\Header{files}{File Manipulation}
\alias{basename}{files}
\alias{dir.create}{files}
\alias{dirname}{files}
\alias{file.append}{files}
\alias{file.copy}{files}
\alias{file.create}{files}
\alias{file.exists}{files}
\alias{file.remove}{files}
\alias{path.expand}{files}
\keyword{file}{files}
\begin{Description}\relax
These functions provide a low-level interface to the computer's
file system.\end{Description}
\begin{Usage}
\begin{verbatim}
file.create(...)
file.exists(...)
file.remove(...)
file.append(file1, file2)
file.copy(from, to, overwrite = FALSE)
dir.create(path)
basename(path)
dirname(path)
path.expand(path)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{..., file1, file2, from, to, path}] character vectors,
containing file names.
\item[\code{overwrite}] logical; should the destination files be overwritten?
\end{ldescription}
\end{Arguments}
\begin{Details}\relax
The \code{...} arguments are concatenated to form one character
string: you can specify the files separately or as one vector.

\code{file.create} creates files with the given names if they
do not already exist and truncates them if they do.
It returns a logical vector indicating the success or failure
of the operation for each file.

\code{file.exists} returns a logical vector indicating whether
the files named by its argument exist.

\code{file.remove} attempts to remove the files named in its
argument.  It returns a logical vector indicating whether or
not it succeeded in removing each file.

\code{file.append} attempts to append the files named by its
second argument to those named by its first.  The \R{} subscript
recycling rule is used to align names given in vectors
of different lengths.

\code{file.copy} works in a similar way to \code{file.append} but with
the arguments in the natural order for copying. Copying to existing
destination files is skipped unless \code{overwrite = TRUE}.
The \code{to} argument can specify a single existing directory.

\code{dir.create} creates the last element of the path. It returns a
logical, true for success.

\code{basename} removes all of the path up to the last path separator
(if any).

\code{dirname} returns the part of the \code{path} up to (but
excluding) the last path separator, or \code{"."} if there is no path
separator.  Tilde expansion is done: see the description for
\code{path.expand} below.

In both \code{basename} and \code{dirname} trailing file separators
are removed before dissecting the path, and for \code{dirname} any
trailing file separators are removed from the result.

\code{path.expand} expands path(s) by replacing a leading tilde by the
user's home directory (if defined on that platform).
On \emph{some Unix} versions, a leading \code{\textasciitilde{}user} will expand to
the home directory of \code{user}, but not on Unix versions without
\code{readline} installed.\end{Details}
\begin{Author}\relax
Ross Ihaka, Brian Ripley\end{Author}
\begin{SeeAlso}\relax
\code{\Link{file.info}}, \code{\Link{file.access}},
\code{\Link{file.show}}, \code{\Link{list.files}},
\code{\Link{unlink}}.\end{SeeAlso}
\begin{Examples}
\begin{ExampleCode}
cat("file A\n", file="A")
cat("file B\n", file="B")
file.append("A", "B")
file.create("A")
file.append("A", rep("B", 10))
if(interactive()) file.show("A")
file.copy("A", "C")
dir.create("tmp")
file.copy(c("A", "B"), "tmp")
unlink("tmp", recursive=TRUE)
file.remove("A", "B", "C")

basename(file.path("","p1","p2","p3","filename"))
dirname(file.path("","p1","p2","p3","filename"))

path.expand("~/foo")
\end{ExampleCode}
\end{Examples}

