+AC_CHECK_FUNCS(inet_aton isdigit sigaction snprintf vsnprintf strlcpy strlcat)
+
+AC_CHECK_FUNCS(poll,[AC_CHECK_HEADER(sys/poll.h)],
+ [AC_CHECK_FUNCS(select,[AC_CHECK_HEADER(sys/select.h)],
+ AC_MSG_ERROR([neither poll() nor select() is available!]))
+ ]
+)