\HeaderA{update.packages}{Download Packages from CRAN-like repositories}{update.packages}
\aliasA{available.packages}{update.packages}{available.packages}
\aliasA{contrib.url}{update.packages}{contrib.url}
\aliasA{download.packages}{update.packages}{download.packages}
\aliasA{install.packages}{update.packages}{install.packages}
\aliasA{new.packages}{update.packages}{new.packages}
\aliasA{old.packages}{update.packages}{old.packages}
\keyword{utilities}{update.packages}
\begin{Description}\relax
These functions can be used to automatically compare the version
numbers of installed packages with the newest available version on
the repositories and update outdated packages on the fly.
\end{Description}
\begin{Usage}
\begin{verbatim}
update.packages(lib.loc = NULL, repos = getOption("repos"),
                contriburl = contrib.url(repos, type),
                method, instlib = NULL,
                ask = TRUE, available = NULL, destdir = NULL,
                installWithVers = FALSE, checkBuilt = FALSE,
                type = getOption("pkgType"))

available.packages(contriburl = contrib.url(getOption("repos")), method)

old.packages(lib.loc = NULL, repos = getOption("repos"),
             contriburl = contrib.url(repos),
             method, available = NULL, checkBuilt = FALSE)

new.packages(lib.loc = NULL, repos = getOption("repos"),
             contriburl = contrib.url(repos),
             method, available = NULL, ask = FALSE)

download.packages(pkgs, destdir, available = NULL,
                  repos = getOption("repos"),
                  contriburl = contrib.url(repos, type),
                  method, type = getOption("pkgType"))

install.packages(pkgs, lib, repos = getOption("repos"),
                 contriburl = contrib.url(repos, type),
                 method, available = NULL, destdir = NULL,
                 installWithVers = FALSE, dependencies = FALSE,
                 type = getOption("pkgType"))

contrib.url(repos, type = getOption("pkgType"))
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{lib.loc}] character vector describing the location of R
library trees to search through (and update packages therein).
\item[\code{repos}] character vector, the base URL(s) of the repositories
to use, i.e., the URL of the CRAN master such as
\code{"http://cran.r-project.org"} or its Statlib mirror,
\code{"http://lib.stat.cmu.edu/R/CRAN"}.
Can be \code{NULL} to install from local \file{.tar.gz} files.

\item[\code{contriburl}] URL(s) of the contrib section of the
repositories. Use this argument only if your CRAN mirror is
incomplete, e.g., because you burned only the \file{contrib} section on a
CD.  Overrides argument \code{repos}.
Can be \code{NULL} to install from local \file{.tar.gz} files.

\item[\code{method}] Download method, see \code{\LinkA{download.file}{download.file}}.
\item[\code{pkgs}] character vector of the short names of packages/bundles whose
current versions should be downloaded from the repositories.
If \code{repos = NULL}, a character vector of file paths of
\file{.tar.gz} files.  These can be source archives or binary
package/bundle archive files (as created by \code{R CMD build --binary}).
If this is a zero-length character vector, a listbox of available
packages (including those contained in bundles) is presented where
possible.

\item[\code{destdir}] directory where downloaded packages are stored.
\item[\code{available}] an object listing packages available at the repositories
as returned by \code{available.packages}.
\item[\code{lib}] character vector giving the library directories where to
install the packages.  Recycled as needed.
\item[\code{ask}] logical indicating whether to ask user before packages
are actually downloaded and installed, or the character string
\code{"graphics"}, which brings up a widget to allow the user to
(de-)select from the list of packages which could be updated.  The
latter only works on systems with a GUI version of
\code{\LinkA{select.list}{select.list}}, and is otherwise equivalent to \code{ask
      = TRUE}.

\item[\code{installWithVers}] If \code{TRUE}, will invoke the install of the
package such that it can be referenced by package version.
\item[\code{checkBuilt}] If \code{TRUE}, a package built under an earlier
minor version of \R{} is considered to be \sQuote{old}.
\item[\code{instlib}] character string giving the library directory where to
install the packages.
\item[\code{dependencies}] logical indicating to also install uninstalled
packages on which these packages depend/suggest/import
(and so on recursively).  Not used if \code{repos = NULL}.
Can also be a character vector, a subset of
\code{c("Depends", "Imports", "Suggests")}.

\item[\code{type}] character, indicating the type of package to download and
install.
Possible values are \code{"source"} (the default except under the
CRAN Mac OS X build), \code{"mac.binary"} and \code{"win.binary"}
(which can be downloaded but not installed).

\end{ldescription}
\end{Arguments}
\begin{Details}\relax
All of these functions work with the names of a package or bundle (and
not the component packages of a bundle, except for
\code{install.packages} if the repository provides the necessary
information).

\code{available.packages} returns a matrix of details corresponding to
packages/bundles currently available at  one or more repositories. The
current list of packages is downloaded over the internet (or copied
from a local mirror).  It returns only packages whose version
requirements are met by the running version of \R.

\code{old.packages} compares the information from
\code{available.packages} with that from
\code{\LinkA{installed.packages}{installed.packages}} and reports installed
packages/bundles that have newer versions on the repositories or, if
\code{checkBuilt = TRUE}, that were built under an earlier minor
version of \R{} (for example built under 2.0.x when running \R{} 2.1.1).

\code{new.packages} does the same comparison but reports uninstalled
packages/bundles that are available at the repositories.  It will also
give warnings about incompletely installed bundles (provided the
information is available) and bundles whose contents has changed.
If \code{ask != FALSE} it asks which packages should be installed
in the first element of \code{lib.loc}.

\code{download.packages} takes a list of package/bundle names and a
destination directory, downloads the newest versions and saves them in
\code{destdir}.  If the list of available packages is not given as
argument, it is obtained from repositories.  If a repository is local,
i.e., the URL starts with \code{"file:"}, then the packages are not
downloaded but used directly.  (Both \code{"file:"} and
\code{"file:///"} are allowed as prefixes to a file path, the latter
for an absolute file path.)

The main function of the set is \code{update.packages}.  First a list
of all packages/bundles found in \code{lib.loc} is created and
compared with those available at the repostories.  If \code{ask =
    TRUE} (the default) packages/bundles with a newer version are
reported and for each one the user can specify if it should be
updated.
If so, the package sources are downloaded from the repositories and
installed in the respective library path (or \code{instlib}
if specified) using the \R{} \code{\LinkA{INSTALL}{INSTALL}} mechanism.

\code{install.packages} can be used to install new packages/bundles.
It takes a vector of names and a destination library, downloads the
packages from the repositories and installs them.  (If the library is
omitted it defaults to the first directory in \code{.libPaths()}, with
a warning if there is more than one.)
An attempt is made to install the packages in an order that respects
their dependencies.  This does assume that all the entries in
\code{lib} are on the default library path for installs (set by
\code{R\_LIBS}). 

\code{contrib.url} adds the appropriate type-specific path within a
repository to each URL in \code{repos}.

For \code{install.packages} and \code{update.packages}, \code{destdir}
is the directory to which packages will be downloaded.  If it is
\code{NULL} (the default) a directory \code{downloaded\_packages} of
the session temporary directory will be used (and the files will be
deleted at the end of the session).

If \code{repos} or \code{contriburl} is a vector of length greater than
one, the newest version of the package is fetched from the first
repository on the list within which it is found.
\end{Details}
\begin{Value}
For \code{available.packages}, a matrix
with one row per package/bundle, row names the package names and
column names \code{"Package"}, \code{"Version"}, \code{"Priority"},
\code{"Bundle"}, \code{"Depends"}, \code{"Imports"}, \code{"Suggests"}
\code{"Contains"} and \code{"Repository"}.

For \code{old.packages}, \code{NULL} or a matrix with one row per
package/bundle, row names the package names and column names
\code{"Package"}, \code{"LibPath"}, \code{"Installed"} (the version),
\code{"Built"} (the version built under), \code{"ReposVer"} and
\code{"Repository"}.

For \code{new.packages} a character vector of package/bundle names,
\emph{after} any have been installed.

For \code{download.packages}, a two-column matrix of names and
destination file names, for those packages/bundles successfully
downloaded.  If packages are not available or there is a problem with
the download, suitable warnings are given.

\code{install.packages} and \code{update.packages} have no return value.
\end{Value}
\begin{Section}{Warning}
Not enough information is recorded to know if a bundle is completely
installed, so a bundle is regarded as installed if any of its
component packages is.
\end{Section}
\begin{Note}\relax
Some binary distributions of \R{} have \code{INSTALL} in a separate
bundle, e.g. an \code{R-devel} RPM.  \code{install.packages} will
give an error if called on such a system.
\end{Note}
\begin{SeeAlso}\relax
\code{\LinkA{installed.packages}{installed.packages}}.

See \code{\LinkA{download.file}{download.file}} for how to handle proxies and
other options to monitor file transfers.

\code{\LinkA{INSTALL}{INSTALL}}, \code{\LinkA{REMOVE}{REMOVE}},
\code{\LinkA{library}{library}}, \code{\LinkA{.packages}{.packages}}, \code{\LinkA{read.dcf}{read.dcf}}
\end{SeeAlso}