Mlocate

mlocate is a fast, database-backed command-line utility for locating files on Unix-like systems. It provides the locate command, which searches a prebuilt index of filesystem paths rather than scanning the disk in real time. This approach makes lookups much faster, especially on large filesystems. Mlocate is part of the locate family of tools and is designed as an efficient replacement for older locate implementations.

The index is stored as a binary database, typically /var/lib/mlocate/mlocate.db. It is created and updated by the updatedb utility, which scans mounted filesystems according to rules in /etc/updatedb.conf. To keep the index current, updatedb is usually run periodically by cron or systemd timers. The database is read-only for regular users; locate reads it to answer queries. Files that are deleted or moved are removed from the database on the next update.

Usage: The standard invocation is locate pattern. For example, “locate README” lists files with “README” in their path. Options commonly include -i for case-insensitive matching, -n to limit results, and -r to treat the pattern as a regular expression. The command is used when fast results are preferred over real-time accuracy, since there can be a delay between filesystem changes and the next update.

History and context: Mlocate emerged as a fast, robust alternative within the Linux ecosystem, and has been superseded in some distributions by newer implementations, though it remains widely available. It interacts with updatedb for indexing and with the manual pages for documentation.