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berkeley db 如何检测数据库已经存在- #include <stdio.h>
- #include <stdlib.h>
- #include <unistd.h>
- #include <string.h>
- #include <pthread.h>
- #include <errno.h>
- #include <db.h>
- void init_dbt (DBT *key, DBT *data)
- {
- memset (key, 0, sizeof (DBT));
- memset (data, 0, sizeof (DBT));
- }
- int main ()
- {
- DB_ENV *dbenv = NULL;
- DB *dbp = NULL;
- int ret = 0;
- DBC *dbc = NULL;
- DBT key = {0,};
- DBT data = {0,};
- int i = 10;
- #if 1
- if (db_env_create (&dbenv, 0)) {
- printf ("db_env_create %s\n", db_strerror (ret));
- goto out;
- }
- printf ("env create success\n");
- //dbenv->set_errpfx (dbenv, "brick_name");
-
- ret = dbenv->open (dbenv, "/tmp/wyz",
- DB_CREATE|DB_INIT_LOG|DB_INIT_LOCK|
- DB_INIT_MPOOL, 0);
- if (ret) {
- printf ("dbenv_open :%s\n", db_strerror (ret));
- goto out;
- }
- #endif
- ret = db_create (&dbp, dbenv, 0);
- if (ret) {
- printf ("db_create %s\n", db_strerror (ret));
- goto out;
- }
- ret = dbp->open (dbp, NULL, "a.db", NULL, DB_HASH, DB_CREATE, 0);
- if (ret) {
- printf ("db_open %s\n", db_strerror (ret));
- goto out;
- }
- ret = dbp->cursor (dbp, NULL, &dbc, 0);
- if (ret) {
- printf ("cursor : %s\n", db_strerror (ret));
- goto out;
- }
- init_dbt (&key, &data);
- key.data = &i;
- key.size = sizeof (int);
- data.data = &i;
- data.size = sizeof (int);
- while (i) {
- printf ("put ===============key = %d data = %d\n",*(int*)key.data, *(int*)data.data );
- ret = dbp->put (dbp, NULL, &key, &data, DB_NOOVERWRITE);
- if (ret) {
- printf ("db_put %s\n", db_strerror (ret));
- break;
- }
- i--;
- }
- while (1) {
- ret = dbc->get (dbc, &key, &data, DB_NEXT);
- sleep (1);
- if (ret) {
- printf ("cursor get : %s\n", db_strerror (ret));
- break;
- }
- printf ("get ===================key = %d data = %d\n",*(int*)key.data, *(int*)data.data );
- }
- out:
- return ret;
- }
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