[util.cpp#L216](https://github.com/bitcoin/bitcoin/blob/master/src/util.cpp#L216) 
if `fopen `failed, a null file pointer could be passed to `FileWriteStr(vMsgsBeforeOpenLog->front(), fileout);`
break;
        
        
        if (str.length() > 1 && str[1] == '-')
            str = str.substr(1);
        InterpretNegativeSetting(str, strValue);
        mapArgs[str] = strValue;
        _mapMultiArgs[str].push_back(strValue);
    }
}
bool IsArgSet(const std::string& strArg)
{
    LOCK(cs_args);
    return mapArgs.count(strArg);
}
std::string GetArg(const std::string& strArg, const std::string& strDefault)
{
    LOCK(cs_args);
    if (mapArgs.count(strArg))
        return mapArgs[strArg];
    return strDefault;
}
int64_t GetArg(const std::string& strArg, int64_t nDefault)
{
    LOCK(cs_args);
    if (mapArgs.count(strArg))
        return atoi64(mapArgs[strArg]);
    return nDefault;
}
bool GetBoolArg(const std::string& strArg, bool fDefault)