Provided by: perl-doc_5.14.2-6ubuntu2_all bug

NAME

       IO::Compress::Zip - Write zip files/buffers

SYNOPSIS

           use IO::Compress::Zip qw(zip $ZipError) ;

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

           my $z = new IO::Compress::Zip $output [,OPTS]
               or die "zip failed: $ZipError\n";

           $z->print($string);
           $z->printf($format, $string);
           $z->write($string);
           $z->syswrite($string [, $length, $offset]);
           $z->flush();
           $z->tell();
           $z->eof();
           $z->seek($position, $whence);
           $z->binmode();
           $z->fileno();
           $z->opened();
           $z->autoflush();
           $z->input_line_number();
           $z->newStream( [OPTS] );

           $z->deflateParams();

           $z->close() ;

           $ZipError ;

           # IO::File mode

           print $z $string;
           printf $z $format, $string;
           tell $z
           eof $z
           seek $z, $position, $whence
           binmode $z
           fileno $z
           close $z ;

DESCRIPTION

       This module provides a Perl interface that allows writing zip compressed data to files or
       buffer.

       The primary purpose of this module is to provide streaming write access to zip files and
       buffers. It is not a general-purpose file archiver. If that is what you want, check out
       "Archive::Zip".

       At present three compression methods are supported by IO::Compress::Zip, namely Store (no
       compression at all), Deflate and Bzip2.

       Note that to create Bzip2 content, the module "IO::Compress::Bzip2" must be installed.

       For reading zip files/buffers, see the companion module IO::Uncompress::Unzip.

Functional Interface

       A top-level function, "zip", is provided to carry out "one-shot" compression between
       buffers and/or files. For finer control over the compression process, see the "OO
       Interface" section.

           use IO::Compress::Zip qw(zip $ZipError) ;

           zip $input => $output [,OPTS]
               or die "zip failed: $ZipError\n";

       The functional interface needs Perl5.005 or better.

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

       The $input parameter

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

       An Input FileGlob string
            If $input is a string that is delimited by the characters "<" and ">" "zip" 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 parameter is any other type, "undef" will be returned.

       In addition, if $input is a simple filename, the default values for the "Name", "Time",
       "ExtAttr" and "exTime" options will be sourced from that file.

       If you do not want to use these defaults they can be overridden by explicitly setting the
       "Name", "Time", "ExtAttr" and "exTime" options or by setting the "Minimal" parameter.

       The $output parameter

       The parameter $output is used to control the destination of the compressed 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 compressed data will be written to it.

       A filehandle
            If the $output parameter is a filehandle, the compressed 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 compressed data will be stored in $$output.

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

       An Output FileGlob
            If $output is a string that is delimited by the characters "<" and ">" "zip" 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.

            See File::GlobMapper for more details.

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

   Notes
       When $input maps to multiple files/buffers and $output is a single file/buffer the input
       files/buffers will each be stored in $output as a distinct entry.

   Optional Parameters
       Unless specified below, the optional parameters for "zip", "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 "zip" 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 "zip" has completed.

            This parameter defaults to 0.

       "BinModeIn => 0|1"
            When reading from a file or filehandle, set "binmode" before reading.

            Defaults to 0.

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

            ·    A Buffer

                 If "Append" is enabled, all compressed data will be append to the end of the
                 output buffer. Otherwise the output buffer will be cleared before any compressed
                 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 compressed 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 compressed 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 compressed 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 compressed data. If the output is a filename, it will be opened for appending. If
            the output is a buffer, all compressed 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 compressed 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 compressed data is
            output.

            Defaults to 0.

   Examples
       To read the contents of the file "file1.txt" and write the compressed data to the file
       "file1.txt.zip".

           use strict ;
           use warnings ;
           use IO::Compress::Zip qw(zip $ZipError) ;

           my $input = "file1.txt";
           zip $input => "$input.zip"
               or die "zip failed: $ZipError\n";

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

           use strict ;
           use warnings ;
           use IO::Compress::Zip qw(zip $ZipError) ;
           use IO::File ;

           my $input = new IO::File "<file1.txt"
               or die "Cannot open 'file1.txt': $!\n" ;
           my $buffer ;
           zip $input => \$buffer
               or die "zip failed: $ZipError\n";

       To create a zip file, "output.zip", that contains the compressed contents of the files
       "alpha.txt" and "beta.txt"

           use strict ;
           use warnings ;
           use IO::Compress::Zip qw(zip $ZipError) ;

           zip [ 'alpha.txt', 'beta.txt' ] => 'output.zip'
               or die "zip failed: $ZipError\n";

       Alternatively, rather than having to explicitly name each of the files that you want to
       compress, you could use a fileglob to select all the "txt" files in the current directory,
       as follows

           use strict ;
           use warnings ;
           use IO::Compress::Zip qw(zip $ZipError) ;

           my @files = <*.txt>;
           zip \@files => 'output.zip'
               or die "zip failed: $ZipError\n";

       or more succinctly

           zip [ <*.txt> ] => 'output.zip'
               or die "zip failed: $ZipError\n";

OO Interface

   Constructor
       The format of the constructor for "IO::Compress::Zip" is shown below

           my $z = new IO::Compress::Zip $output [,OPTS]
               or die "IO::Compress::Zip failed: $ZipError\n";

       It returns an "IO::Compress::Zip" object on success and undef on failure.  The variable
       $ZipError will contain an error message on failure.

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

           $z->print("hello world\n");
           print $z "hello world\n";

       The mandatory parameter $output is used to control the destination of the compressed 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 compressed data will be written to it.

       A filehandle
            If the $output parameter is a filehandle, the compressed 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 compressed data will be stored in $$output.

       If the $output parameter is any other type, "IO::Compress::Zip"::new will return undef.

   Constructor Options
       "OPTS" is any combination of the following options:

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

            This parameter defaults to 0.

       "Append => 0|1"
            Opens $output in append mode.

            The behaviour of this option is dependent on the type of $output.

            ·    A Buffer

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

            ·    A Filename

                 If $output is a filename and "Append" is enabled, the file will be opened in
                 append mode. Otherwise the contents of the file, if any, will be truncated
                 before any compressed data is written to it.

            ·    A Filehandle

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

            This parameter defaults to 0.

       "Name => $string"
            Stores the contents of $string in the zip filename header field.

            If "Name" is not specified and the $input parameter is a filename that will be used
            for the zip filename header field.

            If "Name" is not specified and the $input parameter is not a filename, no zip
            filename field will be created.

       "Time => $number"
            Sets the last modified time field in the zip header to $number.

            This field defaults to the time the "IO::Compress::Zip" object was created if this
            option is not specified and the $input parameter is not a filename.

       "ExtAttr => $attr"
            This option controls the "external file attributes" field in the central header of
            the zip file. This is a 4 byte field.

            If you are running a Unix derivative this value defaults to

                0100644 << 16

            This should allow read/write access to any files that are extracted from the zip
            file/buffer`.

            For all other systems it defaults to 0.

       "exTime => [$atime, $mtime, $ctime]"
            This option expects an array reference with exactly three elements: $atime, "mtime"
            and $ctime. These correspond to the last access time, last modification time and
            creation time respectively.

            It uses these values to set the extended timestamp field (ID is "UT") in the local
            zip header using the three values, $atime, $mtime, $ctime. In addition it sets the
            extended timestamp field in the central zip header using $mtime.

            If any of the three values is "undef" that time value will not be used.  So, for
            example, to set only the $mtime you would use this

                exTime => [undef, $mtime, undef]

            If the "Minimal" option is set to true, this option will be ignored.

            By default no extended time field is created.

       "exUnix2 => [$uid, $gid]"
            This option expects an array reference with exactly two elements: $uid and $gid.
            These values correspond to the numeric user ID and group ID of the owner of the files
            respectively.

            When the "exUnix2" option is present it will trigger the creation of a Unix2 extra
            field (ID is "Ux") in the local zip. This will be populated with $uid and $gid. In
            addition an empty Unix2 extra field will also be created in the central zip header

            If the "Minimal" option is set to true, this option will be ignored.

            By default no Unix2 extra field is created.

       "Comment => $comment"
            Stores the contents of $comment in the Central File Header of the zip file.

            By default, no comment field is written to the zip file.

       "ZipComment => $comment"
            Stores the contents of $comment in the End of Central Directory record of the zip
            file.

            By default, no comment field is written to the zip file.

       "Method => $method"
            Controls which compression method is used. At present three compression methods are
            supported, namely Store (no compression at all), Deflate and Bzip2.

            The symbols, ZIP_CM_STORE, ZIP_CM_DEFLATE and ZIP_CM_BZIP2 are used to select the
            compression method.

            These constants are not imported by "IO::Compress::Zip" by default.

                use IO::Compress::Zip qw(:zip_method);
                use IO::Compress::Zip qw(:constants);
                use IO::Compress::Zip qw(:all);

            Note that to create Bzip2 content, the module "IO::Compress::Bzip2" must be
            installed. A fatal error will be thrown if you attempt to create Bzip2 content when
            "IO::Compress::Bzip2" is not available.

            The default method is ZIP_CM_DEFLATE.

       "Stream => 0|1"
            This option controls whether the zip file/buffer output is created in streaming mode.

            Note that when outputting to a file with streaming mode disabled ("Stream" is 0), the
            output file must be seekable.

            The default is 1.

       "Zip64 => 0|1"
            Create a Zip64 zip file/buffer. This option should only be used if you want to store
            files larger than 4 Gig.

            If you intend to manipulate the Zip64 zip files created with this module using an
            external zip/unzip make sure that it supports Zip64.

            In particular, if you are using Info-Zip you need to have zip version 3.x or better
            to update a Zip64 archive and unzip version 6.x to read a zip64 archive.

            The default is 0.

       "TextFlag => 0|1"
            This parameter controls the setting of a bit in the zip central header. It is used to
            signal that the data stored in the zip file/buffer is probably text.

            The default is 0.

       "ExtraFieldLocal => $data" =item "ExtraFieldCentral => $data"
            The "ExtraFieldLocal" option is used to store additional metadata in the local header
            for the zip file/buffer. The "ExtraFieldCentral" does the same for the matching
            central header.

            An extra field consists of zero or more subfields. Each subfield consists of a two
            byte header followed by the subfield data.

            The list of subfields can be supplied in any of the following formats

                ExtraFieldLocal => [$id1, $data1,
                                    $id2, $data2,
                                     ...
                                   ]

                ExtraFieldLocal => [ [$id1 => $data1],
                                     [$id2 => $data2],
                                     ...
                                   ]

                ExtraFieldLocal => { $id1 => $data1,
                                     $id2 => $data2,
                                     ...
                                   }

            Where $id1, $id2 are two byte subfield ID's.

            If you use the hash syntax, you have no control over the order in which the
            ExtraSubFields are stored, plus you cannot have SubFields with duplicate ID.

            Alternatively the list of subfields can by supplied as a scalar, thus

                ExtraField => $rawdata

            The Extended Time field (ID "UT"), set using the "exTime" option, and the Unix2 extra
            field (ID "Ux), set using the "exUnix2" option, are examples of extra fields.

            If the "Minimal" option is set to true, this option will be ignored.

            The maximum size of an extra field 65535 bytes.

       "Minimal => 1|0"
            If specified, this option will disable the creation of all extra fields in the zip
            local and central headers. So the "exTime", "exUnix2", "ExtraFieldLocal" and
            "ExtraFieldCentral" options will be ignored.

            This parameter defaults to 0.

       "BlockSize100K => number"
            Specify the number of 100K blocks bzip2 uses during compression.

            Valid values are from 1 to 9, where 9 is best compression.

            This option is only valid if the "Method" is ZIP_CM_BZIP2. It is ignored otherwise.

            The default is 1.

       "WorkFactor => number"
            Specifies how much effort bzip2 should take before resorting to a slower fallback
            compression algorithm.

            Valid values range from 0 to 250, where 0 means use the default value 30.

            This option is only valid if the "Method" is ZIP_CM_BZIP2. It is ignored otherwise.

            The default is 0.

       -Level
            Defines the compression level used by zlib. The value should either be a number
            between 0 and 9 (0 means no compression and 9 is maximum compression), or one of the
            symbolic constants defined below.

               Z_NO_COMPRESSION
               Z_BEST_SPEED
               Z_BEST_COMPRESSION
               Z_DEFAULT_COMPRESSION

            The default is Z_DEFAULT_COMPRESSION.

            Note, these constants are not imported by "IO::Compress::Zip" by default.

                use IO::Compress::Zip qw(:strategy);
                use IO::Compress::Zip qw(:constants);
                use IO::Compress::Zip qw(:all);

       -Strategy
            Defines the strategy used to tune the compression. Use one of the symbolic constants
            defined below.

               Z_FILTERED
               Z_HUFFMAN_ONLY
               Z_RLE
               Z_FIXED
               Z_DEFAULT_STRATEGY

            The default is Z_DEFAULT_STRATEGY.

       "Strict => 0|1"
            This is a placeholder option.

   Examples
       TODO

Methods

   print
       Usage is

           $z->print($data)
           print $z $data

       Compresses and outputs the contents of the $data parameter. This has the same behaviour as
       the "print" built-in.

       Returns true if successful.

   printf
       Usage is

           $z->printf($format, $data)
           printf $z $format, $data

       Compresses and outputs the contents of the $data parameter.

       Returns true if successful.

   syswrite
       Usage is

           $z->syswrite $data
           $z->syswrite $data, $length
           $z->syswrite $data, $length, $offset

       Compresses and outputs the contents of the $data parameter.

       Returns the number of uncompressed bytes written, or "undef" if unsuccessful.

   write
       Usage is

           $z->write $data
           $z->write $data, $length
           $z->write $data, $length, $offset

       Compresses and outputs the contents of the $data parameter.

       Returns the number of uncompressed bytes written, or "undef" if unsuccessful.

   flush
       Usage is

           $z->flush;
           $z->flush($flush_type);

       Flushes any pending compressed data to the output file/buffer.

       This method takes an optional parameter, $flush_type, that controls how the flushing will
       be carried out. By default the $flush_type used is "Z_FINISH". Other valid values for
       $flush_type are "Z_NO_FLUSH", "Z_SYNC_FLUSH", "Z_FULL_FLUSH" and "Z_BLOCK". It is strongly
       recommended that you only set the "flush_type" parameter if you fully understand the
       implications of what it does - overuse of "flush" can seriously degrade the level of
       compression achieved. See the "zlib" documentation for details.

       Returns true on success.

   tell
       Usage is

           $z->tell()
           tell $z

       Returns the uncompressed file offset.

   eof
       Usage is

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

       Returns true if the "close" method has been called.

   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 output file/buffer.  It is a fatal error to attempt to seek
       backward.

       Empty parts of the file/buffer will have NULL (0x00) bytes written to them.

       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)

       This method always returns "undef" when compressing.

   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 ;

       Flushes any pending compressed data and then closes the output file/buffer.

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

   newStream([OPTS])
       Usage is

           $z->newStream( [OPTS] )

       Closes the current compressed data stream and starts a new one.

       OPTS consists of any of the the options that are available when creating the $z object.

       See the "Constructor Options" section for more details.

   deflateParams
       Usage is

           $z->deflateParams

       TODO

Importing

       A number of symbolic constants are required by some methods in "IO::Compress::Zip". None
       are imported by default.

       :all Imports "zip", $ZipError and all symbolic constants that can be used by
            "IO::Compress::Zip". Same as doing this

                use IO::Compress::Zip qw(zip $ZipError :constants) ;

       :constants
            Import all symbolic constants. Same as doing this

                use IO::Compress::Zip qw(:flush :level :strategy :zip_method) ;

       :flush
            These symbolic constants are used by the "flush" method.

                Z_NO_FLUSH
                Z_PARTIAL_FLUSH
                Z_SYNC_FLUSH
                Z_FULL_FLUSH
                Z_FINISH
                Z_BLOCK

       :level
            These symbolic constants are used by the "Level" option in the constructor.

                Z_NO_COMPRESSION
                Z_BEST_SPEED
                Z_BEST_COMPRESSION
                Z_DEFAULT_COMPRESSION

       :strategy
            These symbolic constants are used by the "Strategy" option in the constructor.

                Z_FILTERED
                Z_HUFFMAN_ONLY
                Z_RLE
                Z_FIXED
                Z_DEFAULT_STRATEGY

       :zip_method
            These symbolic constants are used by the "Method" option in the constructor.

                ZIP_CM_STORE
                ZIP_CM_DEFLATE
                ZIP_CM_BZIP2

EXAMPLES

   Apache::GZip Revisited
       See IO::Compress::FAQ

   Working with Net::FTP
       See IO::Compress::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::Compress::Lzma, IO::Uncompress::UnLzma,
       IO::Compress::Xz, IO::Uncompress::UnXz, 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) 2005-2011 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.