I've created a simple shell program in c and I need to add this built in command:

Add a new built-in exit command that exits from the shell itself with the exit() system call. It is not to be executed like other programs the user types in. If the exit command is on the same line with other commands, you should ensure that the other commands execute (and finish) before you exit your shell.

These are all valid examples for quitting the shell: prompt> exit prompt> exit; cat file1 prompt> cat file1; exit