developing a shell

[pratik singh]

Hi all,
I am going through Unix(by Sumitabha Das) and C++(Robert Lafore).In order to get through the concepts in a better way I would like to develop a mini project.What I can think right now is developing a shell in which commands will be the same as the one in the available shells but I want to override them.ex.if I write 'ab' (say) it functions as ls.
Is it feasible.if not can u suggest me a feasible project.
thanx.