My interpretation of the requirements are:
1. Write shell one-liners for requirement point #1 (i.e., not in C)
2. You already have an existing command shell for requirement point #2, and only need piping and backgrounding added to it
If interpretation #2 is incorrect, I will have to revise the bid, but please talk to be directly about it first (e.g., What do you have already, and exactly what features the shell needs apart from the piping and backgrounding)