CODEWITHSUNDEEP
cpointersstructsegmentation-faultscanf
ElecLearn
ElecLearn

Reputation: 27

Struct Pointers Segmentation fault

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

struct student

{
    char name[50];
    int St_No;
    float mark[10];
};

int main()
{
    int entrynumber=0;
    int r=0;

    while(r != 1)
    {
        printf("choose one of the following options\n");
        printf("1-Introduce new student\n");
        printf("2-Introduce new mark\n");
        printf("3-Print report of all students\n");
        printf("4-Exit\n");
        char givenname[50];
        int option;
        scanf("%d",&option);
        int n,i,e=0,j=0;
        struct student *St[50], Stu[50];
        St[50] = &Stu[50];

        switch(option)
        {
        case 1:
            entrynumber;
            printf("Enter name of student\n");
            scanf("%s",(*St[entrynumber]).name);
            printf("\nEnter student Number\n"); 
            scanf("%d",&(*St[entrynumber]).St_No);
            entrynumber++;                        
            int noofstudents = entrynumber;       
            break;   

                                           |

I cut the rest out

OK so i get seg fault in this line here 

scanf("%s",(*St[entrynumber]).name);

the scanf works when i put it in, it just gives a seg fault

can anyone help me pls?

Upvotes: 0

Views: 97

Answers (1)

Barmar
Barmar

Reputation: 782717

St[50] = &Stu[50];

is not the way to set all the pointers in St to point to the corresponding elements of Stu. You need a loop:

for (int i = 0; i < 50; i++) {
    St[i] = &Stu[i];
}

BTW, (*St[entrynumber]).name) is usually written as St[entrynumber]->name.

There's really no need for the array of pointers at all. You can just use Stu[entrynumber].name and &Stu[entrynumber].St_No in your scanf() calls.

And don't forget that %s in scanf() just reads a single word. If you try to enter a first and last name, it won't work. You probably should read a whole line with fgets() (and don't forget to remove the newline at the end).

Upvotes: 4

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