通过ifstream去读取文件
void stringSplit(string str, char split,vector<string>& res) {
istringstream streamString(str);
string token;
while (getline(streamString, token, split))
{
//将token存入res
res.push_back(token);
}
}
int readfile(string fileName) {
//打开文件流，文件名为：fileName
ifstream file(fileName);
//如果无法打开此文件，return
if (!file.is_open()) {
ALOGD("getMaxTag: Can not open file!");
return -1;
}
char ch;
std::string firstLine;
std::getline(file, fitstLine);
ALOGD("file first line = %s", firstLine.c_str());
file.close();
if (firstLine == "") {
return 0;
}
long index = 0;
//format as bellow:
//{ tag1:3, tag2:1}
//格式加入是上面这种
vector<string> splitLastLine;
//以:分割字符串，分割后的分别存到splitLastLine,会被分割成“tag1", "3, tag2", "1"
stringSplit(lastLine, ':', splitLastLine);
vector<string> splitLastLineTag;
//以,分割字符串splitLastLine[1]
stringSplit(splitLastLine[1], ',', splitLastLineTag);
string indexMax = splitLastLineTag[0];
char* endptr;
//将string转成long
long num = strtol(indexMax.c_str(), &endptr, 10);
if (*endptr != '\0') {
ALOGD("getMaxTag: Change failed!");
return -1;
} else {
index = num;
}
ALOGD("max index = %ld", index);
return index;
}
)
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