Case insensitive search
By default, grep will simply search for the exact specified pattern within the input file and return the lines it finds. We can make this behavior more useful though by adding some optional flags to grep. If we would want grep to ignore the "case" of our search parameter and search for both upper- and lower-case variations, we can specify the "-i" or "--ignore-case" option. We will search for each instance of the word "license" (with upper, lower, or mixed cases) in the same file as before.