1. First add a small set of commands for ex: mycat, myhead, mytail,
mycp , mymv and myrm commands.
The program should present a prompt, read a command typed
by the user, spawn a process and execute the command in the
spawned process.? After executing the command, the program
should prompt the user for the next command.? The user must
be able to exit the program by typing the command exit.
2. Implement history command to store last 50 commands.
Optional feature : scan for pipe character between two
commands and implement pipe (take output of one command
and give as input to other command