/dev2bitmap?package=base&version=3.6.2) ` , ` [ bitmap
](/link/bitmap?package=base&version=3.6.2) ` and ` [ embedFonts
](/link/embedFonts?package=base&version=3.6.2) ` . Consulted when those
functions are invoked. Since it will be treated as if passed to ` [ system
](/link/system?package=base&version=3.6.2) ` , spaces and shell metacharacters
should be escaped.

` R_HISTFILE ` :

    

Optional. The path of the history file: see [ Startup
](/link/Startup?package=base&version=3.6.2) . 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. For the ` readline ` command-line interface it
takes effect when the history is saved (by ` [ savehistory
](/link/savehistory?package=base&version=3.6.2) ` or at the end of a session).
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: see ` [ Rconsole ](/link/Rconsole?package=base&version=3.6.2) `
.

` R_HOME ` :

    

The top-level directory of the  R  installation: see ` [ R.home
](/link/R.home?package=base&version=3.6.2) ` . 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
](/link/.libPaths?package=base&version=3.6.2) ` .

` R_LIBS_SITE ` :

    

Optional. Used for initial setting of ` [ .libPaths
](/link/.libPaths?package=base&version=3.6.2) ` .

` R_LIBS_USER ` :

    

Optional. Used for initial setting of ` [ .libPaths
](/link/.libPaths?package=base&version=3.6.2) ` .

` R_PAPERSIZE ` :

    

Optional. Used to set the default for ` [ options
](/link/options?package=base&version=3.6.2) ("papersize") ` , e.g.used by ` [
pdf ](/link/pdf?package=base&version=3.6.2) ` and ` [ postscript
](/link/postscript?package=base&version=3.6.2) ` .

` R_PCRE_JIT_STACK_MAXSIZE ` :

    

Optional. Consulted when PCRE's JIT pattern compiler is first used. See ` [
grep ](/link/grep?package=base&version=3.6.2) ` .

` 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  ` , see ` [
R.Version ](/link/R.Version?package=base&version=3.6.2) ` .

` R_PROFILE ` :

    

Optional. The path to the site profile file: see [ Startup
](/link/Startup?package=base&version=3.6.2) . Consulted at startup.

` R_RD4PDF ` :

    

Options for ` pdflatex ` processing of ` Rd ` files. Used by ` R 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. Consulted at startup to set
the default for ` [ options ](/link/options?package=base&version=3.6.2)
("texi2dvi") ` , used by ` [ texi2dvi
](/link/texi2dvi?package=base&version=3.6.2) ` and ` [ texi2pdf
](/link/texi2pdf?package=base&version=3.6.2) ` in package  tools  .

` R_UNZIPCMD ` :

    

The path to ` unzip ` . Sets the initial value for ` [ options
](/link/options?package=base&version=3.6.2) ("unzip") ` on a Unix-alike when
namespace  utils  is loaded.

` R_ZIPCMD ` :

    

The path to ` zip ` . Used by ` [ zip ](/link/zip?package=base&version=3.6.2)
` and by ` R CMD INSTALL --build ` on Windows.

` TMPDIR ` , ` TMP ` , ` TEMP ` :

    

Consulted (in that order) when setting the temporary directory for the
session: see ` [ tempdir ](/link/tempdir?package=base&version=3.6.2) ` . `
TMPDIR ` is also used by some of the utilities see the help for ` [ build
](/link/build?package=base&version=3.6.2) ` .

` TZ ` :

    

Optional. The current time zone. See ` [ Sys.timezone
](/link/Sys.timezone?package=base&version=3.6.2) ` for the system-specific
formats. Consulted as needed.

` no_proxy ` , ` http_prox