Basic shell wish works as a command line interpreter (CLI). When a command accepted (in response to its prompt), the shell creates a child process that executes the command just entered and then prompts for more user input when it has finished.

• basic shell wish: This is an interactive loop which repeatedly prints a prompt wish>, parses the input, executes the command specified on that line of input, and waits for the command to finish. This is repeated until the user types exit.
  

Also implement exit, cd, history, and path as built-in commands.

• exit: When the user types exit, this shell calls the exit system call with 0 as a parameter. It is an error to pass any arguments to exit.

• cd: cd takes one argument (0 or >1 args should be signaled as an error). Used the chdir() system call with the argument supplied by the user to change directories; if chdir fails, that is also an error.

• history: When the user enters the history command with no arguments, then the shell prints a list of all the lines of input which the user has entered since the shell was started including the history command. The user may also supply a single argument to the history command n where n is a number. When this happens the shell prints the previous n lines of input (if n is not an integer, then its value is rounded up to the next greatest integer).