I am using more and more AWK now. I use AWK, for example, to control my window manager. It process the output from lsc (list clients, a C program I wrote to get the list of clients and their attributes) and pipes into wmctrl (window manager control).
When I cannot use AWK directly, I sometimes write a C program that gets the required data and then pipes into AWK to process it (as I have done with window management).

I really want to learn Perl and maybe replace some C+AWK+Shell combinations with a pure Perl solution.

Other than that, I'm learning Scheme/Racket, but it's more for fun than for using it as a glue language to control and interact with the system.