Summary

OK, so we’ve actually really only looked at 3 or 4 tools and called that “advanced shell usage”; what gives?

It turns out that there are a few different implicit learning outcomes that you met by going through this exercise of learning these tools:

• You had a sense that command-line programs had “options” (like ls -a), but now you’re beginning to see that almost all command-line programs have options.

• You’ve learned a little bit about “patterns”. We got a taste of patterns when we looked at .gitignore: “I don’t want files that end with .class to be in my repository, so I add the ‘pattern’ *.class”.

  Patterns are something that you’ll see treated formally if you take a course introducing automata and state machines where you’ll learn about “regular expressions” and their corresponding abstract representation as automata (sort of like graphs).

• You’ve learned that some commands can launch other commands on your behalf. This is something that you’ll actually see in two other courses implicitly and explicitly: implicitly a software engineering course as a “design pattern” and explicitly in an operating systems course as… well, the mechanical API for how programs launch other programs (your shell 🐚 is a program, it’s job is to start other programs).

• You’ve learned a little bit more about how Git works in terms of how to compare different text files to one another (Git uses something like diff internally).

You should now be able to: