Operating Systems,build a linux shell in c

implement a simple shell program by using fork()/execv() system calls. Your code should support the basic bash-like shell functions, such as loading and running a program, and also some advanced features, such as using pipe (|) to direct output from one program as input to another program, and I/O redirection (>) to send output to a file on disk. Your simple shell should also support two special commands, “history”, which displays the latest 100 commands typed by the user, and “histat”, which displays the top 10 most frequently typed commands in the descending order.