Hacking Tools: The Terminal

How to use the command line

Created by jyn with reveal.js

What's a Terminal?

A way to run programs without needing a mouse or desktop

No, not a touchscreen

(Almost) Synonyms

Ask me after if you want to know the difference

  • terminal
  • shell
  • bash
  • command prompt

Terminals are on Windows, too!

What can you do with a terminal?

  • Find files with a certain name
  • Find a specific word in thousands of files
  • Debug your network connection
  • Compile code without an IDE
  • Use git to collaborate with other programmers
  • Run programs on a computer without a monitor
  • Run multiple programs at the same time

Psst - for the upperclassman

If you already know the first half of the talk, try some challenges at overthewire.org

But first, the basics

Directories, a.k.a. folders

Directory Commands

  • pwd - print working directory
  • cd - change directory
  • ls - list directory
  • mkdir - make directory
  • rmdir - remove directory


File Commands

  • file - what type of file is this?
  • cat - concatenate one or more files together
  • cp - copy a file
  • rm - remove file
  • mv - move (or rename) a file
  • vim - edit a file (see also emacs)

File permissions

  • Read
  • Write
  • Execute

Executing programs

  • Not executable by default
  • You can make it executable with
    chmod +x <filename>
  • Runs with the shell you're using

But really, what can I use this for?


Great for doing homework on the lab machines from home

ssh -p 222 [email protected]

(but use your own username)

Doesn't work if you're not on the University Wifi - You need to be on the VPN in that case.

Misc Commands

  • echo - write some text to the terminal
  • man - get help about a command
  • apropos - search for a command if you don't know the name
  • help - get help about commands that 'man' doesn't know about
  • history - show commands you've typed in the past



  • tab to autocomplete (when unambiguous)
  • tab twice to show options
  • up arrow to run previous command
  • Ctrl+R to search through your history
  • !$ - the last argument to the previous command
  • More readline bindings
  • More history expansion (things starting with '!')