Child not Responding - c

Question

Hello I'm having issues with sending signals from the father process to the child process. The Child doesn't respond to the signed sent by the father process:
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
int main()
{
pid_t pid;
pid = fork();
if(pid > 0) {
printf("Hello, my son!\n");
sleep(5); /* Sleep for 5 seconds... */
kill(pid, SIGUSR1);
printf("Goodbye, son!\n");
}
else {
printf("Son is running\n");
pause(); /* Wait for some signal... */
printf("I received the signal!");
}
}
The son doesn't received the signal it only says it's running here is the output:
output

Answer 1

The default behavior when SIGUSR1 is received is termination, so the child never prints the message. To handle the signal, you can use sigaction:
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
void handle(int sig, siginfo_t *i, void *v) { return; }
int
main(void)
{
pid_t pid = fork();
if( pid > 0 ){
printf("Hello, my child!\n");
sleep(1); /* Sleep for 1 second. */
kill(pid, SIGUSR1);
printf("Goodbye, child!\n");
} else {
struct sigaction act;
memset(&act, 0, sizeof act);
act.sa_sigaction = handle;
if( sigaction( SIGUSR1, &act, NULL ) ){
perror("sigaction");
exit(1);
}
printf("Child is running\n");
pause(); /* Wait for some signal... */
printf("I received the signal!\n");
}
}