将值从文件存储到 C 中的结构数组

Question

I am trying to read values from my text file and store them in struct array. My text file has these values:

names.txt

Num_of_rec: 5
3 7 10 1 red
5 6 8 2 red
9 9 16 5 blue
13 4 19 2 green
12 8 15 4 blue

And my code so far is this:

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define ERROR -1
#define MAXLEN 256

struct Point {
    float x;
    float y;
};

struct Rectangle {
    struct Point top_left;
    struct Point bottom_right;
    char color[7];
};


int main() {
    int i, N;
    char junk[MAXLEN];
    struct Rectangle *data;
    FILE  *fp;

    fp = fopen("names.txt", "r");

    fscanf(fp,"%s %d\n",junk,&N);
    printf("No: %d", N);

    data = (struct Rectangle *) malloc(N*sizeof(struct Rectangle));

    for(i=0; i<N; i++) {
        fscanf(fp, "%lf %lf %lf %lf %s", data[i].top_left.x, data[i].top_left.y, data[i].bottom_right.x, data[i].bottom_right.y);
    }

    return 0;
}

I want to add all these values in a struct array(data), but I don't know how to do this properly. Until now the output is:

No: 5

and it just crash. I don't understand if the problem is the method that I am using to read the values from the file and store them to the struct array, or something else.

Answer 1

fscanf(fp, "%lf %lf %lf %lf %s", data[i].top_left.x, data[i].top_left.y, data[i].bottom_right.x, data[i].bottom_right.y);

There are three problems regarding fscanf :

1. fscanf takes pointers, you pass in values
2. fscanf expects 5 pointers, you only provide 4 values.
3. format specifier %lf expects a pointer to a double type

Changing the above statement to the follow should solve the crash.

fscanf(fp, "%f %f %f %f %s", &data[i].top_left.x, &data[i].top_left.y, &data[i].bottom_right.x, &data[i].bottom_right.y, data[i].color);