sigaction - why don't we have to reset the handler?
#include <unistd.h>
#include <stdio.h>
#include <signal.h>

void func(int sig)
{
 printf("caught signal:%dn",sig);
 // Not needed to reset handler. Why?
}

int main()
{
 struct sigaction sa;

 sa.sa_handler=(void*)func;
 sigaction(SIGRTMIN,&sa,NULL);
 kill(0,SIGRTMIN);
 kill(0,SIGRTMIN);
 kill(0,SIGRTMIN);
}
Output:
[root@dhcppc0 signals]# ./a.out
     caught signal:34
     caught signal:34
     caught signal:34 (3 times signal caught by same handler without resetting handler)