readString이 (가) TypeError를 throw합니다. 형식이 잘못된 UTF-8

Question

이 함수는 ctypes.unsigned_char.array()을 반환하고 그 위에 문자열을 읽습니다. 창문의 제목을 얻고 있습니다. 문제는 때로는 TypeError를 throw합니다.

try { 
    console.error('straight readString on XWindowGetProperty data:', rez_GP.data.readString()); 
} catch (ex) { 
    console.error('ex on straight readString:', ex); 
} 

는 예를 들어 rez_GP.data.readString()

이 인스턴스를 통지하십시오 : TypeError: malformed UTF-8 character sequence at offset 48. 이 상황에서 창 제목은 Editing js-macosx/bootstrap.js at base-template · Noitidart/js-macosx - Mozilla Firefox입니다. 48 번째 오프셋은 당신이 보는 도트 처리기입니다.이 코드는 183입니다. 이 오류가 발생하지 않고이 버퍼에서 readString()을 수행하는 방법은 무엇입니까?

감사

Answer 1

readString는 UTF-8 인코딩 된 문자열을 기대하고있다. _NET_WM_NAME에 의해 반환 된 문자열에는 적용되지만 WM_NAME에 대해서는 반환되지 않습니다.

Answer 2

utf-8이 아닌 문자열을 유용하게 읽을 수있는 방법을 찾았습니다.하지만 가장 좋은 방법인지 아니면 권장 된 방법인지 확실하지 않습니다.

function readAsChar8ThenAsChar16(stringPtr, known_len, jschar) { 
    // when reading as jschar it assumes max length of 500 

    // stringPtr is either char or jschar, if you know its jschar for sure, pass 2nd arg as true 
    // if known_len is passed, then assumption is not made, at the known_len position in array we will see a null char 
    // i tried getting known_len from stringPtr but its not possible, it has be known, i tried this: 
     //"stringPtr.contents.toString()" "95" 
     //"stringPtr.toString()" "ctypes.unsigned_char.ptr(ctypes.UInt64("0x7f73d5c87650"))" 
     // so as we see neither of these is 77, this is for the example of "_scratchpad/EnTeHandle.js at master · Noitidart/_scratchpad - Mozilla Firefox" 

    // tries to do read string on stringPtr, if it fails then it falls to read as jschar 

    var readJSCharString = function() { 
     var assumption_max_len = known_len ? known_len : 500; 
     var ptrAsArr = ctypes.cast(stringPtr, ctypes.unsigned_char.array(assumption_max_len).ptr).contents; // MUST cast to unsigned char (not ctypes.jschar, or ctypes.char) as otherwise i dont get foreign characters, as they are got as negative values, and i should read till i find a 0 which is null terminator which will have unsigned_char code of 0 // can test this by reading a string like this: "_scratchpad/EnTeHandle.js at master · Noitidart/_scratchpad - Mozilla Firefox" at js array position 36 (so 37 if count from 1), we see 183, and at 77 we see char code of 0 IF casted to unsigned_char, if casted to char we see -73 at pos 36 but pos 77 still 0, if casted to jschar we see chineese characters in all spots expect spaces even null terminator is a chineese character 
     console.info('ptrAsArr.length:', ptrAsArr.length); 
     //console.log('debug-msg :: dataCasted:', dataCasted, uneval(dataCasted), dataCasted.toString()); 
     var charCode = []; 
     var fromCharCode = [] 
     for (var i=0; i<ptrAsArr.length; i++) { //if known_len is correct, then will not hit null terminator so like in example of "_scratchpad/EnTeHandle.js at master · Noitidart/_scratchpad - Mozilla Firefox" if you pass length of 77, then null term will not get hit by this loop as null term is at pos 77 and we go till `< known_len` 
      var thisUnsignedCharCode = ptrAsArr.addressOfElement(i).contents; 
      if (thisUnsignedCharCode == 0) { 
       // reached null terminator, break 
       console.log('reached null terminator, at pos: ', i); 
       break; 
      } 
      charCode.push(thisUnsignedCharCode); 
      fromCharCode.push(String.fromCharCode(thisUnsignedCharCode)); 
     } 
     console.info('charCode:', charCode); 
     console.info('fromCharCode:', fromCharCode); 
     var char16_val = fromCharCode.join(''); 
     console.info('char16_val:', char16_val); 
     return char16_val; 
    } 

    if (!jschar) { 
     try { 
      var char8_val = stringPtr.readString(); 
      console.info('stringPtr.readString():', char8_val); 
      return char8_val; 
     } catch (ex if ex.message.indexOf('malformed UTF-8 character sequence at offset ') == 0) { 
      console.warn('ex of offset utf8 read error when trying to do readString so using alternative method, ex:', ex); 
      return readJSCharString(); 
     } 
    } else { 
     return readJSCharString(); 
    } 
}