変換文字列\\ u6d4e \\ u5357 \\ u5e02からutf-8データへの変換方法

Question

gccはutf-8エンコーディングデータに\u6d4e\u5357\u5e02をフォーマットします。しかし、私はutf-8エンコーディングデータにucs2文字列をどのようにフォーマットできますか？

char str[] = "\\u6d4e\\u5357\\u5e02"; 

Answer 1

変換機能が必要です。

/* Input: a Unicode code point, "ucs2". 

    Output: UTF-8 characters in buffer "utf8". 

    Return value: the number of bytes written into "utf8", or a 
    negative number if there was an error. 

    This adds a zero byte to the end of the string. It assumes that the 
    buffer "utf8" has at least four bytes of space to write to. */ 

int ucs2_to_utf8 (int ucs2, unsigned char * utf8) 
{ 
    if (ucs2 < 0x80) { 
     utf8[0] = ucs2; 
     utf8[1] = '\0'; 
     return 1; 
    } 
    if (ucs2 >= 0x80 && ucs2 < 0x800) { 
     utf8[0] = (ucs2 >> 6) | 0xC0; 
     utf8[1] = (ucs2 & 0x3F) | 0x80; 
     utf8[2] = '\0'; 
     return 2; 
    } 
    if (ucs2 >= 0x800 && ucs2 < 0xFFFF) { 
    if (ucs2 >= 0xD800 && ucs2 <= 0xDFFF) { 
     /* Ill-formed. */ 
     return UNICODE_SURROGATE_PAIR; 
    } 
     utf8[0] = ((ucs2 >> 12)  ) | 0xE0; 
     utf8[1] = ((ucs2 >> 6) & 0x3F) | 0x80; 
     utf8[2] = ((ucs2  ) & 0x3F) | 0x80; 
     utf8[3] = '\0'; 
     return 3; 
    } 
    if (ucs2 >= 0x10000 && ucs2 < 0x10FFFF) { 
    /* http://tidy.sourceforge.net/cgi-bin/lxr/source/src/utf8.c#L380 */ 
    utf8[0] = 0xF0 | (ucs2 >> 18); 
    utf8[1] = 0x80 | ((ucs2 >> 12) & 0x3F); 
    utf8[2] = 0x80 | ((ucs2 >> 6) & 0x3F); 
    utf8[3] = 0x80 | ((ucs2 & 0x3F)); 
     utf8[4] = '\0'; 
     return 4; 
    } 
    return UNICODE_BAD_INPUT; 
} 

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