Regex Tester & Validator

Matches a line beginning with a fixed 9-character prefix split into capture groups of 1, 2, 1, 2, 1, 1, and 1 characters, followed by a hyphen and the remainder of the filename. It's designed to parse structured filenames (e.g., section/course codes) so the groups can be rewritten as nested folder path segments in bulk-rename tools or file-organization scripts, with multiline flags enabled for processing filename lists.