Command line options can be considered an advanced topic; for ordinary interactive use, no command line arguments should be necessary.
In order to understand the command line argument syntax for SBCL, it is helpful to understand that the SBCL system is implemented as two components, a low-level runtime environment written in C and a higher-level system written in Common Lisp itself. Some command line arguments are processed during the initialization of the low-level runtime environment, some command line arguments are processed during the initialization of the Common Lisp system, and any remaining command line arguments are passed on to user code.
The full, unambiguous syntax for invoking SBCL at the command line is:
For convenience, the
--end-toplevel-options elements can be omitted. Omitting these
elements can be convenient when you are running the program
interactively, and you can see that no ambiguities are possible with
the option values you are using. Omitting these elements is probably a
bad idea for any batch file where any of the options are under user
control, since it makes it impossible for SBCL to detect erroneous
command line input, so that erroneous command line arguments will be
passed on to the user program even if they was intended for the
runtime system or the Lisp system.