I discovered it while looking for a program that would allow me to search my e-book library without needing to open individual books and search their contents via Calibre. ripgrep-all accomplishes this by using Pandoc to convert files to plain text and then running ripgrep on the output. One of the numerous formats supported by Pandoc is EPUB, which is the format I use to store books.
Running Pandoc on every book in my library to extract its text can take some time, but ripgrep-all caches the extracted text so that subsequent runs are similar in speed to simply searching plain text – which is blazing fast thanks to ripgrep’s speed. It takes around two seconds to search 1,706 books.
$ time(rga -li 'pandemic' ~/library/books/ | wc -l) 33 real 0m1.225s user 0m2.458s sys 0m1.759s