我正在阅读某人的代码,我碰巧看到代码如下。
根据评论,这个功能是Convert a UCS character to an UTF-8 string
. 但是什么是ucs字符,ucs转unicode的规则是什么,在哪里可以找到文档呢?
/*
* Convert a UCS character to an UTF-8 string
*
* Returns the string length of the result
*/
size_t
tUcs2Utf8(ULONG ulChar, char *szResult, size_t tMaxResultLen)
{
if (szResult == NULL || tMaxResultLen == 0) {
return 0;
}
if (ulChar < 0x80 && tMaxResultLen >= 2) {
szResult[0] = (char)ulChar;
szResult[1] = '\0';
return 1;
}
if (ulChar < 0x800 && tMaxResultLen >= 3) {
szResult[0] = (char)(0xc0 | ulChar >> 6);
szResult[1] = (char)(0x80 | (ulChar & 0x3f));
szResult[2] = '\0';
return 2;
}
if (ulChar < 0x10000 && tMaxResultLen >= 4) {
szResult[0] = (char)(0xe0 | ulChar >> 12);
szResult[1] = (char)(0x80 | (ulChar >> 6 & 0x3f));
szResult[2] = (char)(0x80 | (ulChar & 0x3f));
szResult[3] = '\0';
return 3;
}
if (ulChar < 0x200000 && tMaxResultLen >= 5) {
szResult[0] = (char)(0xf0 | ulChar >> 18);
szResult[1] = (char)(0x80 | (ulChar >> 12 & 0x3f));
szResult[2] = (char)(0x80 | (ulChar >> 6 & 0x3f));
szResult[3] = (char)(0x80 | (ulChar & 0x3f));
szResult[4] = '\0';
return 4;
}
szResult[0] = '\0';
return 0;
} /* end of tUcs2Utf8 */