C fread() Function Tutorial

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In this section, we will learn what the freed() function is and how it works in C.

C Read from File: C freed() Function

The `fread()` function is used to read binary content from a file.

C fread() Function Syntax:

Here’s the prototype of the function:

size_t fread(void *ptr, size_t size, size_t nmemb, FILE *stream)

C fread() Function Parameters

This function takes 4 arguments:

  1. The first argument is the address of the memory space that incoming data should be stored into.
  2. The second argument represents the size, in bytes, of the chunks to be read from the target file.
  3. The third argument represents the number of chunks to be read.
  4. The last argument identifies the file to read from.

C fread() Function Return Value

The returned value of the function on a successful operation is equal to its third argument, which is the number of chunks. If any other number returned, it means an error happened.

Example: reading from a file in C

#include <stdio.h>
#include <stdlib.h>


int main() {

    char buffer[] = "C programming is cool!";

    FILE *file = fopen("G:/fileOne.txt","w+");

    if (file == NULL){
        printf("Could not open the file");
        exit(EXIT_FAILURE);

    }


    fwrite(buffer, sizeof(buffer), 1, file);

    rewind(file);

    char stored[sizeof(buffer)];

    fread(stored, sizeof(buffer), 1, file);

    printf("%s",stored);

    fclose(file);

    printf("\nDone\n");
    return 0;
}

Output:

C programming is cool!

Done

How Does fread() Function Work in C?

In this example, we first stored a character-string into a file in its binary form via the call to the `fwrite()` function and then via the call to the `fread()` function we took back that data from the file and stored it in another memory-space.

More to Read:

C fwirte() function

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