Jarayon yaratish - fork va exec

#include <stdio.h>
#include <unistd.h>
#include <sys/wait.h>

int main(void) {
    printf("Boshlanish\n");
    fflush(stdout);                 /* fork dan oldin buferni bo'shatamiz */

    pid_t natija = fork();

    if (natija < 0) {
        printf("fork muvaffaqiyatsiz\n");
        return 1;
    }

    if (natija == 0) {
        printf("  Men bola jarayonman\n");
        return 0;
    }

    wait(NULL);                     /* bolani kutamiz */
    printf("Men ota jarayonman\n");

    return 0;
}

#include <stdio.h>
#include <unistd.h>
#include <sys/wait.h>

int global_son = 100;

int main(void) {
    int mahalliy_son = 200;

    pid_t bola = fork();

    if (bola == 0) {
        global_son += 1;
        mahalliy_son += 1;
        printf("  Bola  : global=%d mahalliy=%d\n", global_son, mahalliy_son);
        return 0;
    }

    wait(NULL);
    printf("Ota   : global=%d mahalliy=%d\n", global_son, mahalliy_son);

    return 0;
}

#include <stdio.h>
#include <unistd.h>
#include <sys/wait.h>

int main(void) {
    for (int i = 1; i <= 3; i++) {
        pid_t bola = fork();

        if (bola < 0) {
            return 1;
        }

        if (bola == 0) {
            printf("  %d-bola ishladi\n", i);
            return 0;               /* bola siklni davom ettirmasin! */
        }

        wait(NULL);                 /* har bir bolani navbatma-navbat kutamiz */
    }

    printf("Barcha bolalar tugadi\n");
    return 0;
}

#include <stdio.h>
#include <unistd.h>
#include <sys/wait.h>

int main(void) {
    printf("exec dan oldin\n");
    fflush(stdout);                 /* buferni bo'shatamiz */

    pid_t bola = fork();

    if (bola == 0) {
        char *argumentlar[] = {"echo", "  Men endi echo dasturiman", NULL};
        execvp("echo", argumentlar);

        /* bu yerga faqat exec muvaffaqiyatsiz bo'lganda yetamiz */
        printf("  exec ishlamadi\n");
        _exit(1);
    }

    wait(NULL);
    printf("exec dan keyin (ota)\n");

    return 0;
}

execl("/bin/ls", "ls", "-l", NULL);              /* to'liq yo'l */
execlp("ls", "ls", "-l", NULL);                  /* PATH dan topadi */

char *argv[] = {"ls", "-l", NULL};
execvp("ls", argv);                              /* massiv bilan */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/wait.h>

int buyruq_bajar(char *argumentlar[]) {
    fflush(stdout);                 /* bola buferni takrorlamasin */

    pid_t bola = fork();

    if (bola < 0) {
        return -1;
    }

    if (bola == 0) {
        execvp(argumentlar[0], argumentlar);
        _exit(127);                 /* exec ishlamadi */
    }

    int holat;
    waitpid(bola, &holat, 0);

    if (WIFEXITED(holat)) {
        return WEXITSTATUS(holat);
    }

    return -1;
}

int main(void) {
    char *birinchi[] = {"echo", "Birinchi buyruq", NULL};
    char *ikkinchi[] = {"echo", "Ikkinchi buyruq", NULL};
    char *xato[] = {"bunday_buyruq_yoq_12345", NULL};

    printf("Natija 1: %d\n", buyruq_bajar(birinchi));
    printf("Natija 2: %d\n", buyruq_bajar(ikkinchi));
    printf("Natija 3: %d\n", buyruq_bajar(xato));

    return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/wait.h>

int main(void) {
    pid_t bola = fork();

    if (bola == 0) {
        printf("  Bola 42 kodi bilan tugaydi\n");
        exit(42);
    }

    int holat;
    waitpid(bola, &holat, 0);

    if (WIFEXITED(holat)) {
        printf("Bola normal tugadi, kodi: %d\n", WEXITSTATUS(holat));
    } else if (WIFSIGNALED(holat)) {
        printf("Bola signal bilan to'xtadi: %d\n", WTERMSIG(holat));
    }

    return 0;
}

#include <stdio.h>
#include <unistd.h>
#include <sys/wait.h>

int main(void) {
    pid_t bola = fork();

    if (bola == 0) {
        printf("  Bola darhol tugaydi\n");
        return 0;
    }

    /* Ota bolani kutmasdan ishlashda davom etadi.
       Shu payt bola ZOMBI holatida. */
    sleep(1);

    printf("Ota endi bolani o'qiydi\n");
    wait(NULL);                     /* zombi tozalandi */
    printf("Zombi yo'q qilindi\n");

    return 0;
}

ps aux | awk '$8 ~ /^Z/ {print}'

#include <stdio.h>
#include <unistd.h>

int main(void) {
    pid_t bola = fork();

    if (bola == 0) {
        pid_t oldingi_ota = getppid();
        sleep(2);                   /* ota bu vaqtda tugaydi */
        pid_t yangi_ota = getppid();

        printf("  Bola: ota o'zgardimi? %s\n",
               oldingi_ota != yangi_ota ? "ha" : "yo'q");
        printf("  Bola: yangi ota PID 1 mi? %s\n",
               yangi_ota == 1 ? "ha" : "yo'q (init boshqa jarayon)");
        return 0;
    }

    printf("Ota tugadi (bola hali ishlayapti)\n");
    return 0;
}

Ota tugadi (bola hali ishlayapti)
  Bola: ota o'zgardimi? ha
  Bola: yangi ota PID 1 mi? yo'q (init boshqa jarayon)

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/stat.h>

int demon_bol(void) {
    pid_t bola = fork();

    if (bola < 0) {
        return -1;
    }

    if (bola > 0) {
        _exit(0);                   /* ota chiqadi - bola yetim bo'ladi */
    }

    /* Endi biz yetimmiz. Yangi sessiya boshlaymiz. */
    if (setsid() < 0) {
        return -1;
    }

    /* Ikkinchi fork - terminalga qayta ulanib qolmaslik uchun */
    bola = fork();

    if (bola < 0) {
        return -1;
    }

    if (bola > 0) {
        _exit(0);
    }

    umask(0);
    if (chdir("/") < 0) {
        return -1;
    }

    return 0;
}

int main(void) {
    printf("Demon yaratish qadamlari tayyor\n");
    printf("Haqiqiy demon uchun demon_bol() chaqiriladi\n");
    return 0;
}

#include <stdio.h>
#include <unistd.h>
#include <sys/wait.h>
#include <time.h>

#define MARTA 200

int main(void) {
    struct timespec boshlandi, tugadi;

    clock_gettime(CLOCK_MONOTONIC, &boshlandi);

    for (int i = 0; i < MARTA; i++) {
        pid_t bola = fork();

        if (bola == 0) {
            _exit(0);
        }

        wait(NULL);
    }

    clock_gettime(CLOCK_MONOTONIC, &tugadi);

    double vaqt = (double) (tugadi.tv_sec - boshlandi.tv_sec) +
                  (double) (tugadi.tv_nsec - boshlandi.tv_nsec) / 1e9;

    printf("%d ta jarayon yaratildi\n", MARTA);
    printf("Vaqt musbatmi? %s\n", vaqt > 0.0 ? "ha" : "yo'q");

    /* aniq raqamni ko'rish uchun: */
    /* printf("Bittasiga o'rtacha: %.1f mikrosoniya\n", vaqt / MARTA * 1e6); */

    return 0;
}