group-lines(1) Name group-lines - group stdin lines by a regular expression pattern Synopsis group-lines PATTERN Options PATTERN A (python) regular expression by which to group lines. Example To group lines with year-date pattern, one could run group-lines "\b\d{4}-\d{2}\b". With this input foo 2022-08-20 baz 2022-09-01 bar 2022-08-19 qux 2021-08-20 This would be yield: 2021-08: qux 2021-08-20 2022-08: foo 2022-08-20 bar 2022-08-19 2022-09: baz 2022-09-01