Re: [9fans] signal.h in APE for newbies

["Fernan Bolando" <fernanbolando@mailc.net>]

On 7/4/08, Charles Forsyth <forsyth@terzarima.net> wrote:
> > When I trigger a division by zero the handler is not called, I just
>  > get trap 19 message.
>
>
> if i do a floating-point division by zero, the SIGFPE signal handler is called,
>  because ape's signal recognises the initial "sys: fp: ".  (ie, it works for me.)
>
>  it doesn't work for an integer division by zero, which produces a different message for the underlying notify:
>
>  8.out 205840: suicide: sys: trap: divide error pc=0x00001089
>
>  but that's fine too! Linux's signal(2) says, apparently referring to POSIX rules:
>
>         ....  Integer division by zero  has  undefined  result.
>        On some architectures it will generate a SIGFPE signal.  (Also dividing
>        the most negative integer by -1 may generate  SIGFPE.)   Ignoring  this
>        signal might lead to an endless loop.
>
>  Linux might not be particularly good at documenting this particular area,
>  so perhaps the standard(s) have useful hints or advice that APE could follow.
>
>

Any chance this is some 9vx issue? I tried the test code below it
worked in 9grid.jp ,but gave the following message in 9vx

8.out 89: suicide: sys: trap: 19 (reserved) pc=0x00001067


#include <stdio.h>
#include <signal.h>

void e_hand(int sig)
{
	printf("Signal");
	return;
}
int main()
{
double a, d;

                  d = 5.0;

	signal(SIGFPE, e_hand);
	a = 1/(d-5);
	return 0;
}


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