1IO::Uncompress::AnyUncomPperrelssP(r3opgmr)ammers ReferIeOn:c:eUnGcuoimdperess::AnyUncompress(3pm)
2
6 IO::Uncompress::AnyUncompress - Uncompress gzip, zip, bzip2 or lzop
7 file/buffer
8
10 use IO::Uncompress::AnyUncompress qw(anyuncompress $AnyUncompressError) ;
11 my $status = anyuncompress $input => $output [,OPTS]
13 or die "anyuncompress failed: $AnyUncompressError\n";
14 my $z = new IO::Uncompress::AnyUncompress $input [OPTS]
16 or die "anyuncompress failed: $AnyUncompressError\n";
17 $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 $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 $AnyUncompressError ;
37 # IO::File mode
39 <$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
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 The formats supported are:
57 RFC 1950
59 RFC 1951 (optionally)
60 gzip (RFC 1952)
61 zip
62 bzip2
63 lzop
64 lzf
65 lzma
66 xz
67 The module will auto-detect which, if any, of the supported compression
69 formats is being used.
70
72 A top-level function, "anyuncompress", is provided to carry out "one-
73 shot" uncompression between buffers and/or files. For finer control
74 over the uncompression process, see the "OO Interface" section.
75 use IO::Uncompress::AnyUncompress qw(anyuncompress $AnyUncompressError) ;
77 anyuncompress $input => $output [,OPTS]
79 or die "anyuncompress failed: $AnyUncompressError\n";
80 The functional interface needs Perl5.005 or better.
82 anyuncompress $input => $output [, OPTS]
84 "anyuncompress" expects at least two parameters, $input and $output.
85 The $input parameter
87 The parameter, $input, is used to define the source of the compressed
89 data.
90 It can take one of the following forms:
92 A filename
94 If the $input parameter is a simple scalar, it is assumed to be a
95 filename. This file will be opened for reading and the input data
96 will be read from it.
97 A filehandle
99 If the $input parameter is a filehandle, the input data will be
100 read from it. The string '-' can be used as an alias for standard
101 input.
102 A scalar reference
104 If $input is a scalar reference, the input data will be read from
105 $$input.
106 An array reference
108 If $input is an array reference, each element in the array must be
109 a filename.
110 The input data will be read from each file in turn.
112 The complete array will be walked to ensure that it only contains
114 valid filenames before any data is uncompressed.
115 An Input FileGlob string
117 If $input is a string that is delimited by the characters "<" and
118 ">" "anyuncompress" will assume that it is an input fileglob
119 string. The input is the list of files that match the fileglob.
120 If the fileglob does not match any files ...
122 See File::GlobMapper for more details.
124 If the $input parameter is any other type, "undef" will be returned.
126 The $output parameter
128 The parameter $output is used to control the destination of the
130 uncompressed data. This parameter can take one of these forms.
131 A filename
133 If the $output parameter is a simple scalar, it is assumed to be a
134 filename. This file will be opened for writing and the
135 uncompressed data will be written to it.
136 A filehandle
138 If the $output parameter is a filehandle, the uncompressed data
139 will be written to it. The string '-' can be used as an alias for
140 standard output.
141 A scalar reference
143 If $output is a scalar reference, the uncompressed data will be
144 stored in $$output.
145 An Array Reference
147 If $output is an array reference, the uncompressed data will be
148 pushed onto the array.
149 An Output FileGlob
151 If $output is a string that is delimited by the characters "<" and
152 ">" "anyuncompress" will assume that it is an output fileglob
153 string. The output is the list of files that match the fileglob.
154 When $output is an fileglob string, $input must also be a fileglob
156 string. Anything else is an error.
157 If the $output parameter is any other type, "undef" will be returned.
159 Notes
161 When $input maps to multiple compressed files/buffers and $output is a
162 single file/buffer, after uncompression $output will contain a
163 concatenation of all the uncompressed data from each of the input
164 files/buffers.
165 Optional Parameters
167 Unless specified below, the optional parameters for "anyuncompress",
168 "OPTS", are the same as those used with the OO interface defined in the
169 "Constructor Options" section below.
170 "AutoClose => 0|1"
172 This option applies to any input or output data streams to
173 "anyuncompress" that are filehandles.
174 If "AutoClose" is specified, and the value is true, it will result
176 in all input and/or output filehandles being closed once
177 "anyuncompress" has completed.
178 This parameter defaults to 0.
180 "BinModeOut => 0|1"
182 When writing to a file or filehandle, set "binmode" before writing
183 to the file.
184 Defaults to 0.
186 "Append => 0|1"
188 The behaviour of this option is dependent on the type of output
189 data stream.
190 · A Buffer
192 If "Append" is enabled, all uncompressed data will be append
194 to the end of the output buffer. Otherwise the output buffer
195 will be cleared before any uncompressed data is written to
196 it.
197 · A Filename
199 If "Append" is enabled, the file will be opened in append
201 mode. Otherwise the contents of the file, if any, will be
202 truncated before any uncompressed data is written to it.
203 · A Filehandle
205 If "Append" is enabled, the filehandle will be positioned to
207 the end of the file via a call to "seek" before any
208 uncompressed data is written to it. Otherwise the file
209 pointer will not be moved.
210 When "Append" is specified, and set to true, it will append all
212 uncompressed data to the output data stream.
213 So when the output is a filehandle it will carry out a seek to the
215 eof before writing any uncompressed data. If the output is a
216 filename, it will be opened for appending. If the output is a
217 buffer, all uncompressed data will be appened to the existing
218 buffer.
219 Conversely when "Append" is not specified, or it is present and is
221 set to false, it will operate as follows.
222 When the output is a filename, it will truncate the contents of
224 the file before writing any uncompressed data. If the output is a
225 filehandle its position will not be changed. If the output is a
226 buffer, it will be wiped before any uncompressed data is output.
227 Defaults to 0.
229 "MultiStream => 0|1"
231 If the input file/buffer contains multiple compressed data
232 streams, this option will uncompress the whole lot as a single
233 data stream.
234 Defaults to 0.
236 "TrailingData => $scalar"
238 Returns the data, if any, that is present immediately after the
239 compressed data stream once uncompression is complete.
240 This option can be used when there is useful information
242 immediately following the compressed data stream, and you don't
243 know the length of the compressed data stream.
244 If the input is a buffer, "trailingData" will return everything
246 from the end of the compressed data stream to the end of the
247 buffer.
248 If the input is a filehandle, "trailingData" will return the data
250 that is left in the filehandle input buffer once the end of the
251 compressed data stream has been reached. You can then use the
252 filehandle to read the rest of the input file.
253 Don't bother using "trailingData" if the input is a filename.
255 If you know the length of the compressed data stream before you
257 start uncompressing, you can avoid having to use "trailingData" by
258 setting the "InputLength" option.
259 Examples
261 To read the contents of the file "file1.txt.Compressed" and write the
262 uncompressed data to the file "file1.txt".
263 use strict ;
265 use warnings ;
266 use IO::Uncompress::AnyUncompress qw(anyuncompress $AnyUncompressError) ;
267 my $input = "file1.txt.Compressed";
269 my $output = "file1.txt";
270 anyuncompress $input => $output
271 or die "anyuncompress failed: $AnyUncompressError\n";
272 To read from an existing Perl filehandle, $input, and write the
274 uncompressed data to a buffer, $buffer.
275 use strict ;
277 use warnings ;
278 use IO::Uncompress::AnyUncompress qw(anyuncompress $AnyUncompressError) ;
279 use IO::File ;
280 my $input = new IO::File "<file1.txt.Compressed"
282 or die "Cannot open 'file1.txt.Compressed': $!\n" ;
283 my $buffer ;
284 anyuncompress $input => \$buffer
285 or die "anyuncompress failed: $AnyUncompressError\n";
286 To uncompress all files in the directory "/my/home" that match
288 "*.txt.Compressed" and store the compressed data in the same directory
289 use strict ;
291 use warnings ;
292 use IO::Uncompress::AnyUncompress qw(anyuncompress $AnyUncompressError) ;
293 anyuncompress '</my/home/*.txt.Compressed>' => '</my/home/#1.txt>'
295 or die "anyuncompress failed: $AnyUncompressError\n";
296 and if you want to compress each file one at a time, this will do the
298 trick
299 use strict ;
301 use warnings ;
302 use IO::Uncompress::AnyUncompress qw(anyuncompress $AnyUncompressError) ;
303 for my $input ( glob "/my/home/*.txt.Compressed" )
305 {
306 my $output = $input;
307 $output =~ s/.Compressed// ;
308 anyuncompress $input => $output
309 or die "Error compressing '$input': $AnyUncompressError\n";
310 }
311
313 Constructor
314 The format of the constructor for IO::Uncompress::AnyUncompress is
315 shown below
316 my $z = new IO::Uncompress::AnyUncompress $input [OPTS]
318 or die "IO::Uncompress::AnyUncompress failed: $AnyUncompressError\n";
319 Returns an "IO::Uncompress::AnyUncompress" object on success and undef
321 on failure. The variable $AnyUncompressError will contain an error
322 message on failure.
323 If you are running Perl 5.005 or better the object, $z, returned from
325 IO::Uncompress::AnyUncompress can be used exactly like an IO::File
326 filehandle. This means that all normal input file operations can be
327 carried out with $z. For example, to read a line from a compressed
328 file/buffer you can use either of these forms
329 $line = $z->getline();
331 $line = <$z>;
332 The mandatory parameter $input is used to determine the source of the
334 compressed data. This parameter can take one of three forms.
335 A filename
337 If the $input parameter is a scalar, it is assumed to be a
338 filename. This file will be opened for reading and the compressed
339 data will be read from it.
340 A filehandle
342 If the $input parameter is a filehandle, the compressed data will
343 be read from it. The string '-' can be used as an alias for
344 standard input.
345 A scalar reference
347 If $input is a scalar reference, the compressed data will be read
348 from $$output.
349 Constructor Options
351 The option names defined below are case insensitive and can be
352 optionally prefixed by a '-'. So all of the following are valid
353 -AutoClose
355 -autoclose
356 AUTOCLOSE
357 autoclose
358 OPTS is a combination of the following options:
360 "AutoClose => 0|1"
362 This option is only valid when the $input parameter is a
363 filehandle. If specified, and the value is true, it will result in
364 the file being closed once either the "close" method is called or
365 the IO::Uncompress::AnyUncompress object is destroyed.
366 This parameter defaults to 0.
368 "MultiStream => 0|1"
370 Allows multiple concatenated compressed streams to be treated as a
371 single compressed stream. Decompression will stop once either the
372 end of the file/buffer is reached, an error is encountered
373 (premature eof, corrupt compressed data) or the end of a stream is
374 not immediately followed by the start of another stream.
375 This parameter defaults to 0.
377 "Prime => $string"
379 This option will uncompress the contents of $string before
380 processing the input file/buffer.
381 This option can be useful when the compressed data is embedded in
383 another file/data structure and it is not possible to work out
384 where the compressed data begins without having to read the first
385 few bytes. If this is the case, the uncompression can be primed
386 with these bytes using this option.
387 "Transparent => 0|1"
389 If this option is set and the input file/buffer is not compressed
390 data, the module will allow reading of it anyway.
391 In addition, if the input file/buffer does contain compressed data
393 and there is non-compressed data immediately following it, setting
394 this option will make this module treat the whole file/bufffer as
395 a single data stream.
396 This option defaults to 1.
398 "BlockSize => $num"
400 When reading the compressed input data,
401 IO::Uncompress::AnyUncompress will read it in blocks of $num
402 bytes.
403 This option defaults to 4096.
405 "InputLength => $size"
407 When present this option will limit the number of compressed bytes
408 read from the input file/buffer to $size. This option can be used
409 in the situation where there is useful data directly after the
410 compressed data stream and you know beforehand the exact length of
411 the compressed data stream.
412 This option is mostly used when reading from a filehandle, in
414 which case the file pointer will be left pointing to the first
415 byte directly after the compressed data stream.
416 This option defaults to off.
418 "Append => 0|1"
420 This option controls what the "read" method does with uncompressed
421 data.
422 If set to 1, all uncompressed data will be appended to the output
424 parameter of the "read" method.
425 If set to 0, the contents of the output parameter of the "read"
427 method will be overwritten by the uncompressed data.
428 Defaults to 0.
430 "Strict => 0|1"
432 This option controls whether the extra checks defined below are
433 used when carrying out the decompression. When Strict is on, the
434 extra tests are carried out, when Strict is off they are not.
435 The default for this option is off.
437 "RawInflate => 0|1"
439 When auto-detecting the compressed format, try to test for raw-
440 deflate (RFC 1951) content using the "IO::Uncompress::RawInflate"
441 module.
442 The reason this is not default behaviour is because RFC 1951
444 content can only be detected by attempting to uncompress it. This
445 process is error prone and can result is false positives.
446 Defaults to 0.
448 "UnLzma => 0|1"
450 When auto-detecting the compressed format, try to test for
451 lzma_alone content using the "IO::Uncompress::UnLzma" module.
452 The reason this is not default behaviour is because lzma_alone
454 content can only be detected by attempting to uncompress it. This
455 process is error prone and can result is false positives.
456 Defaults to 0.
458 Examples
460 TODO
461
463 read
464 Usage is
465 $status = $z->read($buffer)
467 Reads a block of compressed data (the size the the compressed block is
469 determined by the "Buffer" option in the constructor), uncompresses it
470 and writes any uncompressed data into $buffer. If the "Append"
471 parameter is set in the constructor, the uncompressed data will be
472 appended to the $buffer parameter. Otherwise $buffer will be
473 overwritten.
474 Returns the number of uncompressed bytes written to $buffer, zero if
476 eof or a negative number on error.
477 read
479 Usage is
480 $status = $z->read($buffer, $length)
482 $status = $z->read($buffer, $length, $offset)
483 $status = read($z, $buffer, $length)
485 $status = read($z, $buffer, $length, $offset)
486 Attempt to read $length bytes of uncompressed data into $buffer.
488 The main difference between this form of the "read" method and the
490 previous one, is that this one will attempt to return exactly $length
491 bytes. The only circumstances that this function will not is if end-of-
492 file or an IO error is encountered.
493 Returns the number of uncompressed bytes written to $buffer, zero if
495 eof or a negative number on error.
496 getline
498 Usage is
499 $line = $z->getline()
501 $line = <$z>
502 Reads a single line.
504 This method fully supports the use of of the variable $/ (or
506 $INPUT_RECORD_SEPARATOR or $RS when "English" is in use) to determine
507 what constitutes an end of line. Paragraph mode, record mode and file
508 slurp mode are all supported.
509 getc
511 Usage is
512 $char = $z->getc()
514 Read a single character.
516 ungetc
518 Usage is
519 $char = $z->ungetc($string)
521 getHeaderInfo
523 Usage is
524 $hdr = $z->getHeaderInfo();
526 @hdrs = $z->getHeaderInfo();
527 This method returns either a hash reference (in scalar context) or a
529 list or hash references (in array context) that contains information
530 about each of the header fields in the compressed data stream(s).
531 tell
533 Usage is
534 $z->tell()
536 tell $z
537 Returns the uncompressed file offset.
539 eof
541 Usage is
542 $z->eof();
544 eof($z);
545 Returns true if the end of the compressed input stream has been
547 reached.
548 seek
550 $z->seek($position, $whence);
551 seek($z, $position, $whence);
552 Provides a sub-set of the "seek" functionality, with the restriction
554 that it is only legal to seek forward in the input file/buffer. It is
555 a fatal error to attempt to seek backward.
556 The $whence parameter takes one the usual values, namely SEEK_SET,
558 SEEK_CUR or SEEK_END.
559 Returns 1 on success, 0 on failure.
561 binmode
563 Usage is
564 $z->binmode
566 binmode $z ;
567 This is a noop provided for completeness.
569 opened
571 $z->opened()
572 Returns true if the object currently refers to a opened file/buffer.
574 autoflush
576 my $prev = $z->autoflush()
577 my $prev = $z->autoflush(EXPR)
578 If the $z object is associated with a file or a filehandle, this method
580 returns the current autoflush setting for the underlying filehandle. If
581 "EXPR" is present, and is non-zero, it will enable flushing after every
582 write/print operation.
583 If $z is associated with a buffer, this method has no effect and always
585 returns "undef".
586 Note that the special variable $| cannot be used to set or retrieve the
588 autoflush setting.
589 input_line_number
591 $z->input_line_number()
592 $z->input_line_number(EXPR)
593 Returns the current uncompressed line number. If "EXPR" is present it
595 has the effect of setting the line number. Note that setting the line
596 number does not change the current position within the file/buffer
597 being read.
598 The contents of $/ are used to to determine what constitutes a line
600 terminator.
601 fileno
603 $z->fileno()
604 fileno($z)
605 If the $z object is associated with a file or a filehandle, "fileno"
607 will return the underlying file descriptor. Once the "close" method is
608 called "fileno" will return "undef".
609 If the $z object is is associated with a buffer, this method will
611 return "undef".
612 close
614 $z->close() ;
615 close $z ;
616 Closes the output file/buffer.
618 For most versions of Perl this method will be automatically invoked if
620 the IO::Uncompress::AnyUncompress object is destroyed (either
621 explicitly or by the variable with the reference to the object going
622 out of scope). The exceptions are Perl versions 5.005 through 5.00504
623 and 5.8.0. In these cases, the "close" method will be called
624 automatically, but not until global destruction of all live objects
625 when the program is terminating.
626 Therefore, if you want your scripts to be able to run on all versions
628 of Perl, you should call "close" explicitly and not rely on automatic
629 closing.
630 Returns true on success, otherwise 0.
632 If the "AutoClose" option has been enabled when the
634 IO::Uncompress::AnyUncompress object was created, and the object is
635 associated with a file, the underlying file will also be closed.
636 nextStream
638 Usage is
639 my $status = $z->nextStream();
641 Skips to the next compressed data stream in the input file/buffer. If a
643 new compressed data stream is found, the eof marker will be cleared and
644 $. will be reset to 0.
645 Returns 1 if a new stream was found, 0 if none was found, and -1 if an
647 error was encountered.
648 trailingData
650 Usage is
651 my $data = $z->trailingData();
653 Returns the data, if any, that is present immediately after the
655 compressed data stream once uncompression is complete. It only makes
656 sense to call this method once the end of the compressed data stream
657 has been encountered.
658 This option can be used when there is useful information immediately
660 following the compressed data stream, and you don't know the length of
661 the compressed data stream.
662 If the input is a buffer, "trailingData" will return everything from
664 the end of the compressed data stream to the end of the buffer.
665 If the input is a filehandle, "trailingData" will return the data that
667 is left in the filehandle input buffer once the end of the compressed
668 data stream has been reached. You can then use the filehandle to read
669 the rest of the input file.
670 Don't bother using "trailingData" if the input is a filename.
672 If you know the length of the compressed data stream before you start
674 uncompressing, you can avoid having to use "trailingData" by setting
675 the "InputLength" option in the constructor.
676
678 No symbolic constants are required by this
679 IO::Uncompress::AnyUncompress at present.
680 :all Imports "anyuncompress" and $AnyUncompressError. Same as doing
682 this
683 use IO::Uncompress::AnyUncompress qw(anyuncompress $AnyUncompressError) ;
685
688 Compress::Zlib, IO::Compress::Gzip, IO::Uncompress::Gunzip,
689 IO::Compress::Deflate, IO::Uncompress::Inflate,
690 IO::Compress::RawDeflate, IO::Uncompress::RawInflate,
691 IO::Compress::Bzip2, IO::Uncompress::Bunzip2, IO::Compress::Lzma,
692 IO::Uncompress::UnLzma, IO::Compress::Xz, IO::Uncompress::UnXz,
693 IO::Compress::Lzop, IO::Uncompress::UnLzop, IO::Compress::Lzf,
694 IO::Uncompress::UnLzf, IO::Uncompress::AnyInflate
695 Compress::Zlib::FAQ
697 File::GlobMapper, Archive::Zip, Archive::Tar, IO::Zlib
699
701 This module was written by Paul Marquess, pmqs@cpan.org.
702
704 See the Changes file.
705
707 Copyright (c) 2005-2010 Paul Marquess. All rights reserved.
708 This program is free software; you can redistribute it and/or modify it
710 under the same terms as Perl itself.
711perl v5.12.4 2011-06-07IO::Uncompress::AnyUncompress(3pm)