extern char *strcat();
extern char *strncat();
extern char *strcpy();
extern char *strncpy();
extern char *stpcpy();
extern char *stpblk();
extern char *stpsym();
extern char *stptok();
extern char *stpchr();
extern char *strchr();
extern char *strrchr();
extern char *stpbrk();
extern char *strpbrk();