if you haven’t noticed by now, in the IOS 15M line we introduced IOS shell. firing it up is just as easy as doing:

C2#conf t
C2(config)#shell processing full

now you have new, UNIX-like commands and options to chain them, including nested grep.

C2#sh running-config | wc -l
C2#sh running-config | grep ip | grep 2001
ipv6 address 2001:DB8:10::10:254/64
ipv6 route ::/0 2001:DB8:10::10:1

if you by now are fun of such capabilities, having been working with IOS XR - it’s a nice touch :)