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

void sigfpe_handler(int sig)
{
  if (sig==SIGFPE)
    puts("SIGFPE handling works properly");
  else
    puts("sigfpe_handler called, but with bad parameter");
  exit(sig!=SIGFPE);
}
double reciprocal(double x)
{
  return 1./x;
}

int main(int argc, char *argv[])
{
  /* signal *ought* to be enough to get SIGFPE delivered
     -- but it never is -- see Yorick/sysdep.c */
#include <ieeefp.h>
  fpsetmask(FP_X_INV | FP_X_DZ | FP_X_OFL);
  /* INV --> invalid operation
     DZ  --> divide by zero
     OFL --> overflow
     are the three conditions you need to catch */

  signal(SIGFPE, &sigfpe_handler);

  printf("SIGFPE handling failed, 1./0.= %g\n",
         reciprocal((double)(argc<-1)));

  exit(2);  /* this is an "error" return! */
}