Questions tagged [smart-contract]
Anything related to decentralized application (dApp) development, concepts, and possibilities with smart contracts, or technical questions for the development of smart contracts.
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What is the eosio private key when running on local?
I was trying to test the smart contract I created in my local but I am currently blocked as I can't create a new account. As per EOS documentation, I used the command below to create a new account:
...
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Generate random numbers in the smart contract
I am writing smart contract and stucked on this line :
int p = 0;
p = (rand() % 997);
This is giving error
error: use of undeclared identifier 'rand'
I do search and got some reference links but ...
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Is it possible to deploy contract via curl?
Using command line i am deploying smart contract "eosio.token".
cleos -u http://127.0.0.1:8888 set contract eosio.token ./eosio.token -p eosio.token
Is it possible to deploy smart contract using ...
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Alternative to std::ifstream for eosio contract
I'm watching for an alternative to "std::ifstream" because "#include " can't include as header in a contract.
My code is:
std::istream& operator>>(std::istream& str, ...
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Deploy Contract from browser using eosjs
so I would like to deploy an EOS contract using eosjs. I encountered several problems (especially with converting the .abi and .wasm files).
All the examples either use node (so fs is available) or an ...
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How to solve !action_type.empty(): Unknown action hi in contract hello?
I am following this doc: https://developers.eos.io/eosio-home/docs/your-first-contract.
This is the hello.cpp contract code which is successfully deployed:
#include <eosiolib/eosio.hpp>
#...
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2
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A possible alternative sign in/login process instead of firebase auth / amazon cognito using an eos contract?
I had the the idea of a secure alternative login process using an EOS smart contract instead of firebase or Amazon cognito. I would like to know if something like this feasible?
My idea is somewhat ...
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How to use recover function in crypto.hpp to verify signature and public key
I want to sign some data in client using eosjs-ecc.sign() and result is a string like "SIG_K1_KcTmv..." I want to use the
recover_key(const checksum256* digest, const char* sig, size_t siglen, char*...
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Token transfer missing_auth_exception
{
"code":500,"message":"Internal Service Error",
"error":{"code":3090004,"name":"missing_auth_exception",
"what":"Missing required authority",
"details":[{"message":"missing authority of thomsoimj21","...
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Transfer tokens inside a smart contract from an account to another account
I need to write a simple function that would send tokens using a different account action. Exactly the same situation as in these questions: one and two
But I have to use not eosio.token contract but ...
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2
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How do tokens that pay dividends work?
If a token is created as a standard eosio.token, what are some approaches for paying out dividends to token holders?
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Execute get_supply function within contract
I want to execute get_supply from currency.hpp.
Here is the definition:
asset get_supply( symbol_name symbol )const {
accounts t( _contract, symbol );
return t.get(symbol).balance;
...
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Is there a way to mark accounts like give an account a property value?
Let's say I'm making a game character and each eos account is a unique character. Is there a way to mark an account with different properties like strength, speed, durability, etc....
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How to setup action access control?
Let's say contract-A has a couple of actions defined. If access to one of the contract-A's action, say action1(), needs to be controlled on account basis, how to do it?
For example, only few ...
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Smart contract compiling loop
When I try to compile the contract the process creates an infinite loop. Here is my code, please help!
kjnjrwsyxszg.cpp
#include "kjnjrwsyxszg.hpp"
void kjnjrwsyxszg::create(const name owner,...
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Immutable smart contract
In EOS, smart contracts can be updated by the account owner.
This could be a problem for certain applications in finance. For instance, if I want to deploy a token, the transfer function should be non-...
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What should I do to specify an optional action parameter for cleos?
I wrote an action that has an optional parameter, as something like:
[[eosio::action]] void foo(..., const std::optional<name>& recipient);
Then in the generated .abi, it is represented as:...
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Why does using available_primary_key() as scope for a table result in this behaviour?
Scenario:
Two tables, each using uint64_t as a primary key
Table A rows need to reference rows in Table B
Why? Relational database data duplication reasoning etc etc
Both table's primary keys are ...
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EOSIO failed when using Smart Contract Action with updated Parameters
I deploy a Smart Contract first time and the action becomes usable as it's supposed to be, but when Action's parameters is updated with a new one between existing p1 and p2 old parameters (result: p1, ...
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Execution order of actions
I want to implement "continious minting" which means first I should call issue, and only then transfer.
My contract has a functionality of eosio.token . I call create to create my token with ...
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How to get name of account which is processing action recent in contract?
I need to authorize with admin table of contract. but I could not account name which is processing action of contract. Let me know about any eos function to get account name, if anyone know well.
...
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I have doubts about intercontract communication
I have read that:
In order to call an inline action, that is to call an action of contract A from contract B, there is a need to set some special permission. In this case, the Ram payer for the ...
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Profiling EOS.IO smart contract code
What's the best way for profiling the code of an EOS.IO smart contract?
I'd like to know what percentage of the CPU time is spent on executing each function\line (including multi index table function ...
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Does EOSIO Have Native Contracts Built-Into Protocol Layer?
On the Bitshares site I read https://bitshares.org/technology/industrial-performance-scalability
Based upon the lessons we learn from LMAX, we know that a virtual machine for a blockchain should be ...
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Eos-sharp jungle Error 3090003 when trying to call external smart contract
I’m trying to achieve something quite simple.
I try to call eosio.token transfer from one of my smartContract (lomtaxjungle dopurchase), but after severals days i still don’t manage to do it.
From ...
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Ico smart contract update
I would like to update this code, because it is CDT 1.2.
I would like to update for CDT 1.5 or CDT 1.6.
What do I need to change?
#include <eosiolib/eosio.hpp>
#include <eosiolib/currency....
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Declare custom structs
I am trying to create a custom struct called Student in a contract. Where do I declare or define the struct? I tried to define it in the abi file, but the file was over written when I compile the ...
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Get table row count or property from the last row
As I said I need to get the count of rows in a table. Preferly via rpc with http plugin or from a new action inside the Smart Contract.
This is my Smart Contract:
#include <eosio/eosio.hpp>
...
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EOS Blockchain How to free up RAM or optimize Smartcontract
We have developed a small program that uses the EOS blockchain and we are storing some of our data in an EOS smart contract. Together with a UUID we are storing the object status. Our goal is to have ...
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Cleos set contract, Internal Service error timeout_exception
I am running EOS on my laptop.
If I execute the "cleos set contract" command and the contract size is more than 200kb, I get an error:
error 2021-06-01T17:44:30.084 http-1 http_plugin.cpp:...
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2
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How to free up used memory
I have this picture for my account
memory:
quota: 220.4 KiB used: 207.5 KiB
I want to free the memory and sellram. Is it possible, and if yes, how to do that?
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What is the maximum size of smart contract?
I'm developing a smart contract and yesterday I couldn't deploy it into testnet with error:
root@698a02be20d9:/# cleos --verbose set contract myaccount /work/mycontract -p myaccount@active
Reading ...
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Contract transaction cannot be found after i get result of pushSignedTransaction
I've send a contract trans on mainnet use eosjs@20, and i've tried for 4 times, every time i get a trans result, but all of them seemed been drop, i cannot find them on explorer or on chain, can any ...
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Duplicate symbol WASM compilation error when using header/hpp for contract
I'm looking to use a hpp file as an interface for multiple contracts. I've created a test contract and receiving a WASM compilation error. I based the test contract on the format used by eosio.token....
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2
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1
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Reclaim RAM for dApp that creates an account and transfers funds
A dApp that creates a new account and transfers EOS to that account will have to 'pay' for 240 bytes of RAM for the new balance object on the new account. When the new account transfers some funds, ...
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Send same action as `cleos push action hello hi ...` in smart contract tutorial
I finished smart contract tutorial, and it worked well.
Now I'm trying to send same action as cleos push action hello hi '["bob"]' -p user@active in tutorial by using RPC API, cause need to implement ...
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ABI File To Communicate With Unity Game Engine
So I'm building an HTML5 Unity game that will run in an internet browser attached to the Interplanetary File System. Unity allows for JSON files to be used to send and receive binary data between ...
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What is the reason for appearance of "misaligned reference"?
I have written a big contract with a lot of template functions and can find a place, which causes
2018-11-19T08:14:11.454 thread-0 binaryen.hpp:608 translate_one ] misaligned ...
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How check deferred transaction logs on EOS jungle testnet?
As I working on jungle testnet and perform a 1 deferred transaction with some scheduled automatic time. But I failed to see transaction logs on the jungle testnet.
Can any please guide me here with ...
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Can a smart contract perform actions on a scheduled delay indefinitely?
I am pretty new to working with EOS, so please excuse my ignorance and improper terminology.
I am trying to repeatedly excecute a given action on a set time delay. For example, trying to submit a ...
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WAX - Signature error : "Message: transaction declares authority, but does not have signatures for it."
I'm trying to send a transaction from my react frontend to local chain, I have signed in wax cloud wallet and made a transaction. But at last I met this signature error.
"Message: transaction ...
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Caller of action detail in code
I need to check Account of caller action ,as in ethereum we have a concept of msg.sender to get the caller eth_address, similar is there a way to get caller of action details in EOS.
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Is there way to retrieve auto incremented primary key after submission of transaction?
I'm working on sample dApp application to understand the working of multi_index table in EOS smart contract.
I have defined two multi_index table. The primary key of table1 is auto incremented using "...
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how can my on_notify trigger calls contract actions (permisson issue)
I need to write a contract that automaticaly mint nfts when tokens are being transferred.
So i have my :
[[eosio::on_notify("*::transfer")]]
void logdeposit(name from,name destination, ...
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What is the difference between transaction.send and action.send?
I found that there are two types of transfer I can use in an EOS contract, but I don't know what is the difference between them.
1st type
2nd type
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How to check in my contract the incomming amount?
I would like to check in my contract the incomming amount.
I tried these:
void mycontract(name from, name to, eosio::asset quantity, std::string memo){
check( quantity.amount > 50, "must ...
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How to Define and use Array of Strings in Struct?
My Sample Struct and its method
// Department Table
struct [[eosio::table]] department_info {
uint32_t ID;
std::string deptname;
std::string deptcode;
std::...
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How to deploy a smart contract on the mainnet?
I created and tested my smart contract on testnet.
Now I want to deploy it on mainnet, I assume I have to purchase some EOS token and buy ram, cpu and net... I can't find anything in the docs about ...
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How to access data inside multi-index table when using 2D vector / 2D array?
What is going on? :D I write data, but cannot find it after I write it.
The following code successfully emplaces the row into the multi-index table:
See specifically the vector<vector <...
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Use UUID as primary key in multi_index
How can I use a uuid as the primary.
struct [[eosio::table]] blackboxdata {
name user;
std::string uuid;
std::string hash;
std::string sqlrequest;
uint64_t ...
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