Regex Tester & Validator

Matches lines conforming to the standard 36-character UUID format (8-4-4-4-12 groups of hexadecimal digits separated by hyphens) using POSIX xdigit character classes. With the multiline flag, each line is validated independently, while the global flag matches all occurrences in the input. Note that it validates the generic UUID structure but does not enforce the v4-specific version and variant nibbles. Useful for validating identifiers in API payloads, database records, and log files.