a good tutorial on bitcoin script

https://blockgeeks.com/guides/bitcoin-script-guide-part-2/

when i run the bitcoin-cli, i got the error

error code: -28
error message:
Loading wallet...

In the protocol.h, the error meaning is:

RPC_IN_WARMUP                   = -28, //!< Client still warming up

i only changed the timestamp, when starting bitcoind, i got the error in debug.log

2018-05-24 07:50:44 mapAddressBook.size() = 1
2018-05-24 07:50:44 ERROR: ReadBlockFromDisk: Errors in block header at CBlockDiskPos(nFile=0, nPos=8)
2018-05-24 07:50:44 *** Failed to read block
2018-05-24 07:50:44 Error: Error: A fatal internal error occurred, see debug.log for details

It is solved by running bitcoind with -reindex

I read it.

i found a good link
https://bitcoin.stackexchange.com/questions/13122/scriptsig-coinbase-structure-of-the-genesis-block

i tried to print out the value in chainparams.cpp before assert in line 125. But value is printed out as 0x0,  and 0x103?


the warning is : format specifies type 'unsigned int' but the argument has type 'uint256'

Update: use this to print uint256. They are string.

Thank you. I would like to fork bitcoin code base.

In src/chainparams.cpp

Can i just change the timestamp and genesis output script, to create a customised bitcoin ?

To start a customised private bitcoin core blockchain, all i need to do is:

1) change the genesis block
2) change the timestamp of genesis block

is there anything else?

i see, the BCH address format has changed.

i kind of think that if i have privates keys on both BTC and BCH, then can replay protection stops me from mining the same transaction twice?

Thank you. Got the point.

I read this https://bitcoin.stackexchange.com/questions/57419/what-would-happen-if-you-send-bitcoin-btc-to-a-bitcoin-cash-bch-aka-bcc-add

I am not sure about the below:

After the implementation of reply protection, is it not possible to send bitcoin from BTC to BCH network , and vice versa?

Now OP_RETURN accepts up to 83 bytes, thank you very much for the link.

I refer to  Open assets spec.

OAP marker is 2 bytes,
version number is 2 bytes,
Asset quantity count (varint) minimum 1 byte.

It looks like we can fit 35 assets into one Open Asset transaction, it each asset quantity field takes up one byte. (for OP_RETURN limit of 40 bytes

In Bitcoin transaction, it can have multiple vin and vout. In vout, it contains bitcoin script. In bitcoin script, the OP_RETURN contains payload, the payload is used to store Open Asset asset id and quantity (see https://en.bitcoin.it/wiki/Colored_Coins#Open_Assets). The encoding is based on LEB128.

OP_RETURN has 40 byte limit. There is a request to increase the size limit to 80 bytes.

"Previously, a single transaction could send assets to up to 34 distinct recipients. After the change, it will be able to send assets to up to 74 recipients". (see http://blog.coinprism.com/2015/02/11/80-bytes-op-return/)

Is the limit of 34 distinct recipient because the header of Open Asset is 6 bytes, so 40-6 = 34 ?

Thanks.

i have a simple question.

Bitcoin core is a reference implementation of bitcoin. Can we run other implementation of bitcoin , such as in Python, Java, or Ruby , as bitcoin node on mainnet ?

I suppose we can.

I do not think blockchain smart contract can offer security, as all info is available in the public.

I often receive kind support from this forum.

In return, I write a simple tutorial on Smart contract with Ethereum ERC20 token. Please take a look and if there is any mistakes in it, you are welcome to criticize.

http://embedded-design-vic.blogspot.com/2018/03/smart-contract-with-ethereum-erc20-token.html

Thank you. The setup of bitcoin core regtest network  on two nodes on two  different machine, is working now. Have to add rpcport entry. The machine A bitcoin.conf

`regtest=1
server=1
port=18332
rpcport = 18333
rpcuser=bitcoinrpc
rpcpassword=password
rpcallowip=0.0.0.0/0`

and machine B bitcoin.conf
`regtest = 1
server = 1
port=18443
rpcport = 18444
connect = 11.0.0.110:18332
rpcuser=bitcoinrpc
rpcpassword=password`

The bitcoin.conf was setup already.  As below:

regtest = 1
server = 1
port=18443
connect = 12.0.0.111:18332
rpcuser=bitcoinrpc
rpcpassword=password

The port is set to 18443. Why is that bitcoind trying to bind to port 18332 ?

"2018-03-15 01:31:32 Binding RPC on address ::1 port 18332 failed.
2018-03-15 01:31:32 Binding RPC on address 127.0.0.1 port 18332 failed."

I can connect regtest on two nodes on the same machine.

However, i cannot connect regtest on two nodes on different machine.

I use bitcoin v0.15.1 , setup the bitcoind to connect to remote host in bitcoin.conf 
`connect = 11.0.0.110:18332`
as well as command line
 `-connect=11.0.0.110:18332`

The bitcoind is still trying to connect to
`2018-03-15 01:31:32 Binding RPC on address ::1 port 18332 failed.
2018-03-15 01:31:32 Binding RPC on address 127.0.0.1 port 18332 failed.`

Anyone knows why ?

I want to run a test program on ethereum code. i have installed ganache-cli. However, i could not run the test. The error is shown as below.

viiic@ubuntu:~/Downloads/project/inbox$ sudo npm install -g ganache-cli
npm WARN deprecated babel-preset-es2015@6.24.1: 🙌  Thanks for using Babel: we recommend using babel-preset-env now: please read babeljs.io/env to update!
npm WARN deprecated nomnom@1.8.1: Package no longer supported. Contact support@npmjs.com for more info.
/usr/bin/ganache-cli -> /usr/lib/node_modules/ganache-cli/build/cli.node.js
npm WARN webpack-cli@2.0.12 requires a peer of webpack@^4.0.0 but none is installed. You must install peer dependencies yourself.

+ ganache-cli@6.1.0
updated 2 packages in 10.897s

viiic@ubuntu:~/Downloads/project/inbox$ sudo npm run test

> inbox@1.0.0 test /home/vic/Downloads/project/inbox
> mocha

module.js:540
    throw err;
    ^

Error: Cannot find module 'ganache-cli'
    at Function.Module._resolveFilename (module.js:538:15)
    at Function.Module._load (module.js:468:25)
    at Module.require (module.js:587:17)
    at require (internal/module.js:11:18)
    at Object.<anonymous> (/home/vic/Downloads/project/inbox/test/Inbox.test.js:2:18)
    at Module._compile (module.js:643:30)
    at Object.Module._extensions..js (module.js:654:10)
    at Module.load (module.js:556:32)
    at tryModuleLoad (module.js:499:12)
    at Function.Module._load (module.js:491:3)
    at Module.require (module.js:587:17)
    at require (internal/module.js:11:18)
    at /home/vic/Downloads/project/inbox/node_modules/mocha/lib/mocha.js:231:27
    at Array.forEach (<anonymous>)
    at Mocha.loadFiles (/home/vic/Downloads/project/inbox/node_modules/mocha/lib/mocha.js:228:14)
    at Mocha.run (/home/vic/Downloads/project/inbox/node_modules/mocha/lib/mocha.js:536:10)
    at Object.<anonymous> (/home/vic/Downloads/project/inbox/node_modules/mocha/bin/_mocha:582:18)
    at Module._compile (module.js:643:30)
    at Object.Module._extensions..js (module.js:654:10)
    at Module.load (module.js:556:32)
    at tryModuleLoad (module.js:499:12)
    at Function.Module._load (module.js:491:3)
    at Function.Module.runMain (module.js:684:10)
    at startup (bootstrap_node.js:187:16)
    at bootstrap_node.js:608:3
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! inbox@1.0.0 test: `mocha`
npm ERR! Exit status 1