Truffle 外部脚本

Truffle中，可以运行与合约交互的外部脚本。

命令

要运行外部脚本，可执行以下操作:

$ truffle exec <path/to/file.js>

在脚本中，可以启动合约，与合约进行交互等。可以把在truffle控制台中手动执行的操作，自动化执行。

文件结构

为了让外部脚本正确运行，Truffle要求它导出一个函数，该函数接受一个参数作为回调:

module.
exports = function
(callback) {
  // perform actions
}

可以在这个脚本中做任何想做的事情，只要在脚本完成时调用回调。回调函数接受一个错误作为它的第一个也是唯一的参数。

如果提供了错误，执行将停止，进程将返回一个非零的退出代码。

示例

在项目根目录下，创建script.js文件，内容如下：

module.
exports = function
(callback) {
  web3.
eth.getBlock
(
'latest'
).
then
(console.log)
}

该脚本将从所连接到的网络中，获取最新区块的信息。

执行脚本:

truffle exec script.js 

输出类似下面这样：

{ author: 
'0x596e8221a30bfe6e7eff67fee664a01c73ba3c56'
,
  difficulty: 
'340282366920938463463374607431768211454'
,
  extraData:
   
'0xde830205058f5061726974792d457468657265756d86312e33362e30826c69'
,
  gasLimit: 
'0x7a1200'
,
  gasUsed: 
'0x5e61'
,
  hash:
   
'0x225a1e0b13fd20396af60d049ce9bb94c2f3f7df06c7db260880b62c91997004'
,
  logsBloom:
   
'0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000'
,
  miner: 
'0x596e8221A30bFe6e7eFF67Fee664A01C73BA3C56'
,
  number: 13448162,
  parentHash:
   
'0x28d00fd7b66771130ed98de5073c7797ee293e7bee4b546793a4b79171555066'
,
  receiptsRoot:
   
'0x44617b5733ee59bde159af08ffd6edae36e0964f1724c333f3d1bef0808dee15'
,
  sealFields:
   [ 
'0x84175e95d7'
,
     
'0xb8412ed900e67f4a72925fb3b495efb3f547411f40d26e972cc0e8b2cf26e40cf84a545e0328199d4880b79c62670129a7db12ac58234bee0866c6376b46ab99e8a200'
 ],
  sha3Uncles:
   
'0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347'
,
  signature:
   
'2ed900e67f4a72925fb3b495efb3f547411f40d26e972cc0e8b2cf26e40cf84a545e0328199d4880b79c62670129a7db12ac58234bee0866c6376b46ab99e8a200'
,
  size: 797,
  stateRoot:
   
'0xe1bbaacfb950361bec70f4ad53a2605e1ac1d2ff0bfd913fe063dc6c5f3252a0'
,
  step: 
'392074711'
,
  timestamp: 1568298844,
  totalDifficulty: 
'4525729278306228651801195598997744985609807728'
,
  transactions:
   [ 
'0xf1ae41eac6b32419bc62a6cde9cab4b4ca244899a3d49b4a2461bcf94f504176'
 ],
  transactionsRoot:
   
'0xf08c8097ea946f84ce9594ce73648fc0f9f683adef105a5db00c5f1f15e61c2c'
,
  uncles: [] }