-c, --count
       prefix lines by the number of occurrences

-d, --repeated
       only print duplicate lines

-D, --all-repeated[=delimit-method]
       print  all duplicate lines delimit-method={none(default),prepend,separate} Delimiting is done with
       blank lines

-f, --skip-fields=N
       avoid comparing the first N fields

-i, --ignore-case
       ignore differences in case when comparing

-s, --skip-chars=N
       avoid comparing the first N characters

-u, --unique
       only print unique lines

-z, --zero-terminated
       end lines with 0 byte, not newline

-w, --check-chars=N
       compare no more than N characters in lines

--help display this help and exit

--version
       output version information and exit