Path: utzoo!utgpu!water!watmath!clyde!rutgers!uwvax!oddjob!gargoyle!ihnp4!occrsh!occrsh.ATT.COM!rjd
From: rjd@occrsh.ATT.COM
Newsgroups: comp.sys.att
Subject: Re: HDB, gnuemacs, & GL
Message-ID: <144800020@occrsh.ATT.COM>
Date: 26 Jan 88 16:46:00 GMT
References: <2272@gryphon.CTS.COM>
Lines: 72
Nf-ID: #R:gryphon.CTS.COM:-227200:occrsh.ATT.COM:144800020:000:3023
Nf-From: occrsh.ATT.COM!rjd    Jan 26 10:46:00 1988


>I recently installed HoneyDanBer UUCP, and wonder why I put it off so
>long.  The only problem is that HDB deals with lock files differently,
>and if I am using kermit or async_main when uucp decides it wants to
>use the phone, I'm out of luck.  uucp just grabs without asking.
>Perhaps something could be done in uudemon.hour to modify the lock
>files before uusched is called (though this wouldn't help if someone
>issued a uucp command and didn't tell it to queue).  Any suggestions?
>I tried a few things, but the debug file for uucp keeps showing, "ok
>to remove lock file," as I shout, "No!  Don't!"

  Leave the uucp commands alone.....

  You just need to create a file by the name LCK..</dev entry> containing the
process ID number of the active process that is using the port.  Uucp checks
for this LCK.. file *AND* checks to see if the process number contained in
the file is still active before opening the port.  If the process number in
the file is not active or there is no process number in the file (but nobody
would do that, would they? :-) ), it *IS* "ok to remove the lck file".
   I wrote a shell script to handle the generation of the lock files which
might explain it better.  This shell script works both ways: it will not let
your process use the port if uucp is using it, and if uucp is not using it,
it will generate the proper lock file so uucp will not "grab" it in the middle
of your session.  Be aware that the lock files are NOT removed religiously
once the using process terminates.  This is not a bad thing, as you should
always check for the existance of the process before assuming that the port is
actually in use, as the existance of the lock file is not the final word.
Here is the pertainent fragment:
--------------------------------------------------------------------------------
# "DK" is the device name I am needing to use, you will need to change it below
# to the desired device name in your Devices file. - RJD
#EXEC=<program name>
#NUM=<set to number of tries this program has found all devices unavailable>
BAD=YES
for PORT in `/bin/grep '^DK	' /usr/lib/uucp/Devices | /usr/bin/cut -c4-9`
 do
  LCKFILE=/usr/spool/locks/LCK..$PORT
  if [ -s $LCKFILE ]
   then
    /bin/ps -p `/bin/cat $LCKFILE` > /dev/null
    if [ $? -eq 1 ]
     then
      BAD=NO
      break
    fi
   else
    BAD=NO
    break
  fi
done

if [ "$BAD" = "NO" ]
 then
  /bin/echo $$ > $LCKFILE
  /bin/chgrp uucp $LCKFILE
  /bin/chmod 444 $LCKFILE
  /bin/chown uucp $LCKFILE
  $EXEC -l/dev/$PORT -s			# Execute the program that uses the port
  if [ $? -ne 0 ]
   then
    BAD=YES
  fi
  /bin/rm -f $LCKFILE
 else
  /bin/echo "${0}: no devices available, count $NUM"
fi
--------------------------------------------------------------------------------

Randy Davis                     		UUCP: ...(ihnp4!)3b2fst!randy
3B2 System Test Engineering                           ...(ihnp4!)occrsh!rjd
AT&T Network Systems, Oklahoma City Works
All opinions and/or advice stated above are MY OWN, not those of AT&T.