[Ma-linux] perplexing hardware problem

[DonJr]

On Fri, 2008-02-15 at 13:31 -0500, Kevin Dwyer wrote:
> On Fri, Feb 15, 2008 at 10:39 AM, Alan McConnell <alan at patriot.net>
> wrote:
>         On Fri, Feb 15, 2008 at 09:29:33AM -0500, Przemek Klosowski
>         wrote:
>         > A couple of short versions in C:
>         >
>         >   int main(){ printf("\a")}
>         >
>         > or
>         >
>         >   int main(){ asm volatile (".data\nA: byte 7\n.text\n mov
>         $0x4,%eax\nmov $0x1,%ebx\nmov $A,%ecx\nmov $0x1,%edx\nint
>         $0x80\nmov $0x1,%eax\nxor %ebx,%ebx\nint $0x80")}
>         >
>         > or even
>         >
>         >    char main[] = {0xB8, 0x04, 0x00, 0x00, 0x00, 0xBB, 0x01,
>         0x00, 0x00, 0x00, 0xB9, 0x00, 0x00, 0x00, 0x00, 0xBA, 0x01,
>         0x00, 0x00, 0x00, 0xCD, 0x80, 0xB8, 0x01, 0x00, 0x00, 0x00,
>         0x31, 0xDB, 0xCD, 0x80, 0xC3};
>         
>         
>                Showoff!!  (Where's the accompanying Makefile???)
> 
> gcc -x c - <<<'int main(){printf("\a");}'

I had to laugh when I saw this, so I just had to try and see if it still
worked and I got the following:
 <stdin>: In function ‘main’:
 <stdin>:1: warning: incompatible implicit declaration of built-in
  function ‘printf’

And YES the a.out still beeped.

Then I wondered how do you get rid of the warning and came up with the
following:

echo -e '#include<stdio.h>\n int main(){printf("\\a");}' | gcc -x c - ;\
./a.out ; rm a.out

Still seems like a lot of bother just to make the little speaker go
beep. <GRIN>

-- 
 DonJr