1package IO::Uncompress::Inflate ; 2# for RFC1950 3 4use strict ; 5use warnings; 6use bytes; 7 8use IO::Compress::Base::Common 2.101 qw(:Status ); 9use IO::Compress::Zlib::Constants 2.101 ; 10 11use IO::Uncompress::RawInflate 2.101 ; 12 13require Exporter ; 14our ($VERSION, @ISA, @EXPORT_OK, %EXPORT_TAGS, $InflateError); 15 16$VERSION = '2.101'; 17$InflateError = ''; 18 19@ISA = qw(IO::Uncompress::RawInflate Exporter); 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 $obj = IO::Compress::Base::Common::createSelfTiedObject($class, \$InflateError); 30 31 $obj->_create(undef, 0, @_); 32} 33 34sub inflate 35{ 36 my $obj = IO::Compress::Base::Common::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->setValue('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 = IO::Uncompress::Inflate->new( $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_filename_or_reference => $output_filename_or_reference [,OPTS] 266 or die "inflate failed: $InflateError\n"; 267 268The functional interface needs Perl5.005 or better. 269 270=head2 inflate $input_filename_or_reference => $output_filename_or_reference [, OPTS] 271 272C<inflate> expects at least two parameters, 273C<$input_filename_or_reference> and C<$output_filename_or_reference> 274and zero or more optional parameters (see L</Optional Parameters>) 275 276=head3 The C<$input_filename_or_reference> parameter 277 278The parameter, C<$input_filename_or_reference>, is used to define the 279source of the compressed data. 280 281It can take one of the following forms: 282 283=over 5 284 285=item A filename 286 287If the C<$input_filename_or_reference> parameter is a simple scalar, it is 288assumed to be a filename. This file will be opened for reading and the 289input data will be read from it. 290 291=item A filehandle 292 293If the C<$input_filename_or_reference> parameter is a filehandle, the input 294data will be read from it. The string '-' can be used as an alias for 295standard input. 296 297=item A scalar reference 298 299If C<$input_filename_or_reference> is a scalar reference, the input data 300will be read from C<$$input_filename_or_reference>. 301 302=item An array reference 303 304If C<$input_filename_or_reference> is an array reference, each element in 305the array must be a filename. 306 307The input data will be read from each file in turn. 308 309The complete array will be walked to ensure that it only 310contains valid filenames before any data is uncompressed. 311 312=item An Input FileGlob string 313 314If C<$input_filename_or_reference> is a string that is delimited by the 315characters "<" and ">" C<inflate> will assume that it is an 316I<input fileglob string>. The input is the list of files that match the 317fileglob. 318 319See L<File::GlobMapper|File::GlobMapper> for more details. 320 321=back 322 323If the C<$input_filename_or_reference> parameter is any other type, 324C<undef> will be returned. 325 326=head3 The C<$output_filename_or_reference> parameter 327 328The parameter C<$output_filename_or_reference> is used to control the 329destination of the uncompressed data. This parameter can take one of 330these forms. 331 332=over 5 333 334=item A filename 335 336If the C<$output_filename_or_reference> parameter is a simple scalar, it is 337assumed to be a filename. This file will be opened for writing and the 338uncompressed data will be written to it. 339 340=item A filehandle 341 342If the C<$output_filename_or_reference> parameter is a filehandle, the 343uncompressed data will be written to it. The string '-' can be used as 344an alias for standard output. 345 346=item A scalar reference 347 348If C<$output_filename_or_reference> is a scalar reference, the 349uncompressed data will be stored in C<$$output_filename_or_reference>. 350 351=item An Array Reference 352 353If C<$output_filename_or_reference> is an array reference, 354the uncompressed data will be pushed onto the array. 355 356=item An Output FileGlob 357 358If C<$output_filename_or_reference> is a string that is delimited by the 359characters "<" and ">" C<inflate> will assume that it is an 360I<output fileglob string>. The output is the list of files that match the 361fileglob. 362 363When C<$output_filename_or_reference> is an fileglob string, 364C<$input_filename_or_reference> must also be a fileglob string. Anything 365else is an error. 366 367See L<File::GlobMapper|File::GlobMapper> for more details. 368 369=back 370 371If the C<$output_filename_or_reference> parameter is any other type, 372C<undef> will be returned. 373 374=head2 Notes 375 376When C<$input_filename_or_reference> maps to multiple compressed 377files/buffers and C<$output_filename_or_reference> is 378a single file/buffer, after uncompression C<$output_filename_or_reference> will contain a 379concatenation of all the uncompressed data from each of the input 380files/buffers. 381 382=head2 Optional Parameters 383 384The optional parameters for the one-shot function C<inflate> 385are (for the most part) identical to those used with the OO interface defined in the 386L</"Constructor Options"> section. The exceptions are listed below 387 388=over 5 389 390=item C<< AutoClose => 0|1 >> 391 392This option applies to any input or output data streams to 393C<inflate> that are filehandles. 394 395If C<AutoClose> is specified, and the value is true, it will result in all 396input and/or output filehandles being closed once C<inflate> has 397completed. 398 399This parameter defaults to 0. 400 401=item C<< BinModeOut => 0|1 >> 402 403This option is now a no-op. All files will be written in binmode. 404 405=item C<< Append => 0|1 >> 406 407The behaviour of this option is dependent on the type of output data 408stream. 409 410=over 5 411 412=item * A Buffer 413 414If C<Append> is enabled, all uncompressed data will be append to the end of 415the output buffer. Otherwise the output buffer will be cleared before any 416uncompressed data is written to it. 417 418=item * A Filename 419 420If C<Append> is enabled, the file will be opened in append mode. Otherwise 421the contents of the file, if any, will be truncated before any uncompressed 422data is written to it. 423 424=item * A Filehandle 425 426If C<Append> is enabled, the filehandle will be positioned to the end of 427the file via a call to C<seek> before any uncompressed data is 428written to it. Otherwise the file pointer will not be moved. 429 430=back 431 432When C<Append> is specified, and set to true, it will I<append> all uncompressed 433data to the output data stream. 434 435So when the output is a filehandle it will carry out a seek to the eof 436before writing any uncompressed data. If the output is a filename, it will be opened for 437appending. If the output is a buffer, all uncompressed data will be 438appended to the existing buffer. 439 440Conversely when C<Append> is not specified, or it is present and is set to 441false, it will operate as follows. 442 443When the output is a filename, it will truncate the contents of the file 444before writing any uncompressed data. If the output is a filehandle 445its position will not be changed. If the output is a buffer, it will be 446wiped before any uncompressed data is output. 447 448Defaults to 0. 449 450=item C<< MultiStream => 0|1 >> 451 452If the input file/buffer contains multiple compressed data streams, this 453option will uncompress the whole lot as a single data stream. 454 455Defaults to 0. 456 457=item C<< TrailingData => $scalar >> 458 459Returns the data, if any, that is present immediately after the compressed 460data stream once uncompression is complete. 461 462This option can be used when there is useful information immediately 463following the compressed data stream, and you don't know the length of the 464compressed data stream. 465 466If the input is a buffer, C<trailingData> will return everything from the 467end of the compressed data stream to the end of the buffer. 468 469If the input is a filehandle, C<trailingData> will return the data that is 470left in the filehandle input buffer once the end of the compressed data 471stream has been reached. You can then use the filehandle to read the rest 472of the input file. 473 474Don't bother using C<trailingData> if the input is a filename. 475 476If you know the length of the compressed data stream before you start 477uncompressing, you can avoid having to use C<trailingData> by setting the 478C<InputLength> option. 479 480=back 481 482=head2 Examples 483 484To read the contents of the file C<file1.txt.1950> and write the 485uncompressed data to the file C<file1.txt>. 486 487 use strict ; 488 use warnings ; 489 use IO::Uncompress::Inflate qw(inflate $InflateError) ; 490 491 my $input = "file1.txt.1950"; 492 my $output = "file1.txt"; 493 inflate $input => $output 494 or die "inflate failed: $InflateError\n"; 495 496To read from an existing Perl filehandle, C<$input>, and write the 497uncompressed data to a buffer, C<$buffer>. 498 499 use strict ; 500 use warnings ; 501 use IO::Uncompress::Inflate qw(inflate $InflateError) ; 502 use IO::File ; 503 504 my $input = IO::File->new( "<file1.txt.1950" ) 505 or die "Cannot open 'file1.txt.1950': $!\n" ; 506 my $buffer ; 507 inflate $input => \$buffer 508 or die "inflate failed: $InflateError\n"; 509 510To uncompress all files in the directory "/my/home" that match "*.txt.1950" and store the compressed data in the same directory 511 512 use strict ; 513 use warnings ; 514 use IO::Uncompress::Inflate qw(inflate $InflateError) ; 515 516 inflate '</my/home/*.txt.1950>' => '</my/home/#1.txt>' 517 or die "inflate failed: $InflateError\n"; 518 519and if you want to compress each file one at a time, this will do the trick 520 521 use strict ; 522 use warnings ; 523 use IO::Uncompress::Inflate qw(inflate $InflateError) ; 524 525 for my $input ( glob "/my/home/*.txt.1950" ) 526 { 527 my $output = $input; 528 $output =~ s/.1950// ; 529 inflate $input => $output 530 or die "Error compressing '$input': $InflateError\n"; 531 } 532 533=head1 OO Interface 534 535=head2 Constructor 536 537The format of the constructor for IO::Uncompress::Inflate is shown below 538 539 my $z = IO::Uncompress::Inflate->new( $input [OPTS] ) 540 or die "IO::Uncompress::Inflate failed: $InflateError\n"; 541 542Returns an C<IO::Uncompress::Inflate> object on success and undef on failure. 543The variable C<$InflateError> will contain an error message on failure. 544 545If you are running Perl 5.005 or better the object, C<$z>, returned from 546IO::Uncompress::Inflate can be used exactly like an L<IO::File|IO::File> filehandle. 547This means that all normal input file operations can be carried out with 548C<$z>. For example, to read a line from a compressed file/buffer you can 549use either of these forms 550 551 $line = $z->getline(); 552 $line = <$z>; 553 554The mandatory parameter C<$input> is used to determine the source of the 555compressed data. This parameter can take one of three forms. 556 557=over 5 558 559=item A filename 560 561If the C<$input> parameter is a scalar, it is assumed to be a filename. This 562file will be opened for reading and the compressed data will be read from it. 563 564=item A filehandle 565 566If the C<$input> parameter is a filehandle, the compressed data will be 567read from it. 568The string '-' can be used as an alias for standard input. 569 570=item A scalar reference 571 572If C<$input> is a scalar reference, the compressed data will be read from 573C<$$input>. 574 575=back 576 577=head2 Constructor Options 578 579The option names defined below are case insensitive and can be optionally 580prefixed by a '-'. So all of the following are valid 581 582 -AutoClose 583 -autoclose 584 AUTOCLOSE 585 autoclose 586 587OPTS is a combination of the following options: 588 589=over 5 590 591=item C<< AutoClose => 0|1 >> 592 593This option is only valid when the C<$input> parameter is a filehandle. If 594specified, and the value is true, it will result in the file being closed once 595either the C<close> method is called or the IO::Uncompress::Inflate object is 596destroyed. 597 598This parameter defaults to 0. 599 600=item C<< MultiStream => 0|1 >> 601 602Allows multiple concatenated compressed streams to be treated as a single 603compressed stream. Decompression will stop once either the end of the 604file/buffer is reached, an error is encountered (premature eof, corrupt 605compressed data) or the end of a stream is not immediately followed by the 606start of another stream. 607 608This parameter defaults to 0. 609 610=item C<< Prime => $string >> 611 612This option will uncompress the contents of C<$string> before processing the 613input file/buffer. 614 615This option can be useful when the compressed data is embedded in another 616file/data structure and it is not possible to work out where the compressed 617data begins without having to read the first few bytes. If this is the 618case, the uncompression can be I<primed> with these bytes using this 619option. 620 621=item C<< Transparent => 0|1 >> 622 623If this option is set and the input file/buffer is not compressed data, 624the module will allow reading of it anyway. 625 626In addition, if the input file/buffer does contain compressed data and 627there is non-compressed data immediately following it, setting this option 628will make this module treat the whole file/buffer as a single data stream. 629 630This option defaults to 1. 631 632=item C<< BlockSize => $num >> 633 634When reading the compressed input data, IO::Uncompress::Inflate will read it in 635blocks of C<$num> bytes. 636 637This option defaults to 4096. 638 639=item C<< InputLength => $size >> 640 641When present this option will limit the number of compressed bytes read 642from the input file/buffer to C<$size>. This option can be used in the 643situation where there is useful data directly after the compressed data 644stream and you know beforehand the exact length of the compressed data 645stream. 646 647This option is mostly used when reading from a filehandle, in which case 648the file pointer will be left pointing to the first byte directly after the 649compressed data stream. 650 651This option defaults to off. 652 653=item C<< Append => 0|1 >> 654 655This option controls what the C<read> method does with uncompressed data. 656 657If set to 1, all uncompressed data will be appended to the output parameter 658of the C<read> method. 659 660If set to 0, the contents of the output parameter of the C<read> method 661will be overwritten by the uncompressed data. 662 663Defaults to 0. 664 665=item C<< Strict => 0|1 >> 666 667This option controls whether the extra checks defined below are used when 668carrying out the decompression. When Strict is on, the extra tests are 669carried out, when Strict is off they are not. 670 671The default for this option is off. 672 673=over 5 674 675=item 1 676 677The ADLER32 checksum field must be present. 678 679=item 2 680 681The value of the ADLER32 field read must match the adler32 value of the 682uncompressed data actually contained in the file. 683 684=back 685 686=back 687 688=head2 Examples 689 690TODO 691 692=head1 Methods 693 694=head2 read 695 696Usage is 697 698 $status = $z->read($buffer) 699 700Reads a block of compressed data (the size of the compressed block is 701determined by the C<Buffer> option in the constructor), uncompresses it and 702writes any uncompressed data into C<$buffer>. If the C<Append> parameter is 703set in the constructor, the uncompressed data will be appended to the 704C<$buffer> parameter. Otherwise C<$buffer> will be overwritten. 705 706Returns the number of uncompressed bytes written to C<$buffer>, zero if eof 707or a negative number on error. 708 709=head2 read 710 711Usage is 712 713 $status = $z->read($buffer, $length) 714 $status = $z->read($buffer, $length, $offset) 715 716 $status = read($z, $buffer, $length) 717 $status = read($z, $buffer, $length, $offset) 718 719Attempt to read C<$length> bytes of uncompressed data into C<$buffer>. 720 721The main difference between this form of the C<read> method and the 722previous one, is that this one will attempt to return I<exactly> C<$length> 723bytes. The only circumstances that this function will not is if end-of-file 724or an IO error is encountered. 725 726Returns the number of uncompressed bytes written to C<$buffer>, zero if eof 727or a negative number on error. 728 729=head2 getline 730 731Usage is 732 733 $line = $z->getline() 734 $line = <$z> 735 736Reads a single line. 737 738This method fully supports the use of the variable C<$/> (or 739C<$INPUT_RECORD_SEPARATOR> or C<$RS> when C<English> is in use) to 740determine what constitutes an end of line. Paragraph mode, record mode and 741file slurp mode are all supported. 742 743=head2 getc 744 745Usage is 746 747 $char = $z->getc() 748 749Read a single character. 750 751=head2 ungetc 752 753Usage is 754 755 $char = $z->ungetc($string) 756 757=head2 inflateSync 758 759Usage is 760 761 $status = $z->inflateSync() 762 763TODO 764 765=head2 getHeaderInfo 766 767Usage is 768 769 $hdr = $z->getHeaderInfo(); 770 @hdrs = $z->getHeaderInfo(); 771 772This method returns either a hash reference (in scalar context) or a list 773or hash references (in array context) that contains information about each 774of the header fields in the compressed data stream(s). 775 776=head2 tell 777 778Usage is 779 780 $z->tell() 781 tell $z 782 783Returns the uncompressed file offset. 784 785=head2 eof 786 787Usage is 788 789 $z->eof(); 790 eof($z); 791 792Returns true if the end of the compressed input stream has been reached. 793 794=head2 seek 795 796 $z->seek($position, $whence); 797 seek($z, $position, $whence); 798 799Provides a sub-set of the C<seek> functionality, with the restriction 800that it is only legal to seek forward in the input file/buffer. 801It is a fatal error to attempt to seek backward. 802 803Note that the implementation of C<seek> in this module does not provide 804true random access to a compressed file/buffer. It works by uncompressing 805data from the current offset in the file/buffer until it reaches the 806uncompressed offset specified in the parameters to C<seek>. For very small 807files this may be acceptable behaviour. For large files it may cause an 808unacceptable delay. 809 810The C<$whence> parameter takes one the usual values, namely SEEK_SET, 811SEEK_CUR or SEEK_END. 812 813Returns 1 on success, 0 on failure. 814 815=head2 binmode 816 817Usage is 818 819 $z->binmode 820 binmode $z ; 821 822This is a noop provided for completeness. 823 824=head2 opened 825 826 $z->opened() 827 828Returns true if the object currently refers to a opened file/buffer. 829 830=head2 autoflush 831 832 my $prev = $z->autoflush() 833 my $prev = $z->autoflush(EXPR) 834 835If the C<$z> object is associated with a file or a filehandle, this method 836returns the current autoflush setting for the underlying filehandle. If 837C<EXPR> is present, and is non-zero, it will enable flushing after every 838write/print operation. 839 840If C<$z> is associated with a buffer, this method has no effect and always 841returns C<undef>. 842 843B<Note> that the special variable C<$|> B<cannot> be used to set or 844retrieve the autoflush setting. 845 846=head2 input_line_number 847 848 $z->input_line_number() 849 $z->input_line_number(EXPR) 850 851Returns the current uncompressed line number. If C<EXPR> is present it has 852the effect of setting the line number. Note that setting the line number 853does not change the current position within the file/buffer being read. 854 855The contents of C<$/> are used to determine what constitutes a line 856terminator. 857 858=head2 fileno 859 860 $z->fileno() 861 fileno($z) 862 863If the C<$z> object is associated with a file or a filehandle, C<fileno> 864will return the underlying file descriptor. Once the C<close> method is 865called C<fileno> will return C<undef>. 866 867If the C<$z> object is associated with a buffer, this method will return 868C<undef>. 869 870=head2 close 871 872 $z->close() ; 873 close $z ; 874 875Closes the output file/buffer. 876 877For most versions of Perl this method will be automatically invoked if 878the IO::Uncompress::Inflate object is destroyed (either explicitly or by the 879variable with the reference to the object going out of scope). The 880exceptions are Perl versions 5.005 through 5.00504 and 5.8.0. In 881these cases, the C<close> method will be called automatically, but 882not until global destruction of all live objects when the program is 883terminating. 884 885Therefore, if you want your scripts to be able to run on all versions 886of Perl, you should call C<close> explicitly and not rely on automatic 887closing. 888 889Returns true on success, otherwise 0. 890 891If the C<AutoClose> option has been enabled when the IO::Uncompress::Inflate 892object was created, and the object is associated with a file, the 893underlying file will also be closed. 894 895=head2 nextStream 896 897Usage is 898 899 my $status = $z->nextStream(); 900 901Skips to the next compressed data stream in the input file/buffer. If a new 902compressed data stream is found, the eof marker will be cleared and C<$.> 903will be reset to 0. 904 905Returns 1 if a new stream was found, 0 if none was found, and -1 if an 906error was encountered. 907 908=head2 trailingData 909 910Usage is 911 912 my $data = $z->trailingData(); 913 914Returns the data, if any, that is present immediately after the compressed 915data stream once uncompression is complete. It only makes sense to call 916this method once the end of the compressed data stream has been 917encountered. 918 919This option can be used when there is useful information immediately 920following the compressed data stream, and you don't know the length of the 921compressed data stream. 922 923If the input is a buffer, C<trailingData> will return everything from the 924end of the compressed data stream to the end of the buffer. 925 926If the input is a filehandle, C<trailingData> will return the data that is 927left in the filehandle input buffer once the end of the compressed data 928stream has been reached. You can then use the filehandle to read the rest 929of the input file. 930 931Don't bother using C<trailingData> if the input is a filename. 932 933If you know the length of the compressed data stream before you start 934uncompressing, you can avoid having to use C<trailingData> by setting the 935C<InputLength> option in the constructor. 936 937=head1 Importing 938 939No symbolic constants are required by IO::Uncompress::Inflate at present. 940 941=over 5 942 943=item :all 944 945Imports C<inflate> and C<$InflateError>. 946Same as doing this 947 948 use IO::Uncompress::Inflate qw(inflate $InflateError) ; 949 950=back 951 952=head1 EXAMPLES 953 954=head2 Working with Net::FTP 955 956See L<IO::Compress::FAQ|IO::Compress::FAQ/"Compressed files and Net::FTP"> 957 958=head1 SUPPORT 959 960General feedback/questions/bug reports should be sent to 961L<https://github.com/pmqs/IO-Compress/issues> (preferred) or 962L<https://rt.cpan.org/Public/Dist/Display.html?Name=IO-Compress>. 963 964=head1 SEE ALSO 965 966L<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::Lzip>, L<IO::Uncompress::UnLzip>, L<IO::Compress::Lzop>, L<IO::Uncompress::UnLzop>, L<IO::Compress::Lzf>, L<IO::Uncompress::UnLzf>, L<IO::Compress::Zstd>, L<IO::Uncompress::UnZstd>, L<IO::Uncompress::AnyInflate>, L<IO::Uncompress::AnyUncompress> 967 968L<IO::Compress::FAQ|IO::Compress::FAQ> 969 970L<File::GlobMapper|File::GlobMapper>, L<Archive::Zip|Archive::Zip>, 971L<Archive::Tar|Archive::Tar>, 972L<IO::Zlib|IO::Zlib> 973 974For RFC 1950, 1951 and 1952 see 975L<http://www.faqs.org/rfcs/rfc1950.html>, 976L<http://www.faqs.org/rfcs/rfc1951.html> and 977L<http://www.faqs.org/rfcs/rfc1952.html> 978 979The I<zlib> compression library was written by Jean-loup Gailly 980C<gzip@prep.ai.mit.edu> and Mark Adler C<madler@alumni.caltech.edu>. 981 982The primary site for the I<zlib> compression library is 983L<http://www.zlib.org>. 984 985The primary site for gzip is L<http://www.gzip.org>. 986 987=head1 AUTHOR 988 989This module was written by Paul Marquess, C<pmqs@cpan.org>. 990 991=head1 MODIFICATION HISTORY 992 993See the Changes file. 994 995=head1 COPYRIGHT AND LICENSE 996 997Copyright (c) 2005-2021 Paul Marquess. All rights reserved. 998 999This program is free software; you can redistribute it and/or 1000modify it under the same terms as Perl itself. 1001