Unix and Magic in a Notebook.

While running a Jupyter Notebook, you can access many Unix commands directly, without opening a terminal window.

These are called "magic" commands and always start with the percent sign %.

Here are a few familiar Unix commands you might find useful:

• %ls -- to list all files in the current directory
• %cd -- to see the name of your current directory
• %cd dirname - to change directory (enter the name of the directory you want)
• %cp oldfile newfile -- to copy the oldfile onto a newfile
• %rm filename -- to remove (delete) the file named "filename"

Thankfully, you can move all around the directory tree using these magic commands. So for instance, you might want to copy a file from Directory1 into Directory2. You would use a command like this:

• %cp /home/myusername/Directory1/filename /home/myusername/Directory2/filename

Where "myusername" is whatever the Jupyter server has called your account. Use the %cd command to see the path name that includes your user name.

To see all possible magic commands available in a Jupyter notebook, type the (magic) command

• %lsmagic

With a double percentage sign %% you signal to Jupyter that the whole cell is to be interpreted accordingly. For instance a cell like this:

%%latex
\[ \int_0^1 f(x) \,dx = F(1) - F(0) \]

tells the notebook to read the whole cell as latex code, and render it accordingly.

A good reference to what all these magic commands can do is here: https://ipython.org/ipython-doc/3/interactive/magics.html