大文件的读写操作

#include <iostream>
#include <string>
#include <fstream>
using namespace std;

int main() {
  ifstream ifs("tuan.sql", ifstream::in);
  ofstream ofs("trv.txt", ofstream::out);
  string s,value;
  char c1;
  int start_pos=0,end_pos=0;
  while(!ifs.eof() && !ifs.fail()) {
    ifs >> s;
    if(s[0] == '(') {
      value += s;
      continue;
    }
    int len = s.length();    
    for(int index=0; index<len;) {
      if((index+1) <= len) {   
        c1 = s[index++];
        if(c1==')'&&index!=len&&s[index]==',') {
            end_pos = index;
            value += " ";
            value += s.substr(start_pos, end_pos);
            value += "
";
            ofs << value;
            value.clear();

            start_pos = index + 1;
            value += s.substr(start_pos,len);
            start_pos=end_pos=0;
            break;
        }
        if(c1==')'&&index==len) {
          value += " ";
          value += s;
          value += "
";
          ofs << value;
          value.clear();
          start_pos=end_pos=0;
        }
      }else {
        break;
      }
    } 
  }
  ifs.close();
  ofs.close();
  return 0;
}