not printing linked list elements

// Online C compiler to run C program online

i have tried to create a linked list and print the elements but its not working.could you please help me

// Online C compiler to run C program online
#include <stdio.h>
#include <stdlib.h>
struct sai{
    int data;//data that needs to be stored
    struct sai *ptr;//self pointer
};
void printplaces();
int main(){
struct sai *head;
struct sai *second;
struct sai *third;
struct sai *fourth;
head = (struct sai*)malloc(sizeof(struct sai));
second = (struct sai*)malloc(sizeof(struct sai));
third = (struct sai*)malloc(sizeof(struct sai));
fourth = (struct sai*)malloc(sizeof(struct sai));
(*head).data = 2;
head->ptr = second;
(*second).data = 2;
second->data = third;
(*third).data = 2;
third->ptr = fourth;
(*fourth).data = 2;
fourth->ptr = '\0';
 printplaces(*head);
/*printf("%d\n",(*head).ptr);
printf("%d\n",(*second).ptr);
printf("%d\n",(*third).ptr);
printf("%d\n",(*fourth).ptr);
printplaces(*head);
}*/
}
void printplaces(struct sai *next){
    for(int i = 0; i<= 2; i++){
       printf("%d", next->data);
       next = next -> ptr; 
    }
}

this line is wrong

second->data = third;

you mean

second->ptr = third;

and all the other places where you are trying to set the 'next' pointer

also

(*head).data = 2;

is better written

head->data = 2;

so you need

head->data = 2;
head->ptr = second;
second->data = 2;
second->ptr = third;
third->data = 2;
third->ptr = fourth;
fourth->data = 2;
fourth->ptr = '\0';