61

Mist DApp Browser Mist is the browser for decentralized web apps. What Mozilla Firefox or Google Chrome are for the Web 2.0, the Mist Browser will be for the Web 3.0 (which will be decentralized). Mist is still in heavy development (for instance it's not recommended to visit untrusted DApps until the full security audit is done). You can find the releases ...


46

First, payable is a modifier that can be added to a function. What you are most likely misinterpreting is a use case like: function () public payable {} It's impossible to have payable() as a function name as it is a reserved keyword. You may use payable only in addition to existing functions like: function deposit() payable {} function register(address ...


26

geth (used in the Ethereum Wallet) saves its internal states for the main network in the chaindata directory. You can find it in the: ~/.ethereum on Linux ~/Library/Ethereum on OS X ~/AppData/Roaming/Ethereum on Windows In these directories, there are: chaindata: production blockchain testnet: test blockchain keystore: your keys


21

The default subdirectory where your Ethereum data files are stored on a Mac is ~/Library/Ethereum . Within this subdirectory, your blockchain data is stored in the subdirectory chaindata, i.e., ~/Library/Ethereum/chaindata . Let's assume that your new drive is mounted on ~/Volumes/Drive2 for this example. Here are 3 alternatives, the first being the ...


18

Not true in the OP's case, but a cause of this problem is missing a semi-colon from the first line specifiying compiler version, e.g.: pragma solidity ^0.4.6;


18

If you are using the new web3.js 1.0.0-beta, then try this (all the syntax has changed, sigh). Tested with testrpc -d. > var Web3 = require('web3'); > var web3 = new Web3('http://localhost:8545'); > web3.version; '1.0.0-beta.11' > web3.eth.getAccounts().then(console.log); Promise { ... } > [ '0x90F8bf6A479f320ead074411a4B0e7944Ea8c9C1', '...


16

Truffle is a development environment, testing framework and asset pipeline for Ethereum, aiming to make life as an Ethereum developer easier. With Truffle, you get: Built-in smart contract compilation, linking, deployment and binary management. Automated contract testing with Mocha and Chai. Configurable build pipeline with support for custom build ...


15

In Truffle, constructor params go in /migrations. So, something like: deployer.deploy(User, "foo"); User.deployed() will be a User contract that was deployed with _name="foo"


14

I used this code to recover the private key from account address and password. firstly, install Keythereum: npm install keythereum Keythereum is a JavaScript tool to generate, import and export Ethereum keys. read the documentation: GitHub Link and this is my code: var keythereum = require("keythereum"); var datadir = "/home/super/.ethereum/rinkeby"; var ...


13

Trashcan Click on the contract you want to delete. On the contract page, hover over the name. You see a trashcan. Click on this to remove the contract. EDIT: As noted by @Vesa, you may not be able to access the contract as Mist freezes. What OS and version of Mist are you using. I have had some problems with Ethereum Wallet 0.7.2 that are not present in 0....


13

Ethereum-Wallet comes packaged with geth.exe which is the Ethereum blockchain node software. Here is the listing from the Ethereum-Wallet-win64-0-5-2.zip file downloaded from https://github.com/ethereum/mist/releases : $ unzip -tv Ethereum-Wallet-win64-0-5-2.zip | grep geth testing: Ethereum-Wallet-win64-0-5-2/resources/node/geth/ OK testing: Ethereum-...


13

Use address payable public receiver; in declaration for the addresses you are looking to transfer Ether in contract. As per the solidity documentation: The address type comes in two flavours, which are largely identical: address: Holds a 20 byte value (size of an Ethereum address). address payable: Same as address, but with the additional ...


12

The address is derived from a random private key. The client does not check if it has been previously used because the chance of that happening is nearly zero.


9

You can deploy a modified contract, but it will be deployed to a new address. Basically, it will be another contract. As an analogy, you can think of your deployed contract like a program that you have burned to a CD(ROM). You can modify your source code and burn it to another CD, but you're not able to modify directly what has already been burned/...


9

This one worked straight away for me: $ /Applications/Mist.app/Contents/MacOS/Mist --rpc http://localhost:8545


9

How to get private key from account address and password? One of the founding notions of public/private key cryptography is that what you are describing should be impossible. No cryptographic system in existence would be trusted if you could reverse engineer the private key from the public address. So not only is it impossible, but it should be impossible. ...


9

approve(address _spender, uint _value) returns (bool success) {...} This function is just being used to make an entry to the allowance array when another contract want to spend some tokens. _ spender is the address of the contract which is going to use it. _value denotes the number of tokens to be spend.approveAndCall(address _spender, uint _value, bytes ...


9

throw was deprecated in solidity version 0.4.13. You need to replace each line that says if(condition) throw; with require(opposite of condition);. For example: if (_to == 0x0) throw; becomes require(_to != 0x0); throw is used a number of times throughout your code, you need to change every one


8

Missing dependencies? First of all try installing meteorjs and electron. These dependencies should be included in the binaries but some operating systems behave weird. Is your GPU blacklisted? Try to run mist or ethereum-wallet with the --ignore-gpu-blacklist flag. This might cause the client to crash. But if it does not crash, you probably run a working ...


8

I think the most important phrase in your question is 'what is the likelihood'. The other answers are correct in determining that there is a 1 in 2^160 likelihood of finding a collision with 100% probability. Due to the birthday paradox, cryptographers give a hash function with output bitlength 160 a bitwise security rating of 80. This is because with 2^80 ...


8

New versions of Ethereum-Wallet (aka: Mist) will do a fast sync the first time they startup. However, if you quit Ethereum-Wallet before it is done syncing it will switch to slow-sync from then on because fast sync can only be done on first launch. Fast sync is much faster than normal sync, it should only take a couple hours on a modern internet connection ...


8

Ropsten (or Görli/Kovan etc) test network is the right choice for you, when you are still testing. I simply install the Chrome Metamask plugin. It communicates with nodes on a remote server (so no downloading, though Ropsten is not as big as the main chain anyway) Create a new account after switching to the Ropsten network. Then you can use the Online ...


7

TL;DR: it's computational too expensive to monitor incoming transactions for accounts on the Ethereum blockchain. linagee asked the developer of Mist: Its because you'd need to traverse the entire blockchain which is very computationally intensive. Ethereum blockchain explorer websites do it, because they are fine with the extra processing load. ...


7

You can do this by creating a contract and having the contract interact with the various token contracts. One method would be to create your contract, then transfer ownership of your balance on each token to the contract. Untested example (for illustrative purposes only, don't use this as is): pragma solidity ^0.4.6; contract ERC20API { function ...


7

If the ether is already in the contract and you do not have the functionality to transfer ether already implemented in it, the ether will be forever in the contract. A simple contract that receives ether and allows for transferring is shown below. Only the person that deploys the contract will be able to transfer the ether. pragma solidity ^0.4.24; ...


6

Using geth and most other implementations you can point the application to the desired data location. In geth: geth --datadir "/home/youruser/.ethereum" In your case point it to the mount point of your external drive. See the geth command line options


6

I'm not familiar with that executable, and in fact I'm not even sure that's eth per say, so I think you think you use eth while you're not eth -h will display at the end : General Options: -d,--db-path,--datadir <path> Load database from path (default: /home/YOURUSER/.ethereum).


6

The DAO address indeed now owns 100 (110?) tokens. This is most likely due to someone using the data field when sending a transaction to send the tokens to The DAO address. Basically, there is a feature that is meant for users who want to send from an exchange. As you (hopefully) know, you cannot send directly from an exchange as the DAO Tokens will be sent ...


6

Since you're running two nodes on two different machines, you need to mention the IP address of the node while connecting through addPeer(enodeURI). Detailed walkthrough: You need to have the same genesis file in every machine you wish to start a node. All the nodes should have the same --networkid The --rpcport and --port should be different for every ...


6

Firstly, great that you are learning more about DApps, it's always great to see the community growing. However, you do have some misunderstanding about the way the DApps should be designed, so I'll try to point you in the helpful direction. Technology Used: Ruby on Rails (Back-End), React (Front end), Solidity(Smart Contract) As pointed in this answer: ...


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