lab-next parent

#include <ctime>
#include <unistd.h>
#include <fstream>

using namespace std;

int main()
{
    ofstream fout;
    fout.open("lab-next.txt");
    char buffer[80];
    time_t seconds;
    tm* timeinfo;
    char* format = "%H:%M:%S";
    int pid = getpid();
    execl("./lab-next-d1", "lab-next-d1", NULL, (char*)0);
    execl("./lab-next-d2", "lab-next-d2", NULL, (char*)0);
    execl("./lab-next-d3", "lab-next-d3", NULL, (char*)0);
    for (int k=0; k<=100; k++) {
        seconds = time (NULL);
        timeinfo = localtime (&seconds);
        strftime(buffer, 80, format, timeinfo);
        fout << k << " " << pid << " " << buffer << "\n";
    }
}