Shells

Both Linux and Windows have CLIs that we will be operating with as power users.

Linux:

• There are a variety of shells that exist in the Linux ecosystem, but the default for many OS's is known as Bash (Bourne Again SHell). You'll be best friends with this eventually.

Windows:

• CMD
  • A legacy interface that allows access to DOS commands
  • MS-DOS was the first Microsoft OS and contained many basic features that are still accessible via CMD
• Powershell
  • A fully featured interface and language that allows complex scripting via cmdlets and pipes. As the entire language was written for working with Windows, it allows fine grained control and easy manipulation of the OS.
• Windows Subsystem for Linux (WSL) - Windows 10 Only
  • The Windows Subsystem for Linux lets developers run a Linux environment -- including most command-line tools, utilities, and applications -- directly on Windows, unmodified, without the overhead of a traditional virtual machine or dualboot setup.
  • Basically, it's a mini-Linux VM, with access to all the same files on the host Windows machine.

We won't be doing much work with Windows in this course, but for your first trick, open the shell by typing "cmd" and enter into the Windows search bar.

• Check to see your network settings by running the command "ipconfig"
• Just doing that and leaving the terminal open in the corner makes you look like you know what you are doing, even if you learn nothing else from this course
• You're welcome.

Command Layout

1. Visit this online shell: JS Linux Browser Shell

2. Once it has loaded, use the command "ls" to list all the files in the directory.

3. Use the command "cat readme.txt" to read the contents of the file in "readme.txt".

4. In that file you will find 3 more commands to run.

5. Use "cat hello.c" to read the contents of hello.c. What do you expect to happen?

6. Use the first command in readme.txt "gcc hello.c -o hello" to create an executable named hello

7. Use "ls" to verify the creation of the new file.

8. Use the command "./hello" to run the new file

Congratulations! In this brief series of commands, we have navigated a new system, found a file written in a programming language named C, turned that file into an executable program, and ran it! That's pretty awesome!

Honestly, you weren't supposed to understand everything you did there, but hopefully you feel very cool! Don't worry about pre-questions for this section.

Assignment

Questions:
1. In your own words, describe what the command 'ls' does
2. Describe what the command 'cat' does
3. Describe what the command using 'gcc' does
4. Describe what the program ./hello did

Resources:
0. Man Pages
1. Google

Write up a few sentences for each of the questions.