DBM#to_hash

static VALUE
fdbm_to_hash(VALUE obj)
{
    datum key, val;
    struct dbmdata *dbmp;
    DBM *dbm;
    VALUE hash;

    GetDBM2(obj, dbmp, dbm);
    hash = rb_hash_new();
    for (key = dbm_firstkey(dbm); key.dptr; key = dbm_nextkey(dbm)) {
        val = dbm_fetch(dbm, key);
        rb_hash_aset(hash, rb_str_new(key.dptr, key.dsize),
                           rb_str_new(val.dptr, val.dsize));
    }

    return hash;
}