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:
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: [] }
