read_big_endian( $input, int $num_bytes ): int

42function read_big_endian( $input, $num_bytes ) {43  if ( $num_bytes == 1 ) {44    return unpack( 'C', $input ) [1];45  } else if ( $num_bytes == 2 ) {46    return unpack( 'n', $input ) [1];47  } else if ( $num_bytes == 3 ) {48    $bytes = unpack( 'C3', $input );49    return ( $bytes[1] << 16 ) | ( $bytes[2] << 8 ) | $bytes[3];50  } else { // $num_bytes is 451    // This might fail to read unsigned values >= 2^31 on 32-bit systems.52    // See https://www.php.net/manual/en/function.unpack.php#10604153    return unpack( 'N', $input ) [1];54  }55}