Btukfyl

#include<stdio.h>

#include<string.h>

#include<stdlib.h>



struct student

{

    char studentName[50];

    int id;

};

struct student_detail

{

    int day, month, year, grade;



    struct student information;

}stu_data;

//---------------------------------//

int main()

{

    struct student_detail stu_data[10];



    int student_no, i=0, choice=0;

    char keyword[50];



    FILE *fptr;



    printf("Add-Information(1) || Get-Information(2): ");

    scanf("%d",&choice);



    if(choice == 1){



        fptr = (fopen("userInfo.txt","ab"));



        system("CLS");

        printf("How many students would you like to add?[MAX 10]: ");

        scanf("%d",&student_no);

        system("CLS");



        for(i=0; i < student_no; i++){

            system("CLS");

            printf("Enter student#%d's name: ",i+1);

            scanf("%s", stu_data[i].information.studentName);



            printf("nWhat is %s's studentID?: ",stu_data[i].information.studentName);

            scanf("%d",&stu_data[i].information.id);



            printf("nWhat is %s's date of birth?(dd/mm/yy):n",stu_data[i].information.studentName);

            scanf("%d %d %d",&stu_data[i].day, &stu_data[i].month, &stu_data[i].year);



            fwrite(&stu_data[i].information.studentName, sizeof(struct student), 1, fptr);

            fwrite(&stu_data[i].information.id, sizeof(struct student), 1, fptr);

            fwrite(&stu_data[i].day, sizeof(struct student), 1, fptr);

            fwrite(&stu_data[i].month, sizeof(struct student), 1, fptr);

            fwrite(&stu_data[i].year, sizeof(struct student), 1, fptr);

        }

        fclose(fptr);

    }

    if(choice == 2){



        fptr = (fopen("userInfo.txt","rb+"));



        system("CLS");



        printf("What students information would you like to retreive?: ");

        scanf("%s",keyword);



        fseek(fptr, sizeof(struct student), SEEK_SET);



        fread(&stu_data[i].information.studentName, sizeof(struct student), 1, fptr);

        fread(&stu_data[i].information.id, sizeof(struct student), 1, fptr);



        fread(&stu_data[i].day, sizeof(struct student), 1, fptr);

        fread(&stu_data[i].month, sizeof(struct student), 1, fptr);

        fread(&stu_data[i].year, sizeof(struct student), 1, fptr);



        printf("Name: %s",stu_data[i].information.studentName);

        printf("nID: %d",stu_data[i].information.id);

        printf("nDate of birth: %d/%d/%dnn",stu_data[i].day, stu_data[i].month, stu_data[i].year);



    system("PAUSE");



    fclose(fptr);

return 0;

    }

}  

This is my code, input into the file looks like this:
Name: Riley

ID: 1

Date of birth: 01/10/2001

When I read the information from the file I get correct information but not all of it, when read in the message looks like this:
Name: y

ID: 1

Date of birth: 10/2001/2686248

The writing works just not reading(sorry for lack of comments inside the program) Any information would be of great help! Thank you!

I doubt you're writing or reading what you intend.

When you write,

fwrite(&stu_data[i].information.studentName, sizeof(struct student), 1, fptr);

you're writing 1 element of sizeof(struct student) bytes, starting not from the beginning of the student struct, but from stu_data[i].information.studentName. So you get the 50-byte name, and whatever happens to follow it in memory. If sizeof(struct student) is 250 bytes, you write 200 bytes of nonsense (at best), and then continue with the next field. Ugh!

Unless you have good reason not to, why not write the whole record at once? Less code, less bother for the computer.

fwrite(&stu_data[i], sizeof(struct student), 1, fptr);

As a rule, that's what you should look for in your code: the address provided as the 1st parameter should be of a data structure whose size is named in the 2nd. Even better:

fwrite(&stu_data[i], sizeof(stu_data[i]), 1, fptr);

The same advice applies to reading. I'll only point out one other error:

    fseek(fptr, sizeof(struct student), SEEK_SET);

No matter what input is provided, you seek to (what you probably intend as) the 2nd record: sizeof(struct student) bytes from the beginning of the file. Likely, you want some multiple of that number, based on the input.

Also, hexdump(1) is your friend, especially the -C option.