uniq

count/select/report unique/repetitive lines

-c, --countprefix lines by the number of occurrences

-d, --repeatedonly 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=Navoid comparing the first N fields

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

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

-u, --uniqueonly print unique lines

-z, --zero-terminatedend lines with 0 byte, not newline

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

--helpdisplay this help and exit

--version output version information and exit