Creating, copying and moving folders and files

So far you have only looked around. Now you change something: you create folders and files, copy them and move them. Try everything out in a practice folder of its own, so that nothing important gets caught up in it. To do that, change into your home folder and create the practice folder with the first new command.

Creating a folder: mkdir

mkdir stands for make directory and creates a folder in the current directory:

cd ~
mkdir uebung
cd uebung

Creating an empty file

Here the two systems differ. On Windows New-Item creates an empty file, on the Mac touch:

New-Item notizen.txt

touch notizen.txt

Usually, though, you create files with the program you also fill them with, such as an editor, and you then need the command line to keep them in order.

Copying: cp

cp (copy) takes two arguments: what is to be copied, and where to. If the target is a folder, the copy ends up inside it under the same name. If the target is a new name, the copy is created under that name:

mkdir archiv
cp notizen.txt archiv
cp notizen.txt notizen-alt.txt

After that, notizen.txt exists three times: the original, a copy in archiv and a copy called notizen-alt.txt. Check it with ls and ls archiv.

Moving and renaming: mv

mv (move) looks like cp, except that nothing stays behind: the file travels to the new place. If mv gets a new name instead of a folder, it renames the file, because for the shell renaming is nothing other than moving to the same place under a different name:

mv notizen-alt.txt archiv
mv notizen.txt ideen.txt

Viewing content: cat

cat prints the content of a text file. First write something into the file, for example with an editor, or directly in the command line, because > redirects the output of a command into a file:

echo "Practising the command line" > ideen.txt
cat ideen.txt

Careful: > overwrites whatever was in the file before.

Deleting: rm

rm (remove) deletes a file:

rm ideen.txt

You remove an empty folder with rmdir and its name. If it is not empty, rmdir refuses on the Mac, and PowerShell asks whether it should delete everything inside as well. Answer N there if you are not completely sure; both are a brake that protects you from deleting whole folders by accident.