# Envro
A crate to load environment variables from a `.env` file into the process environment.
### Getting started
```bash
cargo add envro
```
```rust
use std::env;
use envro::*;
fn main() {
let env_file = env::current_dir().unwrap().join(".env");
// parse only
let vars = load_dotenv(&env_file).unwrap();
// parse and set process env (keep existing non-empty values)
load_dotenv_in_env_vars(&env_file, false).unwrap();
println!("{vars:#?}");
}
```
## API
### Types
- `EnvroVars` — alias for `HashMap<String, String>`
- `EnvroError` — errors from reading or parsing a `.env` file
- `EnvroError::File` — cannot read the file
- `EnvroError::Parse` — invalid line (missing `=`, empty name, unclosed quote, duplicate key, …)
### `load_dotenv(path) -> Result<EnvroVars, EnvroError>`
Parses a `.env` file and returns the variables as a map. Does **not** change process environment variables. Duplicate keys in the file are rejected.
```rust
use std::env;
use envro::*;
let env_file = env::current_dir().unwrap().join(".env");
let vars = load_dotenv(&env_file)?;
assert_eq!(vars.get("DB_POOL_SIZE"), Some(&"32".to_string()));
```
### `load_dotenv_in_env_vars(path, override_existing) -> Result<(), EnvroError>`
Parses the file and sets process environment variables.
| `false` | Keep existing **non-empty** process values; set unset or empty ones from the file |
| `true` | Always set values from the file, overwriting existing process values |
Keep existing values:
```rust
use std::env;
use envro::*;
env::set_var("DB_POOL_SIZE", "8");
let env_file = env::current_dir().unwrap().join(".env");
load_dotenv_in_env_vars(&env_file, false)?;
// process value wins when already set and non-empty
assert_eq!(env::var("DB_POOL_SIZE").unwrap(), "8");
```
Override existing values:
```rust
use std::env;
use envro::*;
env::set_var("DB_POOL_SIZE", "8");
let env_file = env::current_dir().unwrap().join(".env");
load_dotenv_in_env_vars(&env_file, true)?;
// file value wins
assert_eq!(env::var("DB_POOL_SIZE").unwrap(), "32");
```
## `.env` format
```env
# comments are ignored
DB_CONNECTION_STRING=pg://user:pass@db/mydb
DB_POOL_SIZE=32
EMPTY=
QUOTED="value with spaces"
ESCAPED="say \"hello\""
WITH_EQUALS=host=localhost user=admin
```
Supported:
- empty lines and `#` comments
- empty values (`KEY=` or `KEY=""`)
- double-quoted values, with `\"` escapes
- `=` inside values (unquoted or quoted)
Rejected:
- missing `=` / missing value
- empty variable name (`=value`)
- unclosed double quote
- duplicate variable names in the same file
## Test
```bash
cargo test
```
## TODO
- values validation
- github action publish
- publish crate - see https://github.com/googleapis/release-please
- run cz bump on CI, create release commit, create github release, cargo publish
- handle pre release (-dev, -beta ...)
- coerce env vars to types
---
## LICENSE
MIT License
Copyright (c) 2024-2026 Simone Sanfratello
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
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copies of the Software, and to permit persons to whom the Software is
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The above copyright notice and this permission notice shall be included in all
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