What is the purpose of the updatedb command?

• A. Updates the locate database for fast file location
• B. Updates the yum cache
• C. Updates the kernel
• D. Updates the man pages

Answer: (A)

Updatedb updates the locate database that locate uses to find files quickly. locate doesn’t scan the filesystem every time you search; it relies on an index built by updatedb. When updatedb runs (often via cron or a scheduled task), it scans allowed parts of the filesystem and rebuilds the database file (for example, /var/lib/mlocate/mlocate.db). With the up-to-date index, locate can return results instantly without walking the entire filesystem. This is why you’d run updatedb after adding or moving files if you want locate to find them promptly. It doesn’t touch the yum cache, the kernel, or the man pages.