I have occasionally dipped into this book for instruction and consider it a freely accessible reference: Unix Text Processing, Dougherty and O'Reilly, 1987 htt

I have occasionally dipped into this book for instruction and consider it a freely accessible reference: Unix Text Processing, Dougherty and O'Reilly, 1987 https://www.oreilly.com/openbook/utp/ https://www.oreilly.com/openbook/utp/ Cherry pick chapters like those on the Shell and AWK, and avoid those on troff, macros etc unless specifically interested.