#define eq(s,t) (strcmp(s, t) == 0) 
#define n_eq(s,t,n) (strncmp(s, t, n) == 0) 
 unsigned char upcase[256] ;
 unsigned char downcase[256] ;
  int  case_eq(const char *s, const char *t);
  int  case_n_eq(const char *s, const char *t, const int n);