IO::Uncompress::AnyInflate(3p) Perl Programmers Reference Guide

IO::Uncompress::AnyInflate(3p) Perl Programmers Reference Guide #

IO::Uncompress::AnyInflate(3p) Perl Programmers Reference Guide

NNAAMMEE #

 IO::Uncompress::AnyInflate - Uncompress zlib-based (zip, gzip)
 file/buffer

SSYYNNOOPPSSIISS #

     use IO::Uncompress::AnyInflate qw(anyinflate $AnyInflateError) ;

     my $status = anyinflate $input => $output [,OPTS]
         or die "anyinflate failed: $AnyInflateError\n";

     my $z = IO::Uncompress::AnyInflate->new( $input [OPTS] )
         or die "anyinflate failed: $AnyInflateError\n";

     $status = $z->read($buffer)
     $status = $z->read($buffer, $length)
     $status = $z->read($buffer, $length, $offset)
     $line = $z->getline()
     $char = $z->getc()
     $char = $z->ungetc()
     $char = $z->opened()

     $status = $z->inflateSync()

     $data = $z->trailingData()
     $status = $z->nextStream()
     $data = $z->getHeaderInfo()
     $z->tell()
     $z->seek($position, $whence)
     $z->binmode()
     $z->fileno()
     $z->eof()
     $z->close()

     $AnyInflateError ;

     # IO::File mode

     <$z>
     read($z, $buffer);
     read($z, $buffer, $length);
     read($z, $buffer, $length, $offset);
     tell($z)
     seek($z, $position, $whence)
     binmode($z)
     fileno($z)
     eof($z)
     close($z)

DDEESSCCRRIIPPTTIIOONN #

 This module provides a Perl interface that allows the reading of
 files/buffers that have been compressed in a number of formats that use
 the zlib compression library.

 The formats supported are

RFC 1950 #

 RFC 1951 (optionally)
 gzip (RFC 1952)
 zip

 The module will auto-detect which, if any, of the supported compression
 formats is being used.

FFuunnccttiioonnaall IInntteerrffaaccee A top-level function, “anyinflate”, is provided to carry out “one-shot” uncompression between buffers and/or files. For finer control over the uncompression process, see the “OO Interface” section.

     use IO::Uncompress::AnyInflate qw(anyinflate $AnyInflateError) ;

     anyinflate $input_filename_or_reference => $output_filename_or_reference [,OPTS]
         or die "anyinflate failed: $AnyInflateError\n";

 The functional interface needs Perl5.005 or better.

aannyyiinnffllaattee $$iinnppuutt__ffiilleennaammee__oorr__rreeffeerreennccee ==>> $$oouuttppuutt__ffiilleennaammee__oorr__rreeffeerreennccee [[,,

OOPPTTSS]] #

 "anyinflate" expects at least two parameters,
 $input_filename_or_reference and $output_filename_or_reference and zero
 or more optional parameters (see "Optional Parameters")

 _T_h_e _$_i_n_p_u_t___f_i_l_e_n_a_m_e___o_r___r_e_f_e_r_e_n_c_e _p_a_r_a_m_e_t_e_r

 The parameter, $input_filename_or_reference, is used to define the source
 of the compressed data.

 It can take one of the following forms:

 A filename
      If the $input_filename_or_reference parameter is a simple scalar, it
      is assumed to be a filename. This file will be opened for reading
      and the input data will be read from it.

 A filehandle
      If the $input_filename_or_reference parameter is a filehandle, the
      input data will be read from it.  The string '-' can be used as an
      alias for standard input.

 A scalar reference
      If $input_filename_or_reference is a scalar reference, the input
      data will be read from $$input_filename_or_reference.

 An array reference
      If $input_filename_or_reference is an array reference, each element
      in the array must be a filename.

      The input data will be read from each file in turn.

      The complete array will be walked to ensure that it only contains
      valid filenames before any data is uncompressed.

 An Input FileGlob string
      If $input_filename_or_reference is a string that is delimited by the
      characters "<" and ">" "anyinflate" will assume that it is an _i_n_p_u_t
      _f_i_l_e_g_l_o_b _s_t_r_i_n_g. The input is the list of files that match the
      fileglob.

      See File::GlobMapper for more details.

 If the $input_filename_or_reference parameter is any other type, "undef"
 will be returned.

 _T_h_e _$_o_u_t_p_u_t___f_i_l_e_n_a_m_e___o_r___r_e_f_e_r_e_n_c_e _p_a_r_a_m_e_t_e_r

 The parameter $output_filename_or_reference is used to control the
 destination of the uncompressed data. This parameter can take one of
 these forms.

 A filename
      If the $output_filename_or_reference parameter is a simple scalar,
      it is assumed to be a filename.  This file will be opened for
      writing and the uncompressed data will be written to it.

 A filehandle
      If the $output_filename_or_reference parameter is a filehandle, the
      uncompressed data will be written to it.  The string '-' can be used
      as an alias for standard output.

 A scalar reference
      If $output_filename_or_reference is a scalar reference, the
      uncompressed data will be stored in $$output_filename_or_reference.

 An Array Reference
      If $output_filename_or_reference is an array reference, the
      uncompressed data will be pushed onto the array.

 An Output FileGlob
      If $output_filename_or_reference is a string that is delimited by
      the characters "<" and ">" "anyinflate" will assume that it is an
      _o_u_t_p_u_t _f_i_l_e_g_l_o_b _s_t_r_i_n_g. The output is the list of files that match
      the fileglob.

      When $output_filename_or_reference is an fileglob string,
      $input_filename_or_reference must also be a fileglob string.
      Anything else is an error.

      See File::GlobMapper for more details.

 If the $output_filename_or_reference parameter is any other type, "undef"
 will be returned.

NNootteess When $input_filename_or_reference maps to multiple compressed files/buffers and $output_filename_or_reference is a single file/buffer, after uncompression $output_filename_or_reference will contain a concatenation of all the uncompressed data from each of the input files/buffers.

OOppttiioonnaall PPaarraammeetteerrss The optional parameters for the one-shot function “anyinflate” are (for the most part) identical to those used with the OO interface defined in the “Constructor Options” section. The exceptions are listed below

 "AutoClose => 0|1"
      This option applies to any input or output data streams to
      "anyinflate" that are filehandles.

      If "AutoClose" is specified, and the value is true, it will result
      in all input and/or output filehandles being closed once
      "anyinflate" has completed.

      This parameter defaults to 0.

 "BinModeOut => 0|1"
      This option is now a no-op. All files will be written  in binmode.

 "Append => 0|1"
      The behaviour of this option is dependent on the type of output data
      stream.

      •    A Buffer

           If "Append" is enabled, all uncompressed data will be append to
           the end of the output buffer. Otherwise the output buffer will
           be cleared before any uncompressed data is written to it.

      •    A Filename

           If "Append" is enabled, the file will be opened in append mode.
           Otherwise the contents of the file, if any, will be truncated
           before any uncompressed data is written to it.

      •    A Filehandle

           If "Append" is enabled, the filehandle will be positioned to
           the end of the file via a call to "seek" before any
           uncompressed data is written to it.  Otherwise the file pointer
           will not be moved.

      When "Append" is specified, and set to true, it will _a_p_p_e_n_d all
      uncompressed data to the output data stream.

      So when the output is a filehandle it will carry out a seek to the
      eof before writing any uncompressed data. If the output is a
      filename, it will be opened for appending. If the output is a
      buffer, all uncompressed data will be appended to the existing
      buffer.

      Conversely when "Append" is not specified, or it is present and is
      set to false, it will operate as follows.

      When the output is a filename, it will truncate the contents of the
      file before writing any uncompressed data. If the output is a
      filehandle its position will not be changed. If the output is a
      buffer, it will be wiped before any uncompressed data is output.

      Defaults to 0.

 "MultiStream => 0|1"
      If the input file/buffer contains multiple compressed data streams,
      this option will uncompress the whole lot as a single data stream.

      Defaults to 0.

 "TrailingData => $scalar"
      Returns the data, if any, that is present immediately after the
      compressed data stream once uncompression is complete.

      This option can be used when there is useful information immediately
      following the compressed data stream, and you don't know the length
      of the compressed data stream.

      If the input is a buffer, "trailingData" will return everything from
      the end of the compressed data stream to the end of the buffer.

      If the input is a filehandle, "trailingData" will return the data
      that is left in the filehandle input buffer once the end of the
      compressed data stream has been reached. You can then use the
      filehandle to read the rest of the input file.

      Don't bother using "trailingData" if the input is a filename.

      If you know the length of the compressed data stream before you
      start uncompressing, you can avoid having to use "trailingData" by
      setting the "InputLength" option.

EExxaammpplleess To read the contents of the file “file1.txt.Compressed” and write the uncompressed data to the file “file1.txt”.

     use strict ;
     use warnings ;
     use IO::Uncompress::AnyInflate qw(anyinflate $AnyInflateError) ;

     my $input = "file1.txt.Compressed";
     my $output = "file1.txt";
     anyinflate $input => $output
         or die "anyinflate failed: $AnyInflateError\n";

 To read from an existing Perl filehandle, $input, and write the
 uncompressed data to a buffer, $buffer.

     use strict ;
     use warnings ;
     use IO::Uncompress::AnyInflate qw(anyinflate $AnyInflateError) ;
     use IO::File ;

     my $input = IO::File->new( "<file1.txt.Compressed" )
         or die "Cannot open 'file1.txt.Compressed': $!\n" ;
     my $buffer ;
     anyinflate $input => \$buffer
         or die "anyinflate failed: $AnyInflateError\n";

 To uncompress all files in the directory "/my/home" that match
 "*.txt.Compressed" and store the compressed data in the same directory

     use strict ;
     use warnings ;
     use IO::Uncompress::AnyInflate qw(anyinflate $AnyInflateError) ;

     anyinflate '</my/home/*.txt.Compressed>' => '</my/home/#1.txt>'
         or die "anyinflate failed: $AnyInflateError\n";

 and if you want to compress each file one at a time, this will do the
 trick

     use strict ;
     use warnings ;
     use IO::Uncompress::AnyInflate qw(anyinflate $AnyInflateError) ;

     for my $input ( glob "/my/home/*.txt.Compressed" )
     {
         my $output = $input;
         $output =~ s/.Compressed// ;
         anyinflate $input => $output
             or die "Error compressing '$input': $AnyInflateError\n";
     }

OOOO IInntteerrffaaccee CCoonnssttrruuccttoorr The format of the constructor for IO::Uncompress::AnyInflate is shown below

     my $z = IO::Uncompress::AnyInflate->new( $input [OPTS] )
         or die "IO::Uncompress::AnyInflate failed: $AnyInflateError\n";

 Returns an "IO::Uncompress::AnyInflate" object on success and undef on
 failure.  The variable $AnyInflateError will contain an error message on
 failure.

 If you are running Perl 5.005 or better the object, $z, returned from
 IO::Uncompress::AnyInflate can be used exactly like an IO::File
 filehandle.  This means that all normal input file operations can be
 carried out with $z.  For example, to read a line from a compressed
 file/buffer you can use either of these forms

     $line = $z->getline();
     $line = <$z>;

 The mandatory parameter $input is used to determine the source of the
 compressed data. This parameter can take one of three forms.

 A filename
      If the $input parameter is a scalar, it is assumed to be a filename.
      This file will be opened for reading and the compressed data will be
      read from it.

 A filehandle
      If the $input parameter is a filehandle, the compressed data will be
      read from it.  The string '-' can be used as an alias for standard
      input.

 A scalar reference
      If $input is a scalar reference, the compressed data will be read
      from $$input.

CCoonnssttrruuccttoorr OOppttiioonnss The option names defined below are case insensitive and can be optionally prefixed by a ‘-’. So all of the following are valid

     -AutoClose
     -autoclose

AUTOCLOSE #

     autoclose

 OPTS is a combination of the following options:

 "AutoClose => 0|1"
      This option is only valid when the $input parameter is a filehandle.
      If specified, and the value is true, it will result in the file
      being closed once either the "close" method is called or the
      IO::Uncompress::AnyInflate object is destroyed.

      This parameter defaults to 0.

 "MultiStream => 0|1"
      Allows multiple concatenated compressed streams to be treated as a
      single compressed stream. Decompression will stop once either the
      end of the file/buffer is reached, an error is encountered
      (premature eof, corrupt compressed data) or the end of a stream is
      not immediately followed by the start of another stream.

      This parameter defaults to 0.

 "Prime => $string"
      This option will uncompress the contents of $string before
      processing the input file/buffer.

      This option can be useful when the compressed data is embedded in
      another file/data structure and it is not possible to work out where
      the compressed data begins without having to read the first few
      bytes. If this is the case, the uncompression can be _p_r_i_m_e_d with
      these bytes using this option.

 "Transparent => 0|1"
      If this option is set and the input file/buffer is not compressed
      data, the module will allow reading of it anyway.

      In addition, if the input file/buffer does contain compressed data
      and there is non-compressed data immediately following it, setting
      this option will make this module treat the whole file/buffer as a
      single data stream.

      This option defaults to 1.

 "BlockSize => $num"
      When reading the compressed input data, IO::Uncompress::AnyInflate
      will read it in blocks of $num bytes.

      This option defaults to 4096.

 "InputLength => $size"
      When present this option will limit the number of compressed bytes
      read from the input file/buffer to $size. This option can be used in
      the situation where there is useful data directly after the
      compressed data stream and you know beforehand the exact length of
      the compressed data stream.

      This option is mostly used when reading from a filehandle, in which
      case the file pointer will be left pointing to the first byte
      directly after the compressed data stream.

      This option defaults to off.

 "Append => 0|1"
      This option controls what the "read" method does with uncompressed
      data.

      If set to 1, all uncompressed data will be appended to the output
      parameter of the "read" method.

      If set to 0, the contents of the output parameter of the "read"
      method will be overwritten by the uncompressed data.

      Defaults to 0.

 "Strict => 0|1"
      This option controls whether the extra checks defined below are used
      when carrying out the decompression. When Strict is on, the extra
      tests are carried out, when Strict is off they are not.

      The default for this option is off.

      If the input is an RFC 1950 data stream, the following will be
      checked:

      1.   The ADLER32 checksum field must be present.

      2.   The value of the ADLER32 field read must match the adler32
           value of the uncompressed data actually contained in the file.

      If the input is a gzip (RFC 1952) data stream, the following will be
      checked:

      1.   If the FHCRC bit is set in the gzip FLG header byte, the CRC16
           bytes in the header must match the crc16 value of the gzip
           header actually read.

      2.   If the gzip header contains a name field (FNAME) it consists
           solely of ISO 8859-1 characters.

      3.   If the gzip header contains a comment field (FCOMMENT) it
           consists solely of ISO 8859-1 characters plus line-feed.

      4.   If the gzip FEXTRA header field is present it must conform to
           the sub-field structure as defined in RFC 1952.

      5.   The CRC32 and ISIZE trailer fields must be present.

      6.   The value of the CRC32 field read must match the crc32 value of
           the uncompressed data actually contained in the gzip file.

      7.   The value of the ISIZE fields read must match the length of the
           uncompressed data actually read from the file.

 "RawInflate => 0|1"
      When auto-detecting the compressed format, try to test for raw-
      deflate (RFC 1951) content using the "IO::Uncompress::RawInflate"
      module.

      The reason this is not default behaviour is because RFC 1951 content
      can only be detected by attempting to uncompress it. This process is
      error prone and can result is false positives.

      Defaults to 0.

 "ParseExtra => 0|1" If the gzip FEXTRA header field is present and this
 option is set, it will force the module to check that it conforms to the
 sub-field structure as defined in RFC 1952.
      If the "Strict" is on it will automatically enable this option.

      Defaults to 0.

EExxaammpplleess

TODO #

MMeetthhooddss rreeaadd Usage is

     $status = $z->read($buffer)

 Reads a block of compressed data (the size of the compressed block is
 determined by the "Buffer" option in the constructor), uncompresses it
 and writes any uncompressed data into $buffer. If the "Append" parameter
 is set in the constructor, the uncompressed data will be appended to the
 $buffer parameter. Otherwise $buffer will be overwritten.

 Returns the number of uncompressed bytes written to $buffer, zero if eof
 or a negative number on error.

rreeaadd Usage is

     $status = $z->read($buffer, $length)
     $status = $z->read($buffer, $length, $offset)

     $status = read($z, $buffer, $length)
     $status = read($z, $buffer, $length, $offset)

 Attempt to read $length bytes of uncompressed data into $buffer.

 The main difference between this form of the "read" method and the
 previous one, is that this one will attempt to return _e_x_a_c_t_l_y $length
 bytes. The only circumstances that this function will not is if end-of-
 file or an IO error is encountered.

 Returns the number of uncompressed bytes written to $buffer, zero if eof
 or a negative number on error.

ggeettlliinnee Usage is

     $line = $z->getline()
     $line = <$z>

 Reads a single line.

 This method fully supports the use of the variable $/ (or
 $INPUT_RECORD_SEPARATOR or $RS when "English" is in use) to determine
 what constitutes an end of line. Paragraph mode, record mode and file
 slurp mode are all supported.

ggeettcc Usage is

     $char = $z->getc()

 Read a single character.

uunnggeettcc Usage is

     $char = $z->ungetc($string)

iinnffllaatteeSSyynncc Usage is

     $status = $z->inflateSync()

TODO #

ggeettHHeeaaddeerrIInnffoo Usage is

     $hdr  = $z->getHeaderInfo();
     @hdrs = $z->getHeaderInfo();

 This method returns either a hash reference (in scalar context) or a list
 or hash references (in array context) that contains information about
 each of the header fields in the compressed data stream(s).

tteellll Usage is

     $z->tell()
     tell $z

 Returns the uncompressed file offset.

eeooff Usage is

     $z->eof();
     eof($z);

 Returns true if the end of the compressed input stream has been reached.

sseeeekk $z->seek($position, $whence); seek($z, $position, $whence);

 Provides a sub-set of the "seek" functionality, with the restriction that
 it is only legal to seek forward in the input file/buffer.  It is a fatal
 error to attempt to seek backward.

 Note that the implementation of "seek" in this module does not provide
 true random access to a compressed file/buffer. It  works by
 uncompressing data from the current offset in the file/buffer until it
 reaches the uncompressed offset specified in the parameters to "seek".
 For very small files this may be acceptable behaviour. For large files it
 may cause an unacceptable delay.

 The $whence parameter takes one the usual values, namely SEEK_SET,
 SEEK_CUR or SEEK_END.

 Returns 1 on success, 0 on failure.

bbiinnmmooddee Usage is

     $z->binmode
     binmode $z ;

 This is a noop provided for completeness.

ooppeenneedd $z->opened()

 Returns true if the object currently refers to a opened file/buffer.

aauuttoofflluusshh my $prev = $z->autoflush() my $prev = $z->autoflush(EXPR)

 If the $z object is associated with a file or a filehandle, this method
 returns the current autoflush setting for the underlying filehandle. If
 "EXPR" is present, and is non-zero, it will enable flushing after every
 write/print operation.

 If $z is associated with a buffer, this method has no effect and always
 returns "undef".

 NNoottee that the special variable $| ccaannnnoott be used to set or retrieve the
 autoflush setting.

iinnppuutt__lliinnee__nnuummbbeerr $z->input_line_number() $z->input_line_number(EXPR)

 Returns the current uncompressed line number. If "EXPR" is present it has
 the effect of setting the line number. Note that setting the line number
 does not change the current position within the file/buffer being read.

 The contents of $/ are used to determine what constitutes a line
 terminator.

ffiilleennoo $z->fileno() fileno($z)

 If the $z object is associated with a file or a filehandle, "fileno" will
 return the underlying file descriptor. Once the "close" method is called
 "fileno" will return "undef".

 If the $z object is associated with a buffer, this method will return
 "undef".

cclloossee $z->close() ; close $z ;

 Closes the output file/buffer.

 For most versions of Perl this method will be automatically invoked if
 the IO::Uncompress::AnyInflate object is destroyed (either explicitly or
 by the variable with the reference to the object going out of scope). The
 exceptions are Perl versions 5.005 through 5.00504 and 5.8.0. In these
 cases, the "close" method will be called automatically, but not until
 global destruction of all live objects when the program is terminating.

 Therefore, if you want your scripts to be able to run on all versions of
 Perl, you should call "close" explicitly and not rely on automatic
 closing.

 Returns true on success, otherwise 0.

 If the "AutoClose" option has been enabled when the
 IO::Uncompress::AnyInflate object was created, and the object is
 associated with a file, the underlying file will also be closed.

nneexxttSSttrreeaamm Usage is

     my $status = $z->nextStream();

 Skips to the next compressed data stream in the input file/buffer. If a
 new compressed data stream is found, the eof marker will be cleared and
 $. will be reset to 0.

 Returns 1 if a new stream was found, 0 if none was found, and -1 if an
 error was encountered.

ttrraaiilliinnggDDaattaa Usage is

     my $data = $z->trailingData();

 Returns the data, if any, that is present immediately after the
 compressed data stream once uncompression is complete. It only makes
 sense to call this method once the end of the compressed data stream has
 been encountered.

 This option can be used when there is useful information immediately
 following the compressed data stream, and you don't know the length of
 the compressed data stream.

 If the input is a buffer, "trailingData" will return everything from the
 end of the compressed data stream to the end of the buffer.

 If the input is a filehandle, "trailingData" will return the data that is
 left in the filehandle input buffer once the end of the compressed data
 stream has been reached. You can then use the filehandle to read the rest
 of the input file.

 Don't bother using "trailingData" if the input is a filename.

 If you know the length of the compressed data stream before you start
 uncompressing, you can avoid having to use "trailingData" by setting the
 "InputLength" option in the constructor.

IImmppoorrttiinngg No symbolic constants are required by IO::Uncompress::AnyInflate at present.

 :all Imports "anyinflate" and $AnyInflateError.  Same as doing this

          use IO::Uncompress::AnyInflate qw(anyinflate $AnyInflateError) ;

EEXXAAMMPPLLEESS #

WWoorrkkiinngg wwiitthh NNeett::::FFTTPP See IO::Compress::FAQ

SSUUPPPPOORRTT #

 General feedback/questions/bug reports should be sent to
 <https://github.com/pmqs/IO-Compress/issues> (preferred) or
 <https://rt.cpan.org/Public/Dist/Display.html?Name=IO-Compress>.

SSEEEE AALLSSOO #

 Compress::Zlib, IO::Compress::Gzip, IO::Uncompress::Gunzip,
 IO::Compress::Deflate, IO::Uncompress::Inflate, IO::Compress::RawDeflate,
 IO::Uncompress::RawInflate, IO::Compress::Bzip2, IO::Uncompress::Bunzip2,
 IO::Compress::Lzma, IO::Uncompress::UnLzma, IO::Compress::Xz,
 IO::Uncompress::UnXz, IO::Compress::Lzip, IO::Uncompress::UnLzip,
 IO::Compress::Lzop, IO::Uncompress::UnLzop, IO::Compress::Lzf,
 IO::Uncompress::UnLzf, IO::Compress::Zstd, IO::Uncompress::UnZstd,
 IO::Uncompress::AnyUncompress

 IO::Compress::FAQ

 File::GlobMapper, Archive::Zip, Archive::Tar, IO::Zlib

 For RFC 1950, 1951 and 1952 see
 <https://datatracker.ietf.org/doc/html/rfc1950>,
 <https://datatracker.ietf.org/doc/html/rfc1951> and
 <https://datatracker.ietf.org/doc/html/rfc1952>

 The _z_l_i_b compression library was written by Jean-loup Gailly
 "gzip@prep.ai.mit.edu" and Mark Adler "madler@alumni.caltech.edu".

 The primary site for the _z_l_i_b compression library is
 <http://www.zlib.org>.

 The primary site for gzip is <http://www.gzip.org>.

AAUUTTHHOORR #

 This module was written by Paul Marquess, "pmqs@cpan.org".

MMOODDIIFFIICCAATTIIOONN HHIISSTTOORRYY #

 See the Changes file.

CCOOPPYYRRIIGGHHTT AANNDD LLIICCEENNSSEE #

 Copyright (c) 2005-2022 Paul Marquess. All rights reserved.

 This program is free software; you can redistribute it and/or modify it
 under the same terms as Perl itself.

perl v5.36.3 2023-02-15 IO::Uncompress::AnyInflate(3p)