Database checks

It's very important to keep the internal instance of the database up to date. You can watch database changes with the cl_stat..() family of functions.
	int cl_statinidir(const char *dirname, struct cl_stat *dbstat);
	int cl_statchkdir(const struct cl_stat *dbstat);
	int cl_statfree(struct cl_stat *dbstat);
	    struct cl_stat dbstat;

	memset(&dbstat, 0, sizeof(struct cl_stat));
	cl_statinidir(dbdir, &dbstat);
To check for a change you just need to call cl_statchkdir and check its return value (0 - no change, 1 - some change occured). Remember to reset the cl_stat structure after reloading the database.
	if(cl_statchkdir(&dbstat) == 1) {
	    cl_statinidir(cl_retdbdir(), &dbstat);
Libclamav $\ge0.96$ includes and additional call to check the number of signatures that can be loaded from a given directory:
	int cl_countsigs(const char *path, unsigned int countoptions,
	    unsigned int *sigs);
The first argument points to the database directory, the second one specifies what signatures should be counted: CL_COUNTSIGS_OFFICIAL (official signatures),
CL_COUNTSIGS_UNOFFICIAL (third party signatures), CL_COUNTSIGS_ALL (all signatures). The last argument points to the counter to which the number of detected signatures will be added (therefore the counter should be initially set to 0). The call returns CL_SUCCESS or an error code.

Cisco 2016-04-21