Learning to Use the Command Line: Lesson 1

My Sandbox is ready for me to play in! A huge thank you to +Kyle Barnhart for setting up Janebox so I have a safe place to play :-)


As it turns out, before I can learn Python I need to learn to use the command line. Fortunately, Learn Python the Hard Way links to a guide on the subject written by the same author, which is here:

http://cli.learncodethehardway.org/book/

In this post, I'll be taking notes on what I learn from Lesson 1 of the command line tutorial.

Notes:

Command Line Interface (CLI): A window where you type in code that tells the computer what to do

Shell: Software that creates a user interface, such as a CLI

Lesson 1: The Setup

Step 1: Find something name "shell" or "terminal". It is indeed just called "Terminal," and just looks like a black box when open. The icon is a small black box with these characters: >_ . It looks like a one-eyed winky face!

The next step is to learn some abbreviations and what they stand for. I'm going to write them down and define the terms here, because knowing what things mean helps me remember them.

pwd: print working directory (tells you where you are right now.)

hostname: your computer's network name

mkdir: make directory (a directory is like a folder in Windows)

cd: change directory (allows you to move into a different directory or subdirectory)

ls: list directory (lists files in the current working directory)

rmdir: remove directory (deletes an empty directory)

pushd: push directory (puts the file in the stack directory. This saves the file and makes it easy to return to later)

popd: pop directory (removes the file from the stack directory and returns to the path at the top of the stack directory. Path= name that specifies a unique place in a directory. stack directory= holding pen for files you want to switch between)

http://www.eriwen.com/bash/pushd-and-popd/

cp: copy a file or directory

mv: move a file or directory

less: page through a file

cat: print the whole file

xargs: execute arguments

find: find files

grep: find things inside files

man: reads a manual page (manual page= software documentation. "Manual" as in "How-to," not as in "done by hand.")

apropos: find what man page is appropriate

env: look at your environment (I found a lot of definitions for this, I assume it is a versatile command that subsequent lessons will explain.)

echo: print some arguments

export: export/ set a new environment variable (environment variable= characteristic of the environment you're working in, like language).

exit: exit the shell

sudo: become super user root (guide says this is dangerous, +Kyle Barnhart says you need it to do most important things. I assume both are true, I can think of a few important things that could go very wrong.)

chmod: change permission modifiers (who can read, write, and execute files)

chown: change ownership

End of terms! The next assignment is to study the flashcards I've made of the list.

End of Lesson 1! I'm going to go study my list; Lesson 2 will happen in my next post (expect to see that this afternoon as well).