Archive::Zip - Provide an interface to ZIP archive files.


NAME

Archive::Zip - Provide an interface to ZIP archive files.


SYNOPSIS

 use Archive::Zip qw( :ERROR_CODES :CONSTANTS );
 my $zip = Archive::Zip->new();
 my $member = $zip->addDirectory( 'dirname/' );
 $member = $zip->addString( 'This is a test', 'stringMember.txt' );
 $member->desiredCompressionMethod( COMPRESSION_DEFLATED );
 $member = $zip->addFile( 'xyz.pl', 'AnotherName.pl' );
 die 'write error' if $zip->writeToFileNamed( 'someZip.zip' ) != AZ_OK;
 $zip = Archive::Zip->new();
 die 'read error' if $zip->read( 'someZip.zip' ) != AZ_OK;
 $member = $zip->memberNamed( 'stringMember.txt' );
 $member->desiredCompressionMethod( COMPRESSION_STORED );
 die 'write error' if $zip->writeToFileNamed( 'someOtherZip.zip' ) != AZ_OK;


DESCRIPTION

The Archive::Zip module allows a Perl program to create, manipulate, read, and write Zip archive files.

Zip archives can be created, or you can read from existing zip files. Once created, they can be written to files, streams, or strings.

Members can be added, removed, extracted, replaced, rearranged, and enumerated. They can also be renamed or have their dates, comments, or other attributes queried or modified. Their data can be compressed or uncompressed as needed. Members can be created from members in existing Zip files, or from existing directories, files, or strings.

This module uses the Compress::Zlib library to read and write the compressed streams inside the files.


EXPORTS

:CONSTANTS
Exports the following constants:

FA_MSDOS FA_UNIX GPBF_ENCRYPTED_MASK GPBF_DEFLATING_COMPRESSION_MASK GPBF_HAS_DATA_DESCRIPTOR_MASK COMPRESSION_STORED COMPRESSION_DEFLATED IFA_TEXT_FILE_MASK IFA_TEXT_FILE IFA_BINARY_FILE COMPRESSION_LEVEL_NONE COMPRESSION_LEVEL_DEFAULT COMPRESSION_LEVEL_FASTEST COMPRESSION_LEVEL_BEST_COMPRESSION

:MISC_CONSTANTS
Exports the following constants (only necessary for extending the module):

FA_AMIGA FA_VAX_VMS FA_VM_CMS FA_ATARI_ST FA_OS2_HPFS FA_MACINTOSH FA_Z_SYSTEM FA_CPM FA_WINDOWS_NTFS GPBF_IMPLODING_8K_SLIDING_DICTIONARY_MASK GPBF_IMPLODING_3_SHANNON_FANO_TREES_MASK GPBF_IS_COMPRESSED_PATCHED_DATA_MASK COMPRESSION_SHRUNK DEFLATING_COMPRESSION_NORMAL DEFLATING_COMPRESSION_MAXIMUM DEFLATING_COMPRESSION_FAST DEFLATING_COMPRESSION_SUPER_FAST COMPRESSION_REDUCED_1 COMPRESSION_REDUCED_2 COMPRESSION_REDUCED_3 COMPRESSION_REDUCED_4 COMPRESSION_IMPLODED COMPRESSION_TOKENIZED COMPRESSION_DEFLATED_ENHANCED COMPRESSION_PKWARE_DATA_COMPRESSION_LIBRARY_IMPLODED

:ERROR_CODES
Explained below. Returned from most methods.

AZ_OK AZ_STREAM_END AZ_ERROR AZ_FORMAT_ERROR AZ_IO_ERROR


OBJECT MODEL

Inheritance

 Exporter
    Archive::Zip                            Common base class, has defs.
        Archive::Zip::Archive               A Zip archive.
        Archive::Zip::Member                Abstract superclass for all members.
            Archive::Zip::StringMember      Member made from a string
            Archive::Zip::FileMember        Member made from an external file
                Archive::Zip::ZipFileMember Member that lives in a zip file
                Archive::Zip::NewFileMember Member whose data is in a file
            Archive::Zip::DirectoryMember   Member that is a directory


ERROR CODES

Many of the methods in Archive::Zip return error codes. These are implemented as inline subroutines, using the use constant pragma. They can be imported into your namespace using the :CONSTANT tag:

    use Archive::Zip qw( :CONSTANTS );
    ...
    die "whoops!" if $zip->read( 'myfile.zip' ) != AZ_OK;
AZ_OK (0)
Everything is fine.

AZ_STREAM_END (1)
The read stream (or central directory) ended normally.

AZ_ERROR (2)
There was some generic kind of error.

AZ_FORMAT_ERROR (3)
There is a format error in a ZIP file being read.

AZ_IO_ERROR (4)
There was an IO error.


COMPRESSION

Archive::Zip allows each member of a ZIP file to be compressed (using the Deflate algorithm) or uncompressed. Other compression algorithms that some versions of ZIP have been able to produce are not supported.

Each member has two compression methods: the one it's stored as (this is always COMPRESSION_STORED for string and external file members), and the one you desire for the member in the zip file. These can be different, of course, so you can make a zip member that is not compressed out of one that is, and vice versa. You can inquire about the current compression and set the desired compression method:

    my $member = $zip->memberNamed( 'xyz.txt' );
    $member->compressionMethod();    # return current compression
    # set to read uncompressed
    $member->desiredCompressionMethod( COMPRESSION_STORED );
    # set to read compressed
    $member->desiredCompressionMethod( COMPRESSION_DEFLATED );

There are two different compression methods:

COMPRESSION_STORED
file is stored (no compression)

COMPRESSION_DEFLATED
file is Deflated

Compression Levels

If a member's desiredCompressionMethod is COMPRESSION_DEFLATED, you can choose different compression levels. This choice may affect the speed of compression and decompression, as well as the size of the compressed member data.

    $member->desiredCompressionLevel( 9 );

The levels given can be:

  1. or COMPRESSION_LEVEL_NONE
    This is the same as saying
        $member->desiredCompressionMethod( COMPRESSION_STORED );

  2. .. 9
    1 gives the best speed and worst compression, and 9 gives the best compression and worst speed.

    COMPRESSION_LEVEL_FASTEST
    This is a synonym for level 1.

    COMPRESSION_LEVEL_BEST_COMPRESSION
    This is a synonym for level 9.

    COMPRESSION_LEVEL_DEFAULT
    This gives a good compromise between speed and compression, and is currently equivalent to 6 (this is in the zlib code).

    This is the level that will be used if not specified.


Archive::Zip methods

The Archive::Zip class (and its invisible subclass Archive::Zip::Archive) implement generic zip file functionality.

Creating a new Archive::Zip object actually makes an Archive::Zip::Archive object, but you don't have to worry about this unless you're subclassing.

Constructor

new( [$fileName] )
Make a new, empty zip archive.
    my $zip = Archive::Zip->new();

If an additional argument is passed, new() will call read() to read the contents of an archive:

    my $zip = Archive::Zip->new( 'xyz.zip' );

If a filename argument is passed and the read fails for any reason, new will return undef. For this reason, it may be better to call read separately.

Utility Methods

These Archive::Zip methods may be called as functions or as object methods. Do not call them as class methods:

    $zip = Archive::Zip->new();
    $crc = Archive::Zip::computeCRC32( 'ghijkl' );    # OK
    $crc = $zip->computeCRC32( 'ghijkl' );            # also OK
    $crc = Archive::Zip->computeCRC32( 'ghijkl' );    # NOT OK
Archive::Zip::computeCRC32( $string [, $crc] )
This is a utility function that uses the Compress::Zlib CRC routine to compute a CRC-32.

You can get the CRC of a string:

    $crc = Archive::Zip::computeCRC32( $string );

Or you can compute the running CRC:

    $crc = 0;
    $crc = Archive::Zip::computeCRC32( 'abcdef', $crc );
    $crc = Archive::Zip::computeCRC32( 'ghijkl', $crc );

Archive::Zip::setChunkSize( $number )
Change chunk size used for reading and writing. Currently, this defaults to 32K. This is not exportable, so you must call it like:
    Archive::Zip::setChunkSize( 4096 );

or as a method on a zip (though this is a global setting). Returns old chunk size.

Archive::Zip::setErrorHandler( \&subroutine )
Change the subroutine called with error strings. This defaults to \&Carp::carp, but you may want to change it to get the error strings.

This is not exportable, so you must call it like:

    Archive::Zip::setErrorHandler( \&myErrorHandler );

If no error handler is passed, resets handler to default.

Returns old error handler.

Note that if you call Carp::carp or a similar routine or if you're chaining to the default error handler from your error handler, you may want to increment the number of caller levels that are skipped (do not just set it to a number):

    $Carp::CarpLevel++;

Accessors

members()
Return a copy of my members array
    my @members = $zip->members();

numberOfMembers()
Return the number of members I have

memberNames()
Return a list of the (internal) file names of my members

memberNamed( $string )
Return ref to member whose filename equals given filename or undef

membersMatching( $regex )
Return array of members whose filenames match given regular expression in list context. Returns number of matching members in scalar context.
    my @textFileMembers = $zip->membersMatching( '.*\.txt' );
    # or
    my $numberOfTextFiles = $zip->membersMatching( '.*\.txt' );

diskNumber()
Return the disk that I start on. Not used for writing zips, but might be interesting if you read a zip in. This had better be 0, as Archive::Zip does not handle multi-volume archives.

diskNumberWithStartOfCentralDirectory()
Return the disk number that holds the beginning of the central directory. Not used for writing zips, but might be interesting if you read a zip in. This had better be 0, as Archive::Zip does not handle multi-volume archives.

numberOfCentralDirectoriesOnThisDisk()
Return the number of CD structures on this disk. Not used for writing zips, but might be interesting if you read a zip in.

numberOfCentralDirectories()
Return the number of CD structures in the whole zip. Not used for writing zips, but might be interesting if you read a zip in.

centralDirectorySize()
Returns central directory size, as read from an external zip file. Not used for writing zips, but might be interesting if you read a zip in.

centralDirectoryOffsetWRTStartingDiskNumber()
Returns the offset into the zip file where the CD begins. Not used for writing zips, but might be interesting if you read a zip in.

zipfileComment( [$string] )
Get or set the zipfile comment. Returns the old comment.
    print $zip->zipfileComment();
    $zip->zipfileComment( 'New Comment' );

Member Operations

Various operations on a zip file modify members. When a member is passed as an argument, you can either use a reference to the member itself, or the name of a member. Of course, using the name requires that names be unique within a zip (this is not enforced).

removeMember( $memberOrName )
Remove and return the given member, or match its name and remove it. Returns undef if member name doesn't exist in this Zip. No-op if member does not belong to this zip.

replaceMember( $memberOrName, $newMember )
Remove and return the given member, or match its name and remove it. Replace with new member. Returns undef if member name doesn't exist in this Zip.
    my $member1 = $zip->removeMember( 'xyz' );
    my $member2 = $zip->replaceMember( 'abc', $member1 );
    # now, $member2 (named 'abc') is not in $zip,
    # and $member1 (named 'xyz') is, having taken $member2's place.

extractMember( $memberOrName [, $extractedName ] )
Extract the given member, or match its name and extract it. Returns undef if member doesn't exist in this Zip. If optional second arg is given, use it as the name of the extracted member. Otherwise, the internal filename of the member is used as the name of the extracted file or directory.

All necessary directories will be created.

Returns AZ_OK on success.

extractMemberWithoutPaths( $memberOrName [, $extractedName ] )
Extract the given member, or match its name and extract it. Does not use path information (extracts into the current directory). Returns undef if member doesn't exist in this Zip. If optional second arg is given, use it as the name of the extracted member (its paths will be deleted too). Otherwise, the internal filename of the member (minus paths) is used as the name of the extracted file or directory.

Returns AZ_OK on success.

addMember( $member )
Append a member (possibly from another zip file) to the zip file. Returns the new member. Generally, you will use addFile(), addDirectory(), addString(), or read() to add members.
    # Move member named 'abc' to end of zip:
    my $member = $zip->removeMember( 'abc' );
    $zip->addMember( $member );

addFile( $fileName [, $newName ] )
Append a member whose data comes from an external file, returning the member or undef. The member will have its file name set to the name of the external file, and its desiredCompressionMethod set to COMPRESSION_DEFLATED. The file attributes and last modification time will be set from the file.

If the name given does not represent a readable plain file or symbolic link, undef will be returned.

The text mode bit will be set if the contents appears to be text (as returned by the -T perl operator).

The optional second argument sets the internal file name to something different than the given $fileName.

addString( $stringOrStringRef [, $name] )
Append a member created from the given string or string reference. The name is given by the optional second argument. Returns the new member.

The last modification time will be set to now, and the file attributes will be set to permissive defaults.

    my $member = $zip->addString( 'This is a test', 'test.txt' );

addDirectory( $directoryName [, $fileName ] )
Append a member created from the given directory name. The directory name does not have to name an existing directory. If the named directory exists, the file modification time and permissions are set from the existing directory, otherwise they are set to now and permissive default permissions. The optional second argument sets the name of the archive member (which defaults to $directoryName)

Returns the new member.

contents( $memberOrMemberName [, $newContents ] )
Returns the uncompressed data for a particular member, or undef.
    print "xyz.txt contains " . $zip->contents( 'xyz.txt' );

Also can change the contents of a member:

    $zip->contents( 'xyz.txt', 'This is the new contents' );

writeToFileNamed( $fileName )
Write a zip archive to named file. Returns AZ_OK on success.

Note that if you use the same name as an existing zip file that you read in, you will clobber ZipFileMembers. So instead, write to a different file name, then delete the original.

    my $status = $zip->writeToFileNamed( 'xx.zip' );
    die "error somewhere" if $status != AZ_OK;

writeToFileHandle( $fileHandle [, $seekable] )
Write a zip archive to a file handle. Return AZ_OK on success.

The optional second arg tells whether or not to try to seek backwards to re-write headers. If not provided, it is set by testing seekability. This could fail on some operating systems, though.

    my $fh = IO::File->new( 'someFile.zip', 'w' );
    $zip->writeToFileHandle( $fh );

If you pass a file handle that is not seekable (like if you're writing to a pipe or a socket), pass a false as the second argument:

    my $fh = IO::File->new( '| cat > somefile.zip', 'w' );
    $zip->writeToFileHandle( $fh, 0 );   # fh is not seekable

read( $fileName )
Read zipfile headers from a zip file, appending new members. Returns AZ_OK or error code.
    my $zipFile = Archive::Zip->new();
    my $status = $zipFile->read( '/some/FileName.zip' );


MEMBER OPERATIONS

Class Methods

Several constructors allow you to construct members without adding them to a zip archive.

These work the same as the addFile(), addDirectory(), and addString() zip instance methods described above, but they don't add the new members to a zip.

Archive::Zip::Member->newFromString( $stringOrStringRef [, $fileName] )
Construct a new member from the given string. Returns undef on error.
    my $member = Archive::Zip::Member->newFromString( 'This is a test',
                                                     'xyz.txt' );

newFromFile( $fileName )
Construct a new member from the given file. Returns undef on error.
    my $member = Archive::Zip::Member->newFromFile( 'xyz.txt' );

newDirectoryNamed( $directoryName )
Construct a new member from the given directory. Returns undef on error.
    my $member = Archive::Zip::Member->newDirectoryNamed( 'CVS/' );

Simple accessors

These methods get (and/or set) member attribute values.

versionMadeBy()
Gets the field from my member header.

fileAttributeFormat( [$format] )
Gets or sets the field from the member header. These are FA_* values.

versionNeededToExtract()
Gets the field from my member header.

bitFlag()
Gets the general purpose bit field from my member header. This is where the GPBF_* bits live.

compressionMethod()
Returns my compression method. This is the method that is currently being used to compress my data.

This will be COMPRESSION_STORED for added string or file members, or any of the COMPRESSION_* values for members from a zip file. However, this module can only handle members whose data is in COMPRESSION_STORED or COMPRESSION_DEFLATED format.

desiredCompressionMethod( [$method] )
Get or set my desiredCompressionMethod This is the method that will be used to write. Returns prior desiredCompressionMethod.

Only COMPRESSION_DEFLATED or COMPRESSION_STORED are valid arguments.

Changing to COMPRESSION_STORED will change my desiredCompressionLevel to 0; changing to COMPRESSION_DEFLATED will change my desiredCompressionLevel to COMPRESSION_LEVEL_DEFAULT.

desiredCompressionLevel( [$method] )
Get or set my desiredCompressionLevel This is the method that will be used to write. Returns prior desiredCompressionLevel.

Valid arguments are 0 through 9, COMPRESSION_LEVEL_NONE, COMPRESSION_LEVEL_DEFAULT, COMPRESSION_LEVEL_BEST_COMPRESSION, and COMPRESSION_LEVEL_FASTEST.

0 or COMPRESSION_LEVEL_NONE will change the desiredCompressionMethod to COMPRESSION_STORED. All other arguments will change the desiredCompressionMethod to COMPRESSION_DEFLATED.

fileName()
Get or set my internal filename. Returns the (possibly new) filename.

Names will have backslashes converted to forward slashes, and will have multiple consecutive slashes converted to single ones.

lastModFileDateTime()
Return my last modification date/time stamp in MS-DOS format.

lastModTime()
Return my last modification date/time stamp, converted to unix localtime format.
    print "Mod Time: " . scalar( localtime( $member->lastModTime() ) );

setLastModFileDateTimeFromUnix()
Set my lastModFileDateTime from the given unix time.
    $member->setLastModFileDateTimeFromUnix( time() );

internalFileAttributes()
Return the internal file attributes field from the zip header. This is only set for members read from a zip file.

externalFileAttributes()
Return member attributes as read from the ZIP file. Note that these are NOT UNIX!

unixFileAttributes( [$newAttributes] )
Get or set the member's file attributes using UNIX file attributes. Returns old attributes.
    my $oldAttribs = $member->unixFileAttributes( 0666 );

Note that the return value has more than just the file permissions, so you will have to mask off the lowest bits for comparisions.

localExtraField( [$newField] )
Gets or sets the extra field that was read from the local header. This is not set for a member from a zip file until after the member has been written out.

The extra field must be in the proper format.

cdExtraField( [$newField] )
Gets or sets the extra field that was read from the central directory header.

The extra field must be in the proper format.

extraFields()
Return both local and CD extra fields, concatenated.

fileComment( [$newComment] )
Get or set the member's file comment.

hasDataDescriptor()
Get or set the data descriptor flag. If this is set, the local header will not necessarily have the correct data sizes. Instead, a small structure will be stored at the end of the member data with these values.

This should be transparent in normal operation.

crc32()
Return the CRC-32 value for this member. This will not be set for members that were constructed from strings or external files until after the member has been written.

crc32String()
Return the CRC-32 value for this member as an 8 character printable hex string. This will not be set for members that were constructed from strings or external files until after the member has been written.

compressedSize()
Return the compressed size for this member. This will not be set for members that were constructed from strings or external files until after the member has been written.

uncompressedSize()
Return the uncompressed size for this member.

isEncrypted()
Return true if this member is encrypted. The Archive::Zip module does not currently create or extract encrypted members.

isTextFile( [$flag] )
Returns true if I am a text file. Also can set the status if given an argument (then returns old state). Note that this module does not currently do anything with this flag upon extraction or storage. That is, bytes are stored in native format whether or not they came from a text file.

isBinaryFile()
Returns true if I am a binary file. Also can set the status if given an argument (then returns old state). Note that this module does not currently do anything with this flag upon extraction or storage. That is, bytes are stored in native format whether or not they came from a text file.

extractToFileNamed( $fileName )
Extract me to a file with the given name. The file will be created with default modes. Directories will be created as needed.

Returns AZ_OK on success.

isDirectory()
Returns true if I am a directory.

Low-level member data reading

It is possible to use lower-level routines to access member data streams, rather than the extract* methods and contents().

For instance, here is how to print the uncompressed contents of a member in chunks using these methods:

    my ( $member, $status, $bufferRef );
    $member = $zip->memberNamed( 'xyz.txt' );
    $member->desiredCompressionMethod( COMPRESSION_STORED );
    $status = $member->rewindData();
    die "error $status" if $status != AZ_OK;
    while ( ! $member->readIsDone() )
    {
        ( $bufferRef, $status ) = $member->readChunk();
        die "error $status" if $status != AZ_OK;
        # do something with $bufferRef:
        print $$bufferRef;
    }
    $member->endRead();
readChunk( [$chunkSize] )
This reads the next chunk of given size from the member's data stream and compresses or uncompresses it as necessary, returning a reference to the bytes read and a status. If size argument is not given, defaults to global set by Archive::Zip::setChunkSize. Status is AZ_OK on success. Returns ( \$bytes, $status).
    my ( $outRef, $status ) = $self->readChunk();
    print $$outRef if $status != AZ_OK;

rewindData()
Rewind data and set up for reading data streams or writing zip files. Can take options for inflateInit() or deflateInit(), but this isn't likely to be necessary. Subclass overrides should call this method. Returns AZ_OK on success.

endRead()
Reset the read variables and free the inflater or deflater. Must be called to close files, etc.

Returns AZ_OK on success.

readIsDone()
Return true if the read has run out of data or errored out.

contents()
Return the entire uncompressed member data or undef in scalar context. When called in array context, returns ( $string, $status ); status will be AZ_OK on success:
    my $string = $member->contents();
    # or
    my ( $string, $status ) = $member->contents();
    die "error $status" if $status != AZ_OK;

Can also be used to set the contents of a member (this may change the class of the member):

    $member->contents( "this is my new contents" );

extractToFileHandle( $fh )
Extract (and uncompress, if necessary) my contents to the given file handle. Return AZ_OK on success.


Archive::Zip::FileMember methods

The Archive::Zip::FileMember class extends Archive::Zip::Member. It is the base class for both ZipFileMember and NewFileMember classes. This class adds an externalFileName and an fh member to keep track of the external file.

externalFileName()
Return my external filename.

fh()
Return my read file handle. Automatically opens file if necessary.


Archive::Zip::ZipFileMember methods

The Archive::Zip::ZipFileMember class represents members that have been read from external zip files.

diskNumberStart()
Returns the disk number that my local header resides in. Had better be 0.

localHeaderRelativeOffset()
Returns the offset into the zip file where my local header is.

dataOffset()
Returns the offset from the beginning of the zip file to my data.


AUTHOR

Ned Konz, perl@bike-nomad.com


COPYRIGHT

Copyright (c) 2000 Ned Konz. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.


SEE ALSO

the Compress::Zlib manpage

 Archive::Zip - Provide an interface to ZIP archive files.