Linux includes a command called time, which rather than reporting the current time (that’s “date”), is a kind of meta command that can be used to measure the resource usage of the execution of another command.
Running the hash index function I’ve been working on today took all of 244 minutes (in “real” time) — not yet sure what “user” vs “system” time exactly means but imagine it has to do with the way my computer divides it’s resources among the various processes going on in parallel to the timed task.
Not surprisingly, by the time the original command finished, I had already discovered and fixed a bug in the script so it’s time to run the script again 😉