1IO::Uncompress::AnyInflUasteer(3C)ontributed Perl DocumeInOt:a:tUinocnompress::AnyInflate(3)
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_filename_or_reference => $output_filename_or_reference [,OPTS]
76 or die "anyinflate failed: $AnyInflateError\n";
77 The functional interface needs Perl5.005 or better.
79 anyinflate $input_filename_or_reference => $output_filename_or_reference [,
81 OPTS]
82 "anyinflate" expects at least two parameters,
83 $input_filename_or_reference and $output_filename_or_reference.
84 The $input_filename_or_reference parameter
86 The parameter, $input_filename_or_reference, is used to define the
88 source of the compressed data.
89 It can take one of the following forms:
91 A filename
93 If the <$input_filename_or_reference> parameter is a simple
94 scalar, it is assumed to be a filename. This file will be opened
95 for reading and the input data will be read from it.
96 A filehandle
98 If the $input_filename_or_reference parameter is a filehandle, the
99 input data will be read from it. The string '-' can be used as an
100 alias for standard input.
101 A scalar reference
103 If $input_filename_or_reference is a scalar reference, the input
104 data will be read from $$input_filename_or_reference.
105 An array reference
107 If $input_filename_or_reference is an array reference, each
108 element in the array must be a filename.
109 The input data will be read from each file in turn.
111 The complete array will be walked to ensure that it only contains
113 valid filenames before any data is uncompressed.
114 An Input FileGlob string
116 If $input_filename_or_reference is a string that is delimited by
117 the characters "<" and ">" "anyinflate" will assume that it is an
118 input fileglob string. The input is the list of files that match
119 the fileglob.
120 See File::GlobMapper for more details.
122 If the $input_filename_or_reference parameter is any other type,
124 "undef" will be returned.
125 The $output_filename_or_reference parameter
127 The parameter $output_filename_or_reference is used to control the
129 destination of the uncompressed data. This parameter can take one of
130 these forms.
131 A filename
133 If the $output_filename_or_reference parameter is a simple scalar,
134 it is assumed to be a filename. This file will be opened for
135 writing and the uncompressed data will be written to it.
136 A filehandle
138 If the $output_filename_or_reference parameter is a filehandle,
139 the uncompressed data will be written to it. The string '-' can
140 be used as an alias for standard output.
141 A scalar reference
143 If $output_filename_or_reference is a scalar reference, the
144 uncompressed data will be stored in
145 $$output_filename_or_reference.
146 An Array Reference
148 If $output_filename_or_reference is an array reference, the
149 uncompressed data will be pushed onto the array.
150 An Output FileGlob
152 If $output_filename_or_reference is a string that is delimited by
153 the characters "<" and ">" "anyinflate" will assume that it is an
154 output fileglob string. The output is the list of files that match
155 the fileglob.
156 When $output_filename_or_reference is an fileglob string,
158 $input_filename_or_reference must also be a fileglob string.
159 Anything else is an error.
160 See File::GlobMapper for more details.
162 If the $output_filename_or_reference parameter is any other type,
164 "undef" will be returned.
165 Notes
167 When $input_filename_or_reference maps to multiple compressed
168 files/buffers and $output_filename_or_reference is a single
169 file/buffer, after uncompression $output_filename_or_reference will
170 contain a concatenation of all the uncompressed data from each of the
171 input files/buffers.
172 Optional Parameters
174 Unless specified below, the optional parameters for "anyinflate",
175 "OPTS", are the same as those used with the OO interface defined in the
176 "Constructor Options" section below.
177 "AutoClose => 0|1"
179 This option applies to any input or output data streams to
180 "anyinflate" that are filehandles.
181 If "AutoClose" is specified, and the value is true, it will result
183 in all input and/or output filehandles being closed once
184 "anyinflate" has completed.
185 This parameter defaults to 0.
187 "BinModeOut => 0|1"
189 When writing to a file or filehandle, set "binmode" before writing
190 to the file.
191 Defaults to 0.
193 "Append => 0|1"
195 The behaviour of this option is dependent on the type of output
196 data stream.
197 · A Buffer
199 If "Append" is enabled, all uncompressed data will be append
201 to the end of the output buffer. Otherwise the output buffer
202 will be cleared before any uncompressed data is written to
203 it.
204 · A Filename
206 If "Append" is enabled, the file will be opened in append
208 mode. Otherwise the contents of the file, if any, will be
209 truncated before any uncompressed data is written to it.
210 · A Filehandle
212 If "Append" is enabled, the filehandle will be positioned to
214 the end of the file via a call to "seek" before any
215 uncompressed data is written to it. Otherwise the file
216 pointer will not be moved.
217 When "Append" is specified, and set to true, it will append all
219 uncompressed data to the output data stream.
220 So when the output is a filehandle it will carry out a seek to the
222 eof before writing any uncompressed data. If the output is a
223 filename, it will be opened for appending. If the output is a
224 buffer, all uncompressed data will be appended to the existing
225 buffer.
226 Conversely when "Append" is not specified, or it is present and is
228 set to false, it will operate as follows.
229 When the output is a filename, it will truncate the contents of
231 the file before writing any uncompressed data. If the output is a
232 filehandle its position will not be changed. If the output is a
233 buffer, it will be wiped before any uncompressed data is output.
234 Defaults to 0.
236 "MultiStream => 0|1"
238 If the input file/buffer contains multiple compressed data
239 streams, this option will uncompress the whole lot as a single
240 data stream.
241 Defaults to 0.
243 "TrailingData => $scalar"
245 Returns the data, if any, that is present immediately after the
246 compressed data stream once uncompression is complete.
247 This option can be used when there is useful information
249 immediately following the compressed data stream, and you don't
250 know the length of the compressed data stream.
251 If the input is a buffer, "trailingData" will return everything
253 from the end of the compressed data stream to the end of the
254 buffer.
255 If the input is a filehandle, "trailingData" will return the data
257 that is left in the filehandle input buffer once the end of the
258 compressed data stream has been reached. You can then use the
259 filehandle to read the rest of the input file.
260 Don't bother using "trailingData" if the input is a filename.
262 If you know the length of the compressed data stream before you
264 start uncompressing, you can avoid having to use "trailingData" by
265 setting the "InputLength" option.
266 Examples
268 To read the contents of the file "file1.txt.Compressed" and write the
269 uncompressed data to the file "file1.txt".
270 use strict ;
272 use warnings ;
273 use IO::Uncompress::AnyInflate qw(anyinflate $AnyInflateError) ;
274 my $input = "file1.txt.Compressed";
276 my $output = "file1.txt";
277 anyinflate $input => $output
278 or die "anyinflate failed: $AnyInflateError\n";
279 To read from an existing Perl filehandle, $input, and write the
281 uncompressed data to a buffer, $buffer.
282 use strict ;
284 use warnings ;
285 use IO::Uncompress::AnyInflate qw(anyinflate $AnyInflateError) ;
286 use IO::File ;
287 my $input = new IO::File "<file1.txt.Compressed"
289 or die "Cannot open 'file1.txt.Compressed': $!\n" ;
290 my $buffer ;
291 anyinflate $input => \$buffer
292 or die "anyinflate failed: $AnyInflateError\n";
293 To uncompress all files in the directory "/my/home" that match
295 "*.txt.Compressed" and store the compressed data in the same directory
296 use strict ;
298 use warnings ;
299 use IO::Uncompress::AnyInflate qw(anyinflate $AnyInflateError) ;
300 anyinflate '</my/home/*.txt.Compressed>' => '</my/home/#1.txt>'
302 or die "anyinflate failed: $AnyInflateError\n";
303 and if you want to compress each file one at a time, this will do the
305 trick
306 use strict ;
308 use warnings ;
309 use IO::Uncompress::AnyInflate qw(anyinflate $AnyInflateError) ;
310 for my $input ( glob "/my/home/*.txt.Compressed" )
312 {
313 my $output = $input;
314 $output =~ s/.Compressed// ;
315 anyinflate $input => $output
316 or die "Error compressing '$input': $AnyInflateError\n";
317 }
318
320 Constructor
321 The format of the constructor for IO::Uncompress::AnyInflate is shown
322 below
323 my $z = new IO::Uncompress::AnyInflate $input [OPTS]
325 or die "IO::Uncompress::AnyInflate failed: $AnyInflateError\n";
326 Returns an "IO::Uncompress::AnyInflate" object on success and undef on
328 failure. The variable $AnyInflateError will contain an error message
329 on failure.
330 If you are running Perl 5.005 or better the object, $z, returned from
332 IO::Uncompress::AnyInflate can be used exactly like an IO::File
333 filehandle. This means that all normal input file operations can be
334 carried out with $z. For example, to read a line from a compressed
335 file/buffer you can use either of these forms
336 $line = $z->getline();
338 $line = <$z>;
339 The mandatory parameter $input is used to determine the source of the
341 compressed data. This parameter can take one of three forms.
342 A filename
344 If the $input parameter is a scalar, it is assumed to be a
345 filename. This file will be opened for reading and the compressed
346 data will be read from it.
347 A filehandle
349 If the $input parameter is a filehandle, the compressed data will
350 be read from it. The string '-' can be used as an alias for
351 standard input.
352 A scalar reference
354 If $input is a scalar reference, the compressed data will be read
355 from $$input.
356 Constructor Options
358 The option names defined below are case insensitive and can be
359 optionally prefixed by a '-'. So all of the following are valid
360 -AutoClose
362 -autoclose
363 AUTOCLOSE
364 autoclose
365 OPTS is a combination of the following options:
367 "AutoClose => 0|1"
369 This option is only valid when the $input parameter is a
370 filehandle. If specified, and the value is true, it will result in
371 the file being closed once either the "close" method is called or
372 the IO::Uncompress::AnyInflate object is destroyed.
373 This parameter defaults to 0.
375 "MultiStream => 0|1"
377 Allows multiple concatenated compressed streams to be treated as a
378 single compressed stream. Decompression will stop once either the
379 end of the file/buffer is reached, an error is encountered
380 (premature eof, corrupt compressed data) or the end of a stream is
381 not immediately followed by the start of another stream.
382 This parameter defaults to 0.
384 "Prime => $string"
386 This option will uncompress the contents of $string before
387 processing the input file/buffer.
388 This option can be useful when the compressed data is embedded in
390 another file/data structure and it is not possible to work out
391 where the compressed data begins without having to read the first
392 few bytes. If this is the case, the uncompression can be primed
393 with these bytes using this option.
394 "Transparent => 0|1"
396 If this option is set and the input file/buffer is not compressed
397 data, the module will allow reading of it anyway.
398 In addition, if the input file/buffer does contain compressed data
400 and there is non-compressed data immediately following it, setting
401 this option will make this module treat the whole file/buffer as a
402 single data stream.
403 This option defaults to 1.
405 "BlockSize => $num"
407 When reading the compressed input data, IO::Uncompress::AnyInflate
408 will read it in blocks of $num bytes.
409 This option defaults to 4096.
411 "InputLength => $size"
413 When present this option will limit the number of compressed bytes
414 read from the input file/buffer to $size. This option can be used
415 in the situation where there is useful data directly after the
416 compressed data stream and you know beforehand the exact length of
417 the compressed data stream.
418 This option is mostly used when reading from a filehandle, in
420 which case the file pointer will be left pointing to the first
421 byte directly after the compressed data stream.
422 This option defaults to off.
424 "Append => 0|1"
426 This option controls what the "read" method does with uncompressed
427 data.
428 If set to 1, all uncompressed data will be appended to the output
430 parameter of the "read" method.
431 If set to 0, the contents of the output parameter of the "read"
433 method will be overwritten by the uncompressed data.
434 Defaults to 0.
436 "Strict => 0|1"
438 This option controls whether the extra checks defined below are
439 used when carrying out the decompression. When Strict is on, the
440 extra tests are carried out, when Strict is off they are not.
441 The default for this option is off.
443 If the input is an RFC 1950 data stream, the following will be
445 checked:
446 1. The ADLER32 checksum field must be present.
448 2. The value of the ADLER32 field read must match the adler32
450 value of the uncompressed data actually contained in the
451 file.
452 If the input is a gzip (RFC 1952) data stream, the following will
454 be checked:
455 1. If the FHCRC bit is set in the gzip FLG header byte, the
457 CRC16 bytes in the header must match the crc16 value of the
458 gzip header actually read.
459 2. If the gzip header contains a name field (FNAME) it consists
461 solely of ISO 8859-1 characters.
462 3. If the gzip header contains a comment field (FCOMMENT) it
464 consists solely of ISO 8859-1 characters plus line-feed.
465 4. If the gzip FEXTRA header field is present it must conform to
467 the sub-field structure as defined in RFC 1952.
468 5. The CRC32 and ISIZE trailer fields must be present.
470 6. The value of the CRC32 field read must match the crc32 value
472 of the uncompressed data actually contained in the gzip file.
473 7. The value of the ISIZE fields read must match the length of
475 the uncompressed data actually read from the file.
476 "RawInflate => 0|1"
478 When auto-detecting the compressed format, try to test for raw-
479 deflate (RFC 1951) content using the "IO::Uncompress::RawInflate"
480 module.
481 The reason this is not default behaviour is because RFC 1951
483 content can only be detected by attempting to uncompress it. This
484 process is error prone and can result is false positives.
485 Defaults to 0.
487 "ParseExtra => 0|1" If the gzip FEXTRA header field is present and this
489 option is set, it will force the module to check that it conforms to
490 the sub-field structure as defined in RFC 1952.
491 If the "Strict" is on it will automatically enable this option.
492 Defaults to 0.
494 Examples
496 TODO
497
499 read
500 Usage is
501 $status = $z->read($buffer)
503 Reads a block of compressed data (the size the the compressed block is
505 determined by the "Buffer" option in the constructor), uncompresses it
506 and writes any uncompressed data into $buffer. If the "Append"
507 parameter is set in the constructor, the uncompressed data will be
508 appended to the $buffer parameter. Otherwise $buffer will be
509 overwritten.
510 Returns the number of uncompressed bytes written to $buffer, zero if
512 eof or a negative number on error.
513 read
515 Usage is
516 $status = $z->read($buffer, $length)
518 $status = $z->read($buffer, $length, $offset)
519 $status = read($z, $buffer, $length)
521 $status = read($z, $buffer, $length, $offset)
522 Attempt to read $length bytes of uncompressed data into $buffer.
524 The main difference between this form of the "read" method and the
526 previous one, is that this one will attempt to return exactly $length
527 bytes. The only circumstances that this function will not is if end-of-
528 file or an IO error is encountered.
529 Returns the number of uncompressed bytes written to $buffer, zero if
531 eof or a negative number on error.
532 getline
534 Usage is
535 $line = $z->getline()
537 $line = <$z>
538 Reads a single line.
540 This method fully supports the use of of the variable $/ (or
542 $INPUT_RECORD_SEPARATOR or $RS when "English" is in use) to determine
543 what constitutes an end of line. Paragraph mode, record mode and file
544 slurp mode are all supported.
545 getc
547 Usage is
548 $char = $z->getc()
550 Read a single character.
552 ungetc
554 Usage is
555 $char = $z->ungetc($string)
557 inflateSync
559 Usage is
560 $status = $z->inflateSync()
562 TODO
564 getHeaderInfo
566 Usage is
567 $hdr = $z->getHeaderInfo();
569 @hdrs = $z->getHeaderInfo();
570 This method returns either a hash reference (in scalar context) or a
572 list or hash references (in array context) that contains information
573 about each of the header fields in the compressed data stream(s).
574 tell
576 Usage is
577 $z->tell()
579 tell $z
580 Returns the uncompressed file offset.
582 eof
584 Usage is
585 $z->eof();
587 eof($z);
588 Returns true if the end of the compressed input stream has been
590 reached.
591 seek
593 $z->seek($position, $whence);
594 seek($z, $position, $whence);
595 Provides a sub-set of the "seek" functionality, with the restriction
597 that it is only legal to seek forward in the input file/buffer. It is
598 a fatal error to attempt to seek backward.
599 Note that the implementation of "seek" in this module does not provide
601 true random access to a compressed file/buffer. It works by
602 uncompressing data from the current offset in the file/buffer until it
603 reaches the ucompressed offset specified in the parameters to "seek".
604 For very small files this may be acceptable behaviour. For large files
605 it may cause an unacceptable delay.
606 The $whence parameter takes one the usual values, namely SEEK_SET,
608 SEEK_CUR or SEEK_END.
609 Returns 1 on success, 0 on failure.
611 binmode
613 Usage is
614 $z->binmode
616 binmode $z ;
617 This is a noop provided for completeness.
619 opened
621 $z->opened()
622 Returns true if the object currently refers to a opened file/buffer.
624 autoflush
626 my $prev = $z->autoflush()
627 my $prev = $z->autoflush(EXPR)
628 If the $z object is associated with a file or a filehandle, this method
630 returns the current autoflush setting for the underlying filehandle. If
631 "EXPR" is present, and is non-zero, it will enable flushing after every
632 write/print operation.
633 If $z is associated with a buffer, this method has no effect and always
635 returns "undef".
636 Note that the special variable $| cannot be used to set or retrieve the
638 autoflush setting.
639 input_line_number
641 $z->input_line_number()
642 $z->input_line_number(EXPR)
643 Returns the current uncompressed line number. If "EXPR" is present it
645 has the effect of setting the line number. Note that setting the line
646 number does not change the current position within the file/buffer
647 being read.
648 The contents of $/ are used to to determine what constitutes a line
650 terminator.
651 fileno
653 $z->fileno()
654 fileno($z)
655 If the $z object is associated with a file or a filehandle, "fileno"
657 will return the underlying file descriptor. Once the "close" method is
658 called "fileno" will return "undef".
659 If the $z object is associated with a buffer, this method will return
661 "undef".
662 close
664 $z->close() ;
665 close $z ;
666 Closes the output file/buffer.
668 For most versions of Perl this method will be automatically invoked if
670 the IO::Uncompress::AnyInflate object is destroyed (either explicitly
671 or by the variable with the reference to the object going out of
672 scope). The exceptions are Perl versions 5.005 through 5.00504 and
673 5.8.0. In these cases, the "close" method will be called automatically,
674 but not until global destruction of all live objects when the program
675 is terminating.
676 Therefore, if you want your scripts to be able to run on all versions
678 of Perl, you should call "close" explicitly and not rely on automatic
679 closing.
680 Returns true on success, otherwise 0.
682 If the "AutoClose" option has been enabled when the
684 IO::Uncompress::AnyInflate object was created, and the object is
685 associated with a file, the underlying file will also be closed.
686 nextStream
688 Usage is
689 my $status = $z->nextStream();
691 Skips to the next compressed data stream in the input file/buffer. If a
693 new compressed data stream is found, the eof marker will be cleared and
694 $. will be reset to 0.
695 Returns 1 if a new stream was found, 0 if none was found, and -1 if an
697 error was encountered.
698 trailingData
700 Usage is
701 my $data = $z->trailingData();
703 Returns the data, if any, that is present immediately after the
705 compressed data stream once uncompression is complete. It only makes
706 sense to call this method once the end of the compressed data stream
707 has been encountered.
708 This option can be used when there is useful information immediately
710 following the compressed data stream, and you don't know the length of
711 the compressed data stream.
712 If the input is a buffer, "trailingData" will return everything from
714 the end of the compressed data stream to the end of the buffer.
715 If the input is a filehandle, "trailingData" will return the data that
717 is left in the filehandle input buffer once the end of the compressed
718 data stream has been reached. You can then use the filehandle to read
719 the rest of the input file.
720 Don't bother using "trailingData" if the input is a filename.
722 If you know the length of the compressed data stream before you start
724 uncompressing, you can avoid having to use "trailingData" by setting
725 the "InputLength" option in the constructor.
726
728 No symbolic constants are required by this IO::Uncompress::AnyInflate
729 at present.
730 :all Imports "anyinflate" and $AnyInflateError. Same as doing this
732 use IO::Uncompress::AnyInflate qw(anyinflate $AnyInflateError) ;
734
736 Working with Net::FTP
737 See IO::Compress::FAQ
738
740 Compress::Zlib, IO::Compress::Gzip, IO::Uncompress::Gunzip,
741 IO::Compress::Deflate, IO::Uncompress::Inflate,
742 IO::Compress::RawDeflate, IO::Uncompress::RawInflate,
743 IO::Compress::Bzip2, IO::Uncompress::Bunzip2, IO::Compress::Lzma,
744 IO::Uncompress::UnLzma, IO::Compress::Xz, IO::Uncompress::UnXz,
745 IO::Compress::Lzop, IO::Uncompress::UnLzop, IO::Compress::Lzf,
746 IO::Uncompress::UnLzf, IO::Uncompress::AnyUncompress
747 IO::Compress::FAQ
749 File::GlobMapper, Archive::Zip, Archive::Tar, IO::Zlib
751 For RFC 1950, 1951 and 1952 see http://www.faqs.org/rfcs/rfc1950.html,
753 http://www.faqs.org/rfcs/rfc1951.html and
754 http://www.faqs.org/rfcs/rfc1952.html
755 The zlib compression library was written by Jean-loup Gailly
757 gzip@prep.ai.mit.edu and Mark Adler madler@alumni.caltech.edu.
758 The primary site for the zlib compression library is
760 http://www.zlib.org.
761 The primary site for gzip is http://www.gzip.org.
763
765 This module was written by Paul Marquess, pmqs@cpan.org.
766
768 See the Changes file.
769
771 Copyright (c) 2005-2013 Paul Marquess. All rights reserved.
772 This program is free software; you can redistribute it and/or modify it
774 under the same terms as Perl itself.
775perl v5.16.3 2013-05-19 IO::Uncompress::AnyInflate(3)