//Declaration: void exit(int exit_code); #include <stdlib.h> #include <stdio.h> int main(void) { char choice; do { printf("Enter names (E)\n"); printf("Delete name (D)\n"); printf("Print (P)\n"); printf("Quit (Q)\n"); choice = getchar(); } while(!strchr("EDPQ", toupper(choice))); if(choice=='Q') exit(0); return choice; }