uniq

uniq is a command-line utility that filters adjacent matching lines from an input file (or standard input) and writes a single copy of the matching line to the output. It's primarily used to remove duplicate lines, but it requires that the duplicates be next to each other to be effective. Options allow you to count the number of occurrences of each line, display unique lines, or display only duplicate lines.

Visit the following resources to learn more:

• @article@How to use the uniq command to process lists in Linux
• @video@Uniq utility (commands for linux)