OS Lab 05

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oel.cC

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

int main() {
    // getpid() returns the process ID of the current process
    printf("\nProcess ID is: %d\n", getpid());
    return 0;
}

task2.cC

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

int main() {
    pid_t ret_value;

    printf("\nInitial Process ID is: %d\n", getpid());

    ret_value = fork();

    if (ret_value < 0) {
        // Fork failure
        printf("\nFork Failure\n");
        return 1;
    } 
    else if (ret_value == 0) {
        // Child Process
        printf("\n[Child Process]");
        printf("\nChild Process ID: %d", getpid());
        printf("\nParent Process ID (from child): %d\n", getppid());
    } 
    else {
        // Parent Process
        printf("\n[Parent Process]");
        printf("\nParent Process ID: %d", getpid());
        printf("\nCreated Child Process ID: %d\n", ret_value);
    }

    return 0;
}

task3.cC

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

int main() {
    pid_t ret_value;

    printf("\nMain Process Started | ID: %d\n", getpid());

    ret_value = fork();

    if (ret_value < 0) {
        printf("\nFork Failure\n");
        return 1;
    } 
    else if (ret_value == 0) {
        // Child Process executes and finishes
        printf("\n[Child Process] Executing | ID: %d\n", getpid());
    } 
    else {
        // Parent Process sleeps for 20 seconds
        printf("\n[Parent Process] ID: %d | Sleeping for 20 seconds...\n", getpid());
        sleep(20);
        printf("\n[Parent Process] Woke up and exiting.\n");
    }

    return 0;
}

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