ns-load {base}R Documentation

Loading and Unloading Name Spaces


Functions to load and unload namespaces.


attachNamespace(ns, pos = 2, dataPath = NULL)
loadNamespace(package, lib.loc = NULL,
              keep.source = getOption("keep.source.pkgs"),
              partial = FALSE, declarativeOnly = FALSE)


ns string or namespace object.
pos integer specifying position to attach.
dataPath path to directory containing a database of datasets to be lazy-loaded into the attached environment.
package string naming the package/name space to load.
lib.loc character vector specifying library search path.
keep.source logical specifying whether to retain source. This applies only to the specified name space, and not to other name spaces which might be loaded to satisfy imports.
For more details see this argument to library.
partial logical; if true, stop just after loading code.
declarativeOnly logical; disables .Import, etc, if true.


The functions loadNamespace and attachNamespace are usually called implicitly when library is used to load a name space and any imports needed. However it may be useful to call these functions directly at times.

loadNamespace loads the specified name space and registers it in an internal data base. A request to load a name space that is already loaded has no effect. The arguments have the same meaning as the corresponding arguments to library, whose help page explains the details of how a particular installed package comes to be chosen. After loading, loadNamespace looks for a hook function named .onLoad as an internal variable in the name space (it should not be exported). This function is called with the same arguments as .First.lib. Partial loading is used to support installation with the --save and --lazy options.

loadNamespace does not attach the name space it loads to the search path. attachNamespace can be used to attach a frame containing the exported values of a name space to the search path. The hook function .onAttach is run after the name space exports are attached.

loadedNamespaces returns a character vector of the names of the loaded name spaces.

unloadNamespace can be used to force a name space to be unloaded. An error is signaled if the name space is imported by other loaded name spaces. If defined, a hook function .onUnload is run before removing the name space from the internal registry. unloadNamespace will first detach a package of the same name if one is on the path, thereby running a .Last.lib function in the package if one is exported.


Luke Tierney

[Package base version 2.5.0 Index]