fix: hostname truncation (#63)

Co-authored-by: javalsai <javalsai@proton.me>

src/util.c

@@ -103,6 +103,24 @@ size_t utf8len_until(const char* str, const char* until) {
   return len;
 }
 
+size_t utf8trunc(char* str, size_t n) {
+  size_t bytes = 0;
+  while (true) {
+    if(str[bytes] == '\0') break;
+    if (utf8_iscont(str[bytes])) {
+      bytes++;
+      continue;
+    }
+    if(n == 0) {
+      str[bytes] = '\0';
+      break;
+    }
+    bytes++;
+    n--;
+  }
+  return bytes;
+}
+
 const char* utf8back(const char* str) {
   while (utf8_iscont(*(--str))) {
   }