Add optional arguments

[Signum21]

It would be useful to have optional arguments for commands, possibly with selectable values.

An example that works for the ls command.

# List files
ls <parameters>

$ parameters: echo -e "-l\n-a\n"

The last \n creates a blank line that can be selected to avoid choosing an option.

This method doesn't work for optional parameters that require a value, for example head -n 5