Question

I’m trying to search a large file in reverse order from the command line (using terminal). I found the tac command: http://clifgriffin.com/2008/11/25/tac-and-reverse-grep/

tac is the inverse of cat. However, when I try to use the tac command in terminal, it says that command doesn’t exist. Is there a way I’d be able to use tac in terminal? What are some other fast ways to search a file from the end via the command line?

Answer 1

The MacOs version of tail support the -r (“reverse”) option, and defaults
to displaying the entire file from the end. So tail -r filename should be
exactly equivalent to tac filename.

Or, you could try building tac yourself from the source code. It’s part of the GNU coreutils package.