\Header{file.access}{Ascertain File Accessibility}
\keyword{file}{file.access}
\begin{Description}\relax
Utility function to access information about files on the user's
file systems.
\end{Description}
\begin{Usage}
\begin{verbatim}
file.access(names, mode = 0)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{names}] character vector containing file names.
\item[\code{mode}] integer specifying access mode required.
\end{ldescription}
\end{Arguments}
\begin{Details}\relax
The \code{mode} value can be the exclusive or of the following values
\describe{
\item[0] test for existence.
\item[1] test for execute permission.
\item[2] test for write permission.
\item[4] test for read permission.
}
Permission will be computed for real user ID and real group ID (rather
than the effective IDs).
\end{Details}
\begin{Value}
An integer vector with values \code{0} for success and \code{-1} for failure.
\end{Value}
\begin{Note}\relax
This is intended as a replacement for the S-PLUS function
\code{access}, a wrapper for the C function of the same name, which
explains the return value encoding.  Note that
the return value is \bold{false} for \bold{success}.
\end{Note}
\begin{SeeAlso}\relax
\code{\Link{file.info}}
\end{SeeAlso}
\begin{Examples}
\begin{ExampleCode}
fa <- file.access(dir("."))
table(fa) # count successes & failures
\end{ExampleCode}
\end{Examples}

