kevin@cfctech.cfc.com (Kevin Darcy) (05/30/91)
In article <1991May24.212235.8187@otsc.eds.com> snyde_sl@tsca02.uucp (Steve Snyder) writes: >Our site recently established a newsfeed. We are running C news (last >patch date is 24-Mar-91) and rn (last patch date is 01-Jan-91, # 54) >on an Apollo DN3000 under Domain/OS SR10.2 (sys 5.3 environment). >The ASCII terminals we have are connected to Black Box terminal >servers. > >The problem we are having concerns using rn over a telnet or rlogin >connection to the news server. It seems that regardless of what type >of terminal (VT100, VT320, PC, SUN SPARC2, HP9000/380, or even another >Apollo bitmap display) I use to telnet to the news server, this >problem occurs. The problem is that rn repeatedly displays the >first '--read now? [npq]' prompt (beeping every time) as shown below: > > [example given] > >So I just have to quit and get out of rn. [further details] > >Any ideas why rn responds this way over a telnet connection, or >possible solutions to this problem? I've run out of ideas. I posted >this previously to news.software.b and news.newusers.questions but got >no responses. We've seen identical behavior from rn and trn over AT&T Starlan connections on 3B2's. My guess is that the pty driver used by your telnetd is based on STREAMS, and the rn/trn code is known to not handle STREAMS-based tty drivers quite correctly in O_NDELAY mode. Specifically, the code doesn't respect the following critical distinction (this is a quote from the read(2) section of a vendor manual): When attempting to read a file associated with a tty has no data currently available: If O_NDELAY is set, the read will return 0. [...] When attempting to read a file associated with a _stream_ that has no data currently available: If O_NDELAY is set, the read will return a -1 and set errno to EAGAIN. We have a local hack that works around this problem. I can send it to anyone who is interested. Followups to news.software.b and/or comp.unix.programmer. >Steve Snyder | You've got to know when to code 'em, >Electronic Data Systems | know when to modem, know when to load 'em, >snyde_sl@otsc.eds.com | and know when to run. >uunet!tsca02!snyde_sl | --Anonymous ------------------------------------------------------------------------------- kevin@cfctech.cfc.com | Kevin Darcy, CFC Unix Systems Administrator ...sharkey!cfctech!kevin | MIS/Technical-Services/Distributed-Systems Voice: (313) 759-7140 | Chrysler Corporation Fax: (313) 758-8173 | 25999 Lawrence, Center Line, MI 48015 -------------------------------------------------------------------------------