c - 在函数中传递结构体

Question

我花了很多时间在函数中传递结构指针。代码中的所有内容都正常工作，只是我无法弄清楚如何在函数中传递结构，然后我可以在函数内执行一些操作。你能解释一下我到底失败在哪里以及如何解决它吗？谢谢。

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

int i=0;
int* i_ptr=&i;
int count(int q);
int line_count();

struct student {
    int st_id;
    char st_name[20];
    int st_age;
    char st_dep[7];
    float st_grade;
};

int sort_student(struct student line[i],int i)
{
    printf("%f",line[1].st_grade);
    printf("   %s",line[1].st_name);

    return 0;
}

int main()
{
    /* struct loading from the file operation goes  here */
    int x=0;
    int i=line_count();
    struct student line[i];
    char file_line[100];
    char* line_parts;

    FILE * fp;
    if ((fp = fopen (file.txt", "r")) != NULL)
    {
        while (x<i) {
            if(fgets(file_line,100,fp) != NULL);     // gets line from the file.
            {
                line_parts = strtok(file_line,","); // breaks the line
                line[x].st_id  = atoi(line_parts);  // conversition string to int

                line_parts = strtok(NULL, ",");
                strcpy(line[x].st_name,line_parts);

                line_parts = strtok(NULL, ",");
                line[x].st_age = atoi(line_parts);

                line_parts = strtok(NULL, ",");
                strcpy(line[x].st_dep,line_parts);

                line_parts = strtok(NULL, ",");
                line[x].st_grade = atoi(line_parts);
                x++;
            }
        }
    }
    fclose(fp);

    sort_student(&line[i],i);
    return 0;
}

int line_count () //counts the number of line in the file, while loading the program.
{
    FILE * fp;         // file open from here.
    int i=0;
    int c;
    if ((fp = fopen ("/Users/rishav/Desktop/try/try/file.txt", "r")) != NULL)
    {
        while ((c=fgetc(fp)) != EOF) {
            if (c=='\n') {
                i++;
            }
        }
        fclose(fp);
    }
    else printf("file reading Error.\n");
    return i;
}

int count(q)     // keeps track of i
{
    if(q==1)
    {
        (*i_ptr)++;
    }
    return *i_ptr;
}

Answer 1

您需要将 sort_student 函数定义更改为

int sort_student(struct student* line,int i) {
    printf("%f",line->st_grade);
    printf("   %s",line->st_name);

    return 0;  
}