zpackages                package:base                R Documentation

Listing of Packages

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 all libraries currently known.

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'. If versioned installs have been used, the names
     returned will be of the form 'pkgname_version'. 

     For a package to be regarded as being available it must have a
     'DESCRIPTION' file containing a valid 'version' field.

Value:

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

Author(s):

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

See Also:

     'library', '.libPaths'.

Examples:

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

