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Archive-Zip-SimpleZip-0.038
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/ Archive::Zip::SimpleUnzip

NAME

Archive::Zip::SimpleUnzip - Read Zip Archives

SYNOPSIS

use Archive::Zip::SimpleUnzip qw($SimpleUnzipError) ;

my $z = new Archive::Zip::SimpleUnzip "my.zip"
    or die "Cannot open zip file: $SimpleUnzipError\n" ;

# How many members in the archive?
my $members = scalar $z->names();

# Get the names of all the members in a zip archive
my @names = $z->names();

# Test member existence
if ($z->exists("abc.txt"))
{
 ...
}

# Extract member to filesystem
$z->extract("member") ;
$z->extract("member", "outfile") ;


# Read the zip comment
my $comment = $zip->comment();

# Select a member by name
my $member = $z->member("abc.txt");
my $name = $member->name();
my $content = $member->content();
my $comment = $member->comment();

# Iterate through a zip archive
while (my $member = $z->next)
{
    print $member->name() . "\n" ;

    $member->extract();
    $member->extract("outfile");
}

# Archive::Zip::SimpleUnzip::Member

# Open a filehandle to read from a zip member
$fh = $member->open("mydata1.txt");

# Read blocks of data
read($fh, $buffer, 1234) ;

# or a line at a time
$line = <$fh> ;

close $fh;

$z->close();

DESCRIPTION

Archive::Zip::SimpleUnzip is a module that allows reading of Zip archives.

For writing Zip archives, there is a companion module, called Archive::Zip::SimpleZip, that can create Zip archives.

Features

  • Read zip archive from a file, a filehandle or from an in-memory buffer.

    Note that the code assume that the zip archive is being read from a seekable file/filhandle/buffer.

  • Perl Filehandle interface for reading a zip member.

  • Supports deflate, store, bzip2, Zstandard (Zstd), Xz and lzma compression.

  • Supports Zip64, so can read archves larger than 4Gig and/or have greater than 64K members.

Constructor

$z = new Archive::Zip::SimpleUnzip "myzipfile.zip" [, OPTIONS] ;
$z = new Archive::Zip::SimpleUnzip \$buffer [, OPTIONS] ;
$z = new Archive::Zip::SimpleUnzip $filehandle [, OPTIONS] ;

The constructor takes one mandatory parameter along with zero or more optional parameters.

The mandatory parameter controls where the zip archive is read from. This can be any one of the following:

  • Input from a Filename

    When SimpleUnzip is passed a string, it will read the zip archive from the filename stored in the string.

  • Input from a String

    When SimpleUnzip is passed a string reference, like \$buffer, it will read the in-memory zip archive from that string.

  • Input from a Filehandle

    When SimpleUnzip is passed a filehandle, it will read the zip archive from that filehandle. Note the filehandle must be seekable.

See "Options" for a list of the optional parameters that can be specified when calling the constructor.

Options

-FilesOnly => 1|0

When true, ignore members in the zip archive that are directories.

Enabling this option will change the behaviour of the names, next and exists methods.

Default is false.

Methods

$buffer = $z->content($member)

Returns the uncompressed data stored in $member. Returns undef if the member does not exist.

$buffer = $z->extract($member [, $outfile])

Uncompresses the data stored in $member and writes it to the filesystem. By default the filename used is the member name. If the optional parameter $outfile is specified, the payload is written to that file instead.

$string = $z->comment()

Returns the comment, if any, associated with the zip archive.

$z->exists("name")

Tests for the existence of member "name" in the zip archive.

$count = $z->names()
@names = $z->names()

In scalar context returns the number of members in the Zip archive.

In array context returns a list of the names of the members in the Zip archive.

$z->next()

Returns the next member from the zip archive as a Archive::Zip::SimpleUnzip::Member object. See "Archive::Zip::SimpleUnzip::Member"

Standard usage is

use Archive::Zip::SimpleUnzip qw($SimpleUnzipError) ;

my $match = "hello";
my $zipfile = "my.zip";

my $z = new Archive::Zip::SimpleUnzip $zipfile
    or die "Cannot open zip file: $SimpleUnzipError\n" ;

while (my $member = $z->next())
{
    my $name = $member->name();
    my $fh = $member->open();
    while (<$fh>)
    {
        my $offset =
        print "$name, line $.\n" if /$match/;
    }
}
$z->close()

Closes the zip archive.

Archive::Zip::SimpleUnzip::Member

The next method from Archive::Zip::SimpleUnzip returns a member object of type Archive::Zip::SimpleUnzip::Member that has the following methods.

$string = $m->name()

Returns the name of the member.

$string = $m->comment()

Returns the member comment.

$data = $m->content()

Returns the uncompressed content.

$buffer = $z->extract() =item $buffer = $z->extract($outfile])

Uncompresses the data stored in the current member and writes to the filesystem. By default the filename used is the member name. If the optional parameter $outfile is specified, the payload is written to that file instead.

$fh = $m->open()

Returns a filehandle that can be used to read the uncompressed content.

$bool = $m->isDirectory()

Returns true if the member is a directory. Otherwise returns false.

$bool = $m->isFile()

Returns true if the member is standard file. Otherwise returns false.

Examples

The code below shows how this module is used to read the contents of the member "abc.txt" from the zip archive "my1.zip".

use Archive::Zip::SimpleUnzip qw($SimpleUnzipError) ;

my $z = new Archive::Zip::SimpleUnzip "my1.zip"
    or die "Cannot open zip file: $SimpleUnzipError\n" ;

my $name = "abc.txt";
if ($z->exists($name))
{
    print $z->content($name);
}
else
{
    warn "$name not present in my1.zip\n"
}

Iterate through a Zip file

use Archive::Zip::SimpleUnzip qw($SimpleUnzipError) ;

my $zipfile = "my.zip";
my $z = new Archive::Zip::SimpleUnzip $zipfile
    or die "Cannot open zip file: $SimpleUnzipError\n" ;

my $members = $z->names();
print "Zip file '$zipfile' has $members entries\n";

while (my $member = $z->next())
{
    print "$member->name()\n";
}

Filehandle interface

Here is a simple grep, that walks through a zip file and prints matching strings present in the compressed payload. The FilesOnly option has been included in the call to the constructor to automaticaly skip members that just contain directories.

use Archive::Zip::SimpleUnzip qw($SimpleUnzipError) ;

my $match = "hello";
my $zipfile = "my.zip";

my $z = new Archive::Zip::SimpleUnzip $zipfile, FilesOnly => 1
    or die "Cannot open zip file: $SimpleUnzipError\n" ;

while (my $member = $z->next())
{
    my $name = $member->name();
    my $fh = $member->open();
    while (<$fh>)
    {
        my $offset =
        print "$name, line $.\n" if /$match/;
    }
}

rezip

Another example that uses the filehandle interface. This time the code uses Archive::Zip::SimpleUnzip to get a filehandle for each member of a zip archive which it passes to Archive::Zip::SimpleZip to recompress.

use Archive::Zip::SimpleUnzip qw($SimpleUnzipError) ;
use Archive::Zip::SimpleZip qw($SimpleZipError Z_BEST_COMPRESSION) ;

my $input  = shift ;
my $output = shift ;

my $unzip = new Archive::Zip::SimpleUnzip $input
                or die "Cannot open '$input': $SimpleUnzipError";

my $zip = new Archive::Zip::SimpleZip $output, Level => Z_BEST_COMPRESSION
        or die "Cannot create zip file '$output': $SimpleZipError";

while (my $member = $unzip->next())
{
    my $name = $member->name();
    warn "Processing member $name\n"  ;

    my $fh = $member->open();

    $zip->addFileHandle($fh, Name => $name)
            or die "Cannot addFileHandle file '$file': $SimpleZipError\n" ;
}

Zip File Interoperability

The intention is to be interoperable with zip archives created by other programs, like pkzip or WinZip, but the majority of testing carried out used the Info-Zip zip/unzip programs running on Linux.

This doesn't necessarily mean that there is no interoperability with other zip programs like pkzip and WinZip - it just means that I haven't tested them. Please report any issues you find.

Compression Methods Supported

The following compression methods are supported

deflate (8)

This is the most common compression used in zip archives.

store (0)

This is used when no compression has been carried out.

bzip2 (12)

Only if the IO-Compress-Bzip2 module is available.

lzma (14)

Only if the IO-Compress-Lzma module is available.

Xz (95)

To read Xz content, the module IO::Uncompress::UnXz must be installed.

Zstandard (93)

To read Zstandard content, the module IO::Uncompress::UnZstd must be installed.

Zip64 Support

This modules supports Zip64, so it can read archves larger than 4Gig and/or have greater than 64K members.

Limitations

The following features are not currently supported.

SUPPORT

General feedback/questions/bug reports should be sent to https://github.com/pmqs/Archive-Zip-SimpleZip/issues (preferred) or https://rt.cpan.org/Public/Dist/Display.html?Name=Archive-Zip-SimpleZip.

SEE ALSO

Archive::Zip::SimpleZip, Archive::Zip, IO::Compress::Zip, IO::Uncompress::UnZip

AUTHOR

This module was written by Paul Marquess, pmqs@cpan.org.

MODIFICATION HISTORY

See the Changes file.

COPYRIGHT AND LICENSE

Copyright (c) 2018-2019 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.