NAME

Archive::Tar::Wrapper - API wrapper around the 'tar' utility

SYNOPSIS

use Archive::Tar::Wrapper;

my $arch = Archive::Tar::Wrapper->new();

    # Open a tarball, expand it into a temporary directory
$arch->read("archive.tgz");

    # Iterate over all entries in the archive
$arch->list_reset(); # Reset Iterator
                     # Iterate through archive
while(my($tar_path, $phys_path) = $arch->list_next()) {
    print "$tar_path\n";
}

    # Get a huge list with all entries
for my $entry (@{$arch->list_all()}) {
    my($tar_path, $real_path) = @$entry;
    print "Tarpath: $tar_path Tempfile: $real_path\n";
}

    # Add a new entry
$arch->add($logic_path, $file_or_stringref);

    # Remove an entry
$arch->remove($logic_path);

    # Find the physical location of a temporary file
my($tmp_path) = $arch->locate($tar_path);

    # Create a tarball
$arch->write($tarfile, $compress);

DESCRIPTION

Archive::Tar::Wrapper is an API wrapper around the 'tar' command line utility. It never stores anything in memory, but works on temporary directory structures on disk instead. It provides a mapping between the logical paths in the tarball and the 'real' files in the temporary directory on disk.

It differs from Archive::Tar in two ways:

• Archive::Tar::Wrapper doesn't hold anything in memory. Everything is stored on disk.

• Archive::Tar::Wrapper is 100% compliant with the platform's tar utility, because it uses it internally.

METHODS

my $arch = Archive::Tar::Wrapper->new()

Constructor for the tar wrapper class. Finds the tar executable by searching PATH and returning the first hit. In case you want to use a different tar executable, you can specify it as a parameter:

my $arch = Archive::Tar::Wrapper->new(tar => '/path/to/tar');

Since Archive::Tar::Wrapper creates temporary directories to store tar data, the location of the temporary directory can be specified:

my $arch = Archive::Tar::Wrapper->new(tmpdir => '/path/to/tmpdir');

$arch->read("archive.tgz")

read() opens the given tarball, expands it into a temporary directory and returns 1 on success und undef on failure. The temporary directory holding the tar data gets cleaned up when $arch goes out of scope.

read handles both compressed and uncompressed files. To find out if a file is compressed or uncompressed, it tries to guess by extension, then by checking the first couple of bytes in the tarfile.

$arch->list_reset()

Resets the list iterator. To be used before the first call to $arch-list_next()>.

my($tar_path, $phys_path) = $arch->list_next()

Returns the next item in the tarfile. It returns a list of two scalars: the relative path of the item in the tarfile and the physical path to the unpacked file or directory on disk. To determine if the item is a file or directory, use perl's -f and -d operators on the physical path.

my $items = $arch->list_all()

Returns a reference to a (possibly huge) array of items in the tarfile. Each item is a reference to an array, containing two elements: the relative path of the item in the tarfile and the physical path to the unpacked file or directory on disk.

To iterate over the list, the following construct can be used:

    # Get a huge list with all entries
for my $entry (@{$arch->list_all()}) {
    my($tar_path, $real_path) = @$entry;
    print "Tarpath: $tar_path Tempfile: $real_path\n";
}

If the list of items in the tarfile is big, use list_reset() and list_next() instead of list_all.

$arch->add($logic_path, $file_or_stringref)

Add a new file to the tarball. $logic_path is the virtual path of the file within the tarball. $file_or_stringref is either a scalar, in which case it holds the physical path of a file on disk to be transferred (i.e. copied) to the tarball. Or it is a reference to a scalar, in which case its content is interpreted to be the data of the file.

$arch->remove($logic_path)

Removes a file from the tarball. $logic_path is the virtual path of the file within the tarball.

$arch->locate($logic_path)

Finds the physical location of a file, specified by $logic_path, which is the virtual path of the file within the tarball. Returns a path to the temporary file Archive::Tar::Wrapper created to manipulate the tarball on disk.

$arch->write($tarfile, $compress)

Write out the tarball by tarring up all temporary files and directories and store it in $tarfile on disk. If $compress holds a true value, compression is used.

KNOWN LIMITATIONS

• Currently, only tar programs supporting the z option (for compressing/decompressing) are supported. Future version will use gzip alternatively.

• Currently, you can't add empty directories to a tarball directly. You could add a temporary file within a directory, and then remove() the file.

• If you delete a file, the empty directories it was located in stay in the tarball. You could try to locate() them and delete them. This will be fixed, though.

• Filenames containing newlines are causing problems with the list iterators. To be fixed.

LEGALESE

Copyright 2005 by Mike Schilli, all rights reserved. This program is free software, you can redistribute it and/or modify it under the same terms as Perl itself.

AUTHOR

2005, Mike Schilli <cpan@perlmeister.com>