$tar->read ( $filename|$handle, $compressed, {opt => 'val'} )

Read the given tar file into memory.  The first argument can either be
the name of a file or a reference to an already open filehandle (or an
IO::Zlib object if it's compressed) The second argument indicates

##</code><code>##

Note that you can currently not pass a "gzip" compressed filehandle,
which is not opened with "IO::Zlib", nor a string containing the full
archive information (either compressed or uncompressed). These are
worth while features, but not currently implemented. See the "TODO"
section.

##</code><code>##

# untested
open my $fh, '<', \$tarcontent or die "D'oh! $!\n";
my $tar=Archive::Tar->new($fh);