value computed is not used ??

["J." <mailing-lists@xs4all.nl>]

Tuesday, June 01 03:33:22

Hi ...

When I try to compile the listed program, with gcc version 2.95.4 20011002
and the command `gcc -Wall program.c -o program` It gives me a warning
message like: warning: value computed is not used

The program works perfectly fine, as far as I can judge the code isn't
wrong in any way ? And the value is certainly used.. Unfortunatly this
message shows to many times when I try to compile other code at my system.

Can anyone explain to me what the sense behind that warning is ? And what
to do about it ? e.g. what the ``better way`` of coding would be?

#include <stdio.h>

int main(void) {
 char *ptr = NULL;
 char str[] = "whats up";

 for(ptr = str; *ptr; *ptr++) {
  printf("%c", *ptr);
 }

 printf("\n");
 return 0;
}

Thnkx a lot...

Jeroen.