The sort command orders rows by the columns named by -s, here age, ascending by default. Add -R to reverse the order or -N for numeric sorting, since lexicographic sort puts 100 before 20. Sorting a CSV with xsv is safe for quoted fields and embedded commas, which plain sort mishandles. This is the xsv way to order records by any column.
Looking for more? Search all 7,657 commands — works offline, in English or Spanish, and fixes typos.