int main()

{
               FILE *fp;
               char *args[40];
               pid_t child, exited_pid;
               int status = 0;
               *args[0] = "less";
               fp = popen("ls", "r");
               child = fork();
               if(child == 0)
              {
                      dup2(fp->fd, 0);
                      if(execvp(args[0], args) == -1)
                             {
                                printf("error");
                               exit(EXIT_FAILURE);
                              }

                wait(&status);
                wait(&status);
}