Text Processingflags: g

Unix Environment Variable Reference

Match Unix shell environment variable references in both $VAR and ${VAR} forms.

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_]*)\}?   (flags: g)

Raw source: \$\{?([A-Z_][A-Z0-9_]*)\}?

How it works

\$ matches the literal dollar sign. \{? optionally matches an opening brace. ([A-Z_][A-Z0-9_]*) captures the variable name: must start with a letter or underscore, followed by letters, digits, or underscores. \}? optionally matches the closing brace.

Examples

Input

Path is $HOME/.config

Matches

  • $HOME

Input

export ${DATABASE_URL}

Matches

  • ${DATABASE_URL}

Input

no variables here

No match

—

Common use cases

  • •Shell script static analysis
  • •Dockerfile and CI config variable extraction
  • •Documentation generation for environment variables
  • •Config template rendering engines

Related patterns

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Match Terraform / HCL references like `var.name`, `local.foo`, `module.x.output`, or `data.aws_ami.ubuntu.id`.

JavaScript Variable Declaration

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Match JavaScript / TypeScript variable declarations (`var`, `let`, `const`), capturing the keyword and identifier name.

Markdown Link

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Match Markdown links [link text](url) and capture both the display text and the URL.

Single-Line Comment (// or #)

Text Processing

Match single-line comments using either the `//` (C-family) or `#` (shell, Python, Ruby, YAML) marker.

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