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Intro to the Terminal / Command line

The terminal is a command-line interface for interacting with a computer, a way of working with a machine pioneered in the 1960s and still widely used today. Almost anything that can be done with your graphical-user-interface operating system can also be done with the command line.

Terminal Basics

• Open Terminal (or the Terminal app for windows. Git Bash for a bash emulator)
• pwd - print working directory, lists where we are
• ls - lists the contents of our current directory (dir on pc)
• cd foldername - move into the folder called foldername
• cd .. - move up a folder
• cd / - move to the root directory
• open http://softslow.com - open web browser to softslow.com (start on windows)
• open appname - opens that app (start on windows)
• say hello - say the word 'hello' with computer voice (mac only :( ))

Creating/Moving/Deleting Files and Folder

• mkdir myfolder - makes a new folder called myfolder
• echo hello world - write out the phrase hello world
• echo hello world > helloworld.txt - write out the phrase 'hello world' into a file called helloworld.txt
• cat helloworld.txt - write out the contents of helloworld.txt into the terminal (type on windows)
• cp helloworld.txt helloworld2.txt - copy helloworld.txt and name the copy helloworld2.txt (copy on windows)
• mv helloworld.txt newname.txt - rename helloworld.txt to newname.txt (move on windows)
• mv newname.txt myfolder/newname.txt - move newname.txt into a folder called myfolder (move on windows)
• rm newname.txt - delete file, be careful (del on windows)
• rmdir myfolder - delete folder, only works if folder is

Useful Keyboard Shortcuts

• Up and Down Arrow Keys: autofill previous commands
• Tab: autocomplete the name of a file/folder (cat he+Tab -> cat helloworld.txt)
• Ctrl+C:Quit out of a process that is taking too long or has an error

Connecting to Other Machines

• ssh - secure shell, used to remotely connect to another computer
• ssh 137.184.192.23 - connect to the IP address 137.184.192.23
• ssh malware.toddwords.com - connect to the ipaddress mapped to malware.toddwords.com (same ip as above)
• ssh tuesday@malware.toddwords.com - connect to malware.toddwords.com as the user tuesday
• ssh thursday@malware.toddwords.com - connect to malware.toddwords.com as the user thursday
• once you remotely connect to the machine, you will be on the linux operating system of the remote machine and need to use linux bash commands (largely the same as mac)
• explore with cd and ls
• exit or logout - close an ssh session
• scp - secure copy, copy files from a local machine to a remote machine or vice versa
• scp helloworld.txt tuesday@malware.toddwords.com: - from outside an ssh session, copy the file helloworld.txt into the home directory of tuesday@malware.toddwords.com and rename it week1response.txt
• scp response.txt tuesday@malware.toddwords.com:_week1/week1response.txt - copy the file response.txt into the _week1 folder inside the home directory of tuesday@malware.toddwords.com and rename it week1response.txt
• scp -r folderpoem tuesday@malware.toddwords.com:toddsFolderPoem - copy the folder folderpoem and all of its contents into the home directory of tuesday@malware.toddwords.com and rename it toddsFolderPoem

Prompts

• Create a folder poem using terminal commands
• Create a folder with a request for visitors to do something
• Imagine a creative early internet virus, but rather than putting it in a script, run through its commands one-by-one pretending you are the virus

Scripts

• write a series of bash commands using a text editor and save it as myScript.sh to run it later
• sh myScript.sh - run the commands myscript.sh
• sleep 10 - wait for 10 seconds before executing next command (timeout in windows)

Loops

• for value in 1 2 3 4 5
  do
    echo Current number is $value
    sleep 2
  done

  print out 1 2 3 4 5 waiting 2 seconds between each
• can also be written as for value in {1..5} or {1..100} for that matter

• for url in http://softslow.com http://burymewithmymoney.com https://www.youtube.com/watch?v=dQw4w9WgXcQ
  do
    start $url
    sleep 3
  done

  open the listed urls with a 3 second pause between

• while :
  do
    echo This is the song that never ends
  done
  

  an infinite loop, you will need to hit control-c to stop it

Cron Jobs and Scheuled Tasks

To run a script regularly at a certain time or certain frequency, you will need to use a cron job (mac/linux) or scheduled task (windows)

• crontab -e - open the crontab editor
• * * * * * sh myScript.sh - run myScript.sh every minute
• */30 * * * * sh myScript.sh - run myScript.sh every 30 minutes
• 15 16 * * 2 sh myScript.sh - run myScript.sh every Tuesday at 4:15 PM (16:15)
• Guide to making scheduled tasks on windows