Return the R Home Directory

Description

Return the R home directory, or the full path to a component of the R installation.

Usage

R.home(component = "home")

Arguments

Details

The R home directory is the top-level directory of the R installation being run.

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. It can be found outside an R session by R RHOME.

The paths to components often are subdirectories of R_HOME but need not be: "doc", "include" and "share" are not for some Linux binary installations of R.

Value

A character string giving the R home directory or path to a particular component. Normally the components are all subdirectories of the R home directory, but this need not be the case in a Unix-like installation.

The value for "modules" and on Windows "bin" is a sub-architecture-specific location. (This is not so for "etc", which may have sub-architecture-specific files as well as common ones.)

On a Unix-alike, the constructed paths are based on the current values of the environment variables R_HOME and where set R_SHARE_DIR, R_DOC_DIR and R_INCLUDE_DIR (these are set on startup and should not be altered).

On Windows the values of R.home() and R_HOME are switched to the 8.3 short form of path elements if required and if the Windows service to do that is enabled. The value of R_HOME is set to use forward slashes (since many package maintainers pass it unquoted to shells, for example in ‘Makefile’s).

See Also

commandArgs()[1] may provide related information.

Examples

## These result quite platform-dependently :
rbind(home = R.home(),
      bin  = R.home("bin")) # often the 'bin' sub directory of 'home'
                            # but not always ...
list.files(R.home("bin"))