Linux operatsion tizimida signallar nima ekanligini va ular bilan qanday ishlashni tushuntiring

Linuxda signallar, proseslarga voqealar haqida asinxron xabar berish mexanizmi (masalan, uzilish, bolalar jarayonining yakunlanishi, timeout).

Asosiy nuqtalar:

• Signallar raqamli identifikatorlarga ega (masalan, SIGINT, SIGTERM).
• Jarayon signalni signal handler yordamida yoki uni ignor qilish orqali boshqarishi mumkin.
• Agar signal boshqarilmasa, standart harakat qo‘llaniladi (masalan, jarayonni yakunlash).

C tilida SIGINT (Ctrl+C) signali bilan ishlash misoli:

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

void handler(int signum) {
    printf("Signali %d qabul qilindi, yopilmoqda...\n", signum);
    _exit(0);
}

int main() {
    signal(SIGINT, handler);
    while(1) {
        printf("Ishlamoqda...\n");
        sleep(1);
    }
    return 0;
}

Shellda signallarni PID bilan kill komandasi yordamida yuborish mumkin, masalan, kill -SIGTERM 1234.