Sys.getenv
From base v3.3
by R-core R-core@R-project.org
Get Environment Variables
Sys.getenv obtains the values of the environment variables.
- Keywords
- utilities, environment
Usage
Sys.getenv(x = NULL, unset = "", names = NA)Arguments
- x
- a character vector, or
NULL. - unset
- a character string.
- names
- logical: should the result be named? If
NA(the default) single-element results are not named whereas multi-element results are.
Details
Both arguments will be coerced to character if necessary.
Setting unset = NA will enable unset variables and those set to
the value "" to be distinguished, if the OS does. POSIX
requires the OS to distinguish, and all known current R platforms do.
Value
-
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
print method.
See Also
Sys.setenv,
Sys.getlocale for the locale in use,
getwd for the working directory.
The help for ‘environment variables’ lists many of the environment variables used by R.
Examples
library(base)
## 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))]
Community examples
Looks like there are no examples yet.