int strvis __P((char *, const char *, int));
int strvisx __P((char *, const char *, size_t, int));
int strunvis __P((char *, const char *));
int strvis __P((char *, const char *, int));
int strvisx __P((char *, const char *, size_t, int));
int strunvis __P((char *, const char *));