Parse Blockchain Block Header

block.php

<?php

function parse_block($block) {
    $return = [
    'version' => null,
    'prevBlockHash' => null,
    'merkleRoot' => null,
    'timestamp' => null,
    'target' => null,
    'nonce' => null
    ];
    // first 4 bytes (8 hex bytes) are the version
    $version = pack("H*", strrev(substr($block, 0, 8)));
    $return['version'] = unpack("l", $version)[1];
    
    // next 32 bytes (64 hex bytes) we will have the previous block hash
    $prevBlockHash = strrev(substr($block, 8, 64));
    for ($i = 0; $i < strlen($prevBlockHash); $i += 2)
        $return['prevBlockHash'] .= $prevBlockHash[$i + 1] . $prevBlockHash[$i];
    
    // next 32 bytes we will have the merkle root of the txes on this block
    $merkleRoot = strrev(substr($block, 72, 64));
    for ($i = 0; $i < strlen($merkleRoot); $i += 2)
        $return['merkleRoot'] .= $merkleRoot[$i + 1] . $merkleRoot[$i];
        
    // next 4 bytes we will have an uint32_t with the timestamp
    $return['timestamp'] = unpack("V", pack("H*", substr($block, 136, 8)))[1];
    
    // next 4 bytes, another uint32_t with the block threshould
    $return['target'] = unpack("V", pack("H*", substr($block, 144, 8)))[1];
    
    // finally, the nonce
    $return['nonce'] = unpack("V", pack("H*", substr($block, 152, 8)))[1];
    
    return $return;
}

var_dump( parse_block("000000204f5ce6ff5b197f40502d00473b3d5272ca2ff7049fda120000000000000000009c7f1fb04cd7e220f7351f6b0c11cb7dc347d0380bbd1e7ad329a56138772b941139a65d5ca3151706190dc2"));