Command descriptions have a format similar to function descriptions,
except that the word ‘Function’ is replaced by ‘Command’. Commands are
functions that may be called without surrounding their arguments in
parentheses. For example, here is the description for Octave’s
Change the current working directory to dir. For example, cd ~/octave changes the current working directory to ~/octave. If the directory does not exist, an error message is printed and the working directory is not changed.