$ cat data/a.csv a,b,c 1,2,3 4,5,6

$ cat data/b.csv a,b,c 7,8,9

$ mlr --csv cat data/a.csv data/b.csv a,b,c 1,2,3 4,5,6 7,8,9

$ mlr --csv sort -nr b data/a.csv data/b.csv a,b,c 7,8,9 4,5,6 1,2,3

See Reference for more on Miller’s subcommands cat, cut, head, sort, tac, tail, top, and uniq, as well as awk-like mlr filter and mlr put.