child 1 start
child 2 start
child 3 start
child 3 read  (0), finish

child 2 read  (0), finish

child 1 read  (0), finish

else {
        for (int j = 0; j < i; j++) {
            close(childs[j]);
        }
        close(p[1]);
        printf("child %d startn", i + 1);

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

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

    int children_w[3];

    for (int i = 0; i < 3; ++i) {
        int p[2];

        if (0>pipe(p))
            { perror("pipe"); exit(1); }

        pid_t pid;
        if(0> (pid= fork()))
            { perror("fork"); exit(1); }

        if(pid==0) {
            /* Fix -- close the leaked write ends  */
            int j;
            for(j=0; j<i; j++)
                close(children_w[j]);
            /* end fix*/
            close(p[1]);
            printf("child %d startn", i + 1);

            char buf[10];
            buf[0] = 0;
            int r;
            if ((r = read(p[0], buf, 9)) == -1) { perror("read");/*...*/ }

            printf("child %d read %s (%d), finishn", i + 1, buf, r);

            sleep(2);
            exit(0);
        }
        children_w[i] = p[1];
        close(p[0]);
    }

    for (int i = 0; i < 3; ++i) {
    //        if (argc > 1) {
    //            write(childs[i], "42", 2);
    //        }
    // ============== HERE >>>
        close(children_w[i]);
    }

    pid_t pid;
    while ((pid = waitpid(-1, NULL, 0)) > 0) {
         printf("child %d exitedn", pid);
    }

    return 0;
}