1. Invocation Option O
- shopt_option is one of the shell options accepted by the shopt builtin (see SHELL BUILTIN COMMANDS below).
- If shopt_option is present, -O sets the value of that option; +O unsets it.
- If shopt_option is not supplied, the names and values of the shell options accepted by shopt are printed on the standard output.
- If the invocation option is +O, the output is displayed in a format that may be reused as input.