Ubuntu 系统版本: Ubuntu 16.04 LTS
Berkeley DB 版本: Berkeley DB 18.1.25
下载Berkeley DB源代码
https://www.oracle.com/technetwork/database/database-technologies/berkeleydb/downloads/index.html
解压缩文件:
tar -xvf db-18.1.25.tar.gz
进入目录build_unix:
cd build_unix
自动配置,生成Makefile(默认配置不会生成cxx支持库):
…/dist/configure
添加CXX支持,在配置后添加参数“–enalbe-cxx”:
…/dist/configure --enable-cxx
编译源代码:
make
安装:
sudo make install
卸载与重新配置编译命令为:
sudo make uninstall
make realclean
Berkeley DB默认安装路径为:
/usr/local/BerkeleyDB.18.1
在使用时,需要在添加头文件和链接库路径,如:
g++ *.cpp -I"/usr/local/BerkeleyDB.18.1/include" -L"/usr/local/BerkeleyDB.18.1/lib/" -ldb_cxx
链接动态链接库libdb_cxx-18.1.so到/usr/local/lib:
sudo ln /usr/local/BerkeleyDB.18.1/lib/libdb_cxx-18.1.so /usr/local/lib/libdb_cxx-18.1.so
sudo ldconfig
或者在/etc/ld.so.conf.d/目录下添加BerkeleyDB链接库路径:
sudo echo /usr/local/BerkeleyDB.18.1/lib>BerkeleyDB.conf
sudo ldconfig
访问示例:
复制文件 db-18.1.25/examples/cxx/AccessExample.cpp到临时目录:
/*-
* Copyright (c) 1997, 2018 Oracle and/or its affiliates. All rights reserved.
*
* See the file EXAMPLES-LICENSE for license information.
*
* $Id$
*/
#include
#include
#include
#include
#include
#include
#ifdef _WIN32
extern "C" {
extern int getopt(int, char * const *, const char *);
extern int optind;
}
#else
#include
#endif
#include
#define DATABASE "access.db"
using std::cin;
using std::cout;
using std::cerr;
class AccessExample
{
public:
AccessExample();
void run(bool removeExistingDatabase, const char *fileName);
private:
// no need for copy and assignment
AccessExample(const AccessExample &);
void operator = (const AccessExample &);
};
int
usage()
{
(void)fprintf(stderr, "usage: AccessExample [-r] [database]\n");
return (EXIT_FAILURE);
}
int
main(int argc, char *argv[])
{
int ch, rflag;
const char *database;
rflag = 0;
while ((ch = getopt(argc, argv, "r")) != EOF)
switch (ch) {
case 'r':
rflag = 1;
break;
case '?':
default:
return (usage());
}
argc -= optind;
argv += optind;
/* Accept optional database name. */
database = *argv == NULL ? DATABASE : argv[0];
// Use a try block just to report any errors.
// An alternate approach to using exceptions is to
// use error models (see DbEnv::set_error_model()) so
// that error codes are returned for all Berkeley DB methods.
//
try {
AccessExample app;
app.run((bool)(rflag == 1 ? true : false), database);
return (EXIT_SUCCESS);
}
catch (DbException &dbe) {
cerr << "AccessExample: " << dbe.what() << "\n";
return (EXIT_FAILURE);
}
}
AccessExample::AccessExample()
{
}
void AccessExample::run(bool removeExistingDatabase, const char *fileName)
{
// Remove the previous database.
if (removeExistingDatabase)
(void)remove(fileName);
// Create the database object.
// There is no environment for this simple example.
Db db(0, 0);
db.set_error_stream(&cerr);
db.set_errpfx("AccessExample");
db.set_pagesize(1024); /* Page size: 1K. */
db.set_cachesize(0, 32 * 1024, 0);
db.open(NULL, fileName, NULL, DB_BTREE, DB_CREATE, 0664);
//
// Insert records into the database, where the key is the user
// input and the data is the user input in reverse order.
//
char buf[1024], rbuf[1024];
char *p, *t;
int ret;
u_int32_t len;
for (;;) {
cout << "input> ";
cout.flush();
cin.getline(buf, sizeof(buf));
// 修改为终端输入exit推出循环
//if (cin.eof())
if(strcmp(buf,"exit")==0)
break;
if ((len = (u_int32_t)strlen(buf)) <= 0)
continue;
for (t = rbuf, p = buf + (len - 1); p >= buf;)
*t++ = *p--;
*t++ = '\0';
Dbt key(buf, len + 1);
Dbt data(rbuf, len + 1);
ret = db.put(0, &key, &data, DB_NOOVERWRITE);
if (ret == DB_KEYEXIST) {
cout << "Key " << buf << " already exists.\n";
}
}
cout << "\n";
// We put a try block around this section of code
// to ensure that our database is properly closed
// in the event of an error.
//
try {
// Acquire a cursor for the table.
Dbc *dbcp;
db.cursor(NULL, &dbcp, 0);
// Walk through the table, printing the key/data pairs.
Dbt key;
Dbt data;
while (dbcp->get(&key, &data, DB_NEXT) == 0) {
char *key_string = (char *)key.get_data();
char *data_string = (char *)data.get_data();
cout << key_string << " : " << data_string << "\n";
}
dbcp->close();
}
catch (DbException &dbe) {
cerr << "AccessExample: " << dbe.what() << "\n";
}
db.close(0);
}
编译:
g++ -o AccessExample AccessExample.cpp -I /usr/local/BerkeleyDB.18.1/include/ -L /usr/local/BerkeleyDB.18.1/lib/ -ldb_cxx
运行:
./AccessExample
input> 123
input> 456
input> 789
input> abc
input> d
input> efg
input> exit123 : 321
456 : 654
789 : 987
abc : cba
d : d
efg : gfe
程序自动生成一个access.db的文件,并将终端输入数据存储,即数据库文件。