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Cryptocurrency Development Ethereum

How much gigabytes of storage can ethereum block chain handle? And what is the mechanism of distributing data all over the network?

I have read about block chain technology, I became interested in the fact that block chain works like a global distributed data-base and computer, which is amazing. However, that global computer for sure has a maximum memory storage capacity. I am asking for an estimate to that, even though I know it is too much. […]

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Cryptocurrency Development Ethereum

error while installing web3 in ubuntu

gyp WARN install got an error, rolling back install gyp WARN install got an error, rolling back install gyp ERR! configure error gyp ERR! stack Error: EACCES: permission denied, mkdir ‘/usr/lib/node_modules/we b3/node_modules/sha3/.node-gyp’ gyp ERR! System Linux 4.15.0-70-generic gyp ERR! command “/usr/bin/node” “/usr/lib/node_modules/npm/node_modules/node-gy p/bin/node-gyp.js” “rebuild” gyp ERR! cwd /usr/lib/node_modules/web3/node_modules/sha3 gyp ERR! node -v v12.13.1 gyp ERR! […]

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Android Cryptocurrency Development Ethereum Java

Web3J Java Android SendAsync Error

I am trying to interact with a method in my smart contract. The method is a simple method where you send a string value to a global variable. I end up using a SendAsync which appears to initially work, but the data isn’t being sent. The code I am trying to get working is as […]

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Cryptocurrency Development Ethereum

Web3 Ethereum log subscriptions – removed field?

I am trying to subscribe to Ethereum events (via Infura) but I’m a bit confused. I am following this documentation: https://web3js.readthedocs.io/en/v1.2.0/web3-eth-subscribe.html#subscribe-logs Here is my code: const ep = ‘wss://goerli.infura.io/ws/v3/<XXX>’ const Web3 = require(‘web3’) const address = ‘0xdf9E19BB25A200429511bE09892A9B6A4842d483’ const web3ws = new Web3( new Web3.providers.WebsocketProvider( ep ) ) web3ws.eth.subscribe( ‘logs’, { address: address, }, function( error, […]

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Cryptocurrency Development Ethereum

Calling contract method results in metamask error using ganache

I have a simple Vue form, that calls a method in an Ethereum contract. If I don’t provide a callback to my method, Metamask complains: Uncaught Error: The MetaMask Web3 object does not support synchronous methods like eth_sendTransaction without a callback parameter. So I added this. (even though I already have a callback in my […]

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Cryptocurrency Development Ethereum Windows

what kind of Hardware required for run geth private chain for ethereum on windows?

i need to help to find out what were the minimum hardware requirements needed for deploy the private chain on ethereum.

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Cryptocurrency Development Ethereum

Can I estimate the total gas limit of several dependent transactions?

Assume two dependent transactions A and B. Transaction B depends on transaction A and will fail if transaction A has failed. I would like to estimate the gas limit required for the success of both transactions if executed sequentially. Estimating gas for each transaction separately does not work. While there is no problem with estimating […]

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Cryptocurrency Development Ethereum

msg.sender problem for calling ERC20 token contract from another contract returns contract address

when i am going to call approve function of erc20 contract.log prints tokenOwner and tokenSpender address same which is contract address msg.sender returns contract address

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Cryptocurrency Development Ethereum

IPFS add and read file from node

I am currently playing around with IPFS in a docker container. I am able to send HTTP requests to the API using curl. I created a small text file with some text. I would like to add the file with the content to the node and retrieve it afterwards. So I did: curl -F file=test.txt […]

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Cryptocurrency Development Ethereum

How to pass bool from one function to another?

I want two functions to be checked true or false in one contract, that is, I get true in the calculations and want something. The code below shows my idea, but it does not work, I do not know why. function transfer_money(uint _Number) pure public returns (bool){ //code return true; } function transfer_property(bool) private { […]