linear_search
front = linear_search(string, front, back);
char *linear_search(char *, char *, char *);
u_char *linear_search(u_char *, u_char *, u_char *);
front = linear_search(string, front, back);
front = linear_search(tname, front, back);
static char *linear_search(char *, char *, char *);