diff --git a/lib/str.c b/lib/str.c
new file mode 100644
index 0000000..797e9b8
--- /dev/null
+++ b/lib/str.c
@@ -0,0 +1,62 @@
+/*
+ * zebra string function
+ *
+ * these functions are just very basic wrappers around exiting ones and
+ * do not offer the protection that might be expected against buffer
+ * overruns etc
+ */
+
+#include <zebra.h>
+
+#include "str.h"
+
+#ifndef HAVE_SNPRINTF
+/*
+ * snprint() is a real basic wrapper around the standard sprintf()
+ * without any bounds checking
+ */
+int
+snprintf(char *str, size_t size, const char *format, ...)
+{
+  va_list args;
+
+  va_start (args, format);
+
+  return vsprintf (str, format, args);
+}
+#endif
+
+#ifndef HAVE_STRLCPY
+/*
+ * strlcpy is a safer version of strncpy(), checking the total
+ * size of the buffer
+ */
+size_t
+strlcpy(char *dst, const char *src, size_t size)
+{
+  strncpy(dst, src, size);
+
+  return (strlen(dst));
+}
+#endif
+
+#ifndef HAVE_STRLCAT
+/*
+ * strlcat is a safer version of strncat(), checking the total
+ * size of the buffer
+ */
+size_t
+strlcat(char *dst, const char *src, size_t size)
+{
+  /* strncpy(dst, src, size - strlen(dst)); */
+
+  /* I've just added below code only for workable under Linux.  So
+     need rewrite -- Kunihiro. */
+  if (strlen (dst) + strlen (src) >= size)
+    return -1;
+
+  strcat (dst, src);
+
+  return (strlen(dst));
+}
+#endif