Path: utzoo!attcan!uunet!lll-winken!lll-tis!helios.ee.lbl.gov!pasteur!ames!ucsd!rutgers!att!whuts!homxb!hropus!ki4pv!tanner From: tanner@ki4pv.uucp (Dr. T. Andrews) Newsgroups: comp.unix.questions Subject: Re: fcntl() versus ioctl() Keywords: FNDELAY Message-ID: <7034@ki4pv.uucp> Date: 14 Sep 88 01:18:39 GMT References: <1380@solo7.cs.vu.nl> Organization: CompuData Inc., DeLand Lines: 23 In article <1380@solo7.cs.vu.nl>, maart@cs.vu.nl (Maarten Litmaath) writes: ) Isn't it a dubious feature that the PARENT should suffer if a CHILD ) decides) to set the FNDELAY flag of stdin? It's an FCNTL() we're ) talking about, not an IOCTL()! Well, this is a good question. Let's examine it. First of all, note that fcntl(2) operates on file descriptors (just like ioctl(2) does). In many environments, it even offers several of the same sorts of controls. I don't see any moral difference between fcntl(2) and ioctl(2), myself. Thus, if ioctl() might cause a parent to suffer, fcntl() may be expected to have a similar hazard. Now, consider the effect proposed by maart@cs.vu.nl above: that the parent's fd should not be affected by a child's action. Mainly, the "stty" command (remember: commands are run as children of shells) no longer works. It is no longer practical to change your tty modes. You're stuck with whatever "getty" decided was best for you. Alternatively, everything which might be used as a shell needs to learn about the "stty" command, or else to set tty modes to your satisfaction via the RPM instruction. -- ...!bikini.cis.ufl.edu!ki4pv!tanner ...!bpa!cdin-1!cdis-1!ki4pv!tanner or... {allegra killer gatech!uflorida decvax!ucf-cs}!ki4pv!tanner