How to determine which Berkeley DB version is used for RPM's database?

Question

I am attempting to read and write the RPM database located in /var/lib/rpm under CentOS 5, and eventually other system types (CentOS 6, RHEL, etc.)

The problem is that I don't know what version of Berkeley DB is being used.

The file command on the database file reports "data".

I tried opening the database using Berkeley DB versions 3.3, 4.4 and 6.1, but that fails with "Invalid argument".

Here is the code I am using (this for 4.4/6.1)

int main()
{
    #define DATABASE "__db.001"

    DB *dbp;
    int ret;

    if ((ret = db_create(&dbp, NULL, 0)) != 0) {
        fprintf(stderr, "db_create: %s\n", db_strerror(ret));
        exit (1);
    }

    if ((ret = dbp->open(
        dbp, NULL, DATABASE, NULL, DB_UNKNOWN, 0, 0664)) != 0) {
        dbp->err(dbp, ret, "%s", DATABASE);
        exit(1);
    }
}

Any hints about what is going wrong?

Answer 1

It turns out that the files in /var/lib/rpm with db in their names are not Berkeley database files. The files with no db in their names are Berkeley database files.

So trying to open a file named __db.001 is the wrong thing to do.

(Thought about just deleting the question, but other people may run into this).