\Header{file.show}{Display One or More Files}
\keyword{file}{file.show}
\begin{Description}\relax
Display one or more files.\end{Description}
\begin{Usage}
\begin{verbatim}
file.show(..., header, title="R Information",
          delete.file=FALSE, pager=getOption("pager"))
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{...}] one or more character vectors containing the names of the
files to be displayed.
\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.
\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.\end{Details}
\begin{Note}\relax
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 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 ``magic'' 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 arguments as \code{file.show} and take care of interfacing to the
GUI.

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

