C

fread

#include <stdio.h>

#define n 1024 // n bytes

int main(void) {
	FILE *fp;
    size_t numread;
    if ((fp = fopen("yourfile.xy", "rb") != NULL) {
    	char buffer[n];
        numread = fread(buffer, sizeof(*buffer), n, fp);
      	printf("Read %d Bytes: %s", numread, buffer);
      
      	fclose(fp);
      	return 0;
    }
        
    return -1;
}

fread

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

fread

//from tutorialspoint.com
#include <stdio.h>
#include <string.h>

int main () {
   FILE *fp;
   char c[] = "this is tutorialspoint";
   char buffer[100];

   /* Open file for both reading and writing */
   fp = fopen("file.txt", "w+");

   /* Write data to the file */
   fwrite(c, strlen(c) + 1, 1, fp);

   /* Seek to the beginning of the file */
   fseek(fp, 0, SEEK_SET);

   /* Read and display data */
   fread(buffer, strlen(c)+1, 1, fp);
   printf("%s
", buffer);
   fclose(fp);
   
   return(0);
}