#include <stdio.h>
#include <stdlib.h>

int main()
{ int p, s, comm[2];
  printf("step 1\n");
  pipe(comm);
  p = fork();
  if (p == 0)
  { close(1);
    dup(comm[1]);
    execlp("ls", "ls", "-l", NULL);
    fprintf(stderr, "execlp failed\n");
    exit(1); }
  char line[1000];
  while (1)
  { int r = read(comm[0], line, 1000);
    if (r <= 0) break;
    printf("received %s\n", line); }
  p = wait(& s);
  printf("subprocess %d finished, status %d\n", p, s);
  printf("step 2\n"); }