facing problem with Buffer

Hi,
I have written program to take a string from the user using fgets() but its not taking the string, and also later in the program i have used scanf to take an integer value from the user even that not requesting user to enter the value...what may be the problem could anyone explain me how shall i proceed?

post your code

Code:

---

while(1)
{
            printf("\n\n\n**********************************************************\n"

                "****************WELCOME TO STUDENTS DB********************\n"
                        "**********************************************************\n");

                printf("\n\n\n\t1. Add a New Entry\n"

                        "\t2. Delete an Entry\n"

                        "\t3. Update an Entry\n"

                        "\t4. Search\n"

                        "\t5. List\n"

                        "\t6. Exit\n");

                printf("\n\nPlease Enter ur Choice: ");

                scanf("%d",&choice);

                switch(choice)

                {

                        case 1:

                                stud_add(&obj);

                                break;

                        case 2:

                                delete(&obj);

                                break;

                        case 3:

                                update(&obj);

                                break;

                        case 4:

                                search(obj);

                                break;

                        case 5:

                                list(obj);

                                break;

                        case 6:
 
                                _exit(0);

                                break;

                        default:

                                printf("The Choice entered was INVALID\n");

                }

        }

---

In the above code when i enter some invalid numbers or any char after few iterations it goes into an infinite loop.

Replace your scanf call with something better, or if you insist on using it, something like this:

Code:

---

while( scanf("%d", &foo ) != 1 )
    printf("Try again:\n");

---

Quzah.

> scanf("%d",&choice);
If you type in 'a', then two things happen (or rather, two things don't happen)
1. The value 'a' isn't converted
2. The value 'a' isn't removed from the input stream.

So you go round the loop again, and still 'a' is there, and still it fails (ad infinitum)

Code:

---

char buff[BUFSIZ];
if ( fgets( buff, sizeof buff, stdin ) != NULL ) {
  if ( sscanf( buff, "%d", &choice ) == 1 ) {
    // success!!!
  } else {
    // bah, user typed in garbage
  }
}

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