test.c

#include <unistd.h>
#include <sys/wait.h>
#include <assert.h>

int main(void) {
  int fds_to_child[2];
  int fds_to_parent[2];
  int i;
  char ch = 'x';
  int status;
  pid_t child;

  pipe(fds_to_child);
  pipe(fds_to_parent);

  child = fork();
  if (!child) {
    for (i = 0; i < 100000; ++i) {
      read(fds_to_child[0], &ch, 1);
      write(fds_to_parent[1], &ch, 1);
    }
    return 77;
  }

  for (i = 0; i < 100000; ++i) {
    write(fds_to_child[1], &ch, 1);
    read(fds_to_parent[0], &ch, 1);
  }

  wait(&status);
  assert(WIFEXITED(status) && WEXITSTATUS(status) == 77);

  return 0;
}