Compress::Xz, IO::Uncompress::UnXz,
716       IO::Compress::Lzip, IO::Uncompress::UnLzip, IO::Compress::Lzop,
717       IO::Uncompress::UnLzop, IO::Compress::Lzf, IO::Uncompress::UnLzf,
718       IO::Compress::Zstd, IO::Uncompress::UnZstd, IO::Uncompress::AnyInflate
719
720       IO::Compress::FAQ
721
722       File::GlobMapper, Archive::Zip, Archive::Tar, IO::Zlib
723

AUTHOR

725       This module was written by Paul Marquess, "pmqs@cpan.org".
726

MODIFICATION HISTORY

728       See the Changes file.
729
731       Copyright (c) 2005-2021 Paul Marquess. All rights reserved.
732
733       This program is free software; you can redistribute it and/or modify it
734       under the same terms as Perl itself.
735
736
737
738perl v5.34.0                      2022-01-21  IO::Uncompress::AnyUncompress(3)
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