Question

I’m trying to make a stopwatch program, which will write czas to file.txt. I started learning C today, so please be lenient for me, if it’s a stupid question, but the compiler doesn’t throw out any errors, and NetBeans also doesn’t display any exclamation marks. There is my code:

#include <windows.h>
#define sleep(x) Sleep(1000 * x)

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

int a = 0;
int czas = 0;
int main (void)
{
    FILE *file;
    while (a < 30) { /*repeats only 30 times*/
        a = a + 1; /*increases the counter for while loop*/
        file = fopen("file.txt","w"); /*opens file.txt for writing*/
        fprintf(file,"%s", czas); /*writes czas to file.txt*/
        fclose(file); /*closes file.txt to save*/ 
        czas = czas + 1; /*increases czas for writing to file*/
    }
 return 0;
}

Could somebody help me?

Answer 1

%s needs a char* as referring parameter.

You want to write out an int, which expects %d.

For details on this please see man fprintf.

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In case you like to have every new value of czas on a new line you can specify this in the fprintf() statement like so:

fprintf(file,"%d\n", czas);