Path: utzoo!attcan!uunet!tut.cis.ohio-state.edu!brutus.cs.uiuc.edu!apple!ames!sgi!calcite!vjs From: vjs@calcite.UUCP (Vernon Schryver) Newsgroups: comp.unix.microport Subject: Re: life after death (of uport) Keywords: SIGHUP DCD Message-ID: <61@calcite.UUCP> Date: 13 Aug 89 05:21:42 GMT References: <57@calcite.UUCP> <6344@turnkey.gryphon.COM> <1355@ctisbv.cti-software.nl> Organization: Rhyolite Software, Mountain View, CA Lines: 37 > vjs@calcite.UUCP (Vernon Schryver) [the undersigned] wrote: > > The 2.0.2 driver seems to understand NDELAY to mean > >(1) "open even if DCD is false, and die if ever NDELAY and DCD are both > >false", instead of (2) "open even if DCD is false, and do not pay attention > >to DCD until DCD has been true." Whatever, the result is that cu(1) > >looses the port as soon as it turns off NDELAY. In article <1355@ctisbv.cti-software.nl>, pim@cti-software.nl (Pim Zandbergen) writes: > This is exactly how NDELAY should work. You should set CLOCAL immediately > after having opened with O_NDELAY, if you want to keep the line after > having turned off NDELAY. > > Cu and uucp will do this if you specify \M (set CLOCAL) and \m (turn it off) >in the Dialers file. This feature was introduced in HDB uucp in System V r 3.1. > Pim Zandbergen internet : pim@cti-software.nl > CTI Software BV uucp : ..!uunet!ctisbv!pim > Laan Copes van Cattenburch 70 phone : +31 70 542302 > 2585 GD The Hague, The Netherlands fax : +31 70 512837 I disagree. It is fine for open(2) wait until DCD is true unless NDELAY is present. It is good to suffer SIGHUP and permanent "eof" (read(2)==0) after the driver sees a falling edge. It is wrong to generate SIGHUP or eof if DCD has not changed. I did try \M & \m, and there is no way I can find to set CLOCAL soon enough. If ISC is right, then SVR3.2 cu(1) and UUCP do not work for any modem which supports out-going carrier indication. I repeat, if you do it "right" by my definition, not only do cu & UUCP work, but so do uugetty, SLIP, etc. It seems likely to me that my definition of right is not that far from AT&T's. At least, for one major workstation maker, my word is canonical. I don't recall seeing the \[mM] stuff in the source until SVR3.2, at least on the 3B2 tape, from which I merge AT&T changes with local "improvments." Vernon Schryver vjs@calcite.uucp