php string to binary conversion

header("charset=utf-8;");
  
function StrToBin($str){
    //1.列出每个字符
    $arr = preg_split(&#39;/(?<!^)(?!$)/u&#39;, $str);
    //2.unpack字符
    foreach($arr as &$v){
        $temp = unpack(&#39;H*&#39;, $v);
        $v = base_convert($temp[1], 16, 2);
        unset($temp);
    }
  
    return join(&#39; &#39;,$arr);
}
  
function BinToStr($str){
    $arr = explode(&#39; &#39;, $str);
    foreach($arr as &$v){
        $v = pack("H".strlen(base_convert($v, 2, 16)), base_convert($v, 2, 16));
    }
  
    return join(&#39;&#39;, $arr);
}
  
  echo StrToBin("aaaccc天空");
  echo BinToStr(&#39;1100001 1100001 1100001 1100011 1100011 1100011 111001011010010010101001 111001111010100110111010&#39;);