1IO::Uncompress::AnyUncoUmsperresCso(n3t)ributed Perl DocIuOm:e:nUtnactoimopnress::AnyUncompress(3)
2
6 IO::Uncompress::AnyUncompress - Uncompress gzip, zip, bzip2, zstd, xz,
7 lzma, lzip, lzf or lzop 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 = IO::Uncompress::AnyUncompress->new( $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 zstd (Zstandard)
63 bzip2
64 lzop
65 lzf
66 lzma
67 lzip
68 xz
69 The module will auto-detect which, if any, of the supported compression
71 formats is being used.
72
74 A top-level function, "anyuncompress", is provided to carry out "one-
75 shot" uncompression between buffers and/or files. For finer control
76 over the uncompression process, see the "OO Interface" section.
77 use IO::Uncompress::AnyUncompress qw(anyuncompress $AnyUncompressError) ;
79 anyuncompress $input_filename_or_reference => $output_filename_or_reference [,OPTS]
81 or die "anyuncompress failed: $AnyUncompressError\n";
82 The functional interface needs Perl5.005 or better.
84 anyuncompress $input_filename_or_reference => $output_filename_or_reference
86 [, OPTS]
87 "anyuncompress" expects at least two parameters,
88 $input_filename_or_reference and $output_filename_or_reference and zero
89 or more optional parameters (see "Optional Parameters")
90 The $input_filename_or_reference parameter
92 The parameter, $input_filename_or_reference, is used to define the
94 source of the compressed data.
95 It can take one of the following forms:
97 A filename
99 If the $input_filename_or_reference parameter is a simple scalar,
100 it is assumed to be a filename. This file will be opened for
101 reading and the input data will be read from it.
102 A filehandle
104 If the $input_filename_or_reference parameter is a filehandle, the
105 input data will be read from it. The string '-' can be used as an
106 alias for standard input.
107 A scalar reference
109 If $input_filename_or_reference is a scalar reference, the input
110 data will be read from $$input_filename_or_reference.
111 An array reference
113 If $input_filename_or_reference is an array reference, each
114 element in the array must be a filename.
115 The input data will be read from each file in turn.
117 The complete array will be walked to ensure that it only contains
119 valid filenames before any data is uncompressed.
120 An Input FileGlob string
122 If $input_filename_or_reference is a string that is delimited by
123 the characters "<" and ">" "anyuncompress" will assume that it is
124 an input fileglob string. The input is the list of files that
125 match the fileglob.
126 See File::GlobMapper for more details.
128 If the $input_filename_or_reference parameter is any other type,
130 "undef" will be returned.
131 The $output_filename_or_reference parameter
133 The parameter $output_filename_or_reference is used to control the
135 destination of the uncompressed data. This parameter can take one of
136 these forms.
137 A filename
139 If the $output_filename_or_reference parameter is a simple scalar,
140 it is assumed to be a filename. This file will be opened for
141 writing and the uncompressed data will be written to it.
142 A filehandle
144 If the $output_filename_or_reference parameter is a filehandle,
145 the uncompressed data will be written to it. The string '-' can
146 be used as an alias for standard output.
147 A scalar reference
149 If $output_filename_or_reference is a scalar reference, the
150 uncompressed data will be stored in
151 $$output_filename_or_reference.
152 An Array Reference
154 If $output_filename_or_reference is an array reference, the
155 uncompressed data will be pushed onto the array.
156 An Output FileGlob
158 If $output_filename_or_reference is a string that is delimited by
159 the characters "<" and ">" "anyuncompress" will assume that it is
160 an output fileglob string. The output is the list of files that
161 match the fileglob.
162 When $output_filename_or_reference is an fileglob string,
164 $input_filename_or_reference must also be a fileglob string.
165 Anything else is an error.
166 See File::GlobMapper for more details.
168 If the $output_filename_or_reference parameter is any other type,
170 "undef" will be returned.
171 Notes
173 When $input_filename_or_reference maps to multiple compressed
174 files/buffers and $output_filename_or_reference is a single
175 file/buffer, after uncompression $output_filename_or_reference will
176 contain a concatenation of all the uncompressed data from each of the
177 input files/buffers.
178 Optional Parameters
180 The optional parameters for the one-shot function "anyuncompress" are
181 (for the most part) identical to those used with the OO interface
182 defined in the "Constructor Options" section. The exceptions are listed
183 below
184 "AutoClose => 0|1"
186 This option applies to any input or output data streams to
187 "anyuncompress" that are filehandles.
188 If "AutoClose" is specified, and the value is true, it will result
190 in all input and/or output filehandles being closed once
191 "anyuncompress" has completed.
192 This parameter defaults to 0.
194 "BinModeOut => 0|1"
196 This option is now a no-op. All files will be written in binmode.
197 "Append => 0|1"
199 The behaviour of this option is dependent on the type of output
200 data stream.
201 • A Buffer
203 If "Append" is enabled, all uncompressed data will be append
205 to the end of the output buffer. Otherwise the output buffer
206 will be cleared before any uncompressed data is written to
207 it.
208 • A Filename
210 If "Append" is enabled, the file will be opened in append
212 mode. Otherwise the contents of the file, if any, will be
213 truncated before any uncompressed data is written to it.
214 • A Filehandle
216 If "Append" is enabled, the filehandle will be positioned to
218 the end of the file via a call to "seek" before any
219 uncompressed data is written to it. Otherwise the file
220 pointer will not be moved.
221 When "Append" is specified, and set to true, it will append all
223 uncompressed data to the output data stream.
224 So when the output is a filehandle it will carry out a seek to the
226 eof before writing any uncompressed data. If the output is a
227 filename, it will be opened for appending. If the output is a
228 buffer, all uncompressed data will be appended to the existing
229 buffer.
230 Conversely when "Append" is not specified, or it is present and is
232 set to false, it will operate as follows.
233 When the output is a filename, it will truncate the contents of
235 the file before writing any uncompressed data. If the output is a
236 filehandle its position will not be changed. If the output is a
237 buffer, it will be wiped before any uncompressed data is output.
238 Defaults to 0.
240 "MultiStream => 0|1"
242 If the input file/buffer contains multiple compressed data
243 streams, this option will uncompress the whole lot as a single
244 data stream.
245 Defaults to 0.
247 "TrailingData => $scalar"
249 Returns the data, if any, that is present immediately after the
250 compressed data stream once uncompression is complete.
251 This option can be used when there is useful information
253 immediately following the compressed data stream, and you don't
254 know the length of the compressed data stream.
255 If the input is a buffer, "trailingData" will return everything
257 from the end of the compressed data stream to the end of the
258 buffer.
259 If the input is a filehandle, "trailingData" will return the data
261 that is left in the filehandle input buffer once the end of the
262 compressed data stream has been reached. You can then use the
263 filehandle to read the rest of the input file.
264 Don't bother using "trailingData" if the input is a filename.
266 If you know the length of the compressed data stream before you
268 start uncompressing, you can avoid having to use "trailingData" by
269 setting the "InputLength" option.
270 Examples
272 To read the contents of the file "file1.txt.Compressed" and write the
273 uncompressed data to the file "file1.txt".
274 use strict ;
276 use warnings ;
277 use IO::Uncompress::AnyUncompress qw(anyuncompress $AnyUncompressError) ;
278 my $input = "file1.txt.Compressed";
280 my $output = "file1.txt";
281 anyuncompress $input => $output
282 or die "anyuncompress failed: $AnyUncompressError\n";
283 To read from an existing Perl filehandle, $input, and write the
285 uncompressed data to a buffer, $buffer.
286 use strict ;
288 use warnings ;
289 use IO::Uncompress::AnyUncompress qw(anyuncompress $AnyUncompressError) ;
290 use IO::File ;
291 my $input = IO::File->new( "<file1.txt.Compressed" )
293 or die "Cannot open 'file1.txt.Compressed': $!\n" ;
294 my $buffer ;
295 anyuncompress $input => \$buffer
296 or die "anyuncompress failed: $AnyUncompressError\n";
297 To uncompress all files in the directory "/my/home" that match
299 "*.txt.Compressed" and store the compressed data in the same directory
300 use strict ;
302 use warnings ;
303 use IO::Uncompress::AnyUncompress qw(anyuncompress $AnyUncompressError) ;
304 anyuncompress '</my/home/*.txt.Compressed>' => '</my/home/#1.txt>'
306 or die "anyuncompress failed: $AnyUncompressError\n";
307 and if you want to compress each file one at a time, this will do the
309 trick
310 use strict ;
312 use warnings ;
313 use IO::Uncompress::AnyUncompress qw(anyuncompress $AnyUncompressError) ;
314 for my $input ( glob "/my/home/*.txt.Compressed" )
316 {
317 my $output = $input;
318 $output =~ s/.Compressed// ;
319 anyuncompress $input => $output
320 or die "Error compressing '$input': $AnyUncompressError\n";
321 }
322
324 Constructor
325 The format of the constructor for IO::Uncompress::AnyUncompress is
326 shown below
327 my $z = IO::Uncompress::AnyUncompress->new( $input [OPTS] )
329 or die "IO::Uncompress::AnyUncompress failed: $AnyUncompressError\n";
330 Returns an "IO::Uncompress::AnyUncompress" object on success and undef
332 on failure. The variable $AnyUncompressError will contain an error
333 message on failure.
334 If you are running Perl 5.005 or better the object, $z, returned from
336 IO::Uncompress::AnyUncompress can be used exactly like an IO::File
337 filehandle. This means that all normal input file operations can be
338 carried out with $z. For example, to read a line from a compressed
339 file/buffer you can use either of these forms
340 $line = $z->getline();
342 $line = <$z>;
343 The mandatory parameter $input is used to determine the source of the
345 compressed data. This parameter can take one of three forms.
346 A filename
348 If the $input parameter is a scalar, it is assumed to be a
349 filename. This file will be opened for reading and the compressed
350 data will be read from it.
351 A filehandle
353 If the $input parameter is a filehandle, the compressed data will
354 be read from it. The string '-' can be used as an alias for
355 standard input.
356 A scalar reference
358 If $input is a scalar reference, the compressed data will be read
359 from $$input.
360 Constructor Options
362 The option names defined below are case insensitive and can be
363 optionally prefixed by a '-'. So all of the following are valid
364 -AutoClose
366 -autoclose
367 AUTOCLOSE
368 autoclose
369 OPTS is a combination of the following options:
371 "AutoClose => 0|1"
373 This option is only valid when the $input parameter is a
374 filehandle. If specified, and the value is true, it will result in
375 the file being closed once either the "close" method is called or
376 the IO::Uncompress::AnyUncompress object is destroyed.
377 This parameter defaults to 0.
379 "MultiStream => 0|1"
381 Allows multiple concatenated compressed streams to be treated as a
382 single compressed stream. Decompression will stop once either the
383 end of the file/buffer is reached, an error is encountered
384 (premature eof, corrupt compressed data) or the end of a stream is
385 not immediately followed by the start of another stream.
386 This parameter defaults to 0.
388 "Prime => $string"
390 This option will uncompress the contents of $string before
391 processing the input file/buffer.
392 This option can be useful when the compressed data is embedded in
394 another file/data structure and it is not possible to work out
395 where the compressed data begins without having to read the first
396 few bytes. If this is the case, the uncompression can be primed
397 with these bytes using this option.
398 "Transparent => 0|1"
400 If this option is set and the input file/buffer is not compressed
401 data, the module will allow reading of it anyway.
402 In addition, if the input file/buffer does contain compressed data
404 and there is non-compressed data immediately following it, setting
405 this option will make this module treat the whole file/buffer as a
406 single data stream.
407 This option defaults to 1.
409 "BlockSize => $num"
411 When reading the compressed input data,
412 IO::Uncompress::AnyUncompress will read it in blocks of $num
413 bytes.
414 This option defaults to 4096.
416 "InputLength => $size"
418 When present this option will limit the number of compressed bytes
419 read from the input file/buffer to $size. This option can be used
420 in the situation where there is useful data directly after the
421 compressed data stream and you know beforehand the exact length of
422 the compressed data stream.
423 This option is mostly used when reading from a filehandle, in
425 which case the file pointer will be left pointing to the first
426 byte directly after the compressed data stream.
427 This option defaults to off.
429 "Append => 0|1"
431 This option controls what the "read" method does with uncompressed
432 data.
433 If set to 1, all uncompressed data will be appended to the output
435 parameter of the "read" method.
436 If set to 0, the contents of the output parameter of the "read"
438 method will be overwritten by the uncompressed data.
439 Defaults to 0.
441 "Strict => 0|1"
443 This option controls whether the extra checks defined below are
444 used when carrying out the decompression. When Strict is on, the
445 extra tests are carried out, when Strict is off they are not.
446 The default for this option is off.
448 "RawInflate => 0|1"
450 When auto-detecting the compressed format, try to test for raw-
451 deflate (RFC 1951) content using the "IO::Uncompress::RawInflate"
452 module.
453 The reason this is not default behaviour is because RFC 1951
455 content can only be detected by attempting to uncompress it. This
456 process is error prone and can result is false positives.
457 Defaults to 0.
459 "UnLzma => 0|1"
461 When auto-detecting the compressed format, try to test for
462 lzma_alone content using the "IO::Uncompress::UnLzma" module.
463 The reason this is not default behaviour is because lzma_alone
465 content can only be detected by attempting to uncompress it. This
466 process is error prone and can result is false positives.
467 Defaults to 0.
469 Examples
471 TODO
472
474 read
475 Usage is
476 $status = $z->read($buffer)
478 Reads a block of compressed data (the size of the compressed block is
480 determined by the "Buffer" option in the constructor), uncompresses it
481 and writes any uncompressed data into $buffer. If the "Append"
482 parameter is set in the constructor, the uncompressed data will be
483 appended to the $buffer parameter. Otherwise $buffer will be
484 overwritten.
485 Returns the number of uncompressed bytes written to $buffer, zero if
487 eof or a negative number on error.
488 read
490 Usage is
491 $status = $z->read($buffer, $length)
493 $status = $z->read($buffer, $length, $offset)
494 $status = read($z, $buffer, $length)
496 $status = read($z, $buffer, $length, $offset)
497 Attempt to read $length bytes of uncompressed data into $buffer.
499 The main difference between this form of the "read" method and the
501 previous one, is that this one will attempt to return exactly $length
502 bytes. The only circumstances that this function will not is if end-of-
503 file or an IO error is encountered.
504 Returns the number of uncompressed bytes written to $buffer, zero if
506 eof or a negative number on error.
507 getline
509 Usage is
510 $line = $z->getline()
512 $line = <$z>
513 Reads a single line.
515 This method fully supports the use of the variable $/ (or
517 $INPUT_RECORD_SEPARATOR or $RS when "English" is in use) to determine
518 what constitutes an end of line. Paragraph mode, record mode and file
519 slurp mode are all supported.
520 getc
522 Usage is
523 $char = $z->getc()
525 Read a single character.
527 ungetc
529 Usage is
530 $char = $z->ungetc($string)
532 getHeaderInfo
534 Usage is
535 $hdr = $z->getHeaderInfo();
537 @hdrs = $z->getHeaderInfo();
538 This method returns either a hash reference (in scalar context) or a
540 list or hash references (in array context) that contains information
541 about each of the header fields in the compressed data stream(s).
542 tell
544 Usage is
545 $z->tell()
547 tell $z
548 Returns the uncompressed file offset.
550 eof
552 Usage is
553 $z->eof();
555 eof($z);
556 Returns true if the end of the compressed input stream has been
558 reached.
559 seek
561 $z->seek($position, $whence);
562 seek($z, $position, $whence);
563 Provides a sub-set of the "seek" functionality, with the restriction
565 that it is only legal to seek forward in the input file/buffer. It is
566 a fatal error to attempt to seek backward.
567 Note that the implementation of "seek" in this module does not provide
569 true random access to a compressed file/buffer. It works by
570 uncompressing data from the current offset in the file/buffer until it
571 reaches the uncompressed offset specified in the parameters to "seek".
572 For very small files this may be acceptable behaviour. For large files
573 it may cause an unacceptable delay.
574 The $whence parameter takes one the usual values, namely SEEK_SET,
576 SEEK_CUR or SEEK_END.
577 Returns 1 on success, 0 on failure.
579 binmode
581 Usage is
582 $z->binmode
584 binmode $z ;
585 This is a noop provided for completeness.
587 opened
589 $z->opened()
590 Returns true if the object currently refers to a opened file/buffer.
592 autoflush
594 my $prev = $z->autoflush()
595 my $prev = $z->autoflush(EXPR)
596 If the $z object is associated with a file or a filehandle, this method
598 returns the current autoflush setting for the underlying filehandle. If
599 "EXPR" is present, and is non-zero, it will enable flushing after every
600 write/print operation.
601 If $z is associated with a buffer, this method has no effect and always
603 returns "undef".
604 Note that the special variable $| cannot be used to set or retrieve the
606 autoflush setting.
607 input_line_number
609 $z->input_line_number()
610 $z->input_line_number(EXPR)
611 Returns the current uncompressed line number. If "EXPR" is present it
613 has the effect of setting the line number. Note that setting the line
614 number does not change the current position within the file/buffer
615 being read.
616 The contents of $/ are used to determine what constitutes a line
618 terminator.
619 fileno
621 $z->fileno()
622 fileno($z)
623 If the $z object is associated with a file or a filehandle, "fileno"
625 will return the underlying file descriptor. Once the "close" method is
626 called "fileno" will return "undef".
627 If the $z object is associated with a buffer, this method will return
629 "undef".
630 close
632 $z->close() ;
633 close $z ;
634 Closes the output file/buffer.
636 For most versions of Perl this method will be automatically invoked if
638 the IO::Uncompress::AnyUncompress object is destroyed (either
639 explicitly or by the variable with the reference to the object going
640 out of scope). The exceptions are Perl versions 5.005 through 5.00504
641 and 5.8.0. In these cases, the "close" method will be called
642 automatically, but not until global destruction of all live objects
643 when the program is terminating.
644 Therefore, if you want your scripts to be able to run on all versions
646 of Perl, you should call "close" explicitly and not rely on automatic
647 closing.
648 Returns true on success, otherwise 0.
650 If the "AutoClose" option has been enabled when the
652 IO::Uncompress::AnyUncompress object was created, and the object is
653 associated with a file, the underlying file will also be closed.
654 nextStream
656 Usage is
657 my $status = $z->nextStream();
659 Skips to the next compressed data stream in the input file/buffer. If a
661 new compressed data stream is found, the eof marker will be cleared and
662 $. will be reset to 0.
663 Returns 1 if a new stream was found, 0 if none was found, and -1 if an
665 error was encountered.
666 trailingData
668 Usage is
669 my $data = $z->trailingData();
671 Returns the data, if any, that is present immediately after the
673 compressed data stream once uncompression is complete. It only makes
674 sense to call this method once the end of the compressed data stream
675 has been encountered.
676 This option can be used when there is useful information immediately
678 following the compressed data stream, and you don't know the length of
679 the compressed data stream.
680 If the input is a buffer, "trailingData" will return everything from
682 the end of the compressed data stream to the end of the buffer.
683 If the input is a filehandle, "trailingData" will return the data that
685 is left in the filehandle input buffer once the end of the compressed
686 data stream has been reached. You can then use the filehandle to read
687 the rest of the input file.
688 Don't bother using "trailingData" if the input is a filename.
690 If you know the length of the compressed data stream before you start
692 uncompressing, you can avoid having to use "trailingData" by setting
693 the "InputLength" option in the constructor.
694
696 No symbolic constants are required by IO::Uncompress::AnyUncompress at
697 present.
698 :all Imports "anyuncompress" and $AnyUncompressError. Same as doing
700 this
701 use IO::Uncompress::AnyUncompress qw(anyuncompress $AnyUncompressError) ;
703
706 General feedback/questions/bug reports should be sent to
707 <https://github.com/pmqs/IO-Compress/issues> (preferred) or
708 <https://rt.cpan.org/Public/Dist/Display.html?Name=IO-Compress>.
709
711 Compress::Zlib, IO::Compress::Gzip, IO::Uncompress::Gunzip,
712 IO::Compress::Deflate, IO::Uncompress::Inflate,
713 IO::Compress::RawDeflate, IO::Uncompress::RawInflate,
714 IO::Compress::Bzip2, IO::Uncompress::Bunzip2, IO::Compress::Lzma,
715 IO::Uncompress::UnLzma, IO::Compress::Xz, IO::Uncompress::UnXz,
716 IO::Compress::Lzip, IO::Uncompress::UnLzip, IO::Compress::Lzop,
717 IO::Uncompress::UnLzop, IO::Compress::Lzf, IO::Uncompress::UnLzf,
718 IO::Compress::Zstd, IO::Uncompress::UnZstd, IO::Uncompress::AnyInflate
719 IO::Compress::FAQ
721 File::GlobMapper, Archive::Zip, Archive::Tar, IO::Zlib
723
725 This module was written by Paul Marquess, "pmqs@cpan.org".
726
728 See the Changes file.
729
731 Copyright (c) 2005-2021 Paul Marquess. All rights reserved.
732 This program is free software; you can redistribute it and/or modify it
734 under the same terms as Perl itself.
735perl v5.32.1 2021-03-01 IO::Uncompress::AnyUncompress(3)