+typedef void adns_logcallbackfn(adns_state ads, void *logfndata,
+ const char *fmt, va_list al);
+ /* Will be called perhaps several times for each message; when the
+ * message is complete, the string implied by fmt and al will end in
+ * a newline. Log messages start with `adns debug:' or `adns
+ * warning:' or `adns:' (for errors), or `adns debug [PID]:'
+ * etc. if adns_if_logpid is set. */
+
+int adns_init_logfn(adns_state *newstate_r, adns_initflags flags,
+ const char *configtext /*0=>use default config files*/,
+ adns_logcallbackfn *logfn /*0=>logfndata is a FILE* */,
+ void *logfndata /*0 with logfn==0 => discard*/);
+