Coredump

I’m currently playing with Devil’s Pie, a utility that matches windows and window events to a set of rules similar to Emacs’ (yikes! :P) S-expressions.

I installed Devil’s Pie on my work desktop (running FC6), thus:

$ sudo yum install devilspie

(I have previously organized my desktop with four workspaces: for browsing, remote SSH sessions, remote desktop sessions, and other tasks.) I then created a configuration file:

$ mkdir .devilspie && vi ~/.devilspie/workspaces.ds
   (debug)
   (if (is (application_name) "Firefox") (begin maximize (undecorate (set_workspace 1))))
   (if (is (application_name) "Terminal") (begin maximize (undecorate (set_workspace 2))))
   (if (matches (application_name) "^rdesktop.+") (begin center (maximize (set_workspace 3))))

and invoked Devil’s Pie: devilspie -d ~/.devilspie/workspaces.ds &. The (debug) line in the configuration is, heh, for debugging purposes so Devil’s Pie will print out events and other information, which I can then later use.

Seems pretty straightforward, though there isn’t much functionality that I can use. (Then again, my requirement is minimal: I just want to group apps to different workspaces to avoid clutter.) I can then drop Devil’s Pie in my X startup script, along with the other startup apps.

(This is part of an ongoing series on Linux CLI shortcuts and hacks.)

After editing .bashrc and .bash_profile, you can reload the values by running

$ source ~/.bash_profile

I’m still here at the office, watching text scroll down (or is it up?) the monitor. Actually, I’m backing up the whole /var partition from one of the mail servers, to make way for a larger capacity disk.

You’re thinking, duh, LVM. But this server had been set up way before LVM became stable. I could not even back up to tape — not yet, at least — because I have to get this up and fast, while keeping the server live, so I’m doing it over (of all things) USB, and 1.1 at that.

(Heh, fast. I’ve been at it since 5 PM, and I’m not nearly halfway done. *sigh* Such is life.)

Given:

$ ll Archive/
total 8
-rw-r--r-- 1 d3m users 10 2007-01-26 16:29 file1.z
-rw-r--r-- 1 d3m users 15 2007-01-26 16:29 file2.z

What happens if:

$ cd ~/Destination; cp ~/Archive/*.z

It’s been a long time since I did a source tar-ball install. But the production servers at work require that applications that are not part of the standard install base (from Kickstart/Jumpstart and VMWare images) should be compiled from source. It was a very refreshing experience.

So after going through the usual configure; make; make install invocation, it was time to make sure that the app is persistent at boot. I would have copied an init script from my *nix desktop, but good thing SLES had a baseline script in /etc/init.d/skeleton.

In a nutshell, the steps are:

1. Define the INIT INFO section, as per the LSB specs.
2. Fill in the variables.
3. Use /etc/rc.status and rc_* functions for sanity checks.
4. Create the basic start, stop and status functions.
5. Use YAST (System > System Services (Runlevel)) — or, if available, innserv — to enable the startup script.

Below is a script I wrote for Apache:

#!/bin/sh
#
# Author: Ian Dexter R. Marquez
#
# /etc/init.d/httpd
#
### BEGIN INIT INFO
# Provides: httpd
# Required-Start: $local_fs
# Required-Stop: $local_fs
# Default-Start: 3 5
# Default-Stop: 0 1 2 6
# Description: Start the Apache httpd daemon
### END INIT INFO
 
HTTPD=/path/to/apache/2.2.4/bin/httpd
APACHECTL=/path/to/apache/2.2.4/bin/apachectl
PROG=httpd
 
test -x $HTTPD || exit 5
test -s /etc/rc.status && . /etc/rc.status && rc_reset
 
start() {
   echo -n "Starting $PROG: "
   $HTTPD -k start
   rc_status -v
}
 
stop() {
   echo -n "Stopping $PROG: "
   /sbin/killproc $HTTPD
   rc_status -v
}
 
status() {
   echo -n "Checking $PROG: pid "
   /sbin/pidofproc $HTTPD
   rc_status -v
}
 
case "$1" in
   start)
      start
      ;;
   stop)
      stop
      ;;
   restart)
      stop
      start
      rc_status
      ;;
   status)
      status
      ;;
   try-restart|condrestart)
      if test "$1" = "condrestart"; then
         echo "${attn} Use try-restart ${done}(LSB)${attn} rather than condrestart ${warn}(RH)${norm}"
      fi
      $0 status
      if test $? = 0; then
         $0 restart
      else
         rc_reset   # Not running is not a failure.
      fi
      # Remember status and be quiet
      rc_status
      ;;
   graceful|help|configtest|fullstatus)
      $APACHECTL $@
      rc_status
      ;;
   *)
      echo "Usage: $PROG {start|stop|restart|status|graceful|help|configtest|fullstatus}"
      exit 1
esac
rc_exit

References:

• Writing Init Scripts, Novell Developer Net.
• Creating Custom Init Scripts, Novell Cool Solutions.