Skip to Content
Home » Language reference » zpackages {base}

zpackages {base}

Listing of Packages
Package: 
base
Version: 
R 2.15.3

Description

.packages returns information about package availability.

Usage

.packages(all.available = FALSE, lib.loc = NULL)

Arguments

all.available
logical; if TRUE return a character vector of all available packages in lib.loc.
lib.loc
a character vector describing the location of R library trees to search through, or NULL. The default value of NULL corresponds to .libPaths().

Details

.packages() returns the names of the currently attached packages invisibly whereas .packages(all.available = TRUE) gives (visibly) all packages available in the library location path lib.loc. For a package to be regarded as being ‘available’ it must have valid metadata (and hence be an installed package). However, this will report a package as available if the metadata does not match the directory name: use find.package to confirm that the metadata match or installed.packages for a much slower but more comprehensive check of ‘available’ packages.

Values

A character vector of package base names, invisible unless all.available = TRUE.

Note

.packages(all.available = TRUE) is not a way to find out if a small number of packages are available for use: not only is it expensive when thousands of packages are installed, it is an incomplete test. See the help for find.package for why require should be used.

See Also

library, .libPaths, installed.packages.

Examples

(.packages())               # maybe just "base"
.packages(all.available = TRUE) # return all available as character vector
require(splines)
(.packages())               # "splines", too
detach("package:splines")

Author(s)

R core; Guido Masarotto for the all.available = TRUE part of .packages.

Documentation reproduced from R 2.15.3. License: GPL-2.