Ruplacer is a command-line tool written in Rust for finding and replacing text in files. It supports literal string, regex, and case-preserving replacements, and provides a diff-like output of changes. The tool respects .gitignore, allows filtering by file type, and can operate in a dry-run mode. The architecture is modular, with separate modules for argument parsing, console output, directory traversal, file processing, and the core replacement logic. The replacement logic is particularly notable for its use of the strategy pattern to handle different matching algorithms in a uniform way.