Week 1 Review
A five-minute warm-up before Lecture 2. All of it is from Week 1.
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## Put the commands in order to end up inside a new `projects` folder in your home directory, with `README.md` open in Positron
> You cannot step into a folder that does not exist yet.
1. `cd ~`
2. `mkdir projects`
3. `cd projects`
4. `positron README.md`
## Sort the commands: which only look, and which change your files?
- `mv` :: Changes your files
> Moves a file or folder: it appears in the new place and disappears from the old.
- `ls` :: Only looks
> Lists files and folders in the current folder.
- `pwd` :: Only looks
> Just prints the current path showing where we are.
- `rm -r` :: Changes your files
> Deletes a folder with all its contents.
- `head` :: Only looks
> Shows the first lines of a file.
- `cp` :: Changes your files
> Copies a file or folder, the original stays where it was.
## Where does each command leave you?
Your working directory is `/home/username`.
Some directories are used more than once.
- `cd Documents` :: `/home/username/Documents`
> Relative: counted from where you are.
- `cd ..` :: `/home`
> One step up from `/home/username` is `/home`.
- `cd ~` :: `/home/username`
> `~` is your home folder, from anywhere.
- `cd ./Documents` :: `/home/username/Documents`
> `./` is the current folder, so this is the same as `cd Documents`.
- `cd` :: `/home/username`
> `cd` with no argument also goes home.
- `cd /home/username/Documents` :: `/home/username/Documents`
> Absolute: counted from the root of filesystem, so works the same from anywhere.
## The folder looks empty, but your classmate insists something is in it. What do you run?
1. [x] `ls -a`
> `-a` lists all entries, including names that start with a dot (hidden files and folders).
2. [ ] `ls -F`
> Decorates names with `/` and `*`; hidden files stay hidden.
3. [ ] `ls -l`
> Long listing with sizes, dates and permissions; hidden files stay hidden.
4. [ ] `pwd`
> Prints where you are, not what is in the current folder.