$ cd
This command stands for "change directory" and allows you to navigate through directories via the terminal.
$ cd ..
.. roughly translates to "back one folder". By using cd .. we're telling the terminal to jump back one directory, or to the parent folder of where we currently are.
arrow up key
To flip through previously used commands.
⌥ + click
Use option+click to place your cursor inside of a line in your terminal. Shout out to @kelseyinnis for this gem. Applaud her.
Ctrl + c
Use this command to quit or cancel a process in your terminal.
$ ls
This command lists the contents of the directory you're currently in.
$ (Tab) ↹
The tab key allows you to auto-complete a string or path you're typing out in your terminal. This shortcut is a good incentive to make sure you're naming things without spaces in-between words (i.e. Bad: "Personal Projects" vs. Good: "personal-projects").
$ which ruby
The which command allows you to check to see if a gem or package is installed on your machine.
$ ruby -v
The -v command asks your computer which version of something you have installed. This can be super useful when managing and updating "dependencies".
$ sudo gem install
sudo allows you to bypass permissions on your computer and install things using just your system password (the terminal will prompt you for this after you run the command).
sudo !!
If you run a command and forget to add sudo to it, run sudo !! and it'll prepend the previous command with your sudo. Compliments of @joericho.
Git is a type of version control that we can interact with via the terminal.
$ git status
Git status will tell you if you've made any local changes, as well as what branch you're currently working on by returning something like:
On branch gh-pages
Your branch is up-to-date with 'origin/gh-pages'
This command also returns info about whether or not your branch is up-to-date with its "parent" branch.
$ git add .
. tells the terminal to add all changed or edited files to be to be committed.
$ git add . -A
Here appending the -A to the add . command tells the terminal to create (or stage) any files you've added to your project (images included) and simultaneously to delete any files (or images) that you removed. This can be super helpful when you're getting started with a project and adding and deleting a ton of "assets".
$ git commit -m"your commit message here"
This command allows you to write your commit message inline.
$ git checkout -b your-new-branch
This command allows you to create, name, and switch to a new branch at the same time. Super handy.
$ git co -
This command allows you to check out the branch you just switched from. From the mind and workflow of @__Neha
Pro-tip: Search more git commands on http://git-scm.com/.