POSIX-compliant dotenv syntax specification

Rationale

Using dotenv files for application configuration is a widespread practice.

While numerous implementations are available in a wide variety of languages, there is currently no specification for this file format. This result in a multitude of different syntaxes, all vaguely resembling the POSIX shell but fundamentally incompatible due to slightly divergent behaviours.

The goal of this repository is to

• specify a dotenv syntax that is 100% compatible with the POSIX shell syntax,
• provide detailed algorithms for tokenizing and parsing said syntax, evaluating the generated AST to produce a set of environment variables and export them to the current process environment.
• provide language-agnostic conformance tests in machine-readable format.

Table of contents

• Syntax overview
• tokenization
• parsing
• evaluation
• exporting
• tests