Tags: patch On POSIXish hosts it's long been safe to assume at least POSIX.1-1988, as the pre-POSIX platforms died out long ago. Attached is a patch to simplify Emacs to assume this for . I haven't tested this on Windows but have tried to make the Windows port work by renaming its O_NDELAY flag to O_NONBLOCK, as POSIX standardized the spelling of this flag to be O_NONBLOCK. I'll CC: this patch to Eli to give him a heads-up. This patch is relative to trunk bzr 110892.