rflink port to esp8266 seems easy
In "Misc", add the following code:

int
_DEFUN (strncasecmp, (s1, s2, n),
_CONST char *s1 _AND
_CONST char *s2 _AND
size_t n)
{
if (n == 0)
return 0;

while (n-- != 0 && tolower(*s1) == tolower(*s2))
{
if (n == 0 || *s1 == '\0' || *s2 == '\0')
break;
s1 ...