lubkin@cs.rochester.edu (Saul Lubkin) (10/08/90)
I've noticed that there have been some postings about pcomm, in which people had problems with it. I should note that I compiled pcomm, with the standard System V C compiler that comes with ISC V/386 2.0.2, and that I've had absolutely no problems with it. Quite the contrary; I very much like the program. I use it instead of cu (or Procomm running under DOS under VP/ix). I like pcomm's script language: namely, it's simply the Unix shell! So, you don't have to learn a new language. I'm writing this note now, logged onto my account in the Computer Science Dept. at the Univ. of Rochester, from my home ISC Unix computer, connected via a Hayes compatible 2400 Baud modem, using pcomm. I have no trouble running vi remotely, this way (as I am now). I noticed postings to the net, describing strange bugs in pcomm, that seem to suggest memory management problems. I think I might know the source of these problems (anyway, here's a guess:) When you compile pcomm, you're supposed to edit a setup file, which sets certain parameters for your system. One of these, is to indicate whether to use "bcopy"(a standard Berkeley Unix C function, for copying a block of memory), or "memcpy" (essentially the same thing, on System V systems). There is also a third option, that indicates that you don't have either (or that there's something wrong with the one that you have). Although ISC System V/386, and other flavors of V/386, have "memcpy" (but usually not "bcopy"), I chose the third alternative; namely, that I don't have either. The reason: pcomm's documentation indicates that this copying function is supposed to work correctly, EVEN IF COPYING TO A PARTIALLY OVERLAPPING REGION. Berkeley "bcopy" is guaranteed to work correctly, in such cases -- but, on reading the AT&T manuals about "memcpy", the manuals specifically warn that (not quoted exactly) "some implementations of Sys V memcpy" do not work correctly under those circumstances. So, I told "pcomm" that I DIDN'T have a susitable "memcpy" or "bcopy" (since in fact I probably don't). "pcomm" substituted it's own (trivial to program) routine for the missing "bcopy" -- and the resultiong "pcomm" has worked perfectly. Just thought that I would share this with you netlanders. My thanks to the author of pcomm, for an excellent program. Saul Lubkin lubkin@rochester.cs.edu
tmh@prosun.first.gmd.de (Thomas Hoberg) (10/13/90)
There is a version of 'bcopy' in the internet library that comes with ISC (/usr/lib/libinet or -linet on the CC comand line), which I suppose works according to the BSD semantics. There are some other interesting BSDisms there, too, like 'select' (I am not too happy with that one, it doesn't seem to work with EMACS--I get "select error: not a typewriter" when using it with X11). ---- Thomas M. Hoberg tmh@prosun.first.gmd.de GMD Berlin, Hardenbergplatz 2, 1000 Berlin 12, Germany +49-30-254 99-160