options

Many commands take options to modify their behavior, following these rules (similar to UNIX conventions, but not identical):

All options must be immediately preceded by '-'.
Options may be grouped after a single '-'.
Some options may take string, numeric, or time arguments. There must be no space between the option and the argument.
String option-arguments may be delimited by a space, double quotes, single quotes, or backquotes.
A literal delimiter character or '\' within a delimited string must be escaped by preceding it with '\'.
A numeric option-argument may be given as an expression that evaluates to a numeric value. If the expression contains spaces or quotes, they must be quoted or escaped as in a string option-argument.
All options must precede normal arguments.
A '-' or '--' by itself may be used to mark the end of the options. This is useful when the first regular argument begins with '-'.
A '-?' or invalid option will produce a list of valid options.