R.home(component = "home")"home" which gives the R home
directory, other known values are "bin", "doc",
"etc", "modules" and "share" giving the paths to the
corresponding parts of an R installation."modules" and on Windows "bin" is
to a sub-architecture-specific location.The function R.home() bases the constructed paths on the
current value of the environment variable R_HOME which is
normally set on startup.On Windows the values of R.home() and R_HOME are
guaranteed not to contain spaces, switching to the 8.3 short form of
path elements if required. From R 2.13.0 the value of R_HOME
is set on startup to use forward slashes (since many package
maintainers pass it unquoted to shells, for example in Makefiles).
The R home directory is often referred to as R_HOME,
and is the value of an environment variable of that name in an R
session.
unix
It can be found outside an R session by R RHOME.