int sd_journal_get_data(sd_journal *j, const char *field, const void **data, size_t *l);
int sd_journal_enumerate_data(sd_journal *j, const void **data, size_t *l);
void sd_journal_restart_data(sd_journal *j);
int sd_journal_get_data(sd_journal *j, const char *field, const void **data, size_t *l);
int sd_journal_enumerate_data(sd_journal *j, const void **data, size_t *l);
void sd_journal_restart_data(sd_journal *j);