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IO::Uncompress::AnyInfUser(Contributed Perl DocumIO::Uncompress::AnyInflate(3)



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

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

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

           my $z = new IO::Uncompress::AnyInflate $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)

DESCRIPTION
       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.

Functional Interface
       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 => $output [,OPTS]
               or die "anyinflate failed: $AnyInflateError\n";

       The functional interface needs Perl5.005 or better.

       anyinflate $input => $output [, OPTS]

       "anyinflate" 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 ">" "anyinflate" will assume that it is
            an input fileglob string. The input is the list of files that match the fileglob.

            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 ">" "anyinflate" 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 "anyinflate", "OPTS", are the same as those used with the
       OO interface defined in the "Constructor Options" section 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"
            When writing to a file or filehandle, set "binmode" before writing to the file.

            Defaults to 0.

       "Append => 0|1"
            TODO

       "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.

       Examples

       To read the contents of the file "file1.txt.Compressed" and write the compressed 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 = new IO::File "<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";
           }

OO Interface
       Constructor

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

           my $z = new IO::Uncompress::AnyInflate $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 $$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 IO::Uncom-
            press::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, cor-
            rupt 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 imme-
            diately 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::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 uncom-
            pressed 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 con-
                 tained 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.

       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.

       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).

       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.

       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 num-
       ber. 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 descrip-
       tor. 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::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" explic-
       itly 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.

       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 encoun-
       tered.

       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::AnyInflate at present.

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

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

EXAMPLES
       Working with Net::FTP

       See IO::Uncompress::AnyInflate::FAQ

SEE ALSO
       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::Com-
       press::Lzop, IO::Uncompress::UnLzop, IO::Compress::Lzf, IO::Uncompress::UnLzf, 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 gzipATprep.edu and Mark Adler
       madlerATalumni.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, pmqsATcpan.org.

MODIFICATION HISTORY
       See the Changes file.

COPYRIGHT AND LICENSE
       Copyright (c) 2005-2008 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 v5.8.8                       2008-09-03     IO::Uncompress::AnyInflate(3)