1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
|
/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1997-2004
* Sleepycat Software. All rights reserved.
*
* $Id: ex_btrec.c,v 11.22 2004/09/17 22:00:28 mjc 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);
}
|
