\Header{capabilities}{Report Capabilities of this Build of R}
\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{\Link{jpeg}} function operational?
\item[\code{png}] Is the \code{\Link{png}} function operational?
\item[\code{tcltk}] Is the \pkg{tcltk} package operational?
\item[\code{X11}] (Unix)  Are \code{X11} and the data editor available?
\item[\code{GNOME}] (Unix)  Is the GNOME GUI in use and are \code{GTK} and
\code{GNOME} graphics devices available?
\item[\code{libz}] Is \code{\Link{gzfile}} available?  From \R{} 1.5.0 this
will always be true.
\item[\code{http/ftp}] Are \code{\Link{url}} and the internal method for
\code{\Link{download.file}} available?
\item[\code{sockets}] Are \code{\Link{make.socket}} and related functions
available?
\item[\code{libxml}] Is there support for integrating \code{libxml} with
the \R{} event loop?
\item[\code{cledit}] Is command-line editing available in the current \R{}
session?  This is false in non-interactive sessions.
It will be true if \code{readline} supported has been compiled in
and \option{--no-readline} was \emph{not} invoked.

\item[\code{IEEE754}] Does this platform have IEEE 754 arithmetic?  Note
that this is more correctly known by the international standard
IEC 60559.
\item[\code{bzip2}] Is \code{\Link{bzfile}} available?
\item[\code{PCRE}] Is the Perl-Compatible Regular Expression library
available?  This is needed for the \code{perl = TRUE} option to
\code{\Link{grep}} are related function.
\end{ldescription}
\end{Value}
\begin{SeeAlso}\relax
\code{\Link{.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}

