C programming is one of the most efficient programming languages out there, known for its raw power, speed, and ability to handle large data sets. In this article, we will take a closer look at one of C programming's most powerful functions, fwrite.

What is fwrite?

Fwrite is a C library function that allows us to write large data sets to a file in a highly efficient manner. This function can be used to write data of any size, from a single byte to gigabytes of data. The fwrite function is highly optimized and can write data to files at an extremely high speed. This makes it an ideal choice for use in applications that handle large amounts of data.

How does fwrite work?

Fwrite writes a block of data to a file stream. The data is a pointer to the array of characters to be written, the size is the size in bytes of each element to be written, and the count is the number of elements to be written.

Fwrite returns the number of full elements (not bytes) that were written to the file. If this number is less than the count parameter, then an error has occurred.

Fwrite is ideal for writing large arrays of data. Writing to a file with fwrite requires the following steps:

1. Open the file stream: The first step is to open the file stream. We can use the fopen function to open the file. The file mode should be set to "wb" for binary data.

2. Write the data: After opening the file stream, the next step is to write the data. We can use the fwrite function to write the data to the file.

3. Close the file stream: After writing the data to the file, we should close the file stream using the fclose function. This is an important step because it ensures that any remaining data from the fwrite function is written to the file.

Examples of Using fwrite Function

We can use the fwrite function to create a binary file containing an array of integers as follows:

```c

#include

#include

int main()

{

int i, my_array[5] = {10, 20, 30, 40, 50};

FILE *fptr;

fptr = fopen("test.bin", "wb");

if(fptr == NULL)

{

printf("Error!");

exit(1);

}

fwrite(my_array, sizeof(int), 5, fptr);

fclose(fptr);

return 0;

}

```

In this example, we first declare an array of five integers. We then open a file named "test.bin" in binary mode and check if the file pointer is not null. We then use the fwrite function to write the contents of the array to the file.

The fwrite function takes four arguments, the first is the pointer to the data to be written, the second is the size of each element to be written (in this case an integer), the third is the number of elements to be written (in this case 5), and the fourth is the file pointer.

Advantages of Using fwrite Function

There are several advantages of using the fwrite function:

1. Efficiency: Fwrite is highly optimized and can write large data sets to a file at an extremely high speed. This makes it an ideal choice for applications that handle large amounts of data.

2. Flexibility: Fwrite can be used to write data of any size, from a single byte to gigabytes of data. This makes it a very flexible function that can be used in a wide range of applications.

3. Portability: Fwrite is a standard C library function that is available on all major platforms, making it a highly portable function.

4. Binary Data: The fwrite function is ideal for writing binary data to a file. Binary data is data that is not represented as text and is often used to store data that is not human-readable, such as images, audio, or video.

Conclusion

In conclusion, the fwrite function is a highly efficient and flexible function that can be used to efficiently write large data sets to a file in C programming. This function is highly optimized and can write data to files at an extremely high speed, making it an ideal choice for use in applications that handle large amounts of data. Fwrite is also highly portable and available on all major platforms, making it a highly versatile function that can be used in a wide range of applications.