# Command Line Basics
## Hello Terminal!

```{exercise}
:label: hello_terminal

1.  Print your name to the terminal.
2.  Clear your terminal after completing #1.
```
````{solution} hello_terminal
:class: dropdown
<!-- bash_kernel has a bug https://github.com/takluyver/bash_kernel/issues/115. Use python -->
```bash
echo Gökçe
clear
```
````

## Navigating the Command Line

```{exercise}
:label: navigating_the_cmd_line
1.  Set your working directory to the root directory.
2.  Set your working directory to your home directory using three
    different commands.
3.  Find a folder on your computer using your file and folder browser,
    and then set your working directory to that folder using the
    terminal.
4.  List all of the files and folders in the directory you navigated to
    in #3.
```
````{solution} hello_terminal
:class: dropdown
```bash
cd /  # do not confuse `/` with `/root`. The latter is the home folder of the administrator user `root`

cd
cd ~
cd $HOME

# 3. note that some file/folder browsers can *Open Terminal Here*, e.g., Thunar
cd /usr
ls -a  # -a also includes hidden files and folders that start with .
```
````

## Creation and Inspection

```{exercise}
:label: creation_and_inspection

1.  Create a new directory called `workbench` in your home directory.
2.  Without changing directories create a file called `readme.txt`
    inside of `workbench`.
3.  Append the numbers 1, 2, and 3 to `readme.txt` so that each number
    appears on it's own line.
4.  Print `readme.txt` to the command line.
5.  Use output redirection to create a new file in the `workbench`
    directory called `list.txt` which lists the files and folders in
    your home directory.
6.  Find out how many characters are in `list.txt` without opening the
    file or printing it to the command line.
```
````{solution} creation_and_inspection
:class: dropdown
```bash
cd
mkdir workbench
touch workbench/readme.txt
echo -e '1\n2\n3' >> workbench/readme.txt  # in bash, echo needs -n to account for backslash escapes
cat workbench/readme.txt
ls > workbench/list.txt
wc --chars workbench/list.txt
```
````

## Migration and Destruction
```{exercise}
:label: migration_and_destruction
1.  Create a file called `message.txt` in your home directory and move
    it into another directory.
2.  Copy the `message.txt` you just moved into your home directory.
3.  Delete both copies of `message.txt`. Try to do this without using
    `rm`.
```
````{solution} migration_and_destruction
:class: dropdown
```bash
cd  # change directory again, the directory is not preserved between %%sh cells
    # compared to the bash-kernel
echo secret > message.txt
mv message.txt workbench

cp workbench/message.txt ~

mkdir trash
mv message.txt workbench/message.txt trash
# or a trash dir may already be available
# mv message.txt .local/share/Trash
# or if `trash-cli` is installed
# trash message.txt
rm -r trash workbench
```
For further solutions to 3 see [this posting at Stack Exchange](https://unix.stackexchange.com/q/342598/411786)
````