\HeaderA{untgz}{Create a connection to a .tar.gz file}{untgz}
\keyword{IO}{untgz}
\begin{Description}\relax
Return a connection to the contents of filename within the .tar.gz
archive given in description.

If checkExists, stop if filename isn't in the archive.  This
requires reading a list of the entire archive contents.

The idea is to provide a .tar.gz equivalent to the unz() built-in.
\end{Description}
\begin{Usage}
\begin{verbatim}
untgz(description, filename, open = "", checkExists = TRUE)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{description}] The filename of the .tar.gz
\item[\code{filename}] The filename of the file in the .tar.gz archive that
you want to access.
\item[\code{open}] The returned connection will have use this value
\item[\code{checkExists}] If TRUE, then a raise an error if \code{filename}
is not found in \code{description}.  Otherwise, you'll just get such
a message as the supposed contents of the file.  This costs an extra
file open and read.
\end{ldescription}
\end{Arguments}
\begin{Value}
A connection to the contents of the specified file within the archive.
\end{Value}
\begin{Author}\relax
S. Falcon
\end{Author}