/* Time: 2017-02-22 11:11:15 Describe: C++程序将标准输入/输出重定向为文件输入/输出。 */ #include <iostream> #include <fstream> #include <string> using namespace std; void f() { string line; while(getline(cin, line)) //input from the file in.txt { cout << line <<endl; //output to the file out.txt } } // TEST ONE. int main() { ifstream in("in.txt"); streambuf *backinbuf = cin.rdbuf(); //save old buf cin.rdbuf(in.rdbuf()); //redirect std::cin to in.txt! ofstream out("out.txt"); streambuf *backoutbuf = cout.rdbuf(); //save old buf cout.rdbuf(out.rdbuf()); //redirect std::cout to out.txt! // ONE. f(); //call function } // TEST TWO. /* int main() { ifstream in("in.txt"); streambuf *backinbuf = cin.rdbuf(); //save old buf cin.rdbuf(in.rdbuf()); //redirect std::cin to in.txt! ofstream out("out.txt"); streambuf *backoutbuf = cout.rdbuf(); //save old buf cout.rdbuf(out.rdbuf()); //redirect std::cout to out.txt! // TWO. string word; cin >> word; //input from the file in.txt cout << word << "--"; //output to the file out.txt } */ // TEST THREE. /* int main() { ifstream in("in.txt"); streambuf * backinbuf = cin.rdbuf(); //save old buf cin.rdbuf(in.rdbuf()); //redirect std::cin to in.txt! ofstream out("out.txt"); streambuf * backoutbuf = cout.rdbuf(); //save old buf cout.rdbuf(out.rdbuf()); //redirect std::cout to out.txt! // DO SOMETHING...... (redirect.) // RESET. cin.rdbuf(backinbuf); //reset to standard input again cout.rdbuf(backoutbuf); //reset to standard output again // THREE. cin >> word; //input from the standard input cout << word; //output to the standard input } */
时间: 2024-10-08 19:19:26