-char *ascii_filter(const char *str) {
- const char *s;
- char *r, *d;
- size_t l;
-
- assert(str);
-
- l = strlen(str);
- r = malloc(l + 1);
- if (!r)
- return NULL;
-
- for (s = str, d = r; *s; s++)
- if ((unsigned char) *s < 128)
- *(d++) = *s;
-
- *d = 0;
-
- return r;
-}
-