Comments on: Tac and Reverse Grep

By: Reverse grep through large logs | Animoto Labs

Reverse grep through large logs | Animoto Labs — Sun, 12 Jul 2009 21:14:06 +0000

[...] I found an incredibly handy trick that I’ve wanted to know for ages through Clifton Griffin’s blog here. [...]

By: clifgriffin

clifgriffin — Sun, 30 Nov 2008 13:01:29 +0000

This would work, but it seems a bit inefficient. It has to search the whole file, return matches, and take the last match. It is a shortcut to the 7th field…but I’m not sure the iteration from the top of the file is efficient. Especially if you have a large log file (like in my case).

The method I listed starts at the end of the file…a much shorter distance to the information in question. I’m also assuming that cut is about as efficient as awk for this type of search, but I’ll let smarter people than I sort that out.

By: Steve

Steve — Sat, 29 Nov 2008 19:28:30 +0000

awk ‘/match/ { print $7 }’ file | tail -1