bash输出无效选项

while getopts dsf opts 2>/dev/null
do
    case $opts in
    d) echo \"d\";;
    s) echo \"s\";;
    \\?) echo \"Error: An invalid option [?] was entered.\";
        exit 1;;
    esac
done

./myscript -z //output: Error: An invalid option [-z] was entered.

help getopts

getopts reports errors in one of two ways.  If the first character
of OPTSTRING is a colon, getopts uses silent error reporting.  In
this mode, no error messages are printed.  If an invalid option is
seen, getopts places the option character found into OPTARG.