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#define UC(c) (unsigned char)(c)
class ScriptData {
public:
ScriptData(): status(0), lineno(0), string(0) {}
ScriptData(const char *ptr, int no): status(0), lineno((unsigned short)no), string(ptr) {}
public:
unsigned char status;
unsigned short lineno;
const char *string;
} ;
vector<ScriptData> data;
TextReader(const char *name)
:filename(name), read_index(0), buffer(0)
{
CSecurityAttributes sa;
HANDLE hFile = ::CreateFile(name, GENERIC_READ, 0, &sa, OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, 0);
if (hFile != INVALID_HANDLE_VALUE) {
// 求出档案大小
DWORD length = ::GetFileSize(hFile, 0);
buffer = new char [length + 1];
DWORD nread;
if (!::ReadFile(hFile, buffer, length, &nread, 0)
|| length != nread) { // error
delete buffer;
buffer = 0;
}
else {
char *endptr = buffer + length;
char *p = buffer;
int lineno = 1;
*endptr = '\0'; // 卫兵
while (p < endptr && *p != '\027') {
data.push_back(ScriptData(p, lineno));
while (UC(*p) >= ' ' || *p == '\t')
p++;
if (*p == '\0') // 最后没有换行码
break;
if (*p == '\r') // Windows的跳行码是"/r/n"
*p++ = '\0'; // 故字符串后面要以'/r'结尾
if (*p == '\n')
*p++ = '\0';
lineno++;
}
}
::CloseHandle(hFile);
}
data.push_back(ScriptData("end", 0)); // 最后面多加一个空的"end"
}
这是游戏程序例子里面读取地图配置文件的函数,在下有几个不明白的地方,哪位高手可以指点一下:
1 *p != '\027'是什么意思
2 两层while语句的作用(因为不明白上层while语句的 *p != '\027'是什么意思,所以不太明确除了判断文件是否读到末尾还有什么作用)
3 *p++ = '\0'这样不会改变配置文件的原始数据吗
4 哪位耐心的老鸟解释一下windows系统换行符的问题(因为没有查找到系统的介绍换行符的帖子,所以在下偷个懒,请多多包含,呵呵) |
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