I haven't had time to look at it carefully, but a couple of quick reactions:
* I expect it's useful to have a portable way to pass file descriptors; thanks. * The code should be redone to follow the usual GNU and gnulib formatting style. * It's not clear that this will work as part of a general substitute for 'openat'. For example, that would require a separate long-lived process, and the extra process is likely to mess things up for people or programs who do things like 'ps' and 'kill'.
