c语言读取文件中的数据到结构体和数组

1、数组

#include <stdio.h>
#include <stdlib.h>
#define BUF_SIZE 100
#define MAX_SIZE 100

int main()
{
    int **arr;
    int rows, cols;
    int rows_size, cols_size = 5;
    int num, i = 0;
    int arr_size = 0;
    FILE *fp = NULL;
    fp = fopen("filename.txt", "r");
    // open file and read data
    if (fp != NULL)
    {
        printf("open file success\n");
        rows = 0;
        cols = 0;
        while (fscanf(fp, "%d", &num) == 1)
        {
            i++;
            if (i % cols_size == 0)
            {
                rows++;
            }
        }
        if (i % cols_size != 0)
        {
            rows++;
        }
        rows_size = rows;
        arr_size = i;
        printf("data count is %d\n", i);
        printf("rows is %d\n", rows_size);

        // dynamic allocate memory
        arr = (int **)calloc(rows_size, sizeof(int *));
        for (i = 0; i < rows; i++)
        {
            arr[i] = (int *)calloc(cols_size, sizeof(int));
        }

        fp = fopen("filename.txt", "r");
        if (fp != NULL)
        {
            i = 0;
            while (fscanf(fp, "%d", &num) == 1)
            {
                if (i < arr_size)
                {
                    arr[i / cols_size][i % cols_size] = num;
                    i++;
                }
            }
        }
        fclose(fp);

        // print data
        printf("the data from file is:\n");
        for (i = 0; i < rows_size; i++)
        {
            for (int j = 0; j < cols_size; j++)
            {
                printf("%d ", arr[i][j]);
            }
            printf("\n");
        }

        // free memory
        for (i = 0; i < rows_size; i++)
        {
            free(arr[i]);
        }
        free(arr);
    }
    else
    {
        printf("open file failed\n");
        return 0;
    }
    // close file
    if (fclose(fp) == 0)
    {
        printf("close file success\n");
    }
    else
    {
        printf("close file failed\n");
    }
    return 0;
}

2、结构体

#include <stdio.h>
#include <stdlib.h>
#define BUF_SIZE 100
#define MAX_SIZE 100

int main()
{
    // char buf[BUF_SIZE];
    typedef struct _sPerson
    {
        int num;
        char name[MAX_SIZE];
        char email[MAX_SIZE];
        int phone;
    } sPerson;
    sPerson *ps = (sPerson *)(malloc(sizeof(sPerson)));

    FILE *fp = NULL;
    fp = fopen("./data_structure.txt", "r");
    if (fp != NULL)
    {
        printf("open file success\n");
        while (fscanf(fp, "%d %s %s %d", &(ps->num), ps->name, ps->email, &(ps->phone)) == 4)
        {
            printf("%d %s %s %d\n", ps->num, ps->name, ps->email, ps->phone);
        }
    }
    else
    {
        printf("open file failed\n");
        return -1;
    }
    // close file
    if (fclose(fp) == 0)
    {
        printf("close file success\n");
    }
    else
    {
        printf("close file failed\n");
    }
    free(ps);
    return 0;
}