C program question

Question

C++ / C#

There is the following piece of code. If we enter “1”, the program execution ends for some reason, the message “Segmentation error” is displayed. In any other case, everything is ok. If we write int act = X, act, value; similarly - if X == 1, then "Segmentation error", otherwise - everything is OK. Compiler gcc (Ubuntu/Linaro 4.4.4-14ubuntu5) 4.4.5 What could be the problem?

...
int main(int argc, char* argv[])
{
int act, act2, value;

printf("Выберите действие:\n1. Вывод списка\n2. Добавить элемент в список\n0. Выйти из программы\n->");
scanf("%d", &act);

printf("Введенное значение:\n%d\n", act);
...
}

Answer 1

Naturally, the error occurs in return (item->next == NULL)? ten;
when you enter 1, item contains NULL, and you are trying to dereference it and refer to a non-existent offset "next"

Answer 2

On which line is the error thrown? Exactly in this piece of code?
I checked your piece of code on gcc (CentOS) - no errors.

Answer 3

Well, you don’t see the last printf, because it gets into the buffer and your program sigfaults before the buffer has time to be read into the console.
If you do fflush(STDOUT) after printf("+"), you will see "+".