EOS 开发环境运行 Hello World 合约

前提需要搭建好开发环境，可以参考之前的文章：EOS 开发环境搭建。

创建合约目录

cd /Users/mac/eos/contracts
mkdir hello
cd hello

合约代码

创建合约文件：

touch hello.cpp

内容：

#include 
#include 

using namespace eosio;

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

      [[eosio::action]]
      void hi( name user ) {
         print( "Hello, ", name{user});
      }
};
EOSIO_DISPATCH( hello, (hi))

编译

eosio-cpp -o hello.wasm hello.cpp --abigen

为合约创建一个 account

当一个合约被部署了，它是部署在一个 account 上，这个 account 成为了合约的接口。

创建一个 account ：

cleos create account eosio hello EOS5QyuomJdvmynsGH5EAnK3i879nZfT4v97CZ3KXFxYvehm77aio -p eosio@active

key 可以通过命令查询：

cleos wallet keys

设置合约

cleos set contract hello /Users/mac/eos/contracts/hello -p hello@active

# 输出
Reading WASM from /Users/mac/eos/contracts/hello/hello.wasm...
Publishing contract...
executed transaction: ed2521e09e61bdd04ef57c371f1a08a1f541d7b0af6986bd1c145ba8018cfa3a  1432 bytes  1132 us
#         eosio <= eosio::setcode               {"account":"hello","vmtype":0,"vmversion":0,"code":"0061736d0100000001390b60027f7e006000017f60027f7f...
#         eosio <= eosio::setabi                {"account":"hello","abi":"0e656f73696f3a3a6162692f312e31000102686900010475736572046e616d650100000000...
warning: transaction executed locally, but may not be confirmed by the network yet         ]

调用合约

cleos push action hello hi '["bob"]' -p bob@active

# 输出
executed transaction: db32d32a357f734a513ac11400462961858e9fc28c531259dc9fd47566987ff4  104 bytes  537 us
#         hello <= hello::hi                    {"user":"bob"}
>> Hello, bob

添加用户验证

上面的代码可以正常运行，下面添加一个限制：认证的用户必须和参数中的用户名一致。

修改 hi 函数的代码为：

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

重新编译：

eosio-cpp -o hello.wasm hello.cpp --abigen

更新：

cleos set contract hello /Users/mac/eos/contracts/hello -p hello@active

测试：

cleos push action hello hi '["bob"]' -p alice@active

# 输出
Error 3090004: Missing required authority
Ensure that you have the related authority inside your transaction!;
If you are currently using 'cleos push action' command, try to add the relevant authority using -p option.

因为登录的用户是 'alice' 而参数传入的用户名是 'bob'，不一致，所以报错。

重新调用：

cleos push action hello hi '["alice"]' -p alice@active

# 输出
executed transaction: 192928e9fa6046f45067f6c1af062a6078dd9d36fc8c279c5e50cb6448e1594c  104 bytes  579 us
#         hello <= hello::hi                    {"user":"alice"}
>> Hello, alice

这回可以了，因为参数 'alice' 是认证用户。