郑君的学习笔记

要比昨天进步一点点

发表于 分类于 本文字数： 29 阅读时长 ≈ 1 分钟

隔段时间没弄，忘了。先记下来。

配置文件 server.xml

发表于 更新于 分类于 本文字数： 103 阅读时长 ≈ 1 分钟

考完试了，坐地铁回家的时候，看完了这本书。
终极心法，果然化繁为简，返璞归真。简简单单的十句话，其内容如要运用的炉火纯青还需要多多修炼。
页数不多，200多页，推荐阅读。温故而知新，经常用来提醒自己也是不错的。

b7688dc1.png
阅读全文 »

发表于 更新于 分类于 本文字数： 471 阅读时长 ≈ 1 分钟

ubuntu now use systemd instead rc.local, and considered rc.local as a service
it is turned off by default.

user systemd run a service

sudo vi /etc/systemd/system/rc-local.service

添加一个Ubuntu的开机启动服务

可先将脚本复制或者软连接到 /etc/init.d/ 目录下
然后用：update-rc.d xxx defaults NN 命令(NN为启动顺序)，
将脚本添加到初始化执行的队列中去。注意如果脚本需要用到网络，则NN需设置一个比较大的数字，如99。

  1. 将你的启动脚本复制到 /etc/init.d目录下
     以下假设你的脚本文件名为 test。
  2. 设置脚本文件的权限
    sudo chmod 755 /etc/init.d/test
  3. 执行如下命令将脚本放到启动脚本中去：
    cd /etc/init.d
    sudo update-rc.d test defaults 95

卸载启动服务

cd /etc/init.d
sudo update-rc.d -f test remove

发表于 更新于 分类于 本文字数： 689 阅读时长 ≈ 1 分钟 
try:
       # Some Code.... 

except:
       # optional block
       # Handling of exception (if required)

else:
       # execute if no exception

finally:
      # Some code .....(always executed)
阅读全文 »

发表于 分类于 本文字数： 187 阅读时长 ≈ 1 分钟

Go语言中的内建函数new和make是两个用于内存分配的原语（allocation primitives）

new只分配内存，make用于slice，map，和channel的初始化。

返回一个局部变量的地址在Go语言中是绝对没有问题的；变量关联的存储在函数返回之后依然存在。
在Go语言中，如果一个局部变量在函数返回后仍然被使用，这个变量会从heap，而不是stack中分配内存。

发表于 更新于 分类于 本文字数： 7.8k 阅读时长 ≈ 7 分钟

this is a part of mining app. study record.

处理步骤

  1. create coinbase tx，Coinbasevalue, Height, pay2address(这里使用 public key 例如下面的： 030990d68d8b7eb4da4092c168b95d73207d91066747867844c8e21718b1d649d4)
    如果是 p2pk 则 scriptsig 是 <Public Key> OP_CHECKSIG
    如果是 p2pkh 则 scriptsig 是 OP_DUP OP_HASH160 <pubKeyHash> OP_EQUALVERIFY OP_CHECKSIG
  2. create merkle root
  3. create block header

use pay to public key:

ScriptPubKey=<Public Key> OP_CHECKSIG
ScriptSig= <Signature>

This transaction is a very simple use of the OP_CHECKSIG operator and validates the signature as being generated by the required private key and therefore having permission to unlock the specific transaction.

pay to public key hash:

<ScriptPubKey=OP_DUP OP_HASH160<Public KeyHash> OP_EQUALVERIFY OP_CHECKSIG
ScriptSig= <Signature><Public Key>

Pay-to-Script-Hash

scriptPubKey: OP_HASH160 <scriptHash> OP_EQUAL
scriptSig: ..signatures... <serialized script>

m-of-n multi-signature transaction:

scriptSig: 0 <sig1> ... <script>
script: OP_m <pubKey1> ... OP_n OP_CHECKMULTISIG
2dc740f3.png

coinbase tx json example

01000000 version
01 txIn count
0000000000000000000000000000000000000000000000000000000000000000 preTxHash
ffffffff pre Txout index
0f script length
0394292c02900100062f503253482 script
fffffffff sequence no
01 txOut count
00811b2c00000000 value
23 script length
    21 length
        030990d68d8b7eb4da4092c168b95d73207d91066747867844c8e21718b1d649d4
    ac OP_CHECKSIG
00000000 lockTime

{
    "hex": "01000000010000000000000000000000000000000000000000000000000000000000000000ffffffff0f0394292c02900100062f503253482fffffffff0100811b2c000000002321030990d68d8b7eb4da4092c168b95d73207d91066747867844c8e21718b1d649d4ac00000000",
    "txid": "58014cbcbfea738de577ec8301914b076e52594b525bbd2053ea1472fb6002ed",
    "version": 1,
    "locktime": 0,
    "vin": [
        {
            "coinbase": "0394292c02900100062f503253482f",
            "sequence": 4294967295
        }
    ],
    "vout": [
        {
            "value": 7.4,
            "n": 0,
            "scriptPubKey": {
                "asm": "030990d68d8b7eb4da4092c168b95d73207d91066747867844c8e21718b1d649d4 OP_CHECKSIG",
                "hex": "21030990d68d8b7eb4da4092c168b95d73207d91066747867844c8e21718b1d649d4ac",
                "reqSigs": 1,
                "type": "pubkey",
                "addresses": [
                    "AGpNqVQRiFqK4jQDjr1TswfFbqE1AvaMPz"
                ]
            }
        }
    ],
    "blockhash": "221f0f9e95266294285a9d39d3d3e6c103ef83736670e0aac60be652ec3af4fa",
    "confirmations": 2,
    "time": 1540343895,
    "blocktime": 1540343895
}

getblocktemplate

tyler@ubuntu16:~/Documents/primecoin-core-desktop-src$ ./src/primecoin-cli -rpcuser=user -rpcpassword=password getblocktemplate ‘{“capabilities”:[“coinbasetxn”, “coinbasevalue”,”coinbase/append”]}’

{
  "capabilities": [
    "proposal"
  ],
  "version": 536870912,
  "rules": [
  ],
  "vbavailable": {
  },
  "vbrequired": 0,
  "previousblockhash": "7849cb665dfe0929aa83c3da9b33b4d545aea12b5ce1dc0b4350d3919a8a27d6",
  "transactions": [
    {
      "data": "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",
      "txid": "d0e8ded3bdb951aca1d0deeabc20921638f16cddfb2c1977b231cfbbae733c7a",
      "hash": "d0e8ded3bdb951aca1d0deeabc20921638f16cddfb2c1977b231cfbbae733c7a",
      "depends": [
      ],
      "fee": 1000000,
      "sigops": 2,
      "weight": 1492
    },
    {
      "data": "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",
      "txid": "f9e6a8a7621a2ff0ee62a1fc49b6d97e85e9c7f52a1b1e6cbbbc49a81c20b95c",
      "hash": "f9e6a8a7621a2ff0ee62a1fc49b6d97e85e9c7f52a1b1e6cbbbc49a81c20b95c",
      "depends": [
      ],
      "fee": 2000000,
      "sigops": 1,
      "weight": 5496
    }
  ],
  "coinbaseaux": {
    "flags": ""
  },
  "coinbasevalue": 741000000,
  "longpollid": "7849cb665dfe0929aa83c3da9b33b4d545aea12b5ce1dc0b4350d3919a8a27d61412",
  "target": "000000000000000000000000000000000000000000208cbb0000000000000000",
  "mintime": 1539688199,
  "mutable": [
    "time",
    "transactions",
    "prevblock"
  ],
  "noncerange": "00000000ffffffff",
  "sigoplimit": 20000,
  "sizelimit": 1000000,
  "curtime": 1539689133,
  "bits": "0ba08cbb",
  "height": 2883478
}
tyler@ubuntu16:~/Documents/primecoin-core-desktop-src$

发表于 更新于 分类于 本文字数： 107 阅读时长 ≈ 1 分钟

go on…

是否是实例

if isinstance(it,PathCollection):
    it.remove()

是否是子类

issubclass(子类的名字, 父类的名字)
issubclass(Son, Parent)
True

发表于 更新于 分类于 本文字数： 9.9k 阅读时长 ≈ 9 分钟

use PyMongo

Getting a Database

# attribute style access
db = client.test_database

# dictionary style access
db = client['test-database']

Getting a Collection

collection = db.test_collection
collection = db['test-collection']
阅读全文 »

发表于 更新于 分类于 本文字数： 106 阅读时长 ≈ 1 分钟 
nohup python3 -u ./logChecker.py > logChecker.log 2>&1 & echo $! > pidfile.txt

kill -9 `cat pidfile.txt`

发表于 分类于 本文字数： 892 阅读时长 ≈ 1 分钟 
def sendEmail():
    # 第三方 SMTP 服务
    mail_host = "smtp.126.com"  # 设置服务器
    mail_user = "developios2016"  # 用户名
    mail_pass = "xxxx"  # 口令

    sender = 'developios2016@126.com'
    receivers = ['ascomtohom@126.com']  # 接收邮件，可设置为你的QQ邮箱或者其他邮箱

    message = MIMEText('WANR: xxx service maybe not working...', 'plain', 'utf-8')
    message['From'] = "developios2016@126.com"
    message['To'] = "ascomtohom@126.com"

    subject = '日志文件需要检查'
    message['Subject'] = Header(subject, 'utf-8')

    try:
        smtpObj = smtplib.SMTP()
        smtpObj.connect(mail_host, 25)  # 25 为 SMTP 端口号
        smtpObj.set_debuglevel(1)
        smtpObj.login(mail_user, mail_pass)
        smtpObj.sendmail(sender, receivers, message.as_string())
        smtpObj.quit()
        print("邮件发送成功")

    except smtplib.SMTPException:
        import traceback
        traceback.print_exc()
        errMsg = traceback.format_exc()

        print("Error: 无法发送邮件: " + errMsg)