An Odin library managed via Mimir for reading .env files. Call one function at startup and every variable becomes available through the usual os.get_env.

Quick Start

Clone it into your project's pkgs/ directory and import it by folder name.

package main

import "core:fmt"
import "core:os"
import "pkgs:dotenv"

main :: proc() {
	applied, err := dotenv.load() // reads "./.env"; missing file is silently ignored.
	// and handle the error
	// or simply do
	dotenv.load()
	fmt.println(os.get_env("PORT", context.allocator))
}

See examples/basic for a runnable example (odin run examples/basic).

API

All procs live in package dotenv:

Proc	Description
load(path := ".env", override := false) -> (applied: int, err: Error)	Read the file and export every variable into the process environment. Existing variables are kept unless override is set. Returns how many were exported.
overload(path := ".env")	load with override enabled: file values always win.
must_load(path := ".env", override := false) -> int	load that panics when the file cannot be loaded. Use when the file is required.
read(path, allocator := context.allocator) -> (map[string]string, Error)	Load and parse without touching the environment. Free the result with destroy.
parse(content, allocator := context.allocator) -> map[string]string	Parse .env-formatted text. Free the result with destroy.
apply(values, override := false) -> (applied: int, err: Error)	Export a map into the environment, honoring override.
destroy(values, allocator := context.allocator)	Free a map returned by parse/read.

Error is None, File_Not_Found (unreadable file), or Set_Env_Failed. load on a missing file returns (0, .File_Not_Found), so treating .env as optional is just _ = dotenv.load().

File format

One KEY=VALUE pair per line:

# full-line comment
PORT=8080
export HOST=localhost          # optional `export` prefix
GREETING="hello world"         # double quotes: escapes + expansion
LITERAL='no $expansion \n'     # single quotes and backticks are literal
UNQUOTED=some value # comment  # trailing ` #` is stripped when unquoted
EMPTY=
URL="https://${HOST}:${PORT}"  # $VAR / ${VAR} expand from earlier entries,
FALLBACK="${MISSING:-default}" # then the environment (:- / - defaults ok)

Rules:

• Blank lines and lines without = are ignored.
• Keys must match [A-Za-z_][A-Za-z0-9_]*; anything else is ignored.
• Double-quoted values may span multiple lines and understand \n \r \t \b \f \v \0 \\ \" \' \$ and backslash-backtick.
• A # starting a comment must be at line start or follow a space/tab, so PASS=abc#123 keeps its #.
• Files may use LF or CRLF line endings and may start with a BOM.

Testing

odin test tests/

The suite covers parsing, quoting, comments, expansion, overriding, and file loading (24 tests, tracked for memory leaks).