Compiling C++ API on Unix

Question

Hi All,
I am using C++ API for the first time in Unix.
I installed the Berkeley DB and I set LD_RUN_PATH & LD_LIBRARY_PATH
to point to '/usr/local/BerkeleyDB.4.5/lib'.
Here is the sample program that I am trying to compile:
========================================================
* See the file LICENSE for redistribution information.
* Copyright (c) 1997-2006
*     Oracle Corporation. All rights reserved.
* $Id: EnvExample.cpp,v 12.3 2006/08/24 14:45:49 bostic Exp $
#include <sys/types.h>
#include <errno.h>
#include <iostream>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <db_cxx.h>
using std::ostream;
using std::cout;
using std::cerr;
#ifdef macintosh
#define     DATABASE_HOME     ":database"
#define     CONFIG_DATA_DIR     ":database"
#else
#ifdef DB_WIN32
#define     DATABASE_HOME     "\\tmp\\database"
#define     CONFIG_DATA_DIR     "\\database\\files"
#else
#define     DATABASE_HOME     "/tmp/database"
#define     CONFIG_DATA_DIR     "/database/files"
#endif
#endif
void     db_setup(const char *, const char *, ostream&);
void     db_teardown(const char *, const char *, ostream&);
const char progname = "EnvExample";               / Program name. */
// An example of a program creating/configuring a Berkeley DB environment.
int
main(int, char **)
     // Note: it may be easiest to put all Berkeley DB operations in a
     // try block, as seen here. Alternatively, you can change the
     // ErrorModel in the DbEnv so that exceptions are never thrown
     // and check error returns from all methods.
     try {
          const char data_dir, home;
          // All of the shared database files live in /home/database,
          // but data files live in /database.
          home = DATABASE_HOME;
          data_dir = CONFIG_DATA_DIR;
          cout << "Setup env\n";
          db_setup(home, data_dir, cerr);
          cout << "Teardown env\n";
          db_teardown(home, data_dir, cerr);
          return (EXIT_SUCCESS);
     catch (DbException &dbe) {
          cerr << "EnvExample: " << dbe.what() << "\n";
          return (EXIT_FAILURE);
// Note that any of the db calls can throw DbException
void
db_setup(const char home, const char data_dir, ostream& err_stream)
     // Create an environment object and initialize it for error
     // reporting.
     DbEnv *dbenv = new DbEnv(0);
     dbenv->set_error_stream(&err_stream);
     dbenv->set_errpfx(progname);
     // We want to specify the shared memory buffer pool cachesize,
     // but everything else is the default.
     dbenv->set_cachesize(0, 64 * 1024, 0);
     // Databases are in a subdirectory.
     (void)dbenv->set_data_dir(data_dir);
     // Open the environment with full transactional support.
     dbenv->open(home,
DB_CREATE | DB_INIT_LOCK | DB_INIT_LOG | DB_INIT_MPOOL | DB_INIT_TXN, 0);
     // Do something interesting...
     // Close the handle.
     dbenv->close(0);
void
db_teardown(const char home, const char data_dir, ostream& err_stream)
     // Remove the shared database regions.
     DbEnv *dbenv = new DbEnv(0);
     dbenv->set_error_stream(&err_stream);
     dbenv->set_errpfx(progname);
     (void)dbenv->set_data_dir(data_dir);
     dbenv->remove(home, 0);
     delete dbenv;
========================================================
I used the following command to compile:
g++ -o first -L/usr/local/BerkeleyDB.4.5/lib/libdb_cxx-4.5.a first.oand I am getting the following link errors:
first.o(.text+0x244): In function `db_setup(char const*, char const*, std::basic_ostream<char, std::char_traits<char> >&)':
: undefined reference to `DbEnv::DbEnv(unsigned int)'
first.o(.text+0x336): In function `db_teardown(char const*, char const*, std::basic_ostream<char, std::char_traits<char> >&)':
: undefined reference to `DbEnv::DbEnv(unsigned int)'
first.o(.gcc_except_table+0x24): undefined reference to `typeinfo for DbException'
collect2: ld returned 1 exit status
I looked at a couple of threads in the forums that relate to this but NO LUCK !!
Any Help please !

Answer 1

Hi,
You'll want a compile / link command like this:
$ g++ -o first first.o /usr/local/BerkeleyDB.4.5/lib/libdb_cxx-4.5.a
or this:
$ g++ -o first first.o -L/usr/local/BerkeleyDB.4.5/lib -ldb_cxx-4.5
The first command explicitly links against the static library, the second doesn't specify static or shared, but will usually choose the shared library if it is available.
Regards,
Michael.