Introduction to UNIX #

• What is UNIX?
• Where do we find UNIX nowdayas?
  • Linux
    • Android
    • Cloud (AWS, Google)
    • Raspberry PI
  • *BSD (networking)
    • MacOS
• CLI vs. GUI
• Terminal/Console
  • Start a terminal
    • Linux: CTRL + ALT + t
• Basic Commands
  • print working directory

    m@t14s:~$                    # prompt string (user@hostname:directory$)
    m@t14s:~$ pwd                
    /home/m
    

  • changing directory

    m@t14s:~$ cd Desktop         # change to a relative path
    m@t14s:~/Desktop$ cd         # go to home directory (~)
    m@t14s:~$ cd -               # go to previous directory
    /home/m/Desktop
    m@t14s:~/Desktop$ cd /tmp    # change to absolute path
    m@t14s:/tmp$ cd ~/Desktop/   # to Desktop in home directory
    m@t14s:~/Desktop$ 
    

  • create directory

    m@t14s:~$ mkdir sandbox
    

  • list a directory (ls)

    m@t14s:~$ cd sandbox
    m@t14s:~/sandbox$ 
    m@t14s:~/sandbox$ echo 'python("Hello World!")' > hello.py
    m@t14s:~/sandbox$ ls         # list a directory: short
    hello.py
    m@t14s:~/sandbox$ ls -l      # long listing
    total 4
    -rw-rw-r-- 1 m m 21 Feb  5 10:51 hello.py
    

  • show a file (cat)

    m@t14s:~/sandbox$ cat hello.py
    print("Hello World!")
    

  • run a python script (python)

    m@t14s:~/sandbox$ python hello.py
    Hello World!
    

  • copy/copy/remove a file

    m@t14s:~/sandbox$ cp hello.py hello2.py        # copy file
    m@t14s:~/sandbox$ ls
    hello2.py  hello.py
    m@t14s:~/sandbox$ mv hello2.py hello_copy.py   # rename file / directory
    m@t14s:~/sandbox$ ls -l
    total 8
    -rw-rw-r-- 1 m m 21 Feb  5 10:51 hello_copy.py
    -rw-rw-r-- 1 m m 21 Feb  5 10:51 hello.py
    m@t14s:~/sandbox$ rm hello_copy.py             # remove file
    

• Useful CLI keys
  • CTRL + d (EOF)
  • CTRL + c
  • up/down
  • CTRL + r
  • TAB (autocompletion)
• CLI Text editor
  • nano

Exercise #

• Go to ~/sandbox and use nano editor that will create a python file hello_me.py that when executed, will print out your name.
• Cleanup after yourself. You could delete hello_me.py. Better is to move it to /tmp, where it will be deleted after reboot.

Resources: #

• https://linuxsurvival.com/ - practice UNIX basics here