Question

我想在现有文件的末尾添加一个新行（字符串）。但它没有用。这是代码：

    #include <iostream>
    #include <fstream>
    #include <cstdlib>
    #include <string>

    using namespace std;

int main()
{
    ifstream input("Sample.ini");
    ofstream output("Sample.ini",ios::app);

    cout << "Lines that have existed in file:" << endl;

    while (input) // Print out the existed line
    {
        string newstring;
        getline(input,newstring);
        cout << newstring << endl;
    }

    cout << "Line you want to add:" << endl;

    string outputstring;
    getline(outputstring,output); // get the whole line of outputstring,
                                  // and deliver it into output file
    return 0;
}

将文件内部的行读取到字符串的第一个getline运行良好。但是，第二个，不是。编译器返回如下：

... \ file test.cpp | 35 | error：没有匹配函数来调用＆＃39; getline（std :: istream＆amp;，std :: ofstream＆amp;）＆＃39; |

Answer 1

你写了太多代码。你只需要两行：

ofstream output("Sample.ini",ios::app);
output << outputstring;

Answer 2

你可能想尝试poniter提交，简短和＆amp;简单

#include <stdio.h>

int main ()
 {
  FILE * pFile;
  File = fopen ( "you_file_name.txt" , "a" ); //open the file in append mode
  fputs ( "This is an apple." , pFile );
  fseek ( pFile , 0 , SEEK_END); // 0 means from start & SEEK_END will get you the end of file
  fputs ( "Line you want to add:" , pFile );
  fclose ( pFile );
  return 0;
}

将自定义字符串放入文件中

2 个答案: