While Damn Small Linux commands may be quite arcane, they can be very powerful. And efficient. The Linux tools for performing administrative and other technical tasks admittedly take time to learn and master More here
The grep utility has many other uses including validating e-mail addresses. Let’s say that your web site asks potential subscribers to furnish their e-mail accounts when signing up for a newsletter. A sophisticated but relatively short statement coded in grep could validate e-mail accounts.