CentOS - Oct 2008 - Certain scripts "hang" the terminal on logout

I have an init script that after running, causes my terminal not to
log out cleanly.  Here's what i mean:

# /etc/init.d/script restart  << this runs fine, returns my shell prompt
# exit  <<  When I enter this command, my shell window just stays
"stuck" and actually won't close down.

Anyone know why this happens?

On Fri, Oct 24, 2008 at 10:48:53AM -0500, Sean Carolan enlightened
us:
> I have an init script that after running, causes my terminal not to
> log out cleanly.  Here's what i mean:
> 
> # /etc/init.d/script restart  << this runs fine, returns my shell
prompt
> # exit  <<  When I enter this command, my shell window just stays
> "stuck" and actually won't close down.
> 
> Anyone know why this happens?
Are you spawning/backgrounding jobs in the script?

Matt

-- 
Matt Hyclak
Systems and Operations 
Office of Information Technology
Ohio University
(740) 593-1222
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: not available
URL:
<http://lists.centos.org/pipermail/centos/attachments/20081024/dd6f7ffa/attachment-0003.sig>

Hi,

On Fri, Oct 24, 2008 at 11:48, Sean Carolan <scarolan at gmail.com>
wrote:
> # /etc/init.d/script restart  << this runs fine, returns my shell
prompt
> # exit  <<  When I enter this command, my shell window just stays
> "stuck" and actually won't close down.
>
> Anyone know why this happens?
Yes, it's because the daemon started from that script keeps file
descriptors opened to the terminal you are connected to. This might be
considered a bug in the daemon, since a proper daemon should close all
its file descriptors before going background and returning to the
shell.

You might try to change the script in init.d to append
"</dev/null
>/dev/null 2>&1" at the line that starts the daemon, this might
force
it to detach itself from the terminal.

HTH,
Filipe

>> # /etc/init.d/script restart  << this runs fine, returns my shell
prompt
>> # exit  <<  When I enter this command, my shell window just stays
>> "stuck" and actually won't close down.
>>
>> Anyone know why this happens?
>
> Are you spawning/backgrounding jobs in the script?
Here is the script, it is a fairly simple start/stop/reset script that
was written by Jay Farschman. One other question I had about this
script is what the "$PROG" variable in the stop() function is for.

#!/bin/sh
#
# swatchrc      This shell script takes care of starting and stopping
#               swatch.
#
# chkconfig: 2345 81 31
# description: Swatch is a System WATCHdog program that we are
#              using here to block repeated failed ssh logins.
# processname: swatch

# Replace --tail-file with the file you wish to watch, see /etc/swatch/swatchrc

RETVAL=0
test -x /usr/bin/swatch || exit 0
start(){
  echo "Starting swatch"
    # Spawn a new swatch program
      /usr/bin/swatch --daemon --config-file=/etc/swatch/swatchrc
--tail-file=/u
         sr/local/ha-tomcat/logs/catalina.out
--pid-file=/var/run/swatch.pid
      echo $PID
return $RETVAL
}
stop () {
    # stop daemon
  echo "Stopping swatch:" $PROG
  kill -9 `cat /var/run/swatch.pid`
  rm -f /var/run/swatch.pid
  killall tail
  return $RETVAL
}
restart () {
  stop
  start
  RETVAL=$?
  return $RETVAL
}

case "$1" in
  start)
      start
      ;;
  stop)
      stop
       ;;
  restart)
      restart
      ;;
  *)
      echo "Usage: $0 {start|stop|restart}"
      RETVAL=1
esac
exit $RETVAL