【c++】读写txt

#include<iostrea>

#include<fstream>

int main()

{

　　ofstream fout;// 创建一个ofstream对象

　　fout.open("fileName.txt");//要写的txt 放到工程下

　　fout<<123456<<endl;//像cout一样使用

　　fout.close();//关闭

ifstream ifs("outlog.txt");

string str;

FILE *input;
char *str, line[4000];
input = fopen("1", "rt");

for (int i = 0; i < num; i++){
　　str = fgets(line, 4000, input);
　　if (str == NULL) break;
　　str = strtok(str, " ");
　　M[i*2]=atof(str);

}

二。数据长这样，要读入m1 m2

13 34

34 34

98 98

ifstream file1;
file1.open("../data/1.txt");

while(! file1.eof())
{
   string s;
   getline(file,s);
   if(! s.empty)
   {
      stringstream ss;
      ss<<s;
      double m1;
      ss>>m1;
      ss>>m2;
    }   
}

另有

http://blog.csdn.net/syunqiang/article/details/6425302

#include <iostream>
#include <sstream>
#include <fstream>
#include <string>
int main(int args, char **argv)
{
std::ifstream fin("split.txt", std::ios::in);
char line[1024]={0};
std::string x = "";
std::string y = "";
std::string z = "";
while(fin.getline(line, sizeof(line)))
{
std::stringstream word(line);
word >> x;
word >> y;
word >> z;
std::cout << "x: " << x << std::endl;
std::cout << "y: " << y << std::endl;
std::cout << "z: " << z << std::endl;
}
fin.clear();
fin.close();
return 0；
}