1IO::Uncompress::RawInflaPteer(l3pPmr)ogrammers ReferencIeO:G:uUindceompress::RawInflate(3pm)
2
6 IO::Uncompress::RawInflate - Read RFC 1951 files/buffers
7
9 use IO::Uncompress::RawInflate qw(rawinflate $RawInflateError) ;
10 my $status = rawinflate $input => $output [,OPTS]
12 or die "rawinflate failed: $RawInflateError\n";
13 my $z = new IO::Uncompress::RawInflate $input [OPTS]
15 or die "rawinflate failed: $RawInflateError\n";
16 $status = $z->read($buffer)
18 $status = $z->read($buffer, $length)
19 $status = $z->read($buffer, $length, $offset)
20 $line = $z->getline()
21 $char = $z->getc()
22 $char = $z->ungetc()
23 $char = $z->opened()
24 $status = $z->inflateSync()
26 $data = $z->trailingData()
28 $status = $z->nextStream()
29 $data = $z->getHeaderInfo()
30 $z->tell()
31 $z->seek($position, $whence)
32 $z->binmode()
33 $z->fileno()
34 $z->eof()
35 $z->close()
36 $RawInflateError ;
38 # IO::File mode
40 <$z>
42 read($z, $buffer);
43 read($z, $buffer, $length);
44 read($z, $buffer, $length, $offset);
45 tell($z)
46 seek($z, $position, $whence)
47 binmode($z)
48 fileno($z)
49 eof($z)
50 close($z)
51
53 This module provides a Perl interface that allows the reading of
54 files/buffers that conform to RFC 1951.
55 For writing RFC 1951 files/buffers, see the companion module
57 IO::Compress::RawDeflate.
58
60 A top-level function, "rawinflate", is provided to carry out "one-shot"
61 uncompression between buffers and/or files. For finer control over the
62 uncompression process, see the "OO Interface" section.
63 use IO::Uncompress::RawInflate qw(rawinflate $RawInflateError) ;
65 rawinflate $input => $output [,OPTS]
67 or die "rawinflate failed: $RawInflateError\n";
68 The functional interface needs Perl5.005 or better.
70 rawinflate $input => $output [, OPTS]
72 "rawinflate" expects at least two parameters, $input and $output.
73 The $input parameter
75 The parameter, $input, is used to define the source of the compressed
77 data.
78 It can take one of the following forms:
80 A filename
82 If the $input parameter is a simple scalar, it is assumed to be a
83 filename. This file will be opened for reading and the input data
84 will be read from it.
85 A filehandle
87 If the $input parameter is a filehandle, the input data will be
88 read from it. The string '-' can be used as an alias for standard
89 input.
90 A scalar reference
92 If $input is a scalar reference, the input data will be read from
93 $$input.
94 An array reference
96 If $input is an array reference, each element in the array must be
97 a filename.
98 The input data will be read from each file in turn.
100 The complete array will be walked to ensure that it only contains
102 valid filenames before any data is uncompressed.
103 An Input FileGlob string
105 If $input is a string that is delimited by the characters "<" and
106 ">" "rawinflate" will assume that it is an input fileglob string.
107 The input is the list of files that match the fileglob.
108 If the fileglob does not match any files ...
110 See File::GlobMapper for more details.
112 If the $input parameter is any other type, "undef" will be returned.
114 The $output parameter
116 The parameter $output is used to control the destination of the
118 uncompressed data. This parameter can take one of these forms.
119 A filename
121 If the $output parameter is a simple scalar, it is assumed to be a
122 filename. This file will be opened for writing and the
123 uncompressed data will be written to it.
124 A filehandle
126 If the $output parameter is a filehandle, the uncompressed data
127 will be written to it. The string '-' can be used as an alias for
128 standard output.
129 A scalar reference
131 If $output is a scalar reference, the uncompressed data will be
132 stored in $$output.
133 An Array Reference
135 If $output is an array reference, the uncompressed data will be
136 pushed onto the array.
137 An Output FileGlob
139 If $output is a string that is delimited by the characters "<" and
140 ">" "rawinflate" will assume that it is an output fileglob string.
141 The output is the list of files that match the fileglob.
142 When $output is an fileglob string, $input must also be a fileglob
144 string. Anything else is an error.
145 If the $output parameter is any other type, "undef" will be returned.
147 Notes
149 When $input maps to multiple compressed files/buffers and $output is a
150 single file/buffer, after uncompression $output will contain a
151 concatenation of all the uncompressed data from each of the input
152 files/buffers.
153 Optional Parameters
155 Unless specified below, the optional parameters for "rawinflate",
156 "OPTS", are the same as those used with the OO interface defined in the
157 "Constructor Options" section below.
158 "AutoClose => 0|1"
160 This option applies to any input or output data streams to
161 "rawinflate" that are filehandles.
162 If "AutoClose" is specified, and the value is true, it will result
164 in all input and/or output filehandles being closed once
165 "rawinflate" has completed.
166 This parameter defaults to 0.
168 "BinModeOut => 0|1"
170 When writing to a file or filehandle, set "binmode" before writing
171 to the file.
172 Defaults to 0.
174 "Append => 0|1"
176 The behaviour of this option is dependent on the type of output
177 data stream.
178 · A Buffer
180 If "Append" is enabled, all uncompressed data will be append
182 to the end of the output buffer. Otherwise the output buffer
183 will be cleared before any uncompressed data is written to
184 it.
185 · A Filename
187 If "Append" is enabled, the file will be opened in append
189 mode. Otherwise the contents of the file, if any, will be
190 truncated before any uncompressed data is written to it.
191 · A Filehandle
193 If "Append" is enabled, the filehandle will be positioned to
195 the end of the file via a call to "seek" before any
196 uncompressed data is written to it. Otherwise the file
197 pointer will not be moved.
198 When "Append" is specified, and set to true, it will append all
200 uncompressed data to the output data stream.
201 So when the output is a filehandle it will carry out a seek to the
203 eof before writing any uncompressed data. If the output is a
204 filename, it will be opened for appending. If the output is a
205 buffer, all uncompressed data will be appened to the existing
206 buffer.
207 Conversely when "Append" is not specified, or it is present and is
209 set to false, it will operate as follows.
210 When the output is a filename, it will truncate the contents of
212 the file before writing any uncompressed data. If the output is a
213 filehandle its position will not be changed. If the output is a
214 buffer, it will be wiped before any uncompressed data is output.
215 Defaults to 0.
217 "MultiStream => 0|1"
219 This option is a no-op.
220 "TrailingData => $scalar"
222 Returns the data, if any, that is present immediately after the
223 compressed data stream once uncompression is complete.
224 This option can be used when there is useful information
226 immediately following the compressed data stream, and you don't
227 know the length of the compressed data stream.
228 If the input is a buffer, "trailingData" will return everything
230 from the end of the compressed data stream to the end of the
231 buffer.
232 If the input is a filehandle, "trailingData" will return the data
234 that is left in the filehandle input buffer once the end of the
235 compressed data stream has been reached. You can then use the
236 filehandle to read the rest of the input file.
237 Don't bother using "trailingData" if the input is a filename.
239 If you know the length of the compressed data stream before you
241 start uncompressing, you can avoid having to use "trailingData" by
242 setting the "InputLength" option.
243 Examples
245 To read the contents of the file "file1.txt.1951" and write the
246 uncompressed data to the file "file1.txt".
247 use strict ;
249 use warnings ;
250 use IO::Uncompress::RawInflate qw(rawinflate $RawInflateError) ;
251 my $input = "file1.txt.1951";
253 my $output = "file1.txt";
254 rawinflate $input => $output
255 or die "rawinflate failed: $RawInflateError\n";
256 To read from an existing Perl filehandle, $input, and write the
258 uncompressed data to a buffer, $buffer.
259 use strict ;
261 use warnings ;
262 use IO::Uncompress::RawInflate qw(rawinflate $RawInflateError) ;
263 use IO::File ;
264 my $input = new IO::File "<file1.txt.1951"
266 or die "Cannot open 'file1.txt.1951': $!\n" ;
267 my $buffer ;
268 rawinflate $input => \$buffer
269 or die "rawinflate failed: $RawInflateError\n";
270 To uncompress all files in the directory "/my/home" that match
272 "*.txt.1951" and store the compressed data in the same directory
273 use strict ;
275 use warnings ;
276 use IO::Uncompress::RawInflate qw(rawinflate $RawInflateError) ;
277 rawinflate '</my/home/*.txt.1951>' => '</my/home/#1.txt>'
279 or die "rawinflate failed: $RawInflateError\n";
280 and if you want to compress each file one at a time, this will do the
282 trick
283 use strict ;
285 use warnings ;
286 use IO::Uncompress::RawInflate qw(rawinflate $RawInflateError) ;
287 for my $input ( glob "/my/home/*.txt.1951" )
289 {
290 my $output = $input;
291 $output =~ s/.1951// ;
292 rawinflate $input => $output
293 or die "Error compressing '$input': $RawInflateError\n";
294 }
295
297 Constructor
298 The format of the constructor for IO::Uncompress::RawInflate is shown
299 below
300 my $z = new IO::Uncompress::RawInflate $input [OPTS]
302 or die "IO::Uncompress::RawInflate failed: $RawInflateError\n";
303 Returns an "IO::Uncompress::RawInflate" object on success and undef on
305 failure. The variable $RawInflateError will contain an error message
306 on failure.
307 If you are running Perl 5.005 or better the object, $z, returned from
309 IO::Uncompress::RawInflate can be used exactly like an IO::File
310 filehandle. This means that all normal input file operations can be
311 carried out with $z. For example, to read a line from a compressed
312 file/buffer you can use either of these forms
313 $line = $z->getline();
315 $line = <$z>;
316 The mandatory parameter $input is used to determine the source of the
318 compressed data. This parameter can take one of three forms.
319 A filename
321 If the $input parameter is a scalar, it is assumed to be a
322 filename. This file will be opened for reading and the compressed
323 data will be read from it.
324 A filehandle
326 If the $input parameter is a filehandle, the compressed data will
327 be read from it. The string '-' can be used as an alias for
328 standard input.
329 A scalar reference
331 If $input is a scalar reference, the compressed data will be read
332 from $$output.
333 Constructor Options
335 The option names defined below are case insensitive and can be
336 optionally prefixed by a '-'. So all of the following are valid
337 -AutoClose
339 -autoclose
340 AUTOCLOSE
341 autoclose
342 OPTS is a combination of the following options:
344 "AutoClose => 0|1"
346 This option is only valid when the $input parameter is a
347 filehandle. If specified, and the value is true, it will result in
348 the file being closed once either the "close" method is called or
349 the IO::Uncompress::RawInflate object is destroyed.
350 This parameter defaults to 0.
352 "MultiStream => 0|1"
354 Allows multiple concatenated compressed streams to be treated as a
355 single compressed stream. Decompression will stop once either the
356 end of the file/buffer is reached, an error is encountered
357 (premature eof, corrupt compressed data) or the end of a stream is
358 not immediately followed by the start of another stream.
359 This parameter defaults to 0.
361 "Prime => $string"
363 This option will uncompress the contents of $string before
364 processing the input file/buffer.
365 This option can be useful when the compressed data is embedded in
367 another file/data structure and it is not possible to work out
368 where the compressed data begins without having to read the first
369 few bytes. If this is the case, the uncompression can be primed
370 with these bytes using this option.
371 "Transparent => 0|1"
373 If this option is set and the input file/buffer is not compressed
374 data, the module will allow reading of it anyway.
375 In addition, if the input file/buffer does contain compressed data
377 and there is non-compressed data immediately following it, setting
378 this option will make this module treat the whole file/bufffer as
379 a single data stream.
380 This option defaults to 1.
382 "BlockSize => $num"
384 When reading the compressed input data, IO::Uncompress::RawInflate
385 will read it in blocks of $num bytes.
386 This option defaults to 4096.
388 "InputLength => $size"
390 When present this option will limit the number of compressed bytes
391 read from the input file/buffer to $size. This option can be used
392 in the situation where there is useful data directly after the
393 compressed data stream and you know beforehand the exact length of
394 the compressed data stream.
395 This option is mostly used when reading from a filehandle, in
397 which case the file pointer will be left pointing to the first
398 byte directly after the compressed data stream.
399 This option defaults to off.
401 "Append => 0|1"
403 This option controls what the "read" method does with uncompressed
404 data.
405 If set to 1, all uncompressed data will be appended to the output
407 parameter of the "read" method.
408 If set to 0, the contents of the output parameter of the "read"
410 method will be overwritten by the uncompressed data.
411 Defaults to 0.
413 "Strict => 0|1"
415 This option is a no-op.
416 Examples
418 TODO
419
421 read
422 Usage is
423 $status = $z->read($buffer)
425 Reads a block of compressed data (the size the the compressed block is
427 determined by the "Buffer" option in the constructor), uncompresses it
428 and writes any uncompressed data into $buffer. If the "Append"
429 parameter is set in the constructor, the uncompressed data will be
430 appended to the $buffer parameter. Otherwise $buffer will be
431 overwritten.
432 Returns the number of uncompressed bytes written to $buffer, zero if
434 eof or a negative number on error.
435 read
437 Usage is
438 $status = $z->read($buffer, $length)
440 $status = $z->read($buffer, $length, $offset)
441 $status = read($z, $buffer, $length)
443 $status = read($z, $buffer, $length, $offset)
444 Attempt to read $length bytes of uncompressed data into $buffer.
446 The main difference between this form of the "read" method and the
448 previous one, is that this one will attempt to return exactly $length
449 bytes. The only circumstances that this function will not is if end-of-
450 file or an IO error is encountered.
451 Returns the number of uncompressed bytes written to $buffer, zero if
453 eof or a negative number on error.
454 getline
456 Usage is
457 $line = $z->getline()
459 $line = <$z>
460 Reads a single line.
462 This method fully supports the use of of the variable $/ (or
464 $INPUT_RECORD_SEPARATOR or $RS when "English" is in use) to determine
465 what constitutes an end of line. Paragraph mode, record mode and file
466 slurp mode are all supported.
467 getc
469 Usage is
470 $char = $z->getc()
472 Read a single character.
474 ungetc
476 Usage is
477 $char = $z->ungetc($string)
479 inflateSync
481 Usage is
482 $status = $z->inflateSync()
484 TODO
486 getHeaderInfo
488 Usage is
489 $hdr = $z->getHeaderInfo();
491 @hdrs = $z->getHeaderInfo();
492 This method returns either a hash reference (in scalar context) or a
494 list or hash references (in array context) that contains information
495 about each of the header fields in the compressed data stream(s).
496 tell
498 Usage is
499 $z->tell()
501 tell $z
502 Returns the uncompressed file offset.
504 eof
506 Usage is
507 $z->eof();
509 eof($z);
510 Returns true if the end of the compressed input stream has been
512 reached.
513 seek
515 $z->seek($position, $whence);
516 seek($z, $position, $whence);
517 Provides a sub-set of the "seek" functionality, with the restriction
519 that it is only legal to seek forward in the input file/buffer. It is
520 a fatal error to attempt to seek backward.
521 The $whence parameter takes one the usual values, namely SEEK_SET,
523 SEEK_CUR or SEEK_END.
524 Returns 1 on success, 0 on failure.
526 binmode
528 Usage is
529 $z->binmode
531 binmode $z ;
532 This is a noop provided for completeness.
534 opened
536 $z->opened()
537 Returns true if the object currently refers to a opened file/buffer.
539 autoflush
541 my $prev = $z->autoflush()
542 my $prev = $z->autoflush(EXPR)
543 If the $z object is associated with a file or a filehandle, this method
545 returns the current autoflush setting for the underlying filehandle. If
546 "EXPR" is present, and is non-zero, it will enable flushing after every
547 write/print operation.
548 If $z is associated with a buffer, this method has no effect and always
550 returns "undef".
551 Note that the special variable $| cannot be used to set or retrieve the
553 autoflush setting.
554 input_line_number
556 $z->input_line_number()
557 $z->input_line_number(EXPR)
558 Returns the current uncompressed line number. If "EXPR" is present it
560 has the effect of setting the line number. Note that setting the line
561 number does not change the current position within the file/buffer
562 being read.
563 The contents of $/ are used to to determine what constitutes a line
565 terminator.
566 fileno
568 $z->fileno()
569 fileno($z)
570 If the $z object is associated with a file or a filehandle, "fileno"
572 will return the underlying file descriptor. Once the "close" method is
573 called "fileno" will return "undef".
574 If the $z object is is associated with a buffer, this method will
576 return "undef".
577 close
579 $z->close() ;
580 close $z ;
581 Closes the output file/buffer.
583 For most versions of Perl this method will be automatically invoked if
585 the IO::Uncompress::RawInflate object is destroyed (either explicitly
586 or by the variable with the reference to the object going out of
587 scope). The exceptions are Perl versions 5.005 through 5.00504 and
588 5.8.0. In these cases, the "close" method will be called automatically,
589 but not until global destruction of all live objects when the program
590 is terminating.
591 Therefore, if you want your scripts to be able to run on all versions
593 of Perl, you should call "close" explicitly and not rely on automatic
594 closing.
595 Returns true on success, otherwise 0.
597 If the "AutoClose" option has been enabled when the
599 IO::Uncompress::RawInflate object was created, and the object is
600 associated with a file, the underlying file will also be closed.
601 nextStream
603 Usage is
604 my $status = $z->nextStream();
606 Skips to the next compressed data stream in the input file/buffer. If a
608 new compressed data stream is found, the eof marker will be cleared and
609 $. will be reset to 0.
610 Returns 1 if a new stream was found, 0 if none was found, and -1 if an
612 error was encountered.
613 trailingData
615 Usage is
616 my $data = $z->trailingData();
618 Returns the data, if any, that is present immediately after the
620 compressed data stream once uncompression is complete. It only makes
621 sense to call this method once the end of the compressed data stream
622 has been encountered.
623 This option can be used when there is useful information immediately
625 following the compressed data stream, and you don't know the length of
626 the compressed data stream.
627 If the input is a buffer, "trailingData" will return everything from
629 the end of the compressed data stream to the end of the buffer.
630 If the input is a filehandle, "trailingData" will return the data that
632 is left in the filehandle input buffer once the end of the compressed
633 data stream has been reached. You can then use the filehandle to read
634 the rest of the input file.
635 Don't bother using "trailingData" if the input is a filename.
637 If you know the length of the compressed data stream before you start
639 uncompressing, you can avoid having to use "trailingData" by setting
640 the "InputLength" option in the constructor.
641
643 No symbolic constants are required by this IO::Uncompress::RawInflate
644 at present.
645 :all Imports "rawinflate" and $RawInflateError. Same as doing this
647 use IO::Uncompress::RawInflate qw(rawinflate $RawInflateError) ;
649
651 Working with Net::FTP
652 See IO::Uncompress::RawInflate::FAQ
653
655 Compress::Zlib, IO::Compress::Gzip, IO::Uncompress::Gunzip,
656 IO::Compress::Deflate, IO::Uncompress::Inflate,
657 IO::Compress::RawDeflate, IO::Compress::Bzip2, IO::Uncompress::Bunzip2,
658 IO::Compress::Lzma, IO::Uncompress::UnLzma, IO::Compress::Xz,
659 IO::Uncompress::UnXz, IO::Compress::Lzop, IO::Uncompress::UnLzop,
660 IO::Compress::Lzf, IO::Uncompress::UnLzf, IO::Uncompress::AnyInflate,
661 IO::Uncompress::AnyUncompress
662 Compress::Zlib::FAQ
664 File::GlobMapper, Archive::Zip, Archive::Tar, IO::Zlib
666 For RFC 1950, 1951 and 1952 see http://www.faqs.org/rfcs/rfc1950.html,
668 http://www.faqs.org/rfcs/rfc1951.html and
669 http://www.faqs.org/rfcs/rfc1952.html
670 The zlib compression library was written by Jean-loup Gailly
672 gzip@prep.ai.mit.edu and Mark Adler madler@alumni.caltech.edu.
673 The primary site for the zlib compression library is
675 http://www.zlib.org.
676 The primary site for gzip is http://www.gzip.org.
678
680 This module was written by Paul Marquess, pmqs@cpan.org.
681
683 See the Changes file.
684
686 Copyright (c) 2005-2010 Paul Marquess. All rights reserved.
687 This program is free software; you can redistribute it and/or modify it
689 under the same terms as Perl itself.
690perl v5.12.4 2011-06-07 IO::Uncompress::RawInflate(3pm)