Load configuration parameters from .env into environment variables

Description

It has become a practice to store configuration parameters related to a project, in a hidden file called .env, in the working directory of a project, and then set them as environment variables.

Details

This package loads the variables defined in the .env file in the current working directory (as reported by getwd), and sets them as environment variables.

This happens automatically when the dotenv package is loaded, so the typical use-case is to just put a 'library(dotenv)' code at the beginning of your R script.

Alternatively a dotenv::load_dot_env() call can be used to load variables from arbitrary files.

The format of the .env file is also a valid unix shell file format, so e.g. in bash the environment variables can also be set by running source .env.

See load_dot_env for the exact file format.

See Also

load_dot_env

Load environment variables from the specified file

Description

Load variables defined in the given file, as environment variables.

Usage

load_dot_env(file = ".env")

Arguments

Details

The file is parsed line by line, and line is expected to have one of the following formats:

VARIABLE=value
VARIABLE2="quoted value"
VARIABLE3='another quoted variable'
# Comment line
export EXPORTED="exported variable"
export EXPORTED2=another

In more details:

• A leading export is ignored, to keep the file compatible with Unix shells.

• No whitespace is allowed right before or after the equal sign, again, to promote compatilibity with Unix shells.

• No multi-line variables are supported currently. The file is strictly parsed line by line.

• Unlike for Unix shells, unquoted values are not terminated by whitespace.

• Comments start with #, without any leading whitespace. You cannot mix variable definitions and comments in the same line.

• Empty lines (containing whitespace only) are ignored.

It is suggested to keep the file in a form that is parsed the same way with dotenv and bash (or other shells).

Examples

# Remove, if it exists
Sys.unsetenv("dotenvexamplefoo")
Sys.getenv("dotenvexamplefoo")

# Load from a file
tmp <- tempfile()
cat("dotenvexamplefoo=bar\n", file = tmp)
load_dot_env(tmp)
Sys.getenv("dotenvexamplefoo")

# Clean up
unlink(tmp)