When I was doing UNIX development and qa work I used shell scripting in at least these parts of my work:
1. To reduce the enormously long commands we had to type, (especially in the good old green screen days) a nice shell script which was placed in the bin directory, and which could accept a few arguments at the command line, was a big help. Also, cutting down the number of key strokes will reduce the wear & tear on your hands and wrists, and your chances of getting related ailments.
2. Checking application log files -- which I have commented on in several other threads so you can read more about log file checking in my other posts.
3. Sometimes large input files have to be created manually for black box testing, so a quick shell script would make this task much easier. This is more a developer technique.
For QA today, 1 and 2 above are still very important QA shell scripting needs.
The happiest people don't have the best of everything, they make the best of what they have. [Anonymous]