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This article tells you the relevant knowledge points about the interaction between PHP and Ethereum clients. It has certain reference value. Friends in need can follow and learn.
php communicates with ethereum rpc server
1. Json RPC
Json RPC is based on json's remote procedure call, this explanation is relatively abstract. To put it simply, it is to post a json format data and call the method in the rpc server. The json format is fixed. In general, there are the following items:
{ "method": "", "params": [], "id": idNumber }
method: method name
params: parameter list
id: unique identifier for the procedure call No.
##2. Build a Json RPC client
<?php class jsonRPCClient { /** * Debug state * * @var boolean */ private $debug; /** * The server URL * * @var string */ private $url; /** * The request id * * @var integer */ private $id; /** * If true, notifications are performed instead of requests * * @var boolean */ private $notification = false; /** * Takes the connection parameters * * @param string $url * @param boolean $debug */ public function __construct($url,$debug = false) { // server URL $this->url = $url; // proxy empty($proxy) ? $this->proxy = '' : $this->proxy = $proxy; // debug state empty($debug) ? $this->debug = false : $this->debug = true; // message id $this->id = 1; } /** * Sets the notification state of the object. In this state, notifications are performed, instead of requests. * * @param boolean $notification */ public function setRPCNotification($notification) { empty($notification) ? $this->notification = false : $this->notification = true; } /** * Performs a jsonRCP request and gets the results as an array * * @param string $method * @param array $params * @return array */ public function __call($method,$params) { // check if (!is_scalar($method)) { throw new Exception('Method name has no scalar value'); } // check if (is_array($params)) { // no keys $params = $params[0]; } else { throw new Exception('Params must be given as array'); } // sets notification or request task if ($this->notification) { $currentId = NULL; } else { $currentId = $this->id; } // prepares the request $request = array( 'method' => $method, 'params' => $params, 'id' => $currentId ); $request = json_encode($request); $this->debug && $this->debug.='***** Request *****'."\n".$request."\n".'***** End Of request *****'."\n\n"; // performs the HTTP POST $opts = array ('http' => array ( 'method' => 'POST', 'header' => 'Content-type: application/json', 'content' => $request )); $context = stream_context_create($opts); if ($fp = fopen($this->url, 'r', false, $context)) { $response = ''; while($row = fgets($fp)) { $response.= trim($row)."\n"; } $this->debug && $this->debug.='***** Server response *****'."\n".$response.'***** End of server response *****'."\n"; $response = json_decode($response,true); } else { throw new Exception('Unable to connect to '.$this->url); } // debug output if ($this->debug) { echo nl2br($debug); } // final checks and return if (!$this->notification) { // check if ($response['id'] != $currentId) { throw new Exception('Incorrect response id (request id: '.$currentId.', response id: '.$response['id'].')'); } if (!is_null($response['error'])) { throw new Exception('Request error: '. var_export($response['error'], true)); } return $response['result']; } else { return true; } } } ?>Relatively simple code , if you are lazy, just take it and use it. You can also go to packagist.org to find an rpc client yourself.
3. Two types of methods for calling RPC
{ "method": "eth_accounts", "params": [], "id": 1 }RPC Server's own method The listIt is relatively simple to call the built-in method. Refer to the above link, most of them have examples.Contract method call json format
function balanceOf(address _owner) public view returns (uint256 balance)Extract the function prototype:
balanceOf(address)in geth Run the command under the console:
web3.sha3("balanceOf(address)").substring(0, 10)Get the function hash "0x70a08231" Assume that the address to be queried is address _owner = "0x38aabef4cd283ccd5091298dedc88d27c5ec5750", then Remove the "0x" in front and add 24 zeros on the left (the general address length is 42 bits, and it is 40 bits after removing the '0x') to form a 64-bit hexadecimal parameter.Finally obtained The parameter is "0x70a082310000000000000000000000038aabef4cd283ccd5091298dedc88d27c5ec5750" Assume that our contract address is "0xaeab4084194B2a425096fb583Fbcd67385210ac 3".Then the final json data will be:
{ "method": "eth_call", "params": [{"from": "0x38aabef4cd283ccd5091298dedc88d27c5ec5750", "to": "0xaeab4084194B2a425096fb583Fbcd67385210ac3", "data": "0x70a0823100000000000000000000000038aabef4cd283ccd5091298dedc88d27c5ec5750"}, "latest"], "id": 1 }Send the above json data to the server in post mode, then you can call the contract method "balanceOf" to query the token balance in the given address.You must also be new when calling other methods in the contract Following the above method, let's analyze the transfer method again to deepen our impression: First, look at the function implementation in the code:
function transfer(address _to, uint256 _value) public returns (bool)Secondly, extract the function prototype:
transfer(address,uint256) //注意逗号后面不能有空格Again, run the sha3 function on the console:
web3.sha3("transfer(address,uint256)").substring(0, 10)Get the function hash "0xa9059cbb"The first parameter assumes address _to = "0x38aabef4cd283ccd5091298dedc88d27c5ec5750", then go to "0x" and add zeros to 64 bits.
{ "method": "eth_call", "params": [{"from": "0x38aabef4cd283ccd5091298dedc88d27c5ec5750", "to": "0xaeab4084194B2a425096fb583Fbcd67385210ac3", "data": "0xa9059cbb00000000000000000000000038aabef4cd283ccd5091298dedc88d27c5ec5750000000000000000000000000000000000000000000000000000000000000ab00"}, "latest"], "id": 1 }
##from transferor address
Build an Ethereum RPC client
<?php require './jsonRPCClient.php'; //php自带的dechex无法把大整型转换为十六进制 function bc_dechex($decimal) { $result = []; while ($decimal != 0) { $mod = $decimal % 16; $decimal = floor($decimal / 16); array_push($result, dechex($mod)); } return join(array_reverse($result)); } class EthereumRPCClient { public static $client = null; //布署合约的账户地址 const COINBASE = '0x38aabef4cd283ccd5091298dedc88d27c5ec5750'; //合约地址 const CONTRACT = '0xaeab4084194B2a425096fb583Fbcd67385210ac3'; public static function __callStatic($method, $params) { $params = count($params) < 1 ? [] : $params[0]; try { if (is_null(self::$client)) { self::$client = new jsonRPCClient('http://127.0.0.1:8545', true); } } catch (\Exception $e) { echo $e->getMessage(); } return call_user_func([self::$client, $method], $params); } public static function getBalance($address) { $method_hash = '0x70a08231'; $method_param1_hex = str_pad(substr($address, 2), 64, '0', STR_PAD_LEFT); $data = $method_hash . $method_param1_hex; $params = ['from' => $address, 'to' => self::CONTRACT, 'data' => $data]; $total_balance = self::eth_call([$params, "latest"]); return hexdec($total_balance) / (pow(10, 18)); } public static function transfer($to, $value) { self::personal_unlockAccount([self::COINBASE, "123456", 3600]); $value = bcpow(10, 18) * $value; $method_hash = '0xa9059cbb'; $method_param1_hex =str_pad(substr($to, 2), 64, '0', STR_PAD_LEFT); $method_param2_hex = str_pad(strval(bc_dechex($value)), 64, '0', STR_PAD_LEFT); $data = $method_hash . $method_param1_hex . $method_param2_hex; $params = ['from' => self::COINBASE, 'to' => self::CONTRACT, 'data' => $data]; return self::eth_sendTransaction([$params]); } }
The code is relatively simple, there are a few points to note:
##transfer function The value unit is very small, 10 ^ -18, so if you want to transfer 1,000 times, you actually need to multiply by 10 to the 18th power, where 18 is decimals. Because Point 1, bcpow should be used instead of the pow function.<?php var_dump(EthereumRPCClient::personal_newAccount(['password'])); var_dump(EthereumRPCClient::personal_unlockAccount([EthereumRPCClient::COINBASE, "password", 3600]); var_dump(EthereumRPCClient::getBalance("0x...."));
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