C++ Program to Create a Temporary File

Last Updated : 31 Jul, 2022

Here, we will see how to create a temporary file using a C++ program. Temporary file in C++ can be created using the tmpfile() method defined in the <cstdio> header file. The temporary file created has a unique auto-generated filename. The file created is opened in binary mode and has access mode “wb+”. These temporary files are automatically deleted when the program is terminated or when they are closed in the program using fclose().

Syntax:

std::FILE* tmpfile();

Return value: The associated file stream or a null pointer if an error has occurred.

Below is the C++ program to create a temporary file, writing in and reading from the temporary file:

C++

// C++ program to create a temporary file
// read and write to a temporary file.
#include <cstdio>
#include <cstdlib>
#include <iostream>
 
using namespace std;
 
// Driver code
int main()
{
    // Creating a file pointer which 
    // points to the temporary file 
    // created by tmpfile() method
    FILE* fp = tmpfile();
 
    // Content to be written in temporary file
    char write[] = "Welcome to Geeks For Geeks";
 
    // If file pointer is NULL there is 
    // error in creating the file
    if (fp == NULL) 
    {
        perror("Error creating temporary file");
        exit(1);
    }
 
    // Writing in temporary file the content
    fputs(write, fp);
    rewind(fp);
 
    // Reading content from temporary file 
    // and displaying it
    char read[100];
    fgets(read, sizeof(read), fp);
    cout << read;
 
    // Closing the file. Temporary file will 
    // also be deleted here
    fclose(fp);
 
    return 0;
}