Question

This is something simple I came up with for this question. I’m not entirely happy with it and I saw it as a chance to help improve my use of STL and streams based programming.

std::wifstream file(L'\\Windows\\myini.ini'); if (file) {   bool section=false;   while (!file.eof())   {     std::wstring line;     std::getline(file, line);     if (line.empty()) continue;      switch (line[0])     {       // new header       case L'[':       {         std::wstring header;         size_t pos=line.find(L']');         if (pos!=std::wstring::npos)         {           header=line.substr(1, pos);           if (header==L'Section')             section=true;           else             section=false;         }       }   break;       // comments       case ';':       case ' ':       case '#':       break;       // var=value       default:       {         if (!section) continue;  // what if the name = value does not have white space? // what if the value is enclosed in quotes?         std::wstring name, dummy, value;         lineStm >> name >> dummy;         ws(lineStm);         WCHAR _value[256];         lineStm.getline(_value, ELEMENTS(_value));         value=_value;       }     }   } } 

How would you improve this? Please do not recommend alternative libraries – I just want a simple method for parsing out some config strings from an INI file.

Answer 1

// what if the name = value does not have white space?
// what if the value is enclosed in quotes?

I would use boost::regex to match for every different type of element, something like:

boost::smatch matches; boost::regex name_value('(\S+)\s*=\s*(\S+)'); if(boost::regex_match(line, matches, name_value)) {     name = matches[1];     value = matches[2]; } 

the regular expressions might need some tweaking.

I would also replace de stream.getline with std::getline, getting rid of the static char array.