Unlocking the Power of fwrite(): A Comprehensive Guide
What is fwrite() and How Does it Work?
The fwrite() function is a powerful tool in C++ that allows you to write data to a file stream. It’s similar to calling fputc() multiple times, but with a twist. fwrite() writes a specified number of objects, each of a certain size, to the given output stream. The file position indicator is incremented according to the number of characters written, unless an error occurs, in which case the resulting value is indeterminate.
Understanding fwrite() Parameters
To use fwrite() effectively, you need to understand its parameters:
- buffer: A pointer to the block of memory containing the data to be written.
- size: The size of each object in bytes.
- count: The number of objects to be written.
- stream: The file stream to which the data will be written.
The Return Value of fwrite()
So, what does fwrite() return? It returns the number of objects successfully written. If an error occurs, the return value may be less than the specified count.
Real-World Examples: Putting fwrite() into Action
Let’s see how fwrite() works in practice. In our first example, we’ll write the contents of a buffer to a file.
Example 1: Writing Data to a File
When you run this program, the contents of the buffer will be written to the file, and the output will be…
Edge Cases: What Happens When Count or Size is Zero?
But what if either count or size is zero? Let’s find out!
Example 2: fwrite() with Zero Count or Size
When you run this program, the output will be…
Further Reading
Want to learn more about file input/output in C++? Check out our guides on C++ fread() and C++ fopen().