rcmd_safe_env returns a set of environment variables that are more appropriate for rcmd_safe(). It is exported to allow manipulating these variables (e.g. add an extra one), before passing them to the rcmd() functions.
It currently has the following variables:
CYGWIN="nodosfilewarning": On Windows, do not warn about MS-DOS
style file names.
R_TESTS="" This variable is set by R CMD check, and makes the
child R process load a startup file at startup, from the current
working directory, that is assumed to be the /test directory
of the package being checked. If the current working directory is
changed to something else (as it typically is by testthat, then R
cannot start. Setting it to the empty string ensures that callr can
be used from unit tests.
R_BROWSER="false": typically we don't want to start up a browser
from the child R process.
R_PDFVIEWER="false": similarly for the PDF viewer.
rcmd_safe_env()
Note that callr also sets the R_ENVIRON, R_ENVIRON_USER,
R_PROFILE and R_PROFILE_USER environment variables
appropriately, unless these are set by the user in the env argument
of the r, etc. calls.
A named character vector of environment variables.
Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.