\HeaderA{capabilities}{Report Capabilities of this Build of R}{capabilities}
\keyword{utilities}{capabilities}
\begin{Description}\relax
Report on the optional features which have been compiled into this
build of \R.
\end{Description}
\begin{Usage}
\begin{verbatim}
capabilities(what = NULL)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{what}] character vector or \code{NULL}, specifying
required components.  \code{NULL} implies that all are required.
\end{ldescription}
\end{Arguments}
\begin{Value}
A named logical vector. Current components are
\begin{ldescription}
\item[\code{jpeg}] Is the \code{\LinkA{jpeg}{jpeg}} function operational?
\item[\code{png}] Is the \code{\LinkA{png}{png}} function operational?
\item[\code{tcltk}] Is the \pkg{tcltk} package operational?
\item[\code{X11}] (Unix)  Are the \code{X11} graphics device and the
X11-based data editor available?  As from \R{} 2.1.0 this loads the
X11 module if not already loaded, and checks that the default
display can be contacted unless a \code{X11} device has already
been used.
\item[\code{http/ftp}] Are \code{\LinkA{url}{url}} and the internal method for
\code{\LinkA{download.file}{download.file}} available?
\item[\code{sockets}] Are \code{\LinkA{make.socket}{make.socket}} and related functions
available?
\item[\code{libxml}] Is there support for integrating \code{libxml} with
the \R{} event loop?
\item[\code{fifo}] are FIFO connections supported?
\item[\code{cledit}] Is command-line editing available in the current \R{}
session?  This is false in non-interactive sessions.
It will be true for the command-line interface if \code{readline}
support has been compiled in and \option{--no-readline} was
\emph{not} invoked.

\item[\code{iconv}] is internationalization conversion via
\code{\LinkA{iconv}{iconv}} supported?
\item[\code{NLS}] is there Natural Language Support (for message translations)?
\end{ldescription}
\end{Value}
\begin{SeeAlso}\relax
\code{\LinkA{.Platform}{.Platform}}
\end{SeeAlso}
\begin{Examples}
\begin{ExampleCode}
capabilities()

if(!capabilities("http/ftp"))
   warning("internal download.file() is not available")

## See also the examples for 'connections'.
\end{ExampleCode}
\end{Examples}

