Child process can't send signal to itself.
Hi!
When I am trying to execute the following program the child process simply waits for the signal.
Code:
#include <stdio.h>
#include <unistd.h>
#include <signal.h>
#include <stdlib.h>
#include <sys/types.h>
static int alarm_fired = 0;
void ding(int sig)
{
alarm_fired = 1;
}
int main()
{
pid_t pid;
(void)signal(SIGALRM, ding);
printf("alarm application starting.\n");
pid = fork();
switch(pid){
case -1:
/* failure */
perror("Fork failed");
exit(1);
case 0:
/* child */
sleep(1);
kill(getpid(), SIGALRM);
break;
default:
exit(0);
}
printf("waiting for alarm to go off\n");
pause();
if(alarm_fired)
printf("Ding!\n");
exit(0);
}
Output:
linux:~/prog # ./thread
alarm application starting.
linux:~/prog # waiting for alarm to go off
...waits here...
Why can't the child process send the signal to itself?
Regards,
Arun
