Current File : //usr/local/share/zsh/5.8/help/getopts
getopts optstring name [ arg ... ]
Checks the args for legal options. If the args are omitted, use
the positional parameters. A valid option argument begins with a
`+' or a `-'. An argument not beginning with a `+' or a `-', or
the argument `--', ends the options. Note that a single `-' is
not considered a valid option argument. optstring contains the
letters that getopts recognizes. If a letter is followed by a
`:', that option requires an argument. The options can be
separated from the argument by blanks.
Each time it is invoked, getopts places the option letter it finds
in the shell parameter name, prepended with a `+' when arg begins
with a `+'. The index of the next arg is stored in OPTIND. The
option argument, if any, is stored in OPTARG.
The first option to be examined may be changed by explicitly
assigning to OPTIND. OPTIND has an initial value of 1, and is
normally set to 1 upon entry to a shell function and restored upon
exit (this is disabled by the POSIX_BUILTINS option). OPTARG is
not reset and retains its value from the most recent call to
getopts. If either of OPTIND or OPTARG is explicitly unset, it
remains unset, and the index or option argument is not stored.
The option itself is still stored in name in this case.
A leading `:' in optstring causes getopts to store the letter of
any invalid option in OPTARG, and to set name to `?' for an
unknown option and to `:' when a required argument is missing.
Otherwise, getopts sets name to `?' and prints an error message
when an option is invalid. The exit status is nonzero when there
are no more options.
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