Sys.setenv {base}

R Documentation

Set or Unset Environment Variables

Description

Sys.setenv sets environment variables (for other processes called from within R or future calls to Sys.getenv from this R process).

Sys.unsetenv removes environment variables.

Usage

Sys.setenv(...)

Sys.unsetenv(x)

Arguments

...	named arguments with values coercible to a character string.
x	a character vector, or an object coercible to character.

Details

The names setenv and putenv come from different Unix traditions: R also has Sys.putenv, but this is now deprecated. The internal code uses setenv if available, otherwise putenv.

Non-standard R names must be quoted in Sys.setenv: see the examples. Most platforms (and POSIX) do not allow names containing "=".

There may be system-specific limits on the maximum length of the values of individual environment variables or of all environment variables.

Value

A logical vector, with elements being true if (un)setting the corresponding variable succeeded. (For Sys.unsetenv this includes attempting to remove a non-existent variable.)

Note

Not all systems need support Sys.setenv (although all known current platforms do) nor Sys.unsetenv. If Sys.unsetenv is not supported, it will at least try to set the value of the environment variable to "", with a warning.

See Also

Sys.getenv, Startup for ways to set environment variables for the R session.

setwd for the working directory.

The help for ‘environment variables’ lists many of the environment variables used by R.

Examples

print(Sys.setenv(R_TEST="testit", "A+C"=123))  # `A+C` could also be used
Sys.getenv("R_TEST")
Sys.unsetenv("R_TEST")  # may warn and not succeed
Sys.getenv("R_TEST", unset=NA)

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