R: Download packages from CRAN

update.packages {base}

R Documentation

Download packages from CRAN

Description

These functions can be used to automatically compare the version numbers of installed packages with the newest available version on CRAN and update outdated packages on the fly.

Usage

update.packages(lib.loc=.lib.loc, CRAN=options("CRAN"),
                method="auto", instlib=NULL)

installed.packages(lib.loc = .lib.loc)
CRAN.packages(CRAN=options("CRAN"), method="auto")

download.file(url, destfile, method="auto")
download.packages(pkgs, destdir, available=NULL,
                  CRAN=options("CRAN"), method="auto")
install.packages(pkgs, lib, available=NULL,
                  CRAN=options("CRAN"), method="auto")

parse.description <- function(desc)

Arguments

lib.loc

A character vector describing the location of R library trees to search through (and update packages therein).

CRAN

Base URL of the CRAN mirror to use, i.e., URL of a CRAN root such as "http://www.ci.tuwien.ac.at/R" or "http://lib.stat.cmu.edu/R/CRAN".

method

Tool to be used for downloading files. Currently download methods "auto", "wget" and "lynx" are available. The respective program of the same name must be installed on your system and be in the PATH.

url

A character string with the URL of a file to be downloaded.

destfile

A character string with the name where the downloaded file is saved.

pkgs

A character vector of package names that shall be downloaded from CRAN.

destdir

Directory where downloaded packages are stored.

available

List of packages available at CRAN as returned by CRAN.packages().

desc

A character vector with each element containing one line of a package description file.

lib, instlib

A character string giving the library directory where to install the packages.

Details

installed.packages() scans the DESCRIPTION files of each package found along lib.loc and returns a list of package names, library paths and version numbers. CRAN.packages() returns a similar list, but corresponding to packages currently available in the contrib section of CRAN, the comprehensive R archive network. The current list of packages is downloaded over the internet (or copied from a local CRAN mirror). Both functions use parse.description() for parsing the description files.

The function download.file() can be used to download a single file as described by url from the internet and store it in destfile. It makes a system call to the tool given by method, the respective program must be installed on your system and be in the search path for executables. Method "auto" (the default) searches for available tools at runtime.

download.packages() takes a list of package names and a destination directory, downloads the newest versions of the package sources and saves the in destdir. If the list of available packages is not given as argument, it is also directly obtained from CRAN. If CRAN is local, i.e., the URL starts with "file:", then the packages are not downloaded but used directly.

The main function of the bundle is update.packages(). First a list of all packages found in lib.loc is created and compared with the pre-compiled packages available on CRAN. Outdated packages are reported and for each outdated package the user can specify if it should be automatically updated. If so, the pre-compiled packages are downloaded from CRAN and installed in the respective library path (or instlib if specified).

install.packages() can be used to install new packages, it takes a vector of package names and a destination directory, downloads the packages from CRAN and installs them. If the destination directory is omitted it defaults to the first directory in .lib.loc, with a warning.

Download packages from CRAN

Description

Usage

Arguments

Details

See Also