File & Pathflags: m

.env File Key-Value Line

Parse KEY=value lines from .env config files, handling quoted values and trailing comments.

Try it in RegexPro →

Available in

JSSupported

JavaScript / ECMAScript

Browser-native RegExp. Default if you don't pick.

PYSupported

Python (re)

CPython stdlib `re`. Unicode-aware `\w` and `\d` by default.

GOSupported

Go (RE2)

Linear-time matching. No backreferences or lookarounds.

Pattern

regexengine-agnostic
^([A-Z_][A-Z0-9_]*)\s*=\s*(?:"([^"]*)"|'([^']*)'|([^#\s]*))(?:\s*#.*)?$   (flags: m)

Raw source: ^([A-Z_][A-Z0-9_]*)\s*=\s*(?:"([^"]*)"|'([^']*)'|([^#\s]*))(?:\s*#.*)?$

How it works

([A-Z_][A-Z0-9_]*) captures the variable name (uppercase + underscores by convention). The value alternation supports double-quoted, single-quoted, and unquoted values. (?:\s*#.*)? allows an optional inline comment. The m flag lets ^ and $ match individual lines in a multi-line file.

Examples

Input

DATABASE_URL=postgres://localhost/db

Matches

  • DATABASE_URL=postgres://localhost/db

Input

API_KEY="sk_live_abc123" # production

Matches

  • API_KEY="sk_live_abc123" # production

Input

lowercase=bad

No match

—

Common use cases

  • •Linting and validating .env files in CI
  • •Migrating dotenv configs between environments
  • •Generating documentation from .env.example
  • •Detecting committed secrets in PR diffs
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