Quoted from the getopt() Linux Manual page:
If the first character of optstring is a hyphen (-), then each nonoption argv-element is handled as if it were the argument of an option with character code 1. (This is used by programs that were written to expect options and other argv-elements in any order and that care about the ordering of the two.) The special argument double hyphens (--) forces an end of option-scanning regardless of the scanning mode.
Quoted from the manual page of Java GetOpt class:
…The second is to allow options anywhere, but to return all elements in the order they occur on the command line. When a non-option element is ecountered, an integer 1 is returned and the value of the non-option element is stored in optarg is if it were the argument to that option. For example, “-a foo -d”, returns first ‘a’, then 1 (with optarg set to “foo”) then ‘d’ then -1. When this “return in order” functionality is enabled, the only way to stop getopt() from scanning all command line elements is to use the special “–” string by itself as described above. An example is “-a foo -b — bar”, which would return ‘a’, then integer 1 with optarg set to “foo”, then ‘b’, then -1. optind would then point to “bar” as the first non-option argv element. The “–” is discarded.
Yes, I understand what the above statements talking about, but I still cannot imagine what kind of applications use such a behaviour.
Could someone provides an example of a command-line syntax that likely used by applications that implement the “return in order” behavior?
findis an example of a command that mixes options and non-option arguments, and cares about the order.