\HeaderA{file.show}{Display One or More Files}{file.show}
\keyword{file}{file.show}
\begin{Description}\relax
Display one or more files.
\end{Description}
\begin{Usage}
\begin{verbatim}
file.show(..., header = rep("", nfiles),
          title = "R Information",
          delete.file = FALSE, pager = getOption("pager"),
          encoding = "")
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{...}] one or more character vectors containing the names of the
files to be displayed.  These will be tilde-expanded: see
\code{\LinkA{path.expand}{path.expand}}.
\item[\code{header}] character vector (of the same length as the number of files
specified in \code{...}) giving a header for each file being
displayed.  Defaults to empty strings.
\item[\code{title}] an overall title for the display.  If a single separate
window is used for the display, \code{title} will be used as the window
title. If multiple windows are used, their titles should combine the title
and the file-specific header.
\item[\code{delete.file}] should the files be deleted after display?  Used
for temporary files.
\item[\code{pager}] the pager to be used.
\item[\code{encoding}] character string giving the encoding to be assumed for
the file(s).
\end{ldescription}
\end{Arguments}
\begin{Details}\relax
This function provides the core of the R help system, but it can be
used for other purposes as well, such as \code{\LinkA{page}{page}}.

How the pager is implemented is highly system-dependent.

The basic Unix version concatenates the files (using the headers) to a
temporary file, and displays it in the pager selected by the
\code{pager} argument, which is a character vector specifying a system
command (usually \code{less}) to run on the set of files.

Most GUI systems will use a separate pager window for each file, and
let the user leave it up while \R{} continues running.  The selection of
such pagers could either be done using special pager names being
intercepted by lower-level code (such as \code{"internal"} and
\code{"console"} on Windows), or by letting \code{pager} be an R
function which will be called with the same first four arguments as
\code{file.show} and take care of interfacing to the GUI.

Not all implementations will honour \code{delete.file}.
\end{Details}
\begin{Author}\relax
Ross Ihaka, Brian Ripley.
\end{Author}
\begin{SeeAlso}\relax
\code{\LinkA{files}{files}},
\code{\LinkA{list.files}{list.files}},
\code{\LinkA{help}{help}}.
\end{SeeAlso}
\begin{Examples}
\begin{ExampleCode}
file.show(file.path(R.home("doc"), "COPYRIGHTS"))
\end{ExampleCode}
\end{Examples}

