1IO::Uncompress::AnyInflaPteer(l3pPmr)ogrammers ReferencIeO:G:uUindceompress::AnyInflate(3pm)
2
6 IO::Uncompress::AnyInflate - Uncompress zlib-based (zip, gzip)
7 file/buffer
8
10 use IO::Uncompress::AnyInflate qw(anyinflate $AnyInflateError) ;
11 my $status = anyinflate $input => $output [,OPTS]
13 or die "anyinflate failed: $AnyInflateError\n";
14 my $z = new IO::Uncompress::AnyInflate $input [OPTS]
16 or die "anyinflate failed: $AnyInflateError\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 $status = $z->inflateSync()
27 $data = $z->trailingData()
29 $status = $z->nextStream()
30 $data = $z->getHeaderInfo()
31 $z->tell()
32 $z->seek($position, $whence)
33 $z->binmode()
34 $z->fileno()
35 $z->eof()
36 $z->close()
37 $AnyInflateError ;
39 # IO::File mode
41 <$z>
43 read($z, $buffer);
44 read($z, $buffer, $length);
45 read($z, $buffer, $length, $offset);
46 tell($z)
47 seek($z, $position, $whence)
48 binmode($z)
49 fileno($z)
50 eof($z)
51 close($z)
52
54 This module provides a Perl interface that allows the reading of
55 files/buffers that have been compressed in a number of formats that use
56 the zlib compression library.
57 The formats supported are
59 RFC 1950
61 RFC 1951 (optionally)
62 gzip (RFC 1952)
63 zip
64 The module will auto-detect which, if any, of the supported compression
66 formats is being used.
67
69 A top-level function, "anyinflate", is provided to carry out "one-shot"
70 uncompression between buffers and/or files. For finer control over the
71 uncompression process, see the "OO Interface" section.
72 use IO::Uncompress::AnyInflate qw(anyinflate $AnyInflateError) ;
74 anyinflate $input => $output [,OPTS]
76 or die "anyinflate failed: $AnyInflateError\n";
77 The functional interface needs Perl5.005 or better.
79 anyinflate $input => $output [, OPTS]
81 "anyinflate" expects at least two parameters, $input and $output.
82 The $input parameter
84 The parameter, $input, is used to define the source of the compressed
86 data.
87 It can take one of the following forms:
89 A filename
91 If the $input parameter is a simple scalar, it is assumed to be a
92 filename. This file will be opened for reading and the input data
93 will be read from it.
94 A filehandle
96 If the $input parameter is a filehandle, the input data will be
97 read from it. The string '-' can be used as an alias for standard
98 input.
99 A scalar reference
101 If $input is a scalar reference, the input data will be read from
102 $$input.
103 An array reference
105 If $input is an array reference, each element in the array must be
106 a filename.
107 The input data will be read from each file in turn.
109 The complete array will be walked to ensure that it only contains
111 valid filenames before any data is uncompressed.
112 An Input FileGlob string
114 If $input is a string that is delimited by the characters "<" and
115 ">" "anyinflate" will assume that it is an input fileglob string.
116 The input is the list of files that match the fileglob.
117 If the fileglob does not match any files ...
119 See File::GlobMapper for more details.
121 If the $input parameter is any other type, "undef" will be returned.
123 The $output parameter
125 The parameter $output is used to control the destination of the
127 uncompressed data. This parameter can take one of these forms.
128 A filename
130 If the $output parameter is a simple scalar, it is assumed to be a
131 filename. This file will be opened for writing and the
132 uncompressed data will be written to it.
133 A filehandle
135 If the $output parameter is a filehandle, the uncompressed data
136 will be written to it. The string '-' can be used as an alias for
137 standard output.
138 A scalar reference
140 If $output is a scalar reference, the uncompressed data will be
141 stored in $$output.
142 An Array Reference
144 If $output is an array reference, the uncompressed data will be
145 pushed onto the array.
146 An Output FileGlob
148 If $output is a string that is delimited by the characters "<" and
149 ">" "anyinflate" will assume that it is an output fileglob string.
150 The output is the list of files that match the fileglob.
151 When $output is an fileglob string, $input must also be a fileglob
153 string. Anything else is an error.
154 If the $output parameter is any other type, "undef" will be returned.
156 Notes
158 When $input maps to multiple compressed files/buffers and $output is a
159 single file/buffer, after uncompression $output will contain a
160 concatenation of all the uncompressed data from each of the input
161 files/buffers.
162 Optional Parameters
164 Unless specified below, the optional parameters for "anyinflate",
165 "OPTS", are the same as those used with the OO interface defined in the
166 "Constructor Options" section below.
167 "AutoClose => 0|1"
169 This option applies to any input or output data streams to
170 "anyinflate" that are filehandles.
171 If "AutoClose" is specified, and the value is true, it will result
173 in all input and/or output filehandles being closed once
174 "anyinflate" has completed.
175 This parameter defaults to 0.
177 "BinModeOut => 0|1"
179 When writing to a file or filehandle, set "binmode" before writing
180 to the file.
181 Defaults to 0.
183 "Append => 0|1"
185 The behaviour of this option is dependent on the type of output
186 data stream.
187 · A Buffer
189 If "Append" is enabled, all uncompressed data will be append
191 to the end of the output buffer. Otherwise the output buffer
192 will be cleared before any uncompressed data is written to
193 it.
194 · A Filename
196 If "Append" is enabled, the file will be opened in append
198 mode. Otherwise the contents of the file, if any, will be
199 truncated before any uncompressed data is written to it.
200 · A Filehandle
202 If "Append" is enabled, the filehandle will be positioned to
204 the end of the file via a call to "seek" before any
205 uncompressed data is written to it. Otherwise the file
206 pointer will not be moved.
207 When "Append" is specified, and set to true, it will append all
209 uncompressed data to the output data stream.
210 So when the output is a filehandle it will carry out a seek to the
212 eof before writing any uncompressed data. If the output is a
213 filename, it will be opened for appending. If the output is a
214 buffer, all uncompressed data will be appened to the existing
215 buffer.
216 Conversely when "Append" is not specified, or it is present and is
218 set to false, it will operate as follows.
219 When the output is a filename, it will truncate the contents of
221 the file before writing any uncompressed data. If the output is a
222 filehandle its position will not be changed. If the output is a
223 buffer, it will be wiped before any uncompressed data is output.
224 Defaults to 0.
226 "MultiStream => 0|1"
228 If the input file/buffer contains multiple compressed data
229 streams, this option will uncompress the whole lot as a single
230 data stream.
231 Defaults to 0.
233 "TrailingData => $scalar"
235 Returns the data, if any, that is present immediately after the
236 compressed data stream once uncompression is complete.
237 This option can be used when there is useful information
239 immediately following the compressed data stream, and you don't
240 know the length of the compressed data stream.
241 If the input is a buffer, "trailingData" will return everything
243 from the end of the compressed data stream to the end of the
244 buffer.
245 If the input is a filehandle, "trailingData" will return the data
247 that is left in the filehandle input buffer once the end of the
248 compressed data stream has been reached. You can then use the
249 filehandle to read the rest of the input file.
250 Don't bother using "trailingData" if the input is a filename.
252 If you know the length of the compressed data stream before you
254 start uncompressing, you can avoid having to use "trailingData" by
255 setting the "InputLength" option.
256 Examples
258 To read the contents of the file "file1.txt.Compressed" and write the
259 uncompressed data to the file "file1.txt".
260 use strict ;
262 use warnings ;
263 use IO::Uncompress::AnyInflate qw(anyinflate $AnyInflateError) ;
264 my $input = "file1.txt.Compressed";
266 my $output = "file1.txt";
267 anyinflate $input => $output
268 or die "anyinflate failed: $AnyInflateError\n";
269 To read from an existing Perl filehandle, $input, and write the
271 uncompressed data to a buffer, $buffer.
272 use strict ;
274 use warnings ;
275 use IO::Uncompress::AnyInflate qw(anyinflate $AnyInflateError) ;
276 use IO::File ;
277 my $input = new IO::File "<file1.txt.Compressed"
279 or die "Cannot open 'file1.txt.Compressed': $!\n" ;
280 my $buffer ;
281 anyinflate $input => \$buffer
282 or die "anyinflate failed: $AnyInflateError\n";
283 To uncompress all files in the directory "/my/home" that match
285 "*.txt.Compressed" and store the compressed data in the same directory
286 use strict ;
288 use warnings ;
289 use IO::Uncompress::AnyInflate qw(anyinflate $AnyInflateError) ;
290 anyinflate '</my/home/*.txt.Compressed>' => '</my/home/#1.txt>'
292 or die "anyinflate failed: $AnyInflateError\n";
293 and if you want to compress each file one at a time, this will do the
295 trick
296 use strict ;
298 use warnings ;
299 use IO::Uncompress::AnyInflate qw(anyinflate $AnyInflateError) ;
300 for my $input ( glob "/my/home/*.txt.Compressed" )
302 {
303 my $output = $input;
304 $output =~ s/.Compressed// ;
305 anyinflate $input => $output
306 or die "Error compressing '$input': $AnyInflateError\n";
307 }
308
310 Constructor
311 The format of the constructor for IO::Uncompress::AnyInflate is shown
312 below
313 my $z = new IO::Uncompress::AnyInflate $input [OPTS]
315 or die "IO::Uncompress::AnyInflate failed: $AnyInflateError\n";
316 Returns an "IO::Uncompress::AnyInflate" object on success and undef on
318 failure. The variable $AnyInflateError will contain an error message
319 on failure.
320 If you are running Perl 5.005 or better the object, $z, returned from
322 IO::Uncompress::AnyInflate can be used exactly like an IO::File
323 filehandle. This means that all normal input file operations can be
324 carried out with $z. For example, to read a line from a compressed
325 file/buffer you can use either of these forms
326 $line = $z->getline();
328 $line = <$z>;
329 The mandatory parameter $input is used to determine the source of the
331 compressed data. This parameter can take one of three forms.
332 A filename
334 If the $input parameter is a scalar, it is assumed to be a
335 filename. This file will be opened for reading and the compressed
336 data will be read from it.
337 A filehandle
339 If the $input parameter is a filehandle, the compressed data will
340 be read from it. The string '-' can be used as an alias for
341 standard input.
342 A scalar reference
344 If $input is a scalar reference, the compressed data will be read
345 from $$output.
346 Constructor Options
348 The option names defined below are case insensitive and can be
349 optionally prefixed by a '-'. So all of the following are valid
350 -AutoClose
352 -autoclose
353 AUTOCLOSE
354 autoclose
355 OPTS is a combination of the following options:
357 "AutoClose => 0|1"
359 This option is only valid when the $input parameter is a
360 filehandle. If specified, and the value is true, it will result in
361 the file being closed once either the "close" method is called or
362 the IO::Uncompress::AnyInflate object is destroyed.
363 This parameter defaults to 0.
365 "MultiStream => 0|1"
367 Allows multiple concatenated compressed streams to be treated as a
368 single compressed stream. Decompression will stop once either the
369 end of the file/buffer is reached, an error is encountered
370 (premature eof, corrupt compressed data) or the end of a stream is
371 not immediately followed by the start of another stream.
372 This parameter defaults to 0.
374 "Prime => $string"
376 This option will uncompress the contents of $string before
377 processing the input file/buffer.
378 This option can be useful when the compressed data is embedded in
380 another file/data structure and it is not possible to work out
381 where the compressed data begins without having to read the first
382 few bytes. If this is the case, the uncompression can be primed
383 with these bytes using this option.
384 "Transparent => 0|1"
386 If this option is set and the input file/buffer is not compressed
387 data, the module will allow reading of it anyway.
388 In addition, if the input file/buffer does contain compressed data
390 and there is non-compressed data immediately following it, setting
391 this option will make this module treat the whole file/bufffer as
392 a single data stream.
393 This option defaults to 1.
395 "BlockSize => $num"
397 When reading the compressed input data, IO::Uncompress::AnyInflate
398 will read it in blocks of $num bytes.
399 This option defaults to 4096.
401 "InputLength => $size"
403 When present this option will limit the number of compressed bytes
404 read from the input file/buffer to $size. This option can be used
405 in the situation where there is useful data directly after the
406 compressed data stream and you know beforehand the exact length of
407 the compressed data stream.
408 This option is mostly used when reading from a filehandle, in
410 which case the file pointer will be left pointing to the first
411 byte directly after the compressed data stream.
412 This option defaults to off.
414 "Append => 0|1"
416 This option controls what the "read" method does with uncompressed
417 data.
418 If set to 1, all uncompressed data will be appended to the output
420 parameter of the "read" method.
421 If set to 0, the contents of the output parameter of the "read"
423 method will be overwritten by the uncompressed data.
424 Defaults to 0.
426 "Strict => 0|1"
428 This option controls whether the extra checks defined below are
429 used when carrying out the decompression. When Strict is on, the
430 extra tests are carried out, when Strict is off they are not.
431 The default for this option is off.
433 If the input is an RFC 1950 data stream, the following will be
435 checked:
436 1. The ADLER32 checksum field must be present.
438 2. The value of the ADLER32 field read must match the adler32
440 value of the uncompressed data actually contained in the
441 file.
442 If the input is a gzip (RFC 1952) data stream, the following will
444 be checked:
445 1. If the FHCRC bit is set in the gzip FLG header byte, the
447 CRC16 bytes in the header must match the crc16 value of the
448 gzip header actually read.
449 2. If the gzip header contains a name field (FNAME) it consists
451 solely of ISO 8859-1 characters.
452 3. If the gzip header contains a comment field (FCOMMENT) it
454 consists solely of ISO 8859-1 characters plus line-feed.
455 4. If the gzip FEXTRA header field is present it must conform to
457 the sub-field structure as defined in RFC 1952.
458 5. The CRC32 and ISIZE trailer fields must be present.
460 6. The value of the CRC32 field read must match the crc32 value
462 of the uncompressed data actually contained in the gzip file.
463 7. The value of the ISIZE fields read must match the length of
465 the uncompressed data actually read from the file.
466 "RawInflate => 0|1"
468 When auto-detecting the compressed format, try to test for raw-
469 deflate (RFC 1951) content using the "IO::Uncompress::RawInflate"
470 module.
471 The reason this is not default behaviour is because RFC 1951
473 content can only be detected by attempting to uncompress it. This
474 process is error prone and can result is false positives.
475 Defaults to 0.
477 "ParseExtra => 0|1" If the gzip FEXTRA header field is present and this
479 option is set, it will force the module to check that it conforms to
480 the sub-field structure as defined in RFC 1952.
481 If the "Strict" is on it will automatically enable this option.
482 Defaults to 0.
484 Examples
486 TODO
487
489 read
490 Usage is
491 $status = $z->read($buffer)
493 Reads a block of compressed data (the size the the compressed block is
495 determined by the "Buffer" option in the constructor), uncompresses it
496 and writes any uncompressed data into $buffer. If the "Append"
497 parameter is set in the constructor, the uncompressed data will be
498 appended to the $buffer parameter. Otherwise $buffer will be
499 overwritten.
500 Returns the number of uncompressed bytes written to $buffer, zero if
502 eof or a negative number on error.
503 read
505 Usage is
506 $status = $z->read($buffer, $length)
508 $status = $z->read($buffer, $length, $offset)
509 $status = read($z, $buffer, $length)
511 $status = read($z, $buffer, $length, $offset)
512 Attempt to read $length bytes of uncompressed data into $buffer.
514 The main difference between this form of the "read" method and the
516 previous one, is that this one will attempt to return exactly $length
517 bytes. The only circumstances that this function will not is if end-of-
518 file or an IO error is encountered.
519 Returns the number of uncompressed bytes written to $buffer, zero if
521 eof or a negative number on error.
522 getline
524 Usage is
525 $line = $z->getline()
527 $line = <$z>
528 Reads a single line.
530 This method fully supports the use of of the variable $/ (or
532 $INPUT_RECORD_SEPARATOR or $RS when "English" is in use) to determine
533 what constitutes an end of line. Paragraph mode, record mode and file
534 slurp mode are all supported.
535 getc
537 Usage is
538 $char = $z->getc()
540 Read a single character.
542 ungetc
544 Usage is
545 $char = $z->ungetc($string)
547 inflateSync
549 Usage is
550 $status = $z->inflateSync()
552 TODO
554 getHeaderInfo
556 Usage is
557 $hdr = $z->getHeaderInfo();
559 @hdrs = $z->getHeaderInfo();
560 This method returns either a hash reference (in scalar context) or a
562 list or hash references (in array context) that contains information
563 about each of the header fields in the compressed data stream(s).
564 tell
566 Usage is
567 $z->tell()
569 tell $z
570 Returns the uncompressed file offset.
572 eof
574 Usage is
575 $z->eof();
577 eof($z);
578 Returns true if the end of the compressed input stream has been
580 reached.
581 seek
583 $z->seek($position, $whence);
584 seek($z, $position, $whence);
585 Provides a sub-set of the "seek" functionality, with the restriction
587 that it is only legal to seek forward in the input file/buffer. It is
588 a fatal error to attempt to seek backward.
589 The $whence parameter takes one the usual values, namely SEEK_SET,
591 SEEK_CUR or SEEK_END.
592 Returns 1 on success, 0 on failure.
594 binmode
596 Usage is
597 $z->binmode
599 binmode $z ;
600 This is a noop provided for completeness.
602 opened
604 $z->opened()
605 Returns true if the object currently refers to a opened file/buffer.
607 autoflush
609 my $prev = $z->autoflush()
610 my $prev = $z->autoflush(EXPR)
611 If the $z object is associated with a file or a filehandle, this method
613 returns the current autoflush setting for the underlying filehandle. If
614 "EXPR" is present, and is non-zero, it will enable flushing after every
615 write/print operation.
616 If $z is associated with a buffer, this method has no effect and always
618 returns "undef".
619 Note that the special variable $| cannot be used to set or retrieve the
621 autoflush setting.
622 input_line_number
624 $z->input_line_number()
625 $z->input_line_number(EXPR)
626 Returns the current uncompressed line number. If "EXPR" is present it
628 has the effect of setting the line number. Note that setting the line
629 number does not change the current position within the file/buffer
630 being read.
631 The contents of $/ are used to to determine what constitutes a line
633 terminator.
634 fileno
636 $z->fileno()
637 fileno($z)
638 If the $z object is associated with a file or a filehandle, "fileno"
640 will return the underlying file descriptor. Once the "close" method is
641 called "fileno" will return "undef".
642 If the $z object is is associated with a buffer, this method will
644 return "undef".
645 close
647 $z->close() ;
648 close $z ;
649 Closes the output file/buffer.
651 For most versions of Perl this method will be automatically invoked if
653 the IO::Uncompress::AnyInflate object is destroyed (either explicitly
654 or by the variable with the reference to the object going out of
655 scope). The exceptions are Perl versions 5.005 through 5.00504 and
656 5.8.0. In these cases, the "close" method will be called automatically,
657 but not until global destruction of all live objects when the program
658 is terminating.
659 Therefore, if you want your scripts to be able to run on all versions
661 of Perl, you should call "close" explicitly and not rely on automatic
662 closing.
663 Returns true on success, otherwise 0.
665 If the "AutoClose" option has been enabled when the
667 IO::Uncompress::AnyInflate object was created, and the object is
668 associated with a file, the underlying file will also be closed.
669 nextStream
671 Usage is
672 my $status = $z->nextStream();
674 Skips to the next compressed data stream in the input file/buffer. If a
676 new compressed data stream is found, the eof marker will be cleared and
677 $. will be reset to 0.
678 Returns 1 if a new stream was found, 0 if none was found, and -1 if an
680 error was encountered.
681 trailingData
683 Usage is
684 my $data = $z->trailingData();
686 Returns the data, if any, that is present immediately after the
688 compressed data stream once uncompression is complete. It only makes
689 sense to call this method once the end of the compressed data stream
690 has been encountered.
691 This option can be used when there is useful information immediately
693 following the compressed data stream, and you don't know the length of
694 the compressed data stream.
695 If the input is a buffer, "trailingData" will return everything from
697 the end of the compressed data stream to the end of the buffer.
698 If the input is a filehandle, "trailingData" will return the data that
700 is left in the filehandle input buffer once the end of the compressed
701 data stream has been reached. You can then use the filehandle to read
702 the rest of the input file.
703 Don't bother using "trailingData" if the input is a filename.
705 If you know the length of the compressed data stream before you start
707 uncompressing, you can avoid having to use "trailingData" by setting
708 the "InputLength" option in the constructor.
709
711 No symbolic constants are required by this IO::Uncompress::AnyInflate
712 at present.
713 :all Imports "anyinflate" and $AnyInflateError. Same as doing this
715 use IO::Uncompress::AnyInflate qw(anyinflate $AnyInflateError) ;
717
719 Working with Net::FTP
720 See IO::Uncompress::AnyInflate::FAQ
721
723 Compress::Zlib, IO::Compress::Gzip, IO::Uncompress::Gunzip,
724 IO::Compress::Deflate, IO::Uncompress::Inflate,
725 IO::Compress::RawDeflate, IO::Uncompress::RawInflate,
726 IO::Compress::Bzip2, IO::Uncompress::Bunzip2, IO::Compress::Lzma,
727 IO::Uncompress::UnLzma, IO::Compress::Xz, IO::Uncompress::UnXz,
728 IO::Compress::Lzop, IO::Uncompress::UnLzop, IO::Compress::Lzf,
729 IO::Uncompress::UnLzf, IO::Uncompress::AnyUncompress
730 Compress::Zlib::FAQ
732 File::GlobMapper, Archive::Zip, Archive::Tar, IO::Zlib
734 For RFC 1950, 1951 and 1952 see http://www.faqs.org/rfcs/rfc1950.html,
736 http://www.faqs.org/rfcs/rfc1951.html and
737 http://www.faqs.org/rfcs/rfc1952.html
738 The zlib compression library was written by Jean-loup Gailly
740 gzip@prep.ai.mit.edu and Mark Adler madler@alumni.caltech.edu.
741 The primary site for the zlib compression library is
743 http://www.zlib.org.
744 The primary site for gzip is http://www.gzip.org.
746
748 This module was written by Paul Marquess, pmqs@cpan.org.
749
751 See the Changes file.
752
754 Copyright (c) 2005-2010 Paul Marquess. All rights reserved.
755 This program is free software; you can redistribute it and/or modify it
757 under the same terms as Perl itself.
758perl v5.12.4 2011-06-07 IO::Uncompress::AnyInflate(3pm)