int database_match_criteria(struct session_database *db, struct database_criterion *cl);
int session_grep_databases(struct session *se, struct database_criterion *cl,
void (*fun)(void *context, struct session_database *db));
int database_match_criteria(struct session_database *db, struct database_criterion *cl);
int session_grep_databases(struct session *se, struct database_criterion *cl,
void (*fun)(void *context, struct session_database *db));