library.dynam {base}R Documentation

Loading Shared Libraries


Load the specified file of compiled code if it has not been loaded already, or unloads it.


library.dynam(chname, package = NULL, lib.loc = NULL,
              verbose = getOption("verbose"),
              file.ext = .Platform$dynlib.ext, ...)
library.dynam.unload(chname, libpath,
              verbose = getOption("verbose"),
              file.ext = .Platform$dynlib.ext)


chname a character string naming a shared library to load.
package a character vector with the names of packages to search through, or NULL. By default, all packages in the search path are used.
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.
libpath the path to the loaded package whose shared library is to be unloaded.
verbose a logical value indicating whether an announcement is printed on the console before loading the shared library. The default value is taken from the verbose entry in the system options.
file.ext the extension to append to the file name to specify the library to be loaded. This defaults to the appropriate value for the operating system.
... additional arguments needed by some libraries that are passed to the call to dyn.load to control how the library is loaded.
new a list of DLLInfo objects corresponding to the shared libraries loaded by packages.


library.dynam is designed to be used inside a package rather than at the command line, and should really only be used inside .First.lib on .onLoad. The system-specific extension for shared libraries (‘.dll’ on Windows) should not be added.

library.dynam.unload is designed for use in .Last.lib or .onUnload.

.dynLibs is used for getting or setting the shared libraries which were loaded by packages (using library.dynam). Versions of R prior to 2.1.0 simply recorded the (names of) packages which had loaded shared libraries. Versions of R prior to 1.6.0 used an internal global variable .Dyn.libs for storing this information: this variable is now defunct.


If chname is not specified, library.dynam returns an object of class "DLLInfoList" corresponding to the shared libraries loaded by packages.
If chname is specifed, an object of class "DLLInfo" that identifies the DLL and can be used in future calls is returned invisibly. For packages that have namespaces, a list of these objects is stored in the namespace's environment for use at run-time.
library.dynam.unload invisibly returns an object of class "DLLInfo" identifying the DLL successfully unloaded.


Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.

See Also

getLoadedDLLs for information on DLLInfo and DLLInfoList objects.

.First.lib, library, dyn.load, .packages, .libPaths

SHLIB for how to create suitable DLLs.


## Which DLLs were "dynamically loaded" by packages?

[Package base version 2.1.0 Index]