Online PHP editor | output for RkV43

<?php const INT_SIGNED = 1; const INT_LE = 2; function is32Bit() { $test = unpack('N', "\xFF\xFF\xFF\xFF"); return $test[1] === -1; } function unpack_int32($str, $flags = 0) { $length = strlen($str); if ($length < 4) { return false; } else if ($length > 4) { $str = substr($str, 0, 4); } if ($flags & INT_LE) { $str = strrev($str); } $result = unpack('N', $str); $result = current($result); $signBit = (bool) ($result & 0x80000000); $isSigned = (bool) ($flags & INT_SIGNED); $is32bit = is32Bit(); if ($signBit && $isSigned && !$is32bit) { $result = 0xFFFFFFFF00000000 | $result; } else if ($signBit && !$isSigned && $is32bit) { $result = (($result & 0x7FFFFFFF) * 2) + ~$result + 1; } return $result; } function unpack_int64($str, $flags = 0) { $length = strlen($str); if ($length < 8) { return false; } else if ($length > 8) { $str = substr($str, 0, 8); } $is32bit = is32Bit(); if ($flags & INT_LE) { $str = strrev($str); } $longs = array_values(unpack('NN', substr($str, 0, 4), substr($str, 4, 4))); $signBit = (bool) ($longs[0] & 0x80000000); if (PHP_INT_MAX > 0x7FFFFFFF) { $result = ($longs[0] << 32) | $longs[1]; if ($signBit) { $result = (($result & 0x7FFFFFFFFFFFFFFF) * 2) + ~$result + 1; } } return $result; } var_dump(unpack_int32("\x81\x00\x00\x80", INT_SIGNED | INT_LE));