proj1main.cpp

#include "prog1_functions.hpp"

int main(int argc, char** argv) {

    //get number of children from command line
    int user_proc = atoi(argv[1]);

    pid_t pid = getpid();
    int child_num[25]; //array to hold the child number
    //can expect max. 25 children per the spec (section 3c.)
    int n_processes = 0; //counts number of finished child processes


    cout << "Parent pid is " << pid << endl;

    //used to track which proccess is started
    int tracker = 0;
    for(int i = 0; i < user_proc; i++) { //for loop to create child processes
        if (pid != 0) {
            pid = fork();
            child_num[i] = pid;
        }
        tracker++;

        if (pid == 0) { //pid == 0 within child process, child prints its own pid
            cout << "Started child with pid " << getpid() << endl;

            //switch statement with tracker to determine which test should be started on child
            //TODO replace each cout below with execlp call to start each test
            switch(tracker) {
                case 1:
                    execl("./test1", "test1", nullptr);
                    cout << "Error starting child " << getpid() << endl;
                    break;
                case 2:
                    execl("./test2", "test2", nullptr);
                    cout << "Error starting child " << getpid() << endl;
                    break;
                case 3:
                    execl("./test3", "test3", nullptr);
                    cout << "Error starting child " << getpid() << endl;
                    break;
                case 4:
                    execl("./test4", "test4", nullptr);
                    cout << "Error starting child " << getpid() << endl;
                    break;
                case 5:
                    execl("./test5", "test5", nullptr);
                    cout << "Error starting child " << getpid() << endl;
                    break;
            }

            break;
        }
        //once all 5 programs have been started, reset to beginning
        if(tracker == 5){
            tracker = 0;
        }
    }

    
    if (pid > 0) { //pid > 0 within parent process, waits for child to finish
        while(n_processes < user_proc) { //while the number of running processes is less than the amount the user requested
            pid_t child_pid = wait(NULL);
            if(child_pid > 0) { //needed to include this to prevent invalid PIDs of -1? not sure why
                cout << "Child " << findIndex(child_pid, child_num)+1 << " (PID " << child_pid << ") finished" << endl;
                n_processes++; //iterate the number of finished child processes
            }
        }
    }
    return 0;
}