I need to make a menu for my program that links to the following functions that I already put in other files but the menu needs to go back to it after each function finishes.

char *StrChr(char *str, int ch);
char *StrRChr(char *str, int ch);
int StrSpn(char *str, char *set);
int StrCSpn(char *str, char *set);

Only thing is i'm only allowed to use #include <stdio.h>
And it must be written in all C. So if someone could either write it or walk me through writting it by Nov. 2 that would be great. Thank you.