MMV

mmv is a command-line utility for mass renaming of files in Unix-like systems. It renames multiple files by applying a pair of patterns: a source pattern and a destination pattern. For each filename that matches the source pattern, mmv generates a new name according to the destination pattern, typically using placeholders that reference parts of the matched name. This enables batch tasks such as changing extensions, reordering name components, or padding numeric sequences without writing a script.

Usage is generally of the form: mmv 'from-pattern' 'to-pattern', with exact syntax varying by implementation and distribution. mmv is lightweight and widely available in Linux, BSD, and macOS repositories; several independent versions exist under different licenses. It is commonly used in file organization, media collection maintenance, and development workflows where large numbers of files share a common naming scheme.

Precautions: because it operates on file names in bulk, a mistaken pattern can rename or overwrite many files. A dry-run option, if provided, can help preview changes; always back up directories before performing large renames.

See also: batch renaming utilities, rename, pattern substitution tools.