Alright, let's tackle how to work with ERC20 tokens using PHP without any Node.js or JavaScript dependencies. All you need is a connection to an Ethereum node (like a local Geth/Parity instance or a service like Infura) and some PHP code to handle JSON-RPC calls and transaction signing. Here's a step-by-step breakdown of the most common operations:

• A running Ethereum node (or access to a hosted node service)
• Basic understanding of ERC20 standard method signatures
• For transaction signing: Install these PHP packages via Composer:

  composer require kornrunner/keccak simplito/elliptic-php
  

1. Fetch ERC20 Contract Basic Info (name, symbol, decimals, totalSupply) #

All compliant ERC20 contracts expose these read-only view functions. We'll use eth_call to query them without writing to the blockchain.

Example: Get Token Name #

<?php
$nodeUrl = "https://mainnet.infura.io/v3/YOUR_PROJECT_ID"; // Replace with your node URL
$contractAddress = "0x6B175474E89094C44Da98b954EedeAC495271d0F"; // DAI contract example

// ERC20 `name` method signature hash: 0x06fdde03
$payload = [
    "jsonrpc" => "2.0",
    "method" => "eth_call",
    "params" => [
        ["to" => $contractAddress, "data" => "0x06fdde03"],
        "latest"
    ],
    "id" => 1
];

// Send JSON-RPC request
$ch = curl_init($nodeUrl);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($payload));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, ["Content-Type: application/json"]);
$response = curl_exec($ch);
curl_close($ch);

// Parse and format result
$result = json_decode($response, true);
$tokenName = hex2bin(substr($result['result'], 2));
echo "Token Name: " . $tokenName . "\n";
?>

Other Common Info Methods #

• Symbol: Use method signature 0x95d89b41
• Decimals: Use method signature 0x313ce567 (returns a uint8, convert hex to decimal directly)
• Total Supply: Use method signature 0x18160ddd (returns uint256, convert hex to decimal then divide by decimals for human-readable value)

2. Check an Address's ERC20 Balance #

Use the balanceOf method to query how many tokens an address holds.

<?php
$nodeUrl = "https://mainnet.infura.io/v3/YOUR_PROJECT_ID";
$contractAddress = "0x6B175474E89094C44Da98b954EedeAC495271d0F";
$holderAddress = "0xYourTargetAddressHere";

// Encode address to 64-character hex (left-pad with zeros)
$encodedAddress = str_pad(substr($holderAddress, 2), 64, '0', STR_PAD_LEFT);
// `balanceOf` method signature + encoded address
$data = "0x70a08231" . $encodedAddress;

$payload = [
    "jsonrpc" => "2.0",
    "method" => "eth_call",
    "params" => [["to" => $contractAddress, "data" => $data], "latest"],
    "id" => 1
];

// Send request and parse
$ch = curl_init($nodeUrl);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($payload));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, ["Content-Type: application/json"]);
$response = curl_exec($ch);
curl_close($ch);

$result = json_decode($response, true);
$rawBalance = hexdec($result['result']);
$decimals = 18; // Replace with actual token decimals
$humanReadableBalance = $rawBalance / (10 ** $decimals);

echo "Balance: " . $humanReadableBalance . " DAI\n";
?>

3. Send ERC20 Tokens to Another Address #

This requires signing a transaction with your private key and broadcasting it to the network. It's a write operation, so you'll need to pay gas fees in ETH.

<?php
require_once 'vendor/autoload.php';

use Elliptic\EC;
use kornrunner\Keccak;

$nodeUrl = "https://mainnet.infura.io/v3/YOUR_PROJECT_ID";
$contractAddress = "0x6B175474E89094C44Da98b954EedeAC495271d0F";
$fromAddress = "0xYourWalletAddress";
$privateKey = "YOUR_PRIVATE_KEY_WITHOUT_0X_PREFIX";
$toAddress = "0xRecipientAddress";
$amount = 1 * (10 ** 18); // 1 DAI (adjust for token decimals)

// Step 1: Get transaction nonce
$payloadNonce = [
    "jsonrpc" => "2.0",
    "method" => "eth_getTransactionCount",
    "params" => [$fromAddress, "pending"],
    "id" => 1
];
$ch = curl_init($nodeUrl);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($payloadNonce));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, ["Content-Type: application/json"]);
$nonce = hexdec(json_decode(curl_exec($ch), true)['result']);

// Step 2: Get current gas price
$payloadGasPrice = ["jsonrpc" => "2.0", "method" => "eth_gasPrice", "params" => [], "id" => 1];
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($payloadGasPrice));
$gasPrice = hexdec(json_decode(curl_exec($ch), true)['result']);

// Step 3: Encode transfer data
$encodedTo = str_pad(substr($toAddress, 2), 64, '0', STR_PAD_LEFT);
$encodedAmount = str_pad(dechex($amount), 64, '0', STR_PAD_LEFT);
$data = "0xa9059cbb" . $encodedTo . $encodedAmount; // `transfer` method signature

// Step 4: Build transaction structure
$tx = [
    'nonce' => '0x' . dechex($nonce),
    'gasPrice' => '0x' . dechex($gasPrice),
    'gasLimit' => '0x' . dechex(210000), // Safe gas limit for ERC20 transfers
    'to' => $contractAddress,
    'value' => '0x0', // No ETH needed for ERC20 transfers
    'data' => $data,
    'chainId' => 1 // Mainnet=1, Goerli=5, Sepolia=11155111
];

// Step 5: Sign transaction
$ec = new EC('secp256k1');
$key = $ec->keyFromPrivate($privateKey, 'hex');
$txRLP = serializeTransaction($tx);
$hash = Keccak::hash(hex2bin($txRLP), 256);
$signature = $key->sign($hash, ['canonical' => true]);

$r = str_pad($signature->r->toString('hex'), 64, '0', STR_PAD_LEFT);
$s = str_pad($signature->s->toString('hex'), 64, '0', STR_PAD_LEFT);
$v = dechex($signature->recoveryParam + 35 + $tx['chainId'] * 2);
$signedTx = '0x' . $txRLP . $r . $s . $v;

// Step 6: Broadcast transaction
$payloadSendTx = [
    "jsonrpc" => "2.0",
    "method" => "eth_sendRawTransaction",
    "params" => [$signedTx],
    "id" => 1
];
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($payloadSendTx));
$response = json_decode(curl_exec($ch), true);
curl_close($ch);

if (isset($response['result'])) {
    echo "Transaction sent! Hash: " . $response['result'] . "\n";
} else {
    echo "Error: " . $response['error']['message'] . "\n";
}

// Helper: RLP serialize transaction
function serializeTransaction($tx) {
    $elements = [
        hex2bin(substr($tx['nonce'], 2)),
        hex2bin(substr($tx['gasPrice'], 2)),
        hex2bin(substr($tx['gasLimit'], 2)),
        hex2bin(substr($tx['to'], 2)),
        hex2bin(substr($tx['value'], 2)),
        hex2bin(substr($tx['data'], 2)),
        hex2bin(dechex($tx['chainId'])),
        hex2bin('00'),
        hex2bin('00')
    ];
    return rlpEncode($elements);
}

function rlpEncode($input) {
    if (is_string($input)) {
        if (strlen($input) == 1 && ord($input) < 0x80) return $input;
        return encodeLength(strlen($input), 0x80) . $input;
    } elseif (is_array($input)) {
        $output = '';
        foreach ($input as $item) $output .= rlpEncode($item);
        return encodeLength(strlen($output), 0xc0) . $output;
    }
    throw new Exception('Invalid input type');
}

function encodeLength($length, $offset) {
    if ($length < 0x3f) return chr($offset + $length);
    elseif ($length <= 0xff) return chr($offset + 0x80 + 1) . chr($length);
    elseif ($length <= 0xffff) return chr($offset + 0x80 + 2) . pack('n', $length);
    elseif ($length <= 0xffffffff) return chr($offset + 0x80 + 4) . pack('N', $length);
    throw new Exception('Length too large');
}
?>

内容的提问来源于stack exchange，提问作者Furqan Siddiqui