Thread: ***Stack smashing detected***: ./a.out terminated aborted core dumped

Code:

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

struct person{
    char name[100];
    char address[100];
    char IDnumber[20];
    int  age;
};
void copystructure(char structure[100],struct person *ptr);

void main(void){

    FILE *fp1;
    fp1=fopen("file1.txt","r");
    char ch;
    int i=0,j=0;
    char tmp[100];
    struct person *ptr=NULL;
    struct person arr[100];
    ptr=&arr[0];
    while((ch=fgetc(fp1))!=EOF){
        switch(ch){    
            case'\n': copystructure(tmp,ptr); ptr=&arr[j++];  break;
            default: tmp[i]=ch;i=i+1;
        }
    }
}
void copystructure(char structure[100],struct person *ptr){

    int i,k,j=0;
    char tmp[100];
    ptr=(struct person *)malloc(sizeof(struct person));
    for(i=0;structure[i]!='\0';i++,j++){
        if(structure[i]==','){
            break;
        }
     tmp[j]=structure[i];    
    }
    tmp[j]='\0';
    j=0;
    strcpy(ptr->name,tmp);
    for(i=i+1;structure[i]!='\0';i++,j++){
        if(structure[i]==','){
            break;
        }    
     tmp[j]=structure[i];
    }
    tmp[j]='\0';
    j=0;
    strcpy(ptr->address,tmp);
    for(i=i+1;structure[i]!='\0';i++,j++){
        if(structure[i]==','){
            break;
        }
     tmp[j]=structure[i];
    }
    tmp[j]='\0';
    j=0;
    strcpy(ptr->IDnumber,tmp);
    for(i=i+1;structure[i]!='\0';i++,j++){
     tmp[j]=structure[i];
    }
    j=0;
    k=structure[i-2]-'1'+1;
    k=k*10+(structure[i-1]-'1'+1);
    ptr->age=k;
    free(ptr);
}

file1.txt is shown below

Code:

Name1,Address1,IDnumber1,1
Name2,Address2,IDnumber2,2
Name3,Address3,IDnumber3,3
Name4,Address4,IDnumber4,4
Name5,Address5,IDnumber5,5