Previously discussed (66 comments) just a few months ago:
Miller CLI – Like Awk, sed, cut, join, and sort for CSV, TSV and JSON - https://news.ycombinator.com/item?id=28298729 - Aug 2021 (66 comments)
Miller v5.0.0: Autodetected line-endings, in-place mode, user-defined functions - https://news.ycombinator.com/item?id=13751389 - Feb 2017 (20 comments)
Miller = sed, awk, cut, join, sort for CSV and tabular JSON - https://news.ycombinator.com/item?id=11674304 - May 2016 (1 comment)
Miller is like sed, awk, cut, join, and sort for name-indexed data such as CSV - https://news.ycombinator.com/item?id=10073040 - Aug 2015 (2 comments)
Miller is like sed, awk, cut, join, and sort for name-indexed data such as CSV - https://news.ycombinator.com/item?id=10066742 - Aug 2015 (75 comments)