See sigaction. --- On Thu, 1/12/11, naveen yadav <yad.naveen@gmail.com> wrote:

From: naveen yadav <yad.naveen@gmail.com> Subject: About signal handler install info To: Kernelnewbies@kernelnewbies.org, kernelnewbies@nl.linux.org Date: Thursday, 1 December, 2011, 3:33 PM Dear All,

I want to know is there any method/API  to know whether there is previous signal handler for specific signal no.

Example:

In below case  we install 3 handler. So my question is if before calling signal (SIGUSR1, handler2); is there any way i can get info that there is "handler1" already install with SIGUSR1.

        signal (SIGUSR1, handler1);         signal (SIGUSR1, handler2);         signal (SIGUSR1, handler3);

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

void *func ();

void handler1 () {         printf ("\nIn handler 1\n"); }

void handler2 () {         printf ("\nIn handler 2\n"); }

void handler3 () { printf ("\nIn handler 3\n"); } int main () {         int err=-1;         pthread_t t1,t2;

        signal (SIGUSR1, handler1);         sleep(5);         signal (SIGUSR1, handler2);         sleep(5);         signal (SIGUSR1, handler3);         sleep(5);         pthread_create (&t1, NULL, &func, NULL);

        sleep(20);

        return 0; }

void *func() {         while (1) usleep(10); }

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