Parent process forked a child to print() some output using fflush(NULL) and does _exit(0);

After the child exits, the parent where I had added a sigaction for signals 1-15 and 33-300 shows varied signal number each time, the child is forked, prints and exits. sometimes it shows 11, 43 , 100, 123 ....


How to figure out why such bogus values are coming? If I add explicitly a handler for SIGCHLD, it works fine!! If no user-defined handler, some bogus signal no is shown each time ...

Any pointers or help in this regard is appreciated.

Thanks,
bsr

looks like you got a random number from the outer space, not a real signal...

But what is the reason for such signals, which are not standard/real-time? Can I use sigaction to catch and process such signals that is > 64 ?

You did not catch those signals, you got a random number instead of the real signal number.

I used sigaction to register for all signals ranging from 1 to 16 and 18 to 300.
But it is not invoking the handler for any signal in this range.

If I include signal 17 (SIGCHLD), I can see that the handler in sigaction is invoked!

for me sigaction dies for 9, 19, 32, 33 and every other signal above 64. would be nice to see your code....