fprintf and passing functions

[_jamie]

#include <stdio.h>


struct myStruct {
    int day;
    int month;
    int year;
    float pounds;
};




FILE * fptr;


// int output(int i);


main()
{
    fptr = fopen("my_weight.txt", "w");


    if(fptr == 0)
    {
        printf("Error--could not open file.\n");
        exit (1);
    }


    input();
    output();


    return 0;
}


input()
{
    struct myStruct weight[4];
    
    int i;


    for(i=0;i<1;i++)
    {
        printf("Enter date (MM/DD/YY) ");
        scanf("%d/%d/%d", &weight[i].day, &weight[i].month, &weight[i].year);
        printf("Enter weight (in pounds): ");
        scanf("%f", &weight[i].pounds);
    }


    return;
}




output()
{
    fprintf(fptr, "\n\nHere is you weight: \n");


    int i;


    for(i=0;i<1;i++)
    {
        fprintf(fptr, "%d", weight[i].day);
    }


    return;
}

good morning, newbie question again. I finished a book and am starting to pick it up. Just have a question with the structure "weight[i].day' for fprintf at the bottom of the line, I have read development process on this web site and start small and compile often.

And also, was wondering what should be inside "output()" for output() function. Also questioning why line numbers aren't being showed when I do code tags. Thanks and look forward to posting more.

[Salem]

Declare your array in main, and pass it to both functions.

[ddutch]

Don't want to patronize but your functions must have and return a certain data-type. Or void if they return nothing.
Like

int main()
{
    ---------
    return(some_integer_value);
}

[_jamie]

I pasted the final program, structures & scanf

i gave up on the functions part

[christophergray]

static void output(struct myStruct weight[], FILE * fptr) {
  fprintf(fptr, "\n\nHere is your weight: \n");
    for (int i = 0; i < 4; i++)
      fprintf(fptr, "%d/%d/%d,%f\n",
              weight[i].day,
              weight[i].month,
              weight[i].year,
              weight[i].pounds); }

int main(void) {
  ...
    output(weight, fptr); }

[_jamie]

how about this (this code works)

// weight_6.c
// structure to function
// weight_4.c & weight_5.c
// written by Jamie Morrissey 6/12/18

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

struct data {
	int day;
	int month;
	int year;
	float pounds;
} weight;

FILE * fptr;

void fprintf_stuff(struct data print_it);

main()
{
	printf("Enter date: (MM/DD/YY): ");
	scanf("%d/%d/%d", &weight.month, &weight.day, &weight.year);
	printf("Enter your weight in pounds: ");
	scanf("%f", &weight.pounds);

	// call the fprint_stuff() function
	fprintf_stuff(weight);

	return 0;
}

void fprintf_stuff(struct data print_it)
{
	fptr = fopen("new_weight_new.txt", "a+");

	if( fptr == 0)
	{
		printf("Error! File not found!\n");
		exit(1);
	}

	fprintf(fptr, "Here is your weight: ");
	fprintf(fptr, "%d/%d/%d - %.1f\n", weight.month, weight.day, weight.year, weight.pounds);

	fclose(fptr);
}

[Salem]

Better.

Now do it without using any global variables.