READ_PIPE
close(output_pipe[READ_PIPE]);
if ((fp = fdopen(output_pipe[READ_PIPE], "r")) == NULL) {
close(stdout_pipe[READ_PIPE]);
if (stdin_pipe[READ_PIPE] != STDIN_FILENO) {
dup2(stdin_pipe[READ_PIPE], STDIN_FILENO);
close(stdin_pipe[READ_PIPE]);
close(stdin_pipe[READ_PIPE]);
close(stdout_pipe[READ_PIPE]);
in = fdopen(stdout_pipe[READ_PIPE], "r");