All builtin commands other than ‘echo
’ and precommand modifiers, even those that have no options, can be given the argument ‘--
’ to terminate option processing. This indicates that the following words are non-option arguments, but is otherwise ignored. This is useful in cases where arguments to the command may begin with ‘-
’. For historical reasons, most builtin commands (including ‘echo
’) also recognize a single ‘-
’ in a separate word for this purpose; note that this is less standard and use of ‘--
’ is recommended.