The program contains three functions: parse, execute, and main.

When the program runs, the main function prompts the user to put input and reads this input to the buffer array. Then the main calls the parse function to tokenize the words in the buffer and populate the arg array and redirect array. The redirect array stores any redirection symbol and the file name that immediately following it (so the array looks like [symbol1, file1, symbol2, file2]). The arg array stores the rest of arguments. Then the main calls the execute function and passes in the redirect and arg arrays. The execute function first handles the built-in shell commands like "cd" and "rm." Then it handles "bg" and "fg" commands, sending continue signals and giving terminal control to processes accordingly. Then the function handles Input/Output redirects and executes the file. At the end, the function checks the status and prints out messages accordingly.

To compile the program with the "33sh>" prompt, run "./33sh". To compile the program without the "33sh>" prompt, run "./33noprompt".