文件的读写以及大小写转换

• 文件读写
  
• 大小写转化
  直接贴一下代码

• #include <iostream>
  #include <fstream>
  #include <sstream>
  #include <string>
  #include <vector>
  #include <map>
  #include <cstdlib>
  #include <cstring>
  #include <algorithm>
  //using namespace std;
  
  int main(int argc, char *argv[])
  {
      const int N = 1024;
      std::ifstream in(argv[1], std::ios::in);
      std::ofstream out(argv[2], std::ios::out);
      if (!in.is_open() || !out.is_open())
      {
          std::cout << "open file wrong" << std::endl;
          exit(-1);
      }
  
      char line[N];
      while(!in.eof())
      {
          in.getline(line, N);
          std::istringstream strIO(line);
          std::string str;
          while (strIO >> str)
          {
              std::transform(str.begin(), str.end(), str.begin(), ::toupper);
              //transform(str.begin(), str.end(), str.begin(), ::tolower);
              std::cout << str << std::endl;
              out << str << std::endl;
              std::transform(str.begin(), str.end(), str.begin(), ::tolower);
              std::cout << str << std::endl;
          }
      }
      in.close();
      out.close();
      return 0;
  }