Benchmarking runtime performance in the terminal

Benchmarking runtime is the process of timing how long it takes the code to run. This skill is invaluable since it helps compare performance. By externally measuring the runtime as opposed to instrumenting it within the code, we can easily proceed without understanding the inner working of the code. If we're on a Unix-like system such as Linux or OS X, we can use the time command, and on Windows systems, we can use Measure-Command with PowerShell.

Getting ready

Make sure our machine is either Unix-like (such as Linux or OS X) or Windows. Otherwise, we must search online for a way to time execution.

How to do it…

1. On Unix-like systems, there is a built-in time command. When running any piece of code from the terminal, we can prefix it with time as follows:

   $ time runhaskell Main.hs
   real 0m0.663s
   user 0m0.612s
   sys 0m0.057s
   

   The argument to this command is run, and the system resource usage is immediately summarized. The actual accuracy...