int fcntl_flags;
if ((fcntl_flags = fcntl (fd[1], F_GETFL, 0)) < 0
- || fcntl (fd[1], F_SETFL, fcntl_flags | O_NONBLOCK) < 0
+ || fcntl (fd[1], F_SETFL, fcntl_flags | O_NONBLOCK) == -1
|| (fcntl_flags = fcntl (fd[0], F_GETFL, 0)) < 0
- || fcntl (fd[0], F_SETFL, fcntl_flags | O_NONBLOCK) < 0)
+ || fcntl (fd[0], F_SETFL, fcntl_flags | O_NONBLOCK) == -1)
{
if (exit_on_error)
error (EXIT_FAILURE, errno,