While Loop in C

[ChipDIP]

Hi,

I am trying to create a log table to use with a uC.
My program is below. It works for tables up to about 300 lines.
If I increase it, I lose the top lines in the table in the CMD window
How can I make it so it will do 4096 lines.
Also what would be the best way to output it in a .txt file?

Thanks

#include <math.h>
#include <stdio.h>

int main( void )
{

int i=1;
double x = 1.0, y = 1.0067, z;

z= (x*y);
printf("%d  %1f  \n",i,x);
i++;
while (i<=100) {
printf("%d  %1f  \n",i,z);

z= (z*y);
 i++;}


  return 0;
}

[tabstop]

If you want 4096 lines in your command prompt window, you'll have to fiddle with your command prompt. To get a file, you need to look at fopen and fprintf.

[ChipDIP]

Thanks for the tip on the CMD window. That is much better now.

I have looked at the fopen and tried a few things but I am having trouble incorporating
into the loop. All I can get it to do is print the last line to a file.

Any code examples would be helpful. I am a real beginner and am not
getting it.

Thanks

[tabstop]

You shouldn't keep opening/closing the file inside the loop -- open it before the loop starts, then each pass through the loop should just add one line.

[ChipDIP]

Here is how I did it.

#include <math.h>
#include <stdio.h>

int main( void )
{

  int i=1;
  double x = 1.0, y = 1.0020, z;

  FILE *fp;
fp=fopen("test.txt", "w");


z= (x*y);
    printf("%d  %1f \n",i,x);
	fprintf(fp,"%d  %1f \n",i,x);
	i++;
  while (i<=4096) {
	  	    printf("%d  %1f\n",i,z);
				  	    fprintf(fp,"%d  %1f\n",i,z);

z= (z*y);
 i++;}
 
  return 0;
}

[Typpo]

Make sure you call:

fclose(fp);

before your program ends. You should put that before the return.