The first principle of file creation is that when you, as a specific user, create a file, it will be owned by you, and your default group will have some default permissions set on that file. Remember the User – Group – Other trio.
Create a directory:
You can create several at once:
mkdir one two three
Run an ls to see the results:
Especially note the user and group permissions the directories have.
rmdir one two three
…which will work just fine as long as there is nothing inside each directory. But usually there is, so we use a completely different command to deal with directories with files inside them:
rm -r one two three
This will force you to answer “yes” over and over for each file deleted. You can make the process silent by “forcing” it:
rm -rf one two three
Create a file:
If you just want to create an empty file, you can use this method:
Note that touch is actually a command that just updates the last-updated date of the file, so it looks newer. This used to be handy to keep sysadmins from deleting old but critical stuff.
What’s nice about touch is that if a file exists, it just gets its date changed. If the file doesn’t exist, it is created. This is very handy in scripting.
Delete a file:
There is no “recycle bin” – the file is gone for good.