gloader

README

gloader (v.1.0.0)

A lightweight, flexible environment variable loader for Go.

Supports loading from .env files or any io.Reader source (such as strings, network streams, or in-memory data).

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Features

• Load env vars from one or more io.Readers
• Automatically falls back to .env file in none are provided
• Supports panicking or fallback lookups
• Simple API for flexible integration
• No external dependencies

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Installation

go get github.com/RecursionExcursion/gloader

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Usage

Load from default .env file

loader := &gloader.EnvLoader{}
_ = loader.LoadEnv()

foo := loader.MustGet("FOO")

Load from custom readers (in-memory)

r1 := strings.NewReader("FOO=bar")
r2 := strings.NewReader("BAR=baz")

loader := &gloader.EnvLoader{}
_ = loader.LoadEnv(r1, r2)

fmt.Println(os.Getenv("FOO")) // bar

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Get API

loader.Get("FOO")                  // string, error
loader.MustGet("FOO")             // string, panics if missing
loader.GetOrFallback("FOO", "x")  // string, returns fallback
loader.GetOrDefault("FOO")        // string, returns ""

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.env Format

Each line should follow:

KEY=VALUE

Lines starting with # are ignored. Whitespace is trimmed.

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License

MIT License © 2025 RecursionExcursion(https://github.com/RecursionExcursion)

See LICENSE for details.

Documentation

Index

• type EnvLoader
  • func (el *EnvLoader) Get(key string) (string, error)
  • func (el *EnvLoader) GetOrDefault(key string) string
  • func (el *EnvLoader) GetOrFallback(key string, fallback string) string
  • func (el *EnvLoader) LoadEnv(readers ...io.Reader) error
  • func (el *EnvLoader) MustGet(key string) string

Types

type EnvLoader

type EnvLoader struct {
	// contains filtered or unexported fields
}

func (*EnvLoader) Get

func (el *EnvLoader) Get(key string) (string, error)

returns value associated with key or an error if no key is found

func (*EnvLoader) GetOrDefault

func (el *EnvLoader) GetOrDefault(key string) string

returns value associated with key or zero value ("") if no key is found

func (*EnvLoader) GetOrFallback

func (el *EnvLoader) GetOrFallback(key string, fallback string) string

returns value associated with key or fallback if no key is found

func (*EnvLoader) LoadEnv

func (el *EnvLoader) LoadEnv(readers ...io.Reader) error

LoadEnv loads environment variables from one or more files into the process's environment. Files should contain lines in the format KEY=VALUE. If no files are provided, it defaults to loading from ".env".

func (*EnvLoader) MustGet

func (el *EnvLoader) MustGet(key string) string

returns value associated with key or panics if no key is found