Re: [tlug] logic error with code hosted on your servers

[Michael <mohr@example.com>]

Okay, thanks for your corrections. I retried compiling the original code
and it seems to work now.  Strangely enough, the exact same code yesterday
completely failed to work.  It gave a nondescript error saying
"Initialization failed" and refused to start up.  I searched until I found
this error status (there were 2 places) and after disabling the check the
program would start.  Strange that it works today.

I'll replace the binary on my system, since I was quite obviously mistaken
:)

-Mike

On Sun, 14 Mar 2004, Botond Botyanszki wrote:

> On Sun, 14 Mar 2004 02:00:54 -0800 (PST)
> mohr@example.com wrote:
>
> > if ((context = RkwInitialize( (char *)ddname )) < 0)
> >
> > As you can see, this comparison will always fail,
> That's not true, you should review the C grammar.
>
> > causing the program to
> > exit prematurely (giving an extremely nondescript error).  This line
> > should read:
> >
> > if ((context == RkwInitialize( (char *)ddname )) < 0)
> While the RkInitialize function returns either 0 or -1 according to the
> manage, RkwInitialize might return something more complex, otherwise using
> a comparison against context wouldn't make much sense. And the above == is
> a boolean comparison that is either TRUE or FALSE and there is no reason
> you would want to use '<' to compare that value.
>
> Here is an example that will help you understand the scenario:
>
> int returns_zero() {
>   return 0;
> }
> int returns_one() {
>   return 1;
> }
>
> int main (int argc, char **argv) {
>     int retval;
>     if ((retval = returns_zero()) == 0) printf("OK\n");
>     if ((retval = returns_one()) == 1) printf("OK\n");
>     if ((retval = returns_zero()) == 1) printf("NG\n");
>     if ((retval = returns_one()) == 0) printf("NG\n");
> }
>
>
> > Which will perform the comparison correctly and allow the server to run.
> I'm not the author but I think the error is somewhere else.
>
> --
> TLUG server is hosted by Open Source Development Lab Japan
> http://www.osdl.jp/
>
> To unsubscribe from this mailing list,
> please see the instructions at <http://www.tlug.jp/list.html>
>