phpman > man > IO::Compress::Zip

Markdown | JSON | MCP    

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 = IO::Compress::Zip->new( $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.

    At present the following compression methods are supported by IO::Compress::Zip

    Store (0)
    Deflate (8)
    Bzip2 (12)
         To write Bzip2 content, the module "IO::Uncompress::Bunzip2" must be installed.

    Lzma (14)
         To write LZMA content, the module "IO::Uncompress::UnLzma" must be installed.

    Zstandard (93)
         To write Zstandard content, the module "IO::Compress::Zstd" must be installed.

    Xz (95)
         To write Xz content, the module "IO::Uncompress::UnXz" 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_filename_or_reference => $output_filename_or_reference [,OPTS]
            or die "zip failed: $ZipError\n";

    The functional interface needs Perl5.005 or better.

  zip $input_filename_or_reference => $output_filename_or_reference [, OPTS]
    "zip" 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 uncompressed
    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 compressed.

    An Input FileGlob string
         If $input_filename_or_reference 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_filename_or_reference parameter is any other type, "undef" will be returned.

    In addition, if $input_filename_or_reference is a simple filename, the default values for the
    "Name", "Time", "TextFlag", "ExtAttr", "exUnixN" 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", "TextFlag", "ExtAttr", "exUnixN" and "exTime" options or by setting the
    "Minimal" parameter.

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

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

    An Array Reference
         If $output_filename_or_reference is an array reference, the compressed 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
         ">" "zip" 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 files/buffers and
    $output_filename_or_reference is a single file/buffer the input files/buffers will each be
    stored in $output_filename_or_reference as a distinct entry.

  Optional Parameters
    The optional parameters for the one-shot function "zip" 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 "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"
         This option is now a no-op. All files will be read 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 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
    Here are a few example that show the capabilities of the module.

   Streaming
    This very simple command line example demonstrates the streaming capabilities of the module. The
    code reads data from STDIN, compresses it, and writes the compressed data to STDOUT.

        $ echo hello world | perl -MIO::Compress::Zip=zip -e 'zip \*STDIN => \*STDOUT' >output.zip

    The special filename "-" can be used as a standin for both "\*STDIN" and "\*STDOUT", so the
    above can be rewritten as

        $ echo hello world | perl -MIO::Compress::Zip=zip -e 'zip "-" => "-"' >output.zip

    One problem with creating a zip archive directly from STDIN can be demonstrated by looking at
    the contents of the zip file, output.zip, that we have just created.

        $ unzip -l output.zip
        Archive:  output.zip
        Length      Date    Time    Name
        ---------  ---------- -----   ----
            12  2019-08-16 22:21
        ---------                     -------
            12                     1 file

    The archive member (filename) used is the empty string.

    If that doesn't suit your needs, you can explicitly set the filename used in the zip archive by
    specifying the Name option, like so

        echo hello world | perl -MIO::Compress::Zip=zip -e 'zip "-" => "-", Name => "hello.txt"' >output.zip

    Now the contents of the zip file looks like this

        $ unzip -l output.zip
        Archive:  output.zip
        Length      Date    Time    Name
        ---------  ---------- -----   ----
            12  2019-08-16 22:22   hello.txt
        ---------                     -------
            12                     1 file

   Compressing a file from the filesystem
    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";

   Reading from a Filehandle and writing to an in-memory buffer
    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 = IO::File->new( "<file1.txt" )
            or die "Cannot open 'file1.txt': $!\n" ;
        my $buffer ;
        zip $input => \$buffer
            or die "zip failed: $ZipError\n";

   Compressing multiple files
    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 = IO::Compress::Zip->new( $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 zero or more 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.

   File Naming Options
    A quick bit of zip file terminology -- A zip archive consists of one or more *archive members*,
    where each member has an associated filename, known as the *archive member name*.

    The options listed in this section control how the *archive member name* (or filename) is stored
    the zip archive.

    "Name => $string"
         This option is used to explicitly set the *archive member name* in the zip archive to
         $string. Most of the time you don't need to make use of this option. By default when adding
         a filename to the zip archive, the *archive member name* will match the filename.

         You should only need to use this option if you want the *archive member name* to be
         different from the uncompressed filename or when the input is a filehandle or a buffer.

         The default behaviour for what *archive member name* is used when the "Name" option is
         *not* specified depends on the form of the $input parameter:

         *    If the $input parameter is a filename, the value of $input will be used for the
              *archive member name* .

         *    If the $input parameter is not a filename, the *archive member name* will be an empty
              string.

         Note that both the "CanonicalName" and "FilterName" options can modify the value used for
         the *archive member name*.

         Also note that you should set the "Efs" option to true if you are working with UTF8
         filenames.

    "CanonicalName => 0|1"
         This option controls whether the *archive member name* is *normalized* into Unix format
         before being written to the zip file.

         It is recommended that you enable this option unless you really need to create a
         non-standard Zip file.

         This is what APPNOTE.TXT has to say on what should be stored in the zip filename header
         field.

             The name of the file, with optional relative path.
             The path stored should not contain a drive or
             device letter, or a leading slash.  All slashes
             should be forward slashes '/' as opposed to
             backwards slashes '\' for compatibility with Amiga
             and UNIX file systems etc.

         This option defaults to false.

    "FilterName => sub { ... }"
         This option allow the *archive member* name to be modified before it is written to the zip
         file.

         This option takes a parameter that must be a reference to a sub. On entry to the sub the $_
         variable will contain the name to be filtered. If no filename is available $_ will contain
         an empty string.

         The value of $_ when the sub returns will be used as the *archive member name*.

         Note that if "CanonicalName" is enabled, a normalized filename will be passed to the sub.

         If you use "FilterName" to modify the filename, it is your responsibility to keep the
         filename in Unix format.

         Although this option can be used with the OO interface, it is of most use with the one-shot
         interface. For example, the code below shows how "FilterName" can be used to remove the
         path component from a series of filenames before they are stored in $zipfile.

             sub compressTxtFiles
             {
                 my $zipfile = shift ;
                 my $dir     = shift ;

                 zip [ <$dir/*.txt> ] => $zipfile,
                     FilterName => sub { s[^$dir/][] } ;
             }

    "Efs => 0|1"
         This option controls setting of the "Language Encoding Flag" (EFS) in the zip archive. When
         set, the filename and comment fields for the zip archive MUST be valid UTF-8.

         If the string used for the filename and/or comment is not valid UTF-8 when this option is
         true, the script will die with a "wide character" error.

         Note that this option only works with Perl 5.8.4 or better.

         This option defaults to false.

   Overall Zip Archive Structure
    "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", "exUnixN", "ExtraFieldLocal" and
         "ExtraFieldCentral" options will be ignored.

         This parameter defaults to 0.

    "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 is used if you want to store files larger than
         4 Gig or store more than 64K files in a single zip archive.

         "Zip64" will be automatically set, as needed, if working with the one-shot interface when
         the input is either a filename or a scalar reference.

         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.

   Deflate Compression Options
    -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.

   Bzip2 Compression Options
    "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.

   Lzma and Xz Compression Options
    "Preset => number"
         Used to choose the LZMA compression preset.

         Valid values are 0-9 and "LZMA_PRESET_DEFAULT".

         0 is the fastest compression with the lowest memory usage and the lowest compression.

         9 is the slowest compression with the highest memory usage but with the best compression.

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

         Defaults to "LZMA_PRESET_DEFAULT" (6).

    "Extreme => 0|1"
         Makes LZMA compression a lot slower, but a small compression gain.

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

         Defaults to 0.

   Other Options
    "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 (UID) and Group ID (GID) 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 header. This will be populated with $uid and $gid. An empty
         Unix2 extra field will also be created in the central zip header.

         Note - The UID & GID are stored as 16-bit integers in the "Ux" field. Use "exUnixN" if your
         UID or GID are 32-bit.

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

         By default no Unix2 extra field is created.

    "exUnixN => [$uid, $gid]"
         This option expects an array reference with exactly two elements: $uid and $gid. These
         values correspond to the numeric User ID (UID) and Group ID (GID) of the owner of the files
         respectively.

         When the "exUnixN" option is present it will trigger the creation of a UnixN extra field
         (ID is "ux") in both the local and central zip headers. This will be populated with $uid
         and $gid. The UID & GID are stored as 32-bit integers.

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

         By default no UnixN extra field is created.

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

         Set the "Efs" option to true if you want to store a UTF8 comment.

         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 the compression methods supported
         are: Store (no compression at all), Deflate, Bzip2, Zstd, Xz and Lzma.

         The symbols ZIP_CM_STORE, ZIP_CM_DEFLATE, ZIP_CM_BZIP2, ZIP_CM_ZSTD, ZIP_CM_XZ and
         ZIP_CM_LZMA 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.

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

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

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

         The default method is ZIP_CM_DEFLATE.

    "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.

         In one-shot mode this flag will be set to true if the Perl "-T" operator thinks the file
         contains text.

         The default is 0.

    "ExtraFieldLocal => $data"
    "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

         In this case "IO::Compress::Zip" will check that $rawdata consists of zero or more
         conformant sub-fields.

         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.

    "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 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 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

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::Uncompress::RawInflate,
    IO::Compress::Bzip2, IO::Uncompress::Bunzip2, IO::Compress::Lzma, IO::Uncompress::UnLzma,
    IO::Compress::Xz, IO::Uncompress::UnXz, IO::Compress::Lzip, IO::Uncompress::UnLzip,
    IO::Compress::Lzop, IO::Uncompress::UnLzop, IO::Compress::Lzf, IO::Uncompress::UnLzf,
    IO::Compress::Zstd, IO::Uncompress::UnZstd, IO::Uncompress::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.

IO::Compress::Zip
NAME SYNOPSIS DESCRIPTION Functional Interface
Notes Optional Parameters Examples Constructor Constructor Options -Level -Strategy Examples
Methods Importing EXAMPLES SUPPORT SEE ALSO AUTHOR MODIFICATION HISTORY COPYRIGHT AND LICENSE

Generated by phpman v3.7.12 Author: Che Dong Under GNU General Public License
2026-06-13 13:09 @216.73.216.28
CrawledBy Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)
Valid XHTML 1.0 TransitionalValid CSS!

^_back to top