# Basics of GNU/Linux

## Basic File System Commands

| Name              | Command | options                                                | example                          |
|-------------------|---------|--------------------------------------------------------|----------------------------------|
| List files        | ls      | -a shows all <br> -l *long format* <br> -R *recursive* | ls -la                           |
| Current directory | pwd     | -P prints the physical location                        | pwd                              |
|-------------------|---------|--------------------------------------------------------|----------------------------------|
| Change            | cd      | ..  takes you up a level                               | cd /home/gmarx                   |
| directory         |         | ~   takes you to home directory                        | cd ~                             |
|-------------------|---------|--------------------------------------------------------|----------------------------------|
| Make              | mkdir   | -p make parent directories as needed                   | mkdir -p test/example            |
| directory         |         | -v print a message for each directory                  | mkdir -p /test/example           |
|                   |         |                                                        | *first example creates           |
|                   |         |                                                        | folders inside the               |
|                   |         |                                                        | current folder, other one        |
|                   |         |                                                        | creates folder in root directory |
|-------------------|---------|--------------------------------------------------------|----------------------------------|
| Delete a          | rm      | -r recursive (use for directories)                     | rm sample.txt                    |
| file or directory |         | -d remove empty directory                              | rm -r test                       |
|-------------------|---------|--------------------------------------------------------|----------------------------------|
| Copy a file       | cp      | -r recursivec copy                                     | cp a.txt b.txt                   |
| or directory      |         | -u copy only if the source is newer                    | cp test-a test-b                 |
|                   |         | -v verbose (show output)                               |                                  |
|-------------------|---------|--------------------------------------------------------|----------------------------------|
| Move a file or    | mv      | -i prompts before overwrite                            | mv a.txt c.txt                   |
| directory         |         | No -r; Moving into the same directory                  | mv test example                  |
|                   |         | performs a renaming                                    |                                  |
|-------------------|---------|--------------------------------------------------------|----------------------------------|
|                   | touch   |                                                        |                                  |
|-------------------|---------|--------------------------------------------------------|----------------------------------|
|                   | more    |                                                        |                                  |
|-------------------|---------|--------------------------------------------------------|----------------------------------|
|                   | cal     |                                                        |                                  |
|-------------------|---------|--------------------------------------------------------|----------------------------------|
|                   |         |                                                        |                                  |

*** Terminal 
| Command | Description            |
|---------|------------------------|
| CTRL-c  | Stop current command   |
| CTRL-z  | Sleep program          |
| CTRL-a  | Go to start of line    |
| CTRL-e  | Go to end of line      |
| CTRL-u  | Cut from start of line |
| CTRL-k  | Cut to end of line     |
| CTRL-r  | Search history         |
| !!      | Repeat last command    |
| Tab key | Autocompletes          |
|---------|------------------------|
|         |                        |


*** Package management 
| Command                            | Debian               |
|------------------------------------|----------------------|
| Install a package                  | sudo apt install vim |
| Upgrade the package in your system | sudo apt upgrade     |
|------------------------------------|----------------------|
|                                    |                      |

*** Basic file editing with VIM
*** Expanding the file system