#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>

void handler(int);



main()
{
    if (signal(SIGINT, handler) == SIG_ERR) {
        fprintf(stderr, "cannot set handler for SIGUSR1\n");
        exit(1);
    }
for(;;){
write(1,"1HI\n", 4);
write(2,"2By\n", 4);
}
}
void
handler(int sig)
{

    if (signal(SIGINT, handler) == SIG_ERR) {
        fprintf(stderr, "cannot set handler for SIGUSR1\n");
        exit(1);
    }
    psignal(sig, "Received signal");
}