#include <string.h>
#define LEN 5
 
typedef struct Test
{
    int x;
    double y;
}Test;
 
 
int main(void)
{
    Test array[LEN];
    Test res[LEN];
    FILE* fp;
    int i;
    /*Open for writing*/
    fp = fopen("test.bin","wb");
    for (i = 0; i <LEN; i++)
    {
        array[i].x = i;
        array[i].y =  i * 2.5;
        fwrite(&array[i], sizeof(Test), 1, fp);
    }
    fclose(fp);
    /* Open for reading*/
    fp = fopen("test.bin", "rb");
    for (i = 0; i <LEN; i++)
    {
        fread(&res[i], sizeof(Test), 1, fp);
    }
    for (i = 0; i <LEN; i++)
    {
        printf ("%d %g\n", res[i].x, res[i].y);
    }
    fclose(fp);
 
    return 0;
}

#include <stdio.h>
 
#define MAX	1
 
typedef struct {
	short int key;
	char name[21];
	char symbol[6];
	float price;
	float high;
	float low;
	short int ratio;
} STOCK;
 
void get_data(STOCK *);
 
int main(void) {
 
	FILE *fp;
	STOCK data[MAX] = {	{
			{1000}, {"nasdaq"}, {"NAS"}, {100}, {100}, {50}, {2}
		}
	};
	// if the file does not exist, then create it
	if(!(fp = fopen("stockdata.dat", "rb")) )
	{
		if(fp = fopen("stockdata.dat", "wb")) { 
			fwrite(data, sizeof(STOCK), MAX, fp);
			fclose(fp);
			fp = fopen("stockdata.dat", "rb");
		}
		else
		{
			printf("can't write to file\n");
			return 1;
		}
	}
 
	STOCK test[MAX];
	fread(test, sizeof(STOCK), MAX, fp);
	fclose(fp);
	printf("%hd\n", test[0].key);
 
	return 0;
}

void disp_all(FILE *fp) {
 
	FILE *ftemp = fopen("tempdata.dat", "wb");
 
	fwrite(fp, sizeof(STOCK), 1, ftemp);
	fclose(ftemp);
	ftemp = fopen("tempdata.dat", "rb");
 
	STOCK temp[MAX];
	fread(temp, sizeof(STOCK), 1, ftemp);
	printf("%hd\n", temp[0].key);
 
	rewind(fp);
}