# uniq > Output the unique lines from a input or file. > Since it does not detect repeated lines unless they are adjacent, we need to sort them first. > More information: . - Display each line once: `sort {{path/to/file}} | uniq` - Display only unique lines: `sort {{path/to/file}} | uniq {{[-u|--unique]}}` - Display only duplicate lines: `sort {{path/to/file}} | uniq {{[-d|--repeated]}}` - Display number of occurrences of each line along with that line: `sort {{path/to/file}} | uniq {{[-c|--count]}}` - Display number of occurrences of each line, sorted by the most frequent: `sort {{path/to/file}} | uniq {{[-c|--count]}} | sort {{[-nr|--numeric-sort --reverse]}}`