如何將文本附加到 C++ 中的文本文件？

Question

如何將文本附加到 C++ 中的文本文件？ 如果尚不存在，則創建一個新文本文件，如果存在，則將文本附加到其中。

Answer 1

您需要指定附加打開模式，如

#include <fstream>

int main() {  
  std::ofstream outfile;

  outfile.open("test.txt", std::ios_base::app); // append instead of overwrite
  outfile << "Data"; 
  return 0;
}

Answer 2

我用這個代碼。 它確保在文件不存在時創建該文件，並添加一些錯誤檢查。

static void appendLineToFile(string filepath, string line)
{
    std::ofstream file;
    //can't enable exception now because of gcc bug that raises ios_base::failure with useless message
    //file.exceptions(file.exceptions() | std::ios::failbit);
    file.open(filepath, std::ios::out | std::ios::app);
    if (file.fail())
        throw std::ios_base::failure(std::strerror(errno));

    //make sure write fails with exception if something is wrong
    file.exceptions(file.exceptions() | std::ios::failbit | std::ifstream::badbit);

    file << line << std::endl;
}

Answer 3

 #include <fstream>
 #include <iostream>

 FILE * pFileTXT;
 int counter

int main()
{
 pFileTXT = fopen ("aTextFile.txt","a");// use "a" for append, "w" to overwrite, previous content will be deleted

 for(counter=0;counter<9;counter++)
 fprintf (pFileTXT, "%c", characterarray[counter] );// character array to file

 fprintf(pFileTXT,"\n");// newline

 for(counter=0;counter<9;counter++)
 fprintf (pFileTXT, "%d", digitarray[counter] );    // numerical to file

 fprintf(pFileTXT,"A Sentence");                   // String to file

 fprintf (pFileXML,"%.2x",character);              // Printing hex value, 0x31 if character= 1

 fclose (pFileTXT); // must close after opening

 return 0;

}

Answer 4

您可以使用fstream並使用std::ios::app標志打開它。 看看下面的代碼，它應該會讓你清醒。

...
fstream f("filename.ext", f.out | f.app);
f << "any";
f << "text";
f << "written";
f << "wll";
f << "be append";
...

你可以找到關於開放模式的詳細信息，在這里和有關fstreams這里。

Answer 5

你也可以這樣做

#include <fstream>

int main(){   
std::ofstream ost {outputfile, std::ios_base::app};

ost.open(outputfile);
ost << "something you want to add to your outputfile";
ost.close();
return 0;
}

Answer 6

下面的代碼應該工作：

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

using namespace std;

int main()
{
    ofstream writer("filename.file-extension" , ios::app);

    if (!writer)
    {
        cout << "Error Opening File" << endl;
        return -1;
    }

    string info = ""; //insert your text to be appended here
    writer.append(info);
    
    writer << info << endl;
    writer.close;
    return 0;   
} 

我希望這可以幫助你 ：）