#include <iostream>
#include <leveldb/db.h>
#include <leveldb/write_batch.h> //原子更新操作
#include <assert.h>using namespace std;
using namespace leveldb;int main(int argc,char * argv[])
{ leveldb::DB* db; leveldb::Options op; leveldb::Status s ; op.create_if_missing = true; //op.error_if_exists = true;//string dbpath = "/tmp/testdb"; string dbpath = "/data/osd.1/current/omap"; s = leveldb::DB::Open(op, dbpath, &db); assert(s.ok()); cout<<"open db succ"<<std::endl; /*std::string key = "100001"; std::string val = "this is 100001's value"; std::string retVal; s = db->Put(leveldb::WriteOptions(), key, val);s = db->Get(leveldb::ReadOptions(), key, &retVal);s = db->Delete(leveldb::WriteOptions(), key);cout<<retVal<<std::endl; */leveldb::Iterator* it = db->NewIterator( leveldb::ReadOptions() ); std::string mkey,mval;for ( it->SeekToFirst(); it->Valid(); it->Next() ){ mkey = it->key().ToString();mval = it->value().ToString();cout << "key=" << mkey <<", val=" << mval <<std::endl; //if ( mkey.find("s3") != string::npos )//cout << "------------find " << mkey << "----------" << mval << std::endl;}assert(it->status().ok()); //checkdelete it;delete db;cout<<"over!"<<std::endl;return 0;
}

rm ./ldbtest
g++ -g ldbtest.cpp -o ldbtest -L. -I./include -lpthread -lleveldb
./ldbtest

参考：

1.  http://blog.csdn.net/hzqhbc/article/details/9367327

2.  http://blog.csdn.net/cywosp/article/details/20746879