Regex Editor & Tester

This PCRE2 regex matches a `RUN` instruction in a Dockerfile, including multi-line commands separated by backslashes. Using the `s` (dotall) and `m` (multiline) flags, it captures the command and its arguments across multiple lines until a line not ending with a backslash is encountered. It is highly useful for building Dockerfile linters or parsers that need to analyze the execution steps in container builds.