IO::Uncompress::RawInflate(3perl) - man - phpMan

 


IO::Uncompress::RawInflate(3perl)
NAME SYNOPSIS DESCRIPTION Functional Interface Methods Importing EXAMPLES SUPPORT SEE ALSO AUTHOR MODIFICATION HISTORY COPYRIGHT AND LICENSE
NAME
    IO::Uncompress::RawInflate - Read RFC 1951 files/buffers

SYNOPSIS
        use IO::Uncompress::RawInflate qw(rawinflate $RawInflateError) ;

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

        my $z = IO::Uncompress::RawInflate->new( $input [OPTS] )
            or die "rawinflate failed: $RawInflateError\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()

        $RawInflateError ;

        # 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)

DESCRIPTION
    This module provides a Perl interface that allows the reading of
    files/buffers that conform to RFC 1951.

    For writing RFC 1951 files/buffers, see the companion module
    IO::Compress::RawDeflate.

Functional Interface
    A top-level function, "rawinflate", 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::RawInflate qw(rawinflate $RawInflateError) ;

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

    The functional interface needs Perl5.005 or better.

  rawinflate $input_filename_or_reference => $output_filename_or_reference [, OPTS]
    "rawinflate" expects at least two parameters,
    $input_filename_or_reference and $output_filename_or_reference and zero
    or more optional parameters (see "Optional Parameters")

   The $input_filename_or_reference parameter
    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 ">" "rawinflate" will assume that it is an
         *input fileglob string*. 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.

   The $output_filename_or_reference parameter
    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 ">" "rawinflate" will assume that it is an
         *output fileglob string*. 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.

  Notes
    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.

  Optional Parameters
    The optional parameters for the one-shot function "rawinflate" 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
         "rawinflate" 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
         "rawinflate" 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 *append* 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"
         This option is a no-op.

    "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.

  Examples
    To read the contents of the file "file1.txt.1951" and write the
    uncompressed data to the file "file1.txt".

        use strict ;
        use warnings ;
        use IO::Uncompress::RawInflate qw(rawinflate $RawInflateError) ;

        my $input = "file1.txt.1951";
        my $output = "file1.txt";
        rawinflate $input => $output
            or die "rawinflate failed: $RawInflateError\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::RawInflate qw(rawinflate $RawInflateError) ;
        use IO::File ;

        my $input = IO::File->new( "<file1.txt.1951" )
            or die "Cannot open 'file1.txt.1951': $!\n" ;
        my $buffer ;
        rawinflate $input => \$buffer
            or die "rawinflate failed: $RawInflateError\n";

    To uncompress all files in the directory "/my/home" that match
    "*.txt.1951" and store the compressed data in the same directory

        use strict ;
        use warnings ;
        use IO::Uncompress::RawInflate qw(rawinflate $RawInflateError) ;

        rawinflate '</my/home/*.txt.1951>' => '</my/home/#1.txt>'
            or die "rawinflate failed: $RawInflateError\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::RawInflate qw(rawinflate $RawInflateError) ;

        for my $input ( glob "/my/home/*.txt.1951" )
        {
            my $output = $input;
            $output =~ s/.1951// ;
            rawinflate $input => $output
                or die "Error compressing '$input': $RawInflateError\n";
        }

OO Interface
  Constructor
    The format of the constructor for IO::Uncompress::RawInflate is shown
    below

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

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

    If you are running Perl 5.005 or better the object, $z, returned from
    IO::Uncompress::RawInflate 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.

  Constructor Options
    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::RawInflate 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 *primed*
         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::RawInflate
         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 is a no-op.

  Examples
    TODO

Methods
  read
    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.

  read
    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 *exactly* $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.

  getline
    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.

  getc
    Usage is

        $char = $z->getc()

    Read a single character.

  ungetc
    Usage is

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

  inflateSync
    Usage is

        $status = $z->inflateSync()

    TODO

  getHeaderInfo
    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).

  tell
    Usage is

        $z->tell()
        tell $z

    Returns the uncompressed file offset.

  eof
    Usage is

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

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

  seek
        $z->seek($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.

  binmode
    Usage is

        $z->binmode
        binmode $z ;

    This is a noop provided for completeness.

  opened
        $z->opened()

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

  autoflush
        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".

    Note that the special variable $| cannot be used to set or retrieve the
    autoflush setting.

  input_line_number
        $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.

  fileno
        $z->fileno()
        fileno($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".

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

    Closes the output file/buffer.

    For most versions of Perl this method will be automatically invoked if
    the IO::Uncompress::RawInflate 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::RawInflate object was created, and the object is
    associated with a file, the underlying file will also be closed.

  nextStream
    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.

  trailingData
    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.

Importing
    No symbolic constants are required by IO::Uncompress::RawInflate at
    present.

    :all Imports "rawinflate" and $RawInflateError. Same as doing this

             use IO::Uncompress::RawInflate qw(rawinflate $RawInflateError) ;

EXAMPLES
  Working with Net::FTP
    See IO::Compress::FAQ

SUPPORT
    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>.

SEE ALSO
    Compress::Zlib, IO::Compress::Gzip, IO::Uncompress::Gunzip,
    IO::Compress::Deflate, IO::Uncompress::Inflate,
    IO::Compress::RawDeflate, 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::AnyInflate, IO::Uncompress::AnyUncompress

    IO::Compress::FAQ

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

    For RFC 1950, 1951 and 1952 see <http://www.faqs.org/rfcs/rfc1950.html>,
    <http://www.faqs.org/rfcs/rfc1951.html> and
    <http://www.faqs.org/rfcs/rfc1952.html>

    The *zlib* compression library was written by Jean-loup Gailly
    "gzip AT prep.edu" and Mark Adler "madler AT alumni.edu".

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

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

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

MODIFICATION HISTORY
    See the Changes file.

COPYRIGHT AND LICENSE
    Copyright (c) 2005-2021 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.


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