Get Environment Variables
Sys.getenv obtains the values of the environment variables.
Sys.getenv(x = NULL, unset = "", names = NA)
- a character vector, or
- a character string.
- logical: should the result be named? If
NA(the default) single-element results are not named whereas multi-element results are.
Both arguments will be coerced to character if necessary.
unset = NA will enable unset variables and those set to
"" to be distinguished, if the OS does. POSIX
requires the OS to distinguish, and all known current R platforms do.
A vector of the same length as x, with (if names ==
TRUE) the variable names as its names attribute. Each element
holds the value of the environment variable named by the corresponding
component of x (or the value of unset if no environment
variable with that name was found).On most platforms Sys.getenv() will return a named vector
giving the values of all the environment variables, sorted in the
current locale. It may be confused by names containing = which
some platforms allow but POSIX does not. (Windows is such a platform:
there names including = are truncated just before the first
=.)When x is missing and names is not false, the result is
of class "Dlist" in order to get a nice
The help for environment variables lists many of the environment variables used by R.
## whether HOST is set will be shell-dependent e.g. Solaris' csh does not. Sys.getenv(c("R_HOME", "R_PAPERSIZE", "R_PRINTCMD", "HOST")) names(s <- Sys.getenv()) # all settings (the values could be very long) head(s, 12)# using the Dlist print() method ## Language and Locale settings -- but rather use Sys.getlocale() s[grep("^L(C|ANG)", names(s))]