


IO::Uncompress::RPerlfProgrammers RIO::Uncompress::RawInflate(3p)


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 = new IO::Uncompress::RawInflate $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.




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

       The functional interface needs Perl5.005 or better.

   rawinflate $input => $output [, OPTS]
       "rawinflate" expects at least two parameters, $input and
       $output.

       The $input parameter

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

       It can take one of the following forms:

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

       An array reference
            If $input 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 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.




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            If the fileglob does not match any files ...

            See File::GlobMapper for more details.

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

       The $output parameter

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

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

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

       An Output FileGlob
            If $output 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 is an fileglob string, $input must also
            be a fileglob string. Anything else is an error.

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

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

   Optional Parameters
       Unless specified below, the optional parameters for
       "rawinflate", "OPTS", are the same as those used with the
       OO interface defined in the "Constructor Options" section



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       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"
            When writing to a file or filehandle, set "binmode"
            before writing to the file.

            Defaults to 0.

       "Append => 0|1"
            TODO

       "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



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       write the compressed 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 = new IO::File "<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



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IO::Uncompress::RPerlfProgrammers RIO::Uncompress::RawInflate(3p)


       IO::Uncompress::RawInflate is shown below

           my $z = new IO::Uncompress::RawInflate $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 $$output.

   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



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            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/bufffer 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.




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            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 the 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.



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       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 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).





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   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.

       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.



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       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 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 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



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       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 this
       IO::Uncompress::RawInflate at present.

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

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



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EXAMPLES
   Working with Net::FTP
       See IO::Uncompress::RawInflate::FAQ

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::Lzop, IO::Uncompress::UnLzop,
       IO::Compress::Lzf, IO::Uncompress::UnLzf,
       IO::Uncompress::AnyInflate, IO::Uncompress::AnyUncompress

       Compress::Zlib::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@prep.ai.mit.edu and Mark Adler
       madler@alumni.caltech.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@cpan.org.

MODIFICATION HISTORY
       See the Changes file.

COPYRIGHT AND LICENSE
       Copyright (c) 2005-2009 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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