import * as mod from "https://deno.land/std@0.180.0/dotenv/mod.ts";
Load environment variables from .env
files.
Inspired by the node module dotenv
and
dotenv-expand
.
# .env
GREETING=hello world
Then import the configuration using the load
function.
// app.ts
import { load } from "https://deno.land/std@0.180.0/dotenv/mod.ts";
console.log(await load());
Then run your app.
> deno run --allow-env --allow-read app.ts
{ GREETING: "hello world" }
Auto loading
load.ts
automatically loads the local .env
file on import and exports it to
the process environment:
# .env
GREETING=hello world
// app.ts
import "https://deno.land/std@0.180.0/dotenv/load.ts";
console.log(Deno.env.get("GREETING"));
> deno run --allow-env --allow-read app.ts
hello world
Parsing Rules
The parsing engine currently supports the following rules:
- Variables that already exist in the environment are not overridden with
export: true
BASIC=basic
becomes{ BASIC: "basic" }
- empty lines are skipped
- lines beginning with
#
are treated as comments - empty values become empty strings (
EMPTY=
becomes{ EMPTY: "" }
) - single and double quoted values are escaped (
SINGLE_QUOTE='quoted'
becomes{ SINGLE_QUOTE: "quoted" }
) - new lines are expanded in double quoted values (
MULTILINE="new\nline"
becomes
{ MULTILINE: "new\nline" }
- inner quotes are maintained (think JSON) (
JSON={"foo": "bar"}
becomes{ JSON: "{\"foo\": \"bar\"}" }
) - whitespace is removed from both ends of unquoted values (see more on
trim
) (FOO= some value
becomes{ FOO: "some value" }
) - whitespace is preserved on both ends of quoted values (
FOO=" some value "
becomes{ FOO: " some value " }
) - dollar sign with an environment key in or without curly braces in unquoted
values will expand the environment key (
KEY=$KEY
orKEY=${KEY}
becomes{ KEY: "<KEY_VALUE_FROM_ENV>" }
) - escaped dollar sign with an environment key in unquoted values will escape the
environment key rather than expand (
KEY=\$KEY
becomes{ KEY: "\\$KEY" }
) - colon and a minus sign with a default value(which can also be another expand
value) in expanding construction in unquoted values will first attempt to
expand the environment key. If it’s not found, then it will return the default
value (
KEY=${KEY:-default}
If KEY exists it becomes{ KEY: "<KEY_VALUE_FROM_ENV>" }
If not, then it becomes{ KEY: "default" }
. Also there is possible to do this caseKEY=${NO_SUCH_KEY:-${EXISTING_KEY:-default}}
which becomes{ KEY: "<EXISTING_KEY_VALUE_FROM_ENV>" }
)