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/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1997-2006
* Oracle Corporation. All rights reserved.
*
* $Id: ex_btrec.c,v 12.3 2006/08/24 14:45:41 bostic Exp $
*/
#include <sys/types.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <db.h>
#define DATABASE "access.db"
#define WORDLIST "../test/wordlist"
int main __P((void));
int ex_btrec __P((void));
void show __P((const char *, DBT *, DBT *));
int
main()
{
return (ex_btrec() == 1 ? EXIT_FAILURE : EXIT_SUCCESS);
}
int
ex_btrec()
{
DB *dbp;
DBC *dbcp;
DBT key, data;
DB_BTREE_STAT *statp;
FILE *fp;
db_recno_t recno;
size_t len;
int cnt, ret;
char *p, *t, buf[1024], rbuf[1024];
const char *progname = "ex_btrec"; /* Program name. */
/* Open the word database. */
if ((fp = fopen(WORDLIST, "r")) == NULL) {
fprintf(stderr, "%s: open %s: %s\n",
progname, WORDLIST, db_strerror(errno));
return (1);
}
/* Remove the previous database. */
(void)remove(DATABASE);
/* Create and initialize database object, open the database. */
if ((ret = db_create(&dbp, NULL, 0)) != 0) {
fprintf(stderr,
"%s: db_create: %s\n", progname, db_strerror(ret));
return (1);
}
dbp->set_errfile(dbp, stderr);
dbp->set_errpfx(dbp, progname); /* 1K page sizes. */
if ((ret = dbp->set_pagesize(dbp, 1024)) != 0) {
dbp->err(dbp, ret, "set_pagesize");
return (1);
} /* Record numbers. */
if ((ret = dbp->set_flags(dbp, DB_RECNUM)) != 0) {
dbp->err(dbp, ret, "set_flags: DB_RECNUM");
return (1);
}
if ((ret = dbp->open(dbp,
NULL, DATABASE, NULL, DB_BTREE, DB_CREATE, 0664)) != 0) {
dbp->err(dbp, ret, "open: %s", DATABASE);
return (1);
}
/*
* Insert records into the database, where the key is the word
* preceded by its record number, and the data is the same, but
* in reverse order.
*/
memset(&key, 0, sizeof(DBT));
memset(&data, 0, sizeof(DBT));
for (cnt = 1; cnt <= 1000; ++cnt) {
(void)sprintf(buf, "%04d_", cnt);
if (fgets(buf + 4, sizeof(buf) - 4, fp) == NULL)
break;
len = strlen(buf);
for (t = rbuf, p = buf + (len - 2); p >= buf;)
*t++ = *p--;
*t++ = '\0';
key.data = buf;
data.data = rbuf;
data.size = key.size = (u_int32_t)len - 1;
if ((ret =
dbp->put(dbp, NULL, &key, &data, DB_NOOVERWRITE)) != 0) {
dbp->err(dbp, ret, "DB->put");
if (ret != DB_KEYEXIST)
goto err1;
}
}
/* Close the word database. */
(void)fclose(fp);
/* Print out the number of records in the database. */
if ((ret = dbp->stat(dbp, NULL, &statp, 0)) != 0) {
dbp->err(dbp, ret, "DB->stat");
goto err1;
}
printf("%s: database contains %lu records\n",
progname, (u_long)statp->bt_ndata);
free(statp);
/* Acquire a cursor for the database. */
if ((ret = dbp->cursor(dbp, NULL, &dbcp, 0)) != 0) {
dbp->err(dbp, ret, "DB->cursor");
goto err1;
}
/*
* Prompt the user for a record number, then retrieve and display
* that record.
*/
for (;;) {
/* Get a record number. */
printf("recno #> ");
fflush(stdout);
if (fgets(buf, sizeof(buf), stdin) == NULL)
break;
recno = atoi(buf);
/*
* Reset the key each time, the dbp->c_get() routine returns
* the key and data pair, not just the key!
*/
key.data = &recno;
key.size = sizeof(recno);
if ((ret = dbcp->c_get(dbcp, &key, &data, DB_SET_RECNO)) != 0)
goto get_err;
/* Display the key and data. */
show("k/d\t", &key, &data);
/* Move the cursor a record forward. */
if ((ret = dbcp->c_get(dbcp, &key, &data, DB_NEXT)) != 0)
goto get_err;
/* Display the key and data. */
show("next\t", &key, &data);
/*
* Retrieve the record number for the following record into
* local memory.
*/
data.data = &recno;
data.size = sizeof(recno);
data.ulen = sizeof(recno);
data.flags |= DB_DBT_USERMEM;
if ((ret = dbcp->c_get(dbcp, &key, &data, DB_GET_RECNO)) != 0) {
get_err: dbp->err(dbp, ret, "DBcursor->get");
if (ret != DB_NOTFOUND && ret != DB_KEYEMPTY)
goto err2;
} else
printf("retrieved recno: %lu\n", (u_long)recno);
/* Reset the data DBT. */
memset(&data, 0, sizeof(data));
}
if ((ret = dbcp->c_close(dbcp)) != 0) {
dbp->err(dbp, ret, "DBcursor->close");
goto err1;
}
if ((ret = dbp->close(dbp, 0)) != 0) {
fprintf(stderr,
"%s: DB->close: %s\n", progname, db_strerror(ret));
return (1);
}
return (0);
err2: (void)dbcp->c_close(dbcp);
err1: (void)dbp->close(dbp, 0);
return (ret);
}
/*
* show --
* Display a key/data pair.
*/
void
show(msg, key, data)
const char *msg;
DBT *key, *data;
{
printf("%s%.*s : %.*s\n", msg,
(int)key->size, (char *)key->data,
(int)data->size, (char *)data->data);
}
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