strnlen for klibc

@@ -12,3 +12,13 @@
   return ss-s;
 }
 
+size_t strnlen(const char *s, size_t maxlen)
+{
+  const char *ss = s;
+  while(*ss && (maxlen > 0)) {
+	ss++;
+	maxlen--;
+  }
+  return ss-s;
+}
+

@@ -27,6 +27,7 @@
 __extern char *strndup(const char *, size_t);
 __extern char *strerror(int);
 __extern size_t strlen(const char *);
+__extern size_t strnlen(const char *, size_t);
 __extern char *strncat(char *, const char *, size_t);
 __extern int strncmp(const char *, const char *, size_t);
 __extern char *strncpy(char *, const char *, size_t);