+char *utf8_escape_invalid(const char *str) {
+ char *p, *s;
+
+ assert(str);
+
+ p = s = malloc(strlen(str) * 4 + 1);
+ if (!p)
+ return NULL;
+
+ while (*str) {
+ int len;
+
+ len = utf8_encoded_valid_unichar(str);
+ if (len > 0) {
+ s = mempcpy(s, str, len);
+ str += len;
+ } else {
+ s = stpcpy(s, UTF8_REPLACEMENT_CHARACTER);
+ str += 1;
+ }
+ }
+
+ *s = '\0';
+
+ return p;
+}
+
+char *utf8_escape_non_printable(const char *str) {
+ char *p, *s;
+
+ assert(str);
+
+ p = s = malloc(strlen(str) * 4 + 1);
+ if (!p)
+ return NULL;
+
+ while (*str) {
+ int len;
+
+ len = utf8_encoded_valid_unichar(str);
+ if (len > 0) {
+ if (utf8_is_printable(str, len)) {
+ s = mempcpy(s, str, len);
+ str += len;
+ } else {
+ while (len > 0) {
+ *(s++) = '\\';
+ *(s++) = 'x';
+ *(s++) = hexchar((int) *str >> 4);
+ *(s++) = hexchar((int) *str);
+
+ str += 1;
+ len --;
+ }
+ }
+ } else {
+ s = stpcpy(s, UTF8_REPLACEMENT_CHARACTER);
+ str += 1;
+ }
+ }
+
+ *s = '\0';
+
+ return p;
+}
+