md[0].cur = pfd[1]; md[0].want = STDIN_FILENO;
md[1].cur = pfd[1]; md[1].want = STDOUT_FILENO;
md[2].cur = efd[1]; md[2].want = STDERR_FILENO;
md[0].cur = pfd[1]; md[0].want = STDIN_FILENO;
md[1].cur = pfd[1]; md[1].want = STDOUT_FILENO;
md[2].cur = efd[1]; md[2].want = STDERR_FILENO;