kill test

main.cpp

//#include <QCoreApplication>

//int main(int argc, char *argv[])
//{
//    QCoreApplication a(argc, argv);

//    return a.exec();
//}

#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
/* When a SIGUSR1 signal arrives, set this variable. */
volatile sig_atomic_t usr_interrupt = 0;

void
synch_signal (int sig)
{
    usr_interrupt = 1;
}

/* The child process executes this function. */
void
child_function (void)
{
    /* Perform initialization. */
    printf ("I'm child!!!  My pid is %d.\n", (int) getpid ());

    sleep(10000);

    /* Let parent know you’re done. */
//    kill (getppid (), SIGUSR1);

    /* Continue with execution. */
    puts ("Bye, now....");
//    exit (0);
}

int
main (void)
{

//    pid_t pid; //pid_t 선언

//    pid = fork(); //fork 발생
//    if(pid == -1) { //-1 이면 fork생성 에러
//        printf("can't fork, erro\n");
//        exit(0);
//    }

//    if(pid == 0) { //0이면 자식 프로세스
//        int j;
//        for(j = 0; j < 10; j++) {
//            printf("child: %d\n", j);
//            sleep(1);
//        }
//        exit(0);
//    } else { //부모프로세스
//        int i;
//        for(i = 0; i < 10; i++) {
//            printf("parent : %d\n", i);
//            sleep(1);
//        }
//        exit(0);
//    }
//    return 0;

    struct sigaction usr_action;
    sigset_t block_mask;
    pid_t child_id;

    /* Establish the signal handler. */
    sigfillset (&block_mask);
    usr_action.sa_handler = synch_signal;
    usr_action.sa_mask = block_mask;
    usr_action.sa_flags = 0;
    sigaction (SIGUSR1, &usr_action, NULL);

    /* Create the child process. */
    child_id = fork ();
    if (child_id == 0) {
        child_function ();          /* Does not return. */
    } else {
        printf("parent goes child is %d\n", child_id);
        int ret = kill(child_id, SIGHUP);
        printf("kill 1 with %d\n", ret);
        ret = kill(child_id, SIGHUP);
        printf("kill 2 with %d\n", ret);
//        sleep(10000);
    }

    /* Now continue execution. */
    puts ("That's all, folks!");

    return 0;
}

Makefile

all:
        gcc main.cpp -o kill