char *strcat();
char  *strncat(); 
char  *strhcpy(); 
char  *strcpy(); 
char  *strncpy(); 
char  *strclr(); 
char  *strucat(); 
char  *strucpy(); 
char  *index(); 
char  *rindex(); 
char  *reverse(); 
char  *strend();
int   strcmp();
int   strncmp();
int   strlen();
int   strucmp();
int   strnucmp();
int   patmatch();
char  *strchr();
char  *strrchr();
char  *strspn();
char  *strcspn();
char  *strtok();
char  *strpbrk();