EOS智能合约开发（二）

一、使用已有合约

（1）启动Node

$ nodeos -e -p eosio --plugin eosio::chain\_api\_plugin    --plugin eosio::history\_api\_plugin

（2）创建 Wallet

$ cleos wallet create

（3）载入BIOS 合约
合约可以直接控制其他帐户的资源分配、访问其他特权API调用。 在公链中，将管理标记的放样和取消，以保留CPU和网络活动的带宽以及合同的内存。

$ cleos set contract eosio build/contracts/eosio.bios -p eosio@active

（5）、创建账户

$ cleos create key
$ cleos wallet import --private-key
$ cleos create account eosio user  $pubkey
$ cleos create account eosio tester $pubkey
//检索
$ cleos get accounts $pubkey

二、”Hello World” 合约

（1）hello.cpp

\#include <eosiolib/eosio.hpp>
\#include <eosiolib/print.hpp>
using namespace eosio;

class hello : public eosio::contract {
  public:
      using contract::contract;

      /// @abi action 
      void hi( account_name user ) {
         print( "Hello, ", name{user} );
      }
};

EOSIO_ABI( hello, (hi) )

（2）编译

$ eosiocpp -o hello.wast hello.cpp
$ eosiocpp -g hello.abi hello.cpp

（3）创建账户

$ cleos create account eosio hello.code PUBKEY

（4）载入合约

$ cleos set contract hello.code ../hello -p hello.code@active

（5）运行合约

$ cleos push action hello.code hi '["user"]' -p tester@active

（6）加入对输出hello的权限认证

void hi( account_name user ) {
   require_auth( user );
   print( "Hello, ", name{user} );
}

（7）运行

//没有tester允许输出hello，报错
$ cleos push action hello.code hi '["tester"]' -p user@active
Error 3030001: missing required authority
//加入验证
$ cleos push action hello.code hi '["tester"]' -p tester@active
executed transaction: 235bd766c2097f4a698cf

三、debug合约开发

（1）debug.hpp

#include <eoslib/eos.hpp>
#include <eoslib/db.hpp>

namespace debug {
    struct foo {
        account_name from;
        account_name to;
        uint64_t amount;
        void print() const {
            eosio::print("Foo from ", eosio::name(from), " to ",eosio::name(to), " with amount ", amount, "\n");
        }
    };
}

（2）debug.cpp

#include <debug.hpp>

extern "C" {

    void apply( uint64_t receiver, uint64_t code, uint64_t action ) {
        if (code == N(debug)) {
            eosio::print("Code is debug\n");
            if (action == N(foo)) {
                 eosio::print("Action is foo\n");
                debug::foo f = eosio::unpack_action_data<debug::foo>();
               if (f.amount >= 100) {
                    eosio::print("Amount is larger or equal than 100\n");
                } else {
                    eosio::print("Amount is smaller than 100\n");
                    eosio::print("Increase amount by 10\n");
                    f.amount += 10;
                    eosio::print(f);
                }
            }
        }
    }
} // extern "C"

（3）编译运行

$ eosiocpp -o debug.wast debug.cpp
$ cleos set contract debug debug.wast debug.abi