.libPaths
gets/sets the library trees within which packages are
looked for.
.libPaths(new).Library
.Library.site
a character vector with the locations of R library
trees. Tilde expansion (path.expand
) is done, and if
any element contains one of *?[
, globbing is done where
supported by the platform: see Sys.glob
.
A character vector of file paths.
.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
with argument 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.
How paths 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$platform-library/x.y
of the home directory (or Library/R/x.y/library
for
CRAN macOS builds), for R x.y.z.
.Library.site
can be set via the environment variable
R_LIBS_SITE
(as a non-empty colon-separated list of library trees).
The library search path is initialized at startup from the environment
variable R_LIBS
(which should be a semicolon-separated list of
directories at which R library trees are rooted) followed by those in
environment variable R_LIBS_USER
. Only directories which exist
at the time will be included.
By default R_LIBS
is unset, and R_LIBS_USER
is set to
subdirectory R/win-library/x.y
of the home directory,
for R x.y.z.
.Library.site
can be set via the environment variable
R_LIBS_SITE
(as a non-empty semicolon-separated list of library trees).
Both R_LIBS_USER
and R_LIBS_SITE
feature possible
expansion of specifiers for R version specific information as part of
the startup process. The possible conversion specifiers all start
with a % and are followed by a single letter (use %%
to obtain %), with currently available conversion
specifications as follows:
R version number including the patchlevel (e.g., 2.5.0).
R version number excluding the patchlevel (e.g., 2.5).
the platform for which R was built, the value of
R.version$platform
.
the underlying operating system, the value of
R.version$os
.
the architecture (CPU) R was built on/for, the
value of R.version$arch
.
(See version
for details on R version information.)
Function .libPaths
always uses the values of .Library
and .Library.site
in the base namespace. .Library.site
can be set by the site in Rprofile.site
, which should be
followed by a call to .libPaths(.libPaths())
to make use of the
updated value.
For consistency, the paths are always normalized by
normalizePath(winslash = "/")
.
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.
# NOT RUN {
.libPaths() # all library trees R knows about
# }
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