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uniq — remove or count repeated lines

cheat sheet · Ubuntu 24.04 · GNU coreutils 9.4 https://lab.dimsanych.ru/en/wiki/uniq/

Cheat sheet

sort file | uniq drop repeats
sort file | uniq -c how many times each line occurs
sort file | uniq -c | sort -rn most common first
sort file | uniq -d only the lines that repeat
sort file | uniq -u only the lines without a twin
sort file | uniq -ci ignore case

Options

sort -u gives the same result as sort | uniq, but only uniq -c can count the repeats. The full list is in man uniq.