为信号分配特定的信号处理程序

Question

I have a question concerning signals in C. I want to assign some a specific sighandler to a signal.

My function is:

void searchOccurences(char **myString, char chr, int *occurences) {
   /* I perform some search actions here 
    * at the end of this function *occurrence will contain the 
    * the number occurrences of chr in myString*/
}

I want to assign this function to the SIGILL signal (ie Illegal Instruction Signal), but I can't because the __sighandler_t handlers are of this kind of definition:

typedef void (*__sighandler_t) (int);

So How can I assign my function to this signal? What are the alternative solutions to what I want to do?

Thanks :)

Answer 1

Don't use SIGILL, that could mask a genuine error. SIGUSR1 and SIGUSR2 are specifically for user defined signals.

You can't pass additional information, sorry, but there it is. The best you can do is to store information in a global before raising a signal, but you must be certain of the sequence of events, or use some sort of synchronisation like a mutex.

By the way, are you aware that many C runtime library functions are not signal safe?