1package IO::Uncompress::Inflate ;
2# for RFC1950
3
4use strict ;
5use warnings;
6use bytes;
7
8use IO::Compress::Base::Common  2.024 qw(:Status createSelfTiedObject);
9use IO::Compress::Zlib::Constants 2.024 ;
10
11use IO::Uncompress::RawInflate  2.024 ;
12
13require Exporter ;
14our ($VERSION, @ISA, @EXPORT_OK, %EXPORT_TAGS, $InflateError);
15
16$VERSION = '2.024';
17$InflateError = '';
18
19@ISA    = qw( Exporter IO::Uncompress::RawInflate );
20@EXPORT_OK = qw( $InflateError inflate ) ;
21%EXPORT_TAGS = %IO::Uncompress::RawInflate::DEFLATE_CONSTANTS ;
22push @{ $EXPORT_TAGS{all} }, @EXPORT_OK ;
23Exporter::export_ok_tags('all');
24
25
26sub new
27{
28    my $class = shift ;
29    my $obj = createSelfTiedObject($class, \$InflateError);
30
31    $obj->_create(undef, 0, @_);
32}
33
34sub inflate
35{
36    my $obj = createSelfTiedObject(undef, \$InflateError);
37    return $obj->_inf(@_);
38}
39
40sub getExtraParams
41{
42    return ();
43}
44
45sub ckParams
46{
47    my $self = shift ;
48    my $got = shift ;
49
50    # gunzip always needs adler32
51    $got->value('ADLER32' => 1);
52
53    return 1;
54}
55
56sub ckMagic
57{
58    my $self = shift;
59
60    my $magic ;
61    $self->smartReadExact(\$magic, ZLIB_HEADER_SIZE);
62
63    *$self->{HeaderPending} = $magic ;
64
65    return $self->HeaderError("Header size is " .
66                                        ZLIB_HEADER_SIZE . " bytes")
67        if length $magic != ZLIB_HEADER_SIZE;
68
69    #return $self->HeaderError("CRC mismatch.")
70    return undef
71        if ! $self->isZlibMagic($magic) ;
72
73    *$self->{Type} = 'rfc1950';
74    return $magic;
75}
76
77sub readHeader
78{
79    my $self = shift;
80    my $magic = shift ;
81
82    return $self->_readDeflateHeader($magic) ;
83}
84
85sub chkTrailer
86{
87    my $self = shift;
88    my $trailer = shift;
89
90    my $ADLER32 = unpack("N", $trailer) ;
91    *$self->{Info}{ADLER32} = $ADLER32;
92    return $self->TrailerError("CRC mismatch")
93        if *$self->{Strict} && $ADLER32 != *$self->{Uncomp}->adler32() ;
94
95    return STATUS_OK;
96}
97
98
99
100sub isZlibMagic
101{
102    my $self = shift;
103    my $buffer = shift ;
104
105    return 0
106        if length $buffer < ZLIB_HEADER_SIZE ;
107
108    my $hdr = unpack("n", $buffer) ;
109    #return 0 if $hdr % 31 != 0 ;
110    return $self->HeaderError("CRC mismatch.")
111        if $hdr % 31 != 0 ;
112
113    my ($CMF, $FLG) = unpack "C C", $buffer;
114    my $cm =    bits($CMF, ZLIB_CMF_CM_OFFSET,    ZLIB_CMF_CM_BITS) ;
115
116    # Only Deflate supported
117    return $self->HeaderError("Not Deflate (CM is $cm)")
118        if $cm != ZLIB_CMF_CM_DEFLATED ;
119
120    # Max window value is 7 for Deflate.
121    my $cinfo = bits($CMF, ZLIB_CMF_CINFO_OFFSET, ZLIB_CMF_CINFO_BITS) ;
122    return $self->HeaderError("CINFO > " . ZLIB_CMF_CINFO_MAX .
123                              " (CINFO is $cinfo)")
124        if $cinfo > ZLIB_CMF_CINFO_MAX ;
125
126    return 1;
127}
128
129sub bits
130{
131    my $data   = shift ;
132    my $offset = shift ;
133    my $mask  = shift ;
134
135    ($data >> $offset ) & $mask & 0xFF ;
136}
137
138
139sub _readDeflateHeader
140{
141    my ($self, $buffer) = @_ ;
142
143#    if (! $buffer) {
144#        $self->smartReadExact(\$buffer, ZLIB_HEADER_SIZE);
145#
146#        *$self->{HeaderPending} = $buffer ;
147#
148#        return $self->HeaderError("Header size is " .
149#                                            ZLIB_HEADER_SIZE . " bytes")
150#            if length $buffer != ZLIB_HEADER_SIZE;
151#
152#        return $self->HeaderError("CRC mismatch.")
153#            if ! isZlibMagic($buffer) ;
154#    }
155
156    my ($CMF, $FLG) = unpack "C C", $buffer;
157    my $FDICT = bits($FLG, ZLIB_FLG_FDICT_OFFSET,  ZLIB_FLG_FDICT_BITS ),
158
159    my $cm = bits($CMF, ZLIB_CMF_CM_OFFSET, ZLIB_CMF_CM_BITS) ;
160    $cm == ZLIB_CMF_CM_DEFLATED
161        or return $self->HeaderError("Not Deflate (CM is $cm)") ;
162
163    my $DICTID;
164    if ($FDICT) {
165        $self->smartReadExact(\$buffer, ZLIB_FDICT_SIZE)
166            or return $self->TruncatedHeader("FDICT");
167
168        $DICTID = unpack("N", $buffer) ;
169    }
170
171    *$self->{Type} = 'rfc1950';
172
173    return {
174        'Type'          => 'rfc1950',
175        'FingerprintLength'  => ZLIB_HEADER_SIZE,
176        'HeaderLength'  => ZLIB_HEADER_SIZE,
177        'TrailerLength' => ZLIB_TRAILER_SIZE,
178        'Header'        => $buffer,
179
180        CMF     =>      $CMF                                               ,
181        CM      => bits($CMF, ZLIB_CMF_CM_OFFSET,     ZLIB_CMF_CM_BITS    ),
182        CINFO   => bits($CMF, ZLIB_CMF_CINFO_OFFSET,  ZLIB_CMF_CINFO_BITS ),
183        FLG     =>      $FLG                                               ,
184        FCHECK  => bits($FLG, ZLIB_FLG_FCHECK_OFFSET, ZLIB_FLG_FCHECK_BITS),
185        FDICT   => bits($FLG, ZLIB_FLG_FDICT_OFFSET,  ZLIB_FLG_FDICT_BITS ),
186        FLEVEL  => bits($FLG, ZLIB_FLG_LEVEL_OFFSET,  ZLIB_FLG_LEVEL_BITS ),
187        DICTID  =>      $DICTID                                            ,
188
189    };
190}
191
192
193
194
1951 ;
196
197__END__
198
199
200=head1 NAME
201
202IO::Uncompress::Inflate - Read RFC 1950 files/buffers
203
204=head1 SYNOPSIS
205
206    use IO::Uncompress::Inflate qw(inflate $InflateError) ;
207
208    my $status = inflate $input => $output [,OPTS]
209        or die "inflate failed: $InflateError\n";
210
211    my $z = new IO::Uncompress::Inflate $input [OPTS]
212        or die "inflate failed: $InflateError\n";
213
214    $status = $z->read($buffer)
215    $status = $z->read($buffer, $length)
216    $status = $z->read($buffer, $length, $offset)
217    $line = $z->getline()
218    $char = $z->getc()
219    $char = $z->ungetc()
220    $char = $z->opened()
221
222    $status = $z->inflateSync()
223
224    $data = $z->trailingData()
225    $status = $z->nextStream()
226    $data = $z->getHeaderInfo()
227    $z->tell()
228    $z->seek($position, $whence)
229    $z->binmode()
230    $z->fileno()
231    $z->eof()
232    $z->close()
233
234    $InflateError ;
235
236    # IO::File mode
237
238    <$z>
239    read($z, $buffer);
240    read($z, $buffer, $length);
241    read($z, $buffer, $length, $offset);
242    tell($z)
243    seek($z, $position, $whence)
244    binmode($z)
245    fileno($z)
246    eof($z)
247    close($z)
248
249=head1 DESCRIPTION
250
251This module provides a Perl interface that allows the reading of
252files/buffers that conform to RFC 1950.
253
254For writing RFC 1950 files/buffers, see the companion module IO::Compress::Deflate.
255
256=head1 Functional Interface
257
258A top-level function, C<inflate>, is provided to carry out
259"one-shot" uncompression between buffers and/or files. For finer
260control over the uncompression process, see the L</"OO Interface">
261section.
262
263    use IO::Uncompress::Inflate qw(inflate $InflateError) ;
264
265    inflate $input => $output [,OPTS]
266        or die "inflate failed: $InflateError\n";
267
268The functional interface needs Perl5.005 or better.
269
270=head2 inflate $input => $output [, OPTS]
271
272C<inflate> expects at least two parameters, C<$input> and C<$output>.
273
274=head3 The C<$input> parameter
275
276The parameter, C<$input>, is used to define the source of
277the compressed data.
278
279It can take one of the following forms:
280
281=over 5
282
283=item A filename
284
285If the C<$input> parameter is a simple scalar, it is assumed to be a
286filename. This file will be opened for reading and the input data
287will be read from it.
288
289=item A filehandle
290
291If the C<$input> parameter is a filehandle, the input data will be
292read from it.
293The string '-' can be used as an alias for standard input.
294
295=item A scalar reference
296
297If C<$input> is a scalar reference, the input data will be read
298from C<$$input>.
299
300=item An array reference
301
302If C<$input> is an array reference, each element in the array must be a
303filename.
304
305The input data will be read from each file in turn.
306
307The complete array will be walked to ensure that it only
308contains valid filenames before any data is uncompressed.
309
310=item An Input FileGlob string
311
312If C<$input> is a string that is delimited by the characters "<" and ">"
313C<inflate> will assume that it is an I<input fileglob string>. The
314input is the list of files that match the fileglob.
315
316If the fileglob does not match any files ...
317
318See L<File::GlobMapper|File::GlobMapper> for more details.
319
320=back
321
322If the C<$input> parameter is any other type, C<undef> will be returned.
323
324=head3 The C<$output> parameter
325
326The parameter C<$output> is used to control the destination of the
327uncompressed data. This parameter can take one of these forms.
328
329=over 5
330
331=item A filename
332
333If the C<$output> parameter is a simple scalar, it is assumed to be a
334filename.  This file will be opened for writing and the uncompressed
335data will be written to it.
336
337=item A filehandle
338
339If the C<$output> parameter is a filehandle, the uncompressed data
340will be written to it.
341The string '-' can be used as an alias for standard output.
342
343=item A scalar reference
344
345If C<$output> is a scalar reference, the uncompressed data will be
346stored in C<$$output>.
347
348=item An Array Reference
349
350If C<$output> is an array reference, the uncompressed data will be
351pushed onto the array.
352
353=item An Output FileGlob
354
355If C<$output> is a string that is delimited by the characters "<" and ">"
356C<inflate> will assume that it is an I<output fileglob string>. The
357output is the list of files that match the fileglob.
358
359When C<$output> is an fileglob string, C<$input> must also be a fileglob
360string. Anything else is an error.
361
362=back
363
364If the C<$output> parameter is any other type, C<undef> will be returned.
365
366=head2 Notes
367
368When C<$input> maps to multiple compressed files/buffers and C<$output> is
369a single file/buffer, after uncompression C<$output> will contain a
370concatenation of all the uncompressed data from each of the input
371files/buffers.
372
373=head2 Optional Parameters
374
375Unless specified below, the optional parameters for C<inflate>,
376C<OPTS>, are the same as those used with the OO interface defined in the
377L</"Constructor Options"> section below.
378
379=over 5
380
381=item C<< AutoClose => 0|1 >>
382
383This option applies to any input or output data streams to
384C<inflate> that are filehandles.
385
386If C<AutoClose> is specified, and the value is true, it will result in all
387input and/or output filehandles being closed once C<inflate> has
388completed.
389
390This parameter defaults to 0.
391
392=item C<< BinModeOut => 0|1 >>
393
394When writing to a file or filehandle, set C<binmode> before writing to the
395file.
396
397Defaults to 0.
398
399=item C<< Append => 0|1 >>
400
401The behaviour of this option is dependent on the type of output data
402stream.
403
404=over 5
405
406=item * A Buffer
407
408If C<Append> is enabled, all uncompressed data will be append to the end of
409the output buffer. Otherwise the output buffer will be cleared before any
410uncompressed data is written to it.
411
412=item * A Filename
413
414If C<Append> is enabled, the file will be opened in append mode. Otherwise
415the contents of the file, if any, will be truncated before any uncompressed
416data is written to it.
417
418=item * A Filehandle
419
420If C<Append> is enabled, the filehandle will be positioned to the end of
421the file via a call to C<seek> before any uncompressed data is
422written to it.  Otherwise the file pointer will not be moved.
423
424=back
425
426When C<Append> is specified, and set to true, it will I<append> all uncompressed
427data to the output data stream.
428
429So when the output is a filehandle it will carry out a seek to the eof
430before writing any uncompressed data. If the output is a filename, it will be opened for
431appending. If the output is a buffer, all uncompressed data will be appened to
432the existing buffer.
433
434Conversely when C<Append> is not specified, or it is present and is set to
435false, it will operate as follows.
436
437When the output is a filename, it will truncate the contents of the file
438before writing any uncompressed data. If the output is a filehandle
439its position will not be changed. If the output is a buffer, it will be
440wiped before any uncompressed data is output.
441
442Defaults to 0.
443
444=item C<< MultiStream => 0|1 >>
445
446If the input file/buffer contains multiple compressed data streams, this
447option will uncompress the whole lot as a single data stream.
448
449Defaults to 0.
450
451=item C<< TrailingData => $scalar >>
452
453Returns the data, if any, that is present immediately after the compressed
454data stream once uncompression is complete.
455
456This option can be used when there is useful information immediately
457following the compressed data stream, and you don't know the length of the
458compressed data stream.
459
460If the input is a buffer, C<trailingData> will return everything from the
461end of the compressed data stream to the end of the buffer.
462
463If the input is a filehandle, C<trailingData> will return the data that is
464left in the filehandle input buffer once the end of the compressed data
465stream has been reached. You can then use the filehandle to read the rest
466of the input file.
467
468Don't bother using C<trailingData> if the input is a filename.
469
470If you know the length of the compressed data stream before you start
471uncompressing, you can avoid having to use C<trailingData> by setting the
472C<InputLength> option.
473
474=back
475
476=head2 Examples
477
478To read the contents of the file C<file1.txt.1950> and write the
479uncompressed data to the file C<file1.txt>.
480
481    use strict ;
482    use warnings ;
483    use IO::Uncompress::Inflate qw(inflate $InflateError) ;
484
485    my $input = "file1.txt.1950";
486    my $output = "file1.txt";
487    inflate $input => $output
488        or die "inflate failed: $InflateError\n";
489
490To read from an existing Perl filehandle, C<$input>, and write the
491uncompressed data to a buffer, C<$buffer>.
492
493    use strict ;
494    use warnings ;
495    use IO::Uncompress::Inflate qw(inflate $InflateError) ;
496    use IO::File ;
497
498    my $input = new IO::File "<file1.txt.1950"
499        or die "Cannot open 'file1.txt.1950': $!\n" ;
500    my $buffer ;
501    inflate $input => \$buffer
502        or die "inflate failed: $InflateError\n";
503
504To uncompress all files in the directory "/my/home" that match "*.txt.1950" and store the compressed data in the same directory
505
506    use strict ;
507    use warnings ;
508    use IO::Uncompress::Inflate qw(inflate $InflateError) ;
509
510    inflate '</my/home/*.txt.1950>' => '</my/home/#1.txt>'
511        or die "inflate failed: $InflateError\n";
512
513and if you want to compress each file one at a time, this will do the trick
514
515    use strict ;
516    use warnings ;
517    use IO::Uncompress::Inflate qw(inflate $InflateError) ;
518
519    for my $input ( glob "/my/home/*.txt.1950" )
520    {
521        my $output = $input;
522        $output =~ s/.1950// ;
523        inflate $input => $output
524            or die "Error compressing '$input': $InflateError\n";
525    }
526
527=head1 OO Interface
528
529=head2 Constructor
530
531The format of the constructor for IO::Uncompress::Inflate is shown below
532
533    my $z = new IO::Uncompress::Inflate $input [OPTS]
534        or die "IO::Uncompress::Inflate failed: $InflateError\n";
535
536Returns an C<IO::Uncompress::Inflate> object on success and undef on failure.
537The variable C<$InflateError> will contain an error message on failure.
538
539If you are running Perl 5.005 or better the object, C<$z>, returned from
540IO::Uncompress::Inflate can be used exactly like an L<IO::File|IO::File> filehandle.
541This means that all normal input file operations can be carried out with
542C<$z>.  For example, to read a line from a compressed file/buffer you can
543use either of these forms
544
545    $line = $z->getline();
546    $line = <$z>;
547
548The mandatory parameter C<$input> is used to determine the source of the
549compressed data. This parameter can take one of three forms.
550
551=over 5
552
553=item A filename
554
555If the C<$input> parameter is a scalar, it is assumed to be a filename. This
556file will be opened for reading and the compressed data will be read from it.
557
558=item A filehandle
559
560If the C<$input> parameter is a filehandle, the compressed data will be
561read from it.
562The string '-' can be used as an alias for standard input.
563
564=item A scalar reference
565
566If C<$input> is a scalar reference, the compressed data will be read from
567C<$$output>.
568
569=back
570
571=head2 Constructor Options
572
573The option names defined below are case insensitive and can be optionally
574prefixed by a '-'.  So all of the following are valid
575
576    -AutoClose
577    -autoclose
578    AUTOCLOSE
579    autoclose
580
581OPTS is a combination of the following options:
582
583=over 5
584
585=item C<< AutoClose => 0|1 >>
586
587This option is only valid when the C<$input> parameter is a filehandle. If
588specified, and the value is true, it will result in the file being closed once
589either the C<close> method is called or the IO::Uncompress::Inflate object is
590destroyed.
591
592This parameter defaults to 0.
593
594=item C<< MultiStream => 0|1 >>
595
596Allows multiple concatenated compressed streams to be treated as a single
597compressed stream. Decompression will stop once either the end of the
598file/buffer is reached, an error is encountered (premature eof, corrupt
599compressed data) or the end of a stream is not immediately followed by the
600start of another stream.
601
602This parameter defaults to 0.
603
604=item C<< Prime => $string >>
605
606This option will uncompress the contents of C<$string> before processing the
607input file/buffer.
608
609This option can be useful when the compressed data is embedded in another
610file/data structure and it is not possible to work out where the compressed
611data begins without having to read the first few bytes. If this is the
612case, the uncompression can be I<primed> with these bytes using this
613option.
614
615=item C<< Transparent => 0|1 >>
616
617If this option is set and the input file/buffer is not compressed data,
618the module will allow reading of it anyway.
619
620In addition, if the input file/buffer does contain compressed data and
621there is non-compressed data immediately following it, setting this option
622will make this module treat the whole file/bufffer as a single data stream.
623
624This option defaults to 1.
625
626=item C<< BlockSize => $num >>
627
628When reading the compressed input data, IO::Uncompress::Inflate will read it in
629blocks of C<$num> bytes.
630
631This option defaults to 4096.
632
633=item C<< InputLength => $size >>
634
635When present this option will limit the number of compressed bytes read
636from the input file/buffer to C<$size>. This option can be used in the
637situation where there is useful data directly after the compressed data
638stream and you know beforehand the exact length of the compressed data
639stream.
640
641This option is mostly used when reading from a filehandle, in which case
642the file pointer will be left pointing to the first byte directly after the
643compressed data stream.
644
645This option defaults to off.
646
647=item C<< Append => 0|1 >>
648
649This option controls what the C<read> method does with uncompressed data.
650
651If set to 1, all uncompressed data will be appended to the output parameter
652of the C<read> method.
653
654If set to 0, the contents of the output parameter of the C<read> method
655will be overwritten by the uncompressed data.
656
657Defaults to 0.
658
659=item C<< Strict => 0|1 >>
660
661This option controls whether the extra checks defined below are used when
662carrying out the decompression. When Strict is on, the extra tests are
663carried out, when Strict is off they are not.
664
665The default for this option is off.
666
667=over 5
668
669=item 1
670
671The ADLER32 checksum field must be present.
672
673=item 2
674
675The value of the ADLER32 field read must match the adler32 value of the
676uncompressed data actually contained in the file.
677
678=back
679
680=back
681
682=head2 Examples
683
684TODO
685
686=head1 Methods
687
688=head2 read
689
690Usage is
691
692    $status = $z->read($buffer)
693
694Reads a block of compressed data (the size the the compressed block is
695determined by the C<Buffer> option in the constructor), uncompresses it and
696writes any uncompressed data into C<$buffer>. If the C<Append> parameter is
697set in the constructor, the uncompressed data will be appended to the
698C<$buffer> parameter. Otherwise C<$buffer> will be overwritten.
699
700Returns the number of uncompressed bytes written to C<$buffer>, zero if eof
701or a negative number on error.
702
703=head2 read
704
705Usage is
706
707    $status = $z->read($buffer, $length)
708    $status = $z->read($buffer, $length, $offset)
709
710    $status = read($z, $buffer, $length)
711    $status = read($z, $buffer, $length, $offset)
712
713Attempt to read C<$length> bytes of uncompressed data into C<$buffer>.
714
715The main difference between this form of the C<read> method and the
716previous one, is that this one will attempt to return I<exactly> C<$length>
717bytes. The only circumstances that this function will not is if end-of-file
718or an IO error is encountered.
719
720Returns the number of uncompressed bytes written to C<$buffer>, zero if eof
721or a negative number on error.
722
723=head2 getline
724
725Usage is
726
727    $line = $z->getline()
728    $line = <$z>
729
730Reads a single line.
731
732This method fully supports the use of of the variable C<$/> (or
733C<$INPUT_RECORD_SEPARATOR> or C<$RS> when C<English> is in use) to
734determine what constitutes an end of line. Paragraph mode, record mode and
735file slurp mode are all supported.
736
737=head2 getc
738
739Usage is
740
741    $char = $z->getc()
742
743Read a single character.
744
745=head2 ungetc
746
747Usage is
748
749    $char = $z->ungetc($string)
750
751=head2 inflateSync
752
753Usage is
754
755    $status = $z->inflateSync()
756
757TODO
758
759=head2 getHeaderInfo
760
761Usage is
762
763    $hdr  = $z->getHeaderInfo();
764    @hdrs = $z->getHeaderInfo();
765
766This method returns either a hash reference (in scalar context) or a list
767or hash references (in array context) that contains information about each
768of the header fields in the compressed data stream(s).
769
770=head2 tell
771
772Usage is
773
774    $z->tell()
775    tell $z
776
777Returns the uncompressed file offset.
778
779=head2 eof
780
781Usage is
782
783    $z->eof();
784    eof($z);
785
786Returns true if the end of the compressed input stream has been reached.
787
788=head2 seek
789
790    $z->seek($position, $whence);
791    seek($z, $position, $whence);
792
793Provides a sub-set of the C<seek> functionality, with the restriction
794that it is only legal to seek forward in the input file/buffer.
795It is a fatal error to attempt to seek backward.
796
797The C<$whence> parameter takes one the usual values, namely SEEK_SET,
798SEEK_CUR or SEEK_END.
799
800Returns 1 on success, 0 on failure.
801
802=head2 binmode
803
804Usage is
805
806    $z->binmode
807    binmode $z ;
808
809This is a noop provided for completeness.
810
811=head2 opened
812
813    $z->opened()
814
815Returns true if the object currently refers to a opened file/buffer.
816
817=head2 autoflush
818
819    my $prev = $z->autoflush()
820    my $prev = $z->autoflush(EXPR)
821
822If the C<$z> object is associated with a file or a filehandle, this method
823returns the current autoflush setting for the underlying filehandle. If
824C<EXPR> is present, and is non-zero, it will enable flushing after every
825write/print operation.
826
827If C<$z> is associated with a buffer, this method has no effect and always
828returns C<undef>.
829
830B<Note> that the special variable C<$|> B<cannot> be used to set or
831retrieve the autoflush setting.
832
833=head2 input_line_number
834
835    $z->input_line_number()
836    $z->input_line_number(EXPR)
837
838Returns the current uncompressed line number. If C<EXPR> is present it has
839the effect of setting the line number. Note that setting the line number
840does not change the current position within the file/buffer being read.
841
842The contents of C<$/> are used to to determine what constitutes a line
843terminator.
844
845=head2 fileno
846
847    $z->fileno()
848    fileno($z)
849
850If the C<$z> object is associated with a file or a filehandle, C<fileno>
851will return the underlying file descriptor. Once the C<close> method is
852called C<fileno> will return C<undef>.
853
854If the C<$z> object is is associated with a buffer, this method will return
855C<undef>.
856
857=head2 close
858
859    $z->close() ;
860    close $z ;
861
862Closes the output file/buffer.
863
864For most versions of Perl this method will be automatically invoked if
865the IO::Uncompress::Inflate object is destroyed (either explicitly or by the
866variable with the reference to the object going out of scope). The
867exceptions are Perl versions 5.005 through 5.00504 and 5.8.0. In
868these cases, the C<close> method will be called automatically, but
869not until global destruction of all live objects when the program is
870terminating.
871
872Therefore, if you want your scripts to be able to run on all versions
873of Perl, you should call C<close> explicitly and not rely on automatic
874closing.
875
876Returns true on success, otherwise 0.
877
878If the C<AutoClose> option has been enabled when the IO::Uncompress::Inflate
879object was created, and the object is associated with a file, the
880underlying file will also be closed.
881
882=head2 nextStream
883
884Usage is
885
886    my $status = $z->nextStream();
887
888Skips to the next compressed data stream in the input file/buffer. If a new
889compressed data stream is found, the eof marker will be cleared and C<$.>
890will be reset to 0.
891
892Returns 1 if a new stream was found, 0 if none was found, and -1 if an
893error was encountered.
894
895=head2 trailingData
896
897Usage is
898
899    my $data = $z->trailingData();
900
901Returns the data, if any, that is present immediately after the compressed
902data stream once uncompression is complete. It only makes sense to call
903this method once the end of the compressed data stream has been
904encountered.
905
906This option can be used when there is useful information immediately
907following the compressed data stream, and you don't know the length of the
908compressed data stream.
909
910If the input is a buffer, C<trailingData> will return everything from the
911end of the compressed data stream to the end of the buffer.
912
913If the input is a filehandle, C<trailingData> will return the data that is
914left in the filehandle input buffer once the end of the compressed data
915stream has been reached. You can then use the filehandle to read the rest
916of the input file.
917
918Don't bother using C<trailingData> if the input is a filename.
919
920If you know the length of the compressed data stream before you start
921uncompressing, you can avoid having to use C<trailingData> by setting the
922C<InputLength> option in the constructor.
923
924=head1 Importing
925
926No symbolic constants are required by this IO::Uncompress::Inflate at present.
927
928=over 5
929
930=item :all
931
932Imports C<inflate> and C<$InflateError>.
933Same as doing this
934
935    use IO::Uncompress::Inflate qw(inflate $InflateError) ;
936
937=back
938
939=head1 EXAMPLES
940
941=head2 Working with Net::FTP
942
943See L<IO::Uncompress::Inflate::FAQ|IO::Uncompress::Inflate::FAQ/"Compressed files and Net::FTP">
944
945=head1 SEE ALSO
946
947L<Compress::Zlib>, L<IO::Compress::Gzip>, L<IO::Uncompress::Gunzip>, L<IO::Compress::Deflate>, L<IO::Compress::RawDeflate>, L<IO::Uncompress::RawInflate>, L<IO::Compress::Bzip2>, L<IO::Uncompress::Bunzip2>, L<IO::Compress::Lzma>, L<IO::Uncompress::UnLzma>, L<IO::Compress::Xz>, L<IO::Uncompress::UnXz>, L<IO::Compress::Lzop>, L<IO::Uncompress::UnLzop>, L<IO::Compress::Lzf>, L<IO::Uncompress::UnLzf>, L<IO::Uncompress::AnyInflate>, L<IO::Uncompress::AnyUncompress>
948
949L<Compress::Zlib::FAQ|Compress::Zlib::FAQ>
950
951L<File::GlobMapper|File::GlobMapper>, L<Archive::Zip|Archive::Zip>,
952L<Archive::Tar|Archive::Tar>,
953L<IO::Zlib|IO::Zlib>
954
955For RFC 1950, 1951 and 1952 see
956F<http://www.faqs.org/rfcs/rfc1950.html>,
957F<http://www.faqs.org/rfcs/rfc1951.html> and
958F<http://www.faqs.org/rfcs/rfc1952.html>
959
960The I<zlib> compression library was written by Jean-loup Gailly
961F<gzip@prep.ai.mit.edu> and Mark Adler F<madler@alumni.caltech.edu>.
962
963The primary site for the I<zlib> compression library is
964F<http://www.zlib.org>.
965
966The primary site for gzip is F<http://www.gzip.org>.
967
968=head1 AUTHOR
969
970This module was written by Paul Marquess, F<pmqs@cpan.org>.
971
972=head1 MODIFICATION HISTORY
973
974See the Changes file.
975
976=head1 COPYRIGHT AND LICENSE
977
978Copyright (c) 2005-2010 Paul Marquess. All rights reserved.
979
980This program is free software; you can redistribute it and/or
981modify it under the same terms as Perl itself.
982
983