student info file handling

Question

can you help me improve my code... this is all about student information... i'm having trouble in syntax... In editing menu... i try using strcmp but nothing happens, i first use fgets and store it at an array and then ask the user for an input and store it again in another array.. and then i'll compare... but it didn't work.. hope you can help me... this is my code..

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

struct student{
       char name[30];
       char id[8];
       char course[5];
};

int main(void){
    int option =0;

    while(option!=6){
       system("cls");
       printf("Menu:\n");
       printf("[1] Add Student.\n");
       printf("[2] Display Student.\n");
       printf("[3] Delete Student.\n");
       printf("[4] Delete Student.\n");
       printf("[5] Exit.\n");
       scanf("%d",&option);

       switch(option)
       {
          case 1:
                addStudent();
                break;
          case 2:
                displayinfo();
                break;
          case 3:
                break;  
          case 4:
                break;
          default:
                printf("That is not in the options!\nPlease Try again!\n");
                break;
       }

    }
}

addStudent(){
    int i;
    FILE *stream = NULL;
    stream = fopen("studentinfo.txt", "a+");

    struct student s1;
    struct student array[3];//here i wnt 2 apply d malloc but, still didn't know how 2start
    for (i =0; i<1; i++){

       printf("Enter Student ID: ");
       scanf("%s", s1.id);
       fflush(stdin);
       printf("Enter Student Name: ");
       gets(s1.name);
       fflush(stdin);
       printf("Enter Student Course: ");
       scanf("%s", s1.course);

       fprintf(stream, "\n%s,\t%s,\t%s", s1.id, s1.name, s1.course);
    }
       fclose(stream);
    getch();
}
displayinfo(){
    FILE *stream = NULL;
     stream = fopen("studentinfo.txt", "rt");

     char arr[100];
     int i=0;

    while(!feof(stream)){  
     fgets(arr, 100, stream);
     printf("%s", arr);
     }

     fclose(stream);
     getch();
}

here's my plan in EDITING MENU:

     printf("enter details: ");
     gets(arr2);

     while(!feof(stream)){ 
        fgets(arr, 100, stream);
        if(strcmp(arr, arr2)==0){
           //code here
        }

     }

will this work?

thanks guys hope you can help me ^_^

Is this your homework? then tag your question with home-work tag — fardjad, Dec 03 '10 at 10:50
Have you tried running the code yourself before asking if it would work? — Jamie Keeling, Dec 03 '10 at 10:53
the whole program runs... it already does appending and displaying the student info... i'm having problem with the editing and deleting... hope you can help me :) — iamanapprentice, Dec 03 '10 at 11:02
Your menu has two options the same: "printf("[3] Delete Student.\n");" and "printf("[4] Delete Student.\n");" — Tony, Dec 03 '10 at 11:08

score 3 · Accepted Answer · answered Dec 03 '10 at 12:18

3

fgets() keeps the newline. gets() does not. Hence the strings will never match.

Try reading the manual for a function if you're not COMPLETELY sure what it is doing.

Instead of gets(arr2) try doing fgets(arr2, 100, stdin).

answered Dec 03 '10 at 12:18

AlastairG

4,119
5
26
41

You're welcome. Fancy accepting the answer by clicking on the empty arrow and maybe clicking the up arrow above the 0 to indicate you think this is a good answer? :) – AlastairG Dec 03 '10 at 12:38
Avoid `gets` in all circumstances, it's the devil's tool for creating buffer overflows. – Fred Foo Dec 03 '10 at 13:08

score 1 · Answer 2 · answered Dec 03 '10 at 12:40

1

while(!feof(stream)){ 
    fgets(arr, 100, stream);

use

while(fgets(arr, 100, stream) != NULL) {
    ...
}

if (ferror(stream))
    printf("error in file" "\n");

feof() won't see an error while reading, so it may hang the loop

answered Dec 03 '10 at 12:40

c.pyth.user

31
2

student info file handling

2 Answers2

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