EnvVar {base} | R Documentation |
Environment Variables
Description
Details of some of the environment variables which affect an R session.
Details
It is impossible to list all the environment variables which can affect an R session: some affect the OS system functions which R uses, and others will affect add-on packages. But here are notes on some of the more important ones. Those that set the defaults for options are consulted only at startup (as are some of the others).
- HOME:
The user's ‘home’ directory.
- LANGUAGE:
Optional. The language(s) to be used for message translations. This is consulted when needed.
- LC_ALL:
(etc) Optional. Use to set various aspects of the locale – see
Sys.getlocale
. Consulted at startup.- MAKEINDEX:
The path to
makeindex
. If unset to a value determined when R was built. Used by the emulation mode oftexi2dvi
andtexi2pdf
.- R_BATCH:
Optional – set in a batch session, that is one started by
R CMD BATCH
. Most often set to""
, so test by something like!is.na(Sys.getenv("R_BATCH", NA))
.- R_BROWSER:
The path to the default browser. Used to set the default value of
options("browser")
.- R_COMPLETION:
Optional. If set to
FALSE
, command-line completion is not used. (Not used by the macOS GUI.)- R_DEFAULT_PACKAGES:
A comma-separated list of packages which are to be attached in every session. See
options
.- R_DOC_DIR:
The location of the R ‘doc’ directory. Set by R.
- R_ENVIRON:
Optional. The path to the site environment file: see Startup. Consulted at startup.
- R_GSCMD:
Optional. The path to Ghostscript, used by
dev2bitmap
,bitmap
andembedFonts
. Consulted when those functions are invoked. Since it will be treated as if passed tosystem
, spaces and shell metacharacters should be escaped.- R_HISTFILE:
Optional. The path of the history file: see Startup. Consulted at startup and when the history is saved.
- R_HISTSIZE:
Optional. The maximum size of the history file, in lines. Exactly how this is used depends on the interface.
- On Unix-alikes,
for the
readline
command-line interface it takes effect when the history is saved (bysavehistory
or at the end of a session).- On Windows,
for
Rgui
it controls the number of lines saved to the history file: the size of the history used in the session is controlled by the console customization: seeRconsole
.
- R_HOME:
The top-level directory of the R installation: see
R.home
. Set by R.- R_INCLUDE_DIR:
The location of the R ‘include’ directory. Set by R.
- R_LIBS:
Optional. Used for initial setting of
.libPaths
.- R_LIBS_SITE:
Optional. Used for initial setting of
.libPaths
.- R_LIBS_USER:
Optional. Used for initial setting of
.libPaths
.- R_PAPERSIZE:
Optional. Used to set the default for
options("papersize")
, e.g. used bypdf
andpostscript
.- R_PCRE_JIT_STACK_MAXSIZE:
Optional. Consulted when PCRE's JIT pattern compiler is first used. See
grep
.- R_PDFVIEWER:
The path to the default PDF viewer. Used by
R CMD Rd2pdf
.- R_PLATFORM:
The platform – a string of the form
"cpu-vendor-os"
, seeR.Version
.- R_PROFILE:
Optional. The path to the site profile file: see Startup. Consulted at startup.
- R_RD4PDF:
Options for
pdflatex
processing ofRd
files. Used byR CMD Rd2pdf
.- R_SHARE_DIR:
The location of the R ‘share’ directory. Set by R.
- R_TEXI2DVICMD:
The path to
texi2dvi
. Defaults to the value of TEXI2DVI, and if that is unset to a value determined when R was built.Only on Unix-alikes:
Consulted at startup to set the default foroptions("texi2dvi")
, used bytexi2dvi
andtexi2pdf
in package tools.- R_TIDYCMD:
The path to HTML
tidy
. Used byR CMD check
if _R_CHECK_RD_VALIDATE_RD2HTML_ is set to a true value (as it is by --as-cran.- R_UNZIPCMD:
The path to
unzip
. Sets the initial value foroptions("unzip")
on a Unix-alike when namespace utils is loaded.- R_ZIPCMD:
The path to
zip
. Used byzip
and byR CMD INSTALL --build
on Windows.- TMPDIR, TMP, TEMP:
Consulted (in that order) when setting the temporary directory for the session: see
tempdir
. TMPDIR is also used by some of the utilities: see the help forbuild
.- TZ:
Optional. The current time zone. See
Sys.timezone
for the system-specific formats. Consulted as needed.- TZDIR:
Optional. The top-level directory of the time-zone database. See
Sys.timezone
.- no_proxy, http_proxy, ftp_proxy:
-
(and more). Optional. Settings for
download.file
: see its help for further details.
Unix-specific
Some variables set on Unix-alikes, and not (in general) on Windows.
- DISPLAY:
Optional: used by
X11
, Tk (in package tcltk), the data editor and various packages.- EDITOR:
The path to the default editor: sets the default for
options("editor")
when namespace utils is loaded.- PAGER:
The path to the pager with the default setting of
options("pager")
. The default value is chosen at configuration, usually as the path toless
.- R_PRINTCMD:
Sets the default for
options("printcmd")
, which sets the default print command to be used bypostscript
.- R_SUPPORT_OLD_TARS
logical. Sets the default for the
support_old_tars
argument ofuntar
. Should be set toTRUE
if an old systemtar
command is used which does not support eitherxz
compression or automagically detecting compression type.
Windows-specific
Some Windows-specific variables are
- GSC:
Optional: the path to Ghostscript, used if R_GSCMD is not set.
- R_USER:
The user's ‘home’ directory. Set by R. (HOME will be set to the same value if not already set.)
See Also
Sys.getenv
and Sys.setenv
to read and set
environmental variables in an R session.
gctorture
for environment variables controlling garbage
collection.