xsv is a command-line program for indexing, slicing, analyzing, splitting and joining CSV files. Commands should be simple, fast and composable. I was sold on joining, you can use 2 csv file and do a join as you do on a table.
Binaries for Windows, Linux and macOS are available from Github.
If you’re a macOS Homebrew user, then you can install xsv from homebrew-core:
$ brew install xsv
If you’re a macOS MacPorts user, then you can install xsv from the official ports:
$ sudo port install xsv
If you’re a Nix/NixOS user, you can install xsv from nixpkgs:
$ nix-env -i xsv
For example and tutorial check out https://github.com/BurntSushi/xsv. also, check out https://www.johndcook.com/blog/2019/12/31/sql-join-csv-files/.