pub unsafe static mut optind: c_intExpand description
Index in ARGV of the next element to be scanned. This is used for communication to and from the caller and for communication between successive calls to ‘getopt’.
On entry to ‘getopt’, zero means this is the first call; initialize.
When ‘getopt’ returns -1, this is the index of the first of the non-option elements that the caller should itself scan.
Otherwise, ‘optind’ communicates from one call to the next how much of ARGV has been scanned so far.