.libPaths gets/sets the library trees within which packages are
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.libPaths(new) .Library .Library.site
a character vector with the locations of R library
trees. Tilde expansion (
.Library is a character string giving the location of the
default library, the ‘library’ subdirectory of R_HOME.
.Library.site is a (possibly empty) character vector giving the
locations of the site libraries, by default the ‘site-library’
subdirectory of R_HOME (which may not exist).
.libPaths is used for getting or setting the library trees that
R knows about (and hence uses when looking for packages). If called
new, the library search path is set to
the existing directories in
unique(c(new, .Library.site, .Library))
and this is returned. If given no argument, a character vector with
the currently active library trees is returned.
new with a trailing slash are treated is
OS-dependent. On a POSIX filesystem existing directories can usually
be specified with a trailing slash: on Windows filepaths with a
trailing slash (or backslash) are invalid and so will never be added
to the library search path.
The library search path is initialized at startup from the environment variable R_LIBS (which should be a colon-separated list of directories at which R library trees are rooted) followed by those in environment variable R_LIBS_USER. Only directories which exist at the time will be included.
By default R_LIBS is unset, and R_LIBS_USER is set to directory ‘R/R.version$platform-library/x.y’ of the home directory (or ‘Library/R/x.y/library’ for CRAN macOS builds), for R x.y.z.
.Library.site can be set via the environment variable
R_LIBS_SITE (as a non-empty colon-separated list of library trees).
Both R_LIBS_USER and R_LIBS_SITE feature possible expansion of specifiers for R version specific information as part of the startup process. The possible conversion specifiers all start with a % and are followed by a single letter (use %% to obtain %), with currently available conversion specifications as follows:
R version number including the patchlevel (e.g., 2.5.0).
R version number excluding the patchlevel (e.g., 2.5).
the platform for which R was built, the value of
the underlying operating system, the value of
the architecture (CPU) R was built on/for, the
version for details on R version information.)
.libPaths always uses the values of
.Library.site in the base namespace.
can be set by the site in ‘Rprofile.site’, which should be
followed by a call to
.libPaths(.libPaths()) to make use of the
For consistency, the paths are always normalized by
normalizePath(winslash = "/").
A character vector of file paths.
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.
.libPaths() # all library trees R knows about