Stop scanf in while loop with EOF

Asked Jun 22 '19 at 01:16

Active Jun 22 '19 at 06:48

Viewed 350 times

I need to get float inputs and only stop when the user hit a ctrl + Z.

However, with my loop like that, my program is needing 3 crtl + Z in sequence. Does anyone know how exactly to stop it with EOF?

This is my code:

I have the while loop condition analyzing if the input was a float.

int capacity = 5;

double* numSet = (double*)malloc(capacity * sizeof(*numSet));
if (numSet == NULL)
    return NULL;

double number;
char ch = 0;


while (fscanf_s(stdin,"%lf", &number) == 1)
{


    numSet[size] = number;
    size++;

    if (size == capacity)
    {
        double* numSetDouble = realloc(numSet, (capacity *= 2) * sizeof(*numSetDouble));

        if (numSetDouble == NULL)
        {
            free(numSet);
            return NULL;
        }
        numSet = numSetDouble;
    }
}

return numSet;

I need the loop to stop when the user enters ctrl ^ Z

edited Jun 22 '19 at 06:48

S.S. Anne

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asked Jun 22 '19 at 01:16

lostwhispers

ctrl-z needs to be entered on a line on its own – Antti Haapala -- Слава Україні Jun 22 '19 at 01:24
I did it. Does not work. – lostwhispers Jun 22 '19 at 01:25
@AnttiHaapala He says that didn't work, yet you closed it as a duplicate anyway? – Barmar Jun 22 '19 at 01:27
@Barmar of course I closed it as a duplicate, because it is 100 % a duplicate. Besides there is no way of making `fscanf_s` stopping at a single ctrl-z. – Antti Haapala -- Слава Україні Jun 22 '19 at 01:31
It should stop at a single ctl-z on a line of its own. @AnttiHaapala – Barmar Jun 22 '19 at 01:32
@Barmar and it does but that line needs to be flushed too. OP asks "how to make it stop at EOF", but the problem is that he needs 3 ctrl-z to send the one EOF if not at the beginning of the line (I believe). 2 Ctrl-D are required in Unix. – Antti Haapala -- Слава Україні Jun 22 '19 at 01:33
Ah, Enter Ctl-z Enter – Barmar Jun 22 '19 at 01:34
@lostwhispers your code breaks the loop at exactly the first time `fscanf_s` meets the EOF *condition* (it is **not** a character!). The problem is that you need more Ctrl-Zs to send an EOF if not at the beginning of the line, and the Ctrl-Z might need to be flushed too. – Antti Haapala -- Слава Україні Jun 22 '19 at 01:38
@lostwhispers Do the duplicates answer your question? – S.S. Anne Jun 22 '19 at 18:00

Stop scanf in while loop with EOF

0 Answers0