.:ATTALAYA.::.අට්ටාලය:.

Split an Array Gradually

2010-05-20T12:43:00.007+05:30

Simple code snippet to devide and print an array of size 2 to the power x gradually.The code divides array and print elements in equal granularity at each stage. However, it will not repeat printed elements twice. Test it and find out.

/*
# Copyright (C) 2008 Kenneth Manjula Thilakarathna mail: kenneth.tux@gmail.com
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
# 3. All advertising materials mentioning features or use of this software
#    must display the following acknowledgement:
#    This product includes software developed by the <organization>.
# 4. Neither the name of the <organization> nor the
#    names of its contributors may be used to endorse or promote products
#    derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY <COPYRIGHT HOLDER> ''AS IS'' AND ANY
# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/* Simple code snippet to devide and print an array of size 2 to the power x gradually.
 * The code divides array and print elements in equal granularity at each stage.
 * However, it will not repeat printed elements twise. Test it and find out.
 ************************************************************************************/
#include <stdio.h>

int main(){

 // Declaration and initialization of variables 
  int i,j,k,l,a,interval;
  printf("Insert a value for array size: ");
  scanf("%d", &i);
  // Check if you entered a valid number and if so continue
  if(i>1 && ((i & (i-1))==0)){
    // array initialization 
    int sample_array[i-1];
    for (l=0;l<i;l++)
      sample_array[l]=l+1;


    // Here goes the algo ..
    printf("Sending %d and %d\n", sample_array[0], sample_array[i-1]);

    for(j=2;j<=i;){
      interval = i/j;
      j = j*2;
      printf("Sending ");
      k=1;
      if(interval == 1)a = 2;else a = 0;
      for(a;a<i;){
        if(a!=0 && (k%2)==0)
          printf(" %d",sample_array[a-1]);
        k = k +1;
        a = a+interval;
      }
      printf("\n");
    }
    // algo ends
  }else
    printf("Number %d is not a power of two :D\n", i);
return 0;
}

Moodle Email Delete from Users

2010-05-11T21:29:00.016+05:30

The main intention of creating this moodle hack is to get rid of bouncing mails. When you install this in the steps described below, you will be able to easily delete bouncing email addresses from using the moodle admin interface itself. Please, test the script before using it. Hope it is useful.
1. step: Copy these two scripts to the directory moodle_wwwroot/admin/. Change the permissions appropriately.
chown apache:apache del_gen_email*
chmod 644 del_gen_email*

<?php 

/*
# Copyright (C) 2008 Kenneth Manjula Thilakarathna mail: kenneth.tux@gmail.com
#   
#   This program is free software: you may copy, redistribute and/or modify it  
#   under the terms of the GNU General Public License as published by the  
#   Free Software Foundation, either version 2 of the License, or (at your  
#   option) any later version.  
#   
#   This program is distributed in the hope that it will be useful, but  
#   WITHOUT ANY WARRANTY; without even the implied warranty of  
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU  
#   General Public License for more details.  
#   
#   You should have received a copy of the GNU General Public License  
#   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/
// Hack script by Kenneth
// Deletes the moodle bouncing email content from all users COMPLETELY!!
// Then once they log in next time they will be prompted for updating their email address
// Thank you Yasiru for your idea
// BE VERY CAREFUL USING THIS!  

require_once $CFG->libdir.'/formslib.php';

class del_gen_email_form extends moodleform {

    function definition() {
        $mform    =& $this->_form;
        $renderer =& $mform->defaultRenderer();

        $mform->addElement('header', '', 'Enter Bouncing Email Address', '');

        $mform->addElement('text', 'del_email', get_string('email'));
        $mform->setType('del_email', PARAM_RAW);

        $this->add_action_buttons(true, get_string('ok'));
    }

}

?>

<?php

/*
# Copyright (C) 2008 Kenneth Manjula Thilakarathna mail: kenneth.tux@gmail.com
#   
#   This program is free software: you may copy, redistribute and/or modify it  
#   under the terms of the GNU General Public License as published by the  
#   Free Software Foundation, either version 2 of the License, or (at your  
#   option) any later version.  
#   
#   This program is distributed in the hope that it will be useful, but  
#   WITHOUT ANY WARRANTY; without even the implied warranty of  
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU  
#   General Public License for more details.  
#   
#   You should have received a copy of the GNU General Public License  
#   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/
// Hack script by Kenneth
// Deletes the moodle bouncing email content from all users COMPLETELY!!
// Then once they log in next time they will be prompted for updating their email address
// Thank you Yasiru for your idea
// BE VERY CAREFUL USING THIS!  

  
    require_once('../config.php');
    require_once($CFG->libdir.'/adminlib.php');
    require_once('del_gen_email_form.php');

    admin_externalpage_setup('delgenemail');

    require_login();

    $reallysure = optional_param('reallysure', 0, PARAM_BOOL);
    $del_email_addr= optional_param('del_email', '', PARAM_RAW);
    if (empty($sesskey)){
    $sesskey= sesskey();
       }else{
        $sesskey= optional_param('sesskey');
       }

    require_capability('moodle/site:config', get_context_instance(CONTEXT_SYSTEM));

    $mform = new del_gen_email_form();

    if ($mform->is_cancelled()){
       redirect($CFG->wwwroot);    

   }else if($data =  $mform->get_data()){

     if (!empty($data->del_email) or ($data->del_email)!= ''){

       if (empty($reallysure)) {

          admin_externalpage_print_header();
          print_heading('Delete Not Updated Email Addresses');
          $optionsyes = array('del_email'=>$data->del_email, 'sesskey'=>sesskey(), 'reallysure'=>'yes');
          notice_yesno ('Are you REALLY REALLY completely sure you want to delete all site default email '.$data->del_email.' from all users?',
           'del_gen_email.php', 'del_gen_email.php', $optionsyes, NULL, 'post', 'get');
          admin_externalpage_print_footer();
          exit;

         } 
     }
   }else if($del_email_addr!='' and $sesskey == sesskey()){
          admin_externalpage_print_header();
          print_heading('Delete Not Updated Email Addresses');
        // OK Here we go
          print($del_email_addr);
          delete_gen_emails($del_email_addr,$CFG->dbhost,$CFG->dbuser, $CFG->dbpass, $CFG->dbname,$CFG->prefix); 
          print_box('All email fields having email address '.$del_email_addr.' have been deleted from database', 'generalbox boxwidthnormal boxaligncenter');
          print_continue($CFG->wwwroot.'/admin/del_gen_email.php');
          admin_externalpage_print_footer();
          exit;

   }else if ($sesskey != sesskey()){
     error('This script was called wrongly');
   }

   function delete_gen_emails($due_del_email,$dbhost,$dbuser,$dbpass,$dbname,$tblprefix){
    
    // test connection
    if (!mysql_connect($dbhost, $dbuser, $dbpass)) {
        die ("Connection to server failed.");
    }
   
    // connect to database
    if (!mysql_select_db($dbname)) {
        die ("Database not found.");
    }
    //make sure all users who are having bouncing email addresses will not have a email address anymore
    $query_del_email= 'UPDATE '.$tblprefix.'user SET email="" where email="'.$due_del_email.'"';
    $result = mysql_query($query_del_email);
    
   //close database connection
    mysql_close();
}

  // Display form
admin_externalpage_print_header();
print_heading('Delete Not Updated Email Addresses');
$mform->display();
print_footer();

?>

2. step: There is a php file named users.php at the location moodle_wwwroot/admin/settings/ directory. Edit the file and put the following line in the section "stuff under the "accounts" subcategory". Note: it is around code line number 80. This is to bring the menu item in the interface Users->Accounts->Delete General Email

$ADMIN->add('accounts', new admin_externalpage('delgenemail', 'delete general email', "$CFG->wwwroot/admin/del_gen_email.php", 'moodle/user:update'));

Hope it helps :D

Moodle Backup Script

2010-05-05T00:49:00.015+05:30

The main intention of creating this backup script is to back up moodle. However, the script is generalized in a way that, once it is configure, users can use it in any GNU/Linux server to backup data and sqldump databases. Hope this is helpful. Note: the script is originally posted by Mr. N. M. Laxaman and I have done some improvements to work it with iSCSI and reporting features.
To get things to work.
1. Install ssmtp and configure it as a smart host -- Simple How to
2. Install and configure iscsi with your iscsi server -- Simple How to . Make sure that you test iscsi properly mounts intended devices.
3. Configure the script for your requirements - only edit configuration section
4. Make it executable and put it in /etc/cron. directory as per your requirement

#!/bin/bash
# Moodle system backup script Version: 0.1.1
#  
# Copyright (C) 2008 Nayanajit Mahendra Laxaman mail: nmlaxaman@gmail.com
#   
#   This program is free software: you may copy, redistribute and/or modify it  
#   under the terms of the GNU General Public License as published by the  
#   Free Software Foundation, either version 2 of the License, or (at your  
#   option) any later version.  
#   
#   This program is distributed in the hope that it will be useful, but  
#   WITHOUT ANY WARRANTY; without even the implied warranty of  
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU  
#   General Public License for more details.  
#   
#   You should have received a copy of the GNU General Public License  
#   along with this program.  If not, see <http://www.gnu.org/licenses/>.  
#   
#  This file incorporates work covered by the following copyright and  
#  permission notice:  
#   
#   Copyright (c) 2010, Kenneth Manjula Thilakarathna <kenneth.tux@gmail.com>  
#   
#      Permission to use, copy, modify, and/or distribute this software  
#      for any purpose with or without fee is hereby granted, provided  
#      that the above copyright notice and this permission notice appear  
#      in all copies.  
#   
#      THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL  
#      WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED  
#      WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE  
#      AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR  
#      CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS  
#      OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,  
#      NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN  
#      CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.  
#  

#     +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
#     Note: This script requires working ssmtp application installed
#     +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

DAILY=true
WEEKLY=true
MONTHLY=true
YEARLY=true
SEMESTERLY=true

#Set the number of backups to keep in each level
DAYS_TO_KEEP=60
WEEKS_TO_KEEP=26
MONTHS_TO_KEEP=24
YEARS_TO_KEEP=5
SEMESTERS_TO_KEEP=10
DELETE_OLD=true

#Relative backup directories for each level
DAILY_BAK=daily
WEEKLY_BAK=weekly
MONTHLY_BAK=monthly
YEARLY_BAK=yearly
SEMESTER_BAK=semesterly

END_SEMESTER_ONE=31-07   # dd-mm
END_SEMESTER_TWO=31-01  # dd-mm

# Server fqdn
WHICH_SERVER='yourserver.com'

# Enable/Disable backup types
MYSQLDUMP_BACKUP=true

# MySQL Configuration
DATABASES=( db_one db_two )
DB_USER=dbuser
DB_PASS=dbpass

#++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
# There MUST be a backup destination directory coresponding to each source 
# directory
#++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

#Source(s) of backup directory
BACKUP_SOURCES=( /www/lms/ /www/moodledata/ /mysql/db_pg/ )

#Coresponding destination(s) of backup sources
BACK_DIR_LIST=( moodle_web moodle_data moodle_db )

#Mount points and alternative backup locations
ISCSI_MOUNT_POINT=/backup/iscsi-backup/
ALT_BACKUP_DEST=/backup/alternatestorage/

#Weekly backup day (0 - SUN, 1 - MON, ...., 6 - SAT)
BACKUP_DAY=5 # Friday morning

#iSCSI device
BACKUP_DEV=/dev/sda2

# mail address which you wish to receive alerts
MAIL=xxx@yourmail.com

# tmp mail file
TMP_MAIL=/tmp/srvalertmail

# mail address which you wish to send mail from the server
MAIL_FROM=xxx@university.com

# daemon name of iscsi service ...
SERVICE='iscsid'

# End of configuration section 
# -------------------------------------------------------------------- #

MOUNT_STATUS=true

function msg_sender(){
echo "To: $MAIL" > $TMP_MAIL
echo "From: $MAIL_FROM" >> $TMP_MAIL
echo "Subject: Server Alert" >> $TMP_MAIL
echo " " >> $TMP_MAIL
echo "$1" >> $TMP_MAIL
if [ $# -eq 2 ]; then
 echo " " >> $TMP_MAIL
 cat $2 >> $TMP_MAIL
fi
ssmtp $MAIL < $TMP_MAIL
rm $TMP_MAIL
}

if [ ${#BACKUP_SOURCES[*]} != ${#BACK_DIR_LIST[*]} ]; then
 msg_sender "Configuration Error: Check Source and Destination directory lists. Backup is not taken. System Exited"
 exit 0
fi

#Check if iscsi is running. if not backup alternate location and send message
function mount_iscsi(){
#mount iscsi device and if error backup alternate location and send message
[[ -d $ISCSI_MOUNT_POINT ]] || mkdir -p  $ISCSI_MOUNT_POINT
# check if it is already mounted
cat /etc/mtab | grep $BACKUP_DEV >/dev/null 
 if [ "$?" -eq "0" ]; then
   msg_sender "iSCSI unmount may have failed in previous atempt in $WHICH_SERVER server ..." 
# BUG Here ... correct it
 elif [ `mount $BACKUP_DEV $ISCSI_MOUNT_POINT` ] ; then
   [[ -d $ALT_BACKUP_DEST ]] || mkdir -p $ALT_BACKUP_DEST
   ISCSI_MOUNT_POINT=$ALT_BACKUP_DEST
   MOUNT_STATUS=false
   msg_sender "iSCSI mount failed for device $BACKUP_DEV on mount point $ISCSI_MOUNT_POINT in $WHICH_SERVER server ..."
 fi
}

if ps ax | grep -v grep | grep iscsid > /dev/null; then
mount_iscsi
else
 for i in {1..1}; do
  /etc/init.d/$SERVICE start
  sleep 10
 done
 if ps ax | grep -v grep | grep iscsid > /dev/null; then
  msg_sender "One atempt made successfully to start the iSCSI service in $WHICH_SERVER server ... I do not know how it stopped ..."
  mount_iscsi
 else
  [[ -d $ALT_BACKUP_DEST ]] || mkdir -p $ALT_BACKUP_DEST
  ISCSI_MOUNT_POINT=$ALT_BACKUP_DEST
  MOUNT_STATUS=false
  msg_sender "One atempts made to start the iscsid service in $WHICH_SERVER server. iSCSI service is not running ..."
 fi
fi

YEAR=`date +%Y`
DAY_OF_WEEK=`date +%u`
TOMORROW_DATE=`date --date="next day" +%d`;
TOMORROW_MONTH=`date --date="next day" +%m`;
YESTERDAY=`date --date="yesterday" +%d-%m-%Y`;
END_SEMESTER_I=$END_SEMESTER_ONE-`date +%Y`
END_SEMESTER_II=$END_SEMESTER_TWO-`date +%Y`


END_OF_WEEK=false
END_OF_MONTH=false
END_OF_YEAR=false

cd $ISCSI_MOUNT_POINT

# Using ISO week numbers
[[ $DAY_OF_WEEK == $BACKUP_DAY ]] && END_OF_WEEK=true;
[[ $TOMORROW_DATE == 01 ]] && END_OF_MONTH=true;
[[ $TOMORROW_DATE == 01 ]] && [[ $TOMORROW_MONTH == 01 ]] && END_OF_YEAR=true;

if $DAILY; then 
 [[ -d $DAILY_BAK ]] || mkdir $DAILY_BAK 
fi
if $WEEKLY; then
 [[ -d $WEEKLY_BAK ]] || mkdir $WEEKLY_BAK
fi
if $MONTHLY; then
 [[ -d $MONTHLY_BAK ]] || mkdir $MONTHLY_BAK
fi
if $YEARLY; then
 [[ -d $YEARLY_BAK ]] || mkdir $YEARLY_BAK
fi
if $SEMESTERLY; then
 [[ -d $SEMESTER_BAK ]] || mkdir $SEMESTER_BAK
fi

TODAY_BACKUP=`date +%d-%m-%Y`;

function backup(){
# Getting directory backups
RET_VAL=0
echo "" > /tmp/status_mail
echo "Daily backup report for $WHICH_SERVER server." >> /tmp/status_mail
if [ ! -d $1 ]; then
 for i in ${BACK_DIR_LIST[@]}
 do
  mkdir -p $TODAY_BACKUP/$i
 done
else
 if [ -d $TODAY_BACKUP ]; then
  echo "$TODAY_BACKUP tries to run twise in $WHICH_SERVER server... ???" >> /tmp/status_mail
 else
  cp -al $1 $TODAY_BACKUP
  if [ "$?" != 0 ]; then
   RET_VAL=1
   echo " There is an error when trying to copy backup to new directory !!!" >> /tmp/status_mail
  fi
 fi
fi
COUNT=0
for j in ${BACKUP_SOURCES[@]}
do
 if [ ${#BACK_DIR_LIST[*]} -gt $COUNT ]; then
  rsync -a --delete $j $TODAY_BACKUP/${BACK_DIR_LIST[$COUNT]}
  if [ "$?" != 0 ]; then
   RET_VAL=1
   echo "There is an rsync error when processing $j into $TODAY_BACKUP !!!" >> /tmp/status_mail
  fi
  COUNT=`expr $COUNT + 1`
 fi
done

# Getting database dump backups
if $MYSQLDUMP_BACKUP; then
 for k in ${DATABASES[@]}
 do
  if [ `rm $TODAY_BACKUP/mysqldump-$k-$1.gz` ]; then
  echo "Yesterday mysqldump deletion failed for $WHICH_SERVER server... This may be the initial mysql dump" >> /tmp/status_mail
  fi
  if [ `mysqldump -u $DB_USER --password=$DB_PASS $k |gzip > $TODAY_BACKUP/mysqldump-$k-$TODAY_BACKUP.gz` ]; then
  RET_VAL=1
  echo  "$TODAY_BACKUP mysqldump failed for $WHICH_SERVER server..." >> /tmp/status_mail
  fi
 done
fi

# Deleting old backups
if $DELETE_OLD; then
 if [ $(ls . | wc -l) -gt $3 ]; then
  rm -fr $( ls -t . | tail -1 )
  if [ "$?" != 0 ]; then
   echo "Old backup remove failed ..." >> /tmp/status_mail
  fi
# expr $( ls . | wc -l ) \> $2 && rm -fr $( ls -t . | tail -1 )
 fi
# Reporting 
 if [ $RET_VAL == 1 ]; then
  echo "WARNING: Backup failed ... " >> /tmp/status_mail
  msg_sender "" /tmp/status_mail
 else
  echo "Backup Successfull ... " >> /tmp/status_mail
  msg_sender "" /tmp/status_mail
 fi
fi
}

# LAST_WEEK calculation
function last_week(){
TODAY=`date`
THIS_WEEK=`date -d "$TODAY" +%U`
DATE=1
WEEK=`date -d "$YEAR-1-$DATE" +%U`

while [ "$WEEK" != 01 ]
 do
  DATE=`expr $DATE + 1`
  WEEK=`date -d "$YEAR-1-$DATE" +%U`
 done

FIRST_DATE_OF_FIRST_WEEK=`date --date "$YEAR-01-$DATE"`
THE_DAY_OF_FIRST_DATE_OF_FIRST_WEEK=`date -d "$FIRST_DATE_OF_FIRST_WEEK" +%u`

if [ $BACKUP_DAY == $THE_DAY_OF_FIRST_DATE_OF_FIRST_WEEK ]; then
 FIRST_BACKUP_DATE= $FIRST_DATE_OF_FIRST_WEEK
elif [ $BACKUP_DAY > $THE_DAY_OF_FIRST_DATE_OF_FIRST_WEEK ]; then
 DIFFERENCE=` expr $BACKUP_DAY - $THE_DAY_OF_FIRST_DATE_OF_FIRST_WEEK`
 FIRST_BACKUP_DATE=`date -d "$FIRST_DATE_OF_FIRST_WEEK $DIFFERENCE days"`
elif [ $BACKUP_DAY < $THE_DAY_OF_FIRST_DATE_OF_FIRST_WEEK ]; then
 DIFFERENCE=` expr $BACKUP_DAY + 7 - $THE_DAY_OF_FIRST_DATE_OF_FIRST_WEEK`
 FIRST_BACKUP_DATE=`date -d "$FIRST_DATE_OF_FIRST_WEEK $DIFFERENCE days"`
fi

LAST_WEEK_BACKUP_DATE=`date -d "$FIRST_BACKUP_DATE $((7*(($THIS_WEEK - 1)))) days"`
LAST_WEEK_BACKUP=`date -d "$LAST_WEEK_BACKUP_DATE" +%d-%m-%Y`
}


if $YEARLY && $END_OF_YEAR; then
cd $YEARLY_BAK
LASTYEAR_BACKUP=`date +%d-%m-$((YEAR-1))`
[[ -d $LASTYEAR_BACKUP ]] || msg_sender "$LASTYEAR_BACKUP yearly backup is not there in $WHICH_SERVER server..."
backup $LASTYEAR_BACKUP $YEARS_TO_KEEP
cd ..
fi

if [ $SEMESTERLY ] && [ $END_SEMESTER_I == $TODAY_BACKUP ] || [ $END_SEMESTER_II == $TODAY_BACKUP ]; then
cd $SEMESTER_BAK
if [ $TODAY_BACKUP == $END_SEMESTER_I ]; then
 [[ -d $END_SEMESTER_TWO-`expr $YEAR - 1` ]] || msg_sender "$END_SEMESTER_TWO-`expr $YEAR - 1` semester backup is not there in $WHICH_SERVER server..."
 LAST_SEMESTER=$END_SEMESTER_II
elif [ $TODAY_BACKUP == $END_SEMESTER_II ]; then
 [[ -d $END_SEMESTER_I ]] || msg_sender "$END_SEMESTER_I semester backup is not there in $WHICH_SERVER server..."
 LAST_SEMESTER=$END_SEMESTER_I
fi
backup $LAST_SEMESTER $SEMESTERS_TO_KEEP
cd ..
fi

if $MONTHLY && $END_OF_MONTH; then
cd $MONTHLY_BAK
LASTMONTH_BACKUP=`date -d "$(date +%Y-%m-1) -1 day" +%d-%m-%Y`
[[ -d $LASTMONTH_BACKUP ]] || msg_sender "$LASTMONTH_BACKUP monthly backup is not there in $WHICH_SERVER server..."
backup $LASTMONTH_BACKUP $MONTHS_TO_KEEP
cd ..
fi

if $WEEKLY && $END_OF_WEEK; then
cd $WEEKLY_BAK
LAST_WEEK_BACKUP= 
last_week
[[ -d $LAST_WEEK_BACKUP ]] || msg_sender "$LAST_WEEK_BACKUP weekly backup is not there in $WHICH_SERVER server..."
backup $LAST_WEEK_BACKUP $WEEKS_TO_KEEP
cd ..
echo " weekly disk usage report for $WHICH_SERVER " > /tmp/week_mail
df -h >> /tmp/week_mail
msg_sender " " /tmp/week_mail 
rm /tmp/week_mail
fi

if $DAILY; then
cd $DAILY_BAK
YESTERDAY_BACKUP=$YESTERDAY;
[[ -d $YESTERDAY_BACKUP ]] || msg_sender "$YESTERDAY_BACKUP daily backup is not there in $WHICH_SERVER server..."
backup $YESTERDAY_BACKUP $DAYS_TO_KEEP
cd ..
fi

if $MOUNT_STATUS; then
 cd /
 if [ `umount $BACKUP_DEV` ]; then
  msg_sender " $BACKUP_DEV unmount failed on $TODAY_BACKUP ??? "
 fi
fi

exit 0

VirtualBox Configuration

2009-07-20T12:01:00.003+05:30

It is very well explained in Ubuntu community help site
https://help.ubuntu.com/community/VirtualBox
Note that when configuring networking the hosts may not be able to ping each other but network applications works perfectly

Installing ATI Radeon HD2600 propriatory driver on Debian/Lenny

2009-07-18T20:11:00.003+05:30

Download the installer from http://support.amd.com/us/gpudownload/Pages/index.aspx ...

$mkdir fglrx
$cp ati-driver-installer-9-6-x86.x86_64.run fglrx/
$cd fglrx
$chmod +x ati-driver-installer-9-6-x86.x86_64.run
$./ati-driver-installer-9-6-x86.x86_64.run --buildpkg Debian/lenny
$ su
#dpkg -i *.deb

Reboot the system for single user mode
#apt-get install build-essential linux-headers-$(uname -r) module-assistant
#m-a prepare
#m-a a-i fglrx
#modprobe -v fglrx

If this is the first installation
#dpkg-reconfigure xserver-xorg

Statistical Data Collection and Analysis Tools for Linux

2009-07-09T18:24:00.006+05:30

I was searching for tools which I could use to analyse statistical data for my research work and found three popular tools. I won't talk about the most famous SPSS here as it is not for free
1. R - http://www.r-project.org/
2. PSPP - http://www.gnu.org/software/pspp/
3. SOFA - Statistics Open For All - http://www.sofastatistics.com/home.php

Installing R
R is available in universe repositories. But if you want to get the latest version then you have to add a repository as follows.
Add a repository to your /etc/apt/sources.list file
deb http://ftp.sunet.se/pub/lang/CRAN/bin/linux/ubuntu jaunty/
You can select a suitable mirror from the following list of mirrors
http://cran.r-project.org/mirrors.html
Then you have to update your package list
sudo apt-get update
Now you are ready to install R into your system
sudo apt-get install r-base
Now it is time to install GUI for r-base called R Commander
sudo R
install.packages("Rcmdr", dependencies=TRUE)
When you want to update your R then it is simple as this
>update.packages(lib.loc = "/usr/local/lib/R/site-library")

Installing PSPP
PSPP is also available in Ubuntu repositories.

sudo apt-get install pspp

Installing SOFA

wget http://www.vislab.uq.edu.au/debuntu/uqvislab-pubkey.asc
sudo apt-key add uqvislab-pubkey.asc
sudo apt-get update
wget http://www.vislab.uq.edu.au/debuntu/uqvislab-pubkey.asc -O - | sudo apt-key add -
sudo wget http://www.vislab.uq.edu.au/debuntu/sources.list.d/jaunty.list -O /etc/apt/sources.list.d/uqvislab.list
sudo apt-get update
sudo wget http://www.vislab.uq.edu.au/debuntu/sources.list.d/jaunty.list -O /etc/apt/sources.list.d/uqvislab.list
sudo apt-get install python-webkitwx

Download SOFA from http://www.sofastatistics.com/downloads.php
Double click on the downloaded file and install

Mother Nature

2009-02-25T22:43:00.002+05:30

I feel that it is worth of sharing this experience with you.

Today, I needed to get wheel barrow to bring some wood. As the case in most houses, my wheel barrow was also filled with some junk. I picked out one peace of the stuff at a time to unload the wheel barrow and I was in a hurry. Suddenly a mouse jumped off from it an ran away. Then I heard some noises from under the stuff loaded in the wheel barrow. I continued the cleaning and I found 5 mouse kids who are not even had their eyelids open. I was really worried about what I have done and I picked them and placed them in a box with the garbage that the mouse had make in the same place where the wheel barrow was. I was really worried about that mother who left her children will not come back as I cleaned the things up.

After some time we heard some noise from the place we left the mouse kiddies. Oh, mom has come to pick her babies and she is hanging around. After few hours we checked for little mouse kiddies and found that mother mouse has taken her children away from that place.

See how wonderful. But why some of the women are not gifted by such a gift which gives them the courage and feeling to protect their children. Also it is worth to remember that life cannot be valued regardless of being a human or other living being.

Dual booting using Windows Vista boot loader

2009-02-10T22:39:00.009+05:30

I wanted to dual boot my laptop with Windows Vista and Ubuntu GNU/Linux. I used Windows Vista boot manager to boot my GNU/Linux system. I had to do this because, if I would have installed grub boot loader of Ubuntu system in Master Boot Record then I loose F11 option to recover Windows Vista system (Which I may have to do very frequently). So I decided to use Windows Vista boot loader to boot my Ubuntu GNU/Linux system. I installed Ubuntu boot loader in /boot mounted device. Make sure you don't reboot your system when asked to do so. If you forgot to not to reboot, don't worry, see bellow. Then get a console and execute following command as root user (replace device files with appropriate). The device should be your /boot partition

dd if=/dev/sda5 of=/dev/sdb1/boot.lnx bs=512 count=1

I plugged my pen drive and directly copied the file into it. Then unmount pen drive from the system and rebooted the system into Windows Vista. Get a command line interface by right clicking on the application icon from the menu bar and choosing "Run as Administrator". Then execute following commands ...

bcdedit.exe /create {ntldr} /d "GNU/LInux Ubuntu"
This will create a legacy boot loader entry

bcdedit.exe /set {ntldr} device boot
This will declare it as it contains a bootable system

bcdedit.exe /set {ntldr} path /Windows/system32/boot.lnx
This will set the path of the bootable image. Note that it only worked for me when I copied the boot.lnx file into /Windows/system32/

bcdedit.exe /displayorder {ntldr} /addfirst
This will set this boot option to appear at first line

bcdedit.exe /default {ntldr}
This will make Ubuntu system as default booted system

OK if you have successfully created the entry reboot and see it work ...

If you already have a Windows Xp also installed in your machine then creating an ntldr will not be allowed as it may have been already created. Then you can use one of the following options. I recommend the second option.

1^st Option
Open a command line same as above and you have to have the boot.lnx file with you.

bcdedit.exe /copy {ntldr} /d "GNU/Linux Ubuntu"
This will copy a legacy boot loader entry to new one and give you an ID for that for further configurations. and the ID would be something like {81ed7925-47ee-11db-bd26-cbb4e160eb27} I will refer to it as .:ID:. hereafter

bcdedit.exe /set .:ID:. device boot
This will declare it as it contains a bootable system

bcdedit.exe /set .:ID:. path /Windows/system32/boot.lnx
bcdedit.exe /displayorder .:ID:. /addfirst
bcdedit.exe /default .:ID:.

2^nd Option

bcdedit.exe /create /d "GNU/Linux Ubuntu" /application BOOTSECTOR
This will create a location to hold a bootsector application and give you an ID for that for further configurations. I will refer to it as .:ID:. hereafter

bcdedit.exe /set .:ID:. device boot
bcdedit.exe /set .:ID:. path \boot.lnx
Note that you can copy your boot.lnx boot image into C:/ and use above command to set the path for it.

bcdedit.exe /displayorder .:ID:. /addfirst
bcdedit.exe /default .:ID:.

OK now reboot your system and see it works ....
Oh let's say that you unfortunately rebooted Ubuntu after installing it and then installed Vista which result Ubuntu partitions inaccessible. Don't worry. Then you need to boot your system using a Ubuntu Live CD. Then get a gnome terminal ... execute the following commands..
Find your linux installed "/" partition and mount it.
sudo mount /dev/sda6 /media/disk
If your /boot partition is separated from root partition then you have to mount it also ...
sudo mount /dev/sda5 /media/disk/boot
Then you have to change your root ... using the following command ...
sudo chroot /media/disk
Mount following partitions which are essential to run a system ...
sudo mount /proc
sudo mount /sys
Now you should be able to run above commands as you are in the installed system ...

Openclipart Gallary for cliparts

2009-02-10T20:47:00.003+05:30

I hope you know about Inkscape and Openclipart.org. It now has a very good collection of clip arts which may benefit you in your day to day activities. You can found my small collection of open clip arts at Openclipart.org here. It is also a very good way to contribute to open community. enjoy :-D .

Encrypted USB with Ubuntu 8.10 Installed

2009-01-17T23:05:00.001+05:30

I got my first own pen drive 2 days before. I wanted a portable GNU/Linux OS in it to use in the places that I can't have a GNU/Linux box. At the same time I wanted it to be secured. I choose LUKS to get the thing done. Would like to share my experience with you. Hope you find it useful.
OK let's get started ...
First of all boot you Laptop or Desktop with Ubuntu 8.10 Live CD. Then plug in the pen drive which you want to install GNU/Linux (backup all the data before starting this, otherwise you will loss your data forever). Use dmesg to find the device file of your pen drive.
dmesg
In my case it was /dev/sdb
Now it is time to fill your pen drive with some random data. You can use either
dd if=/dev/urandom of=/dev/sdb
or
shred -n 1 -v /dev/sdb
Use fdisk to create a new partition table. If you want to use this pen drive in Windows systems, then you will have to create your first most partition in FAT. If you create it elsewhere then Windows will not give a drive letter for that partition and hence it will be not accessible though Windows systems. In my pen drive I have the following partition table

    Name          Part Type       FS Type                Size (MB)
 ------------------------------------------------------------------------------
   sdb1             Primary          FAT                 2836.52
   sdb2             Primary          Linux                541.81
   sdb5             Logical          Linux ext2           111.55
   sdb6             Logical          Linux               4310.55
   sdb7             Logical          Linux                326.68

Once you finish partitioning you need to create file systems on each partition. Before doing this required encrypted partitions should make encrypted using LUKS. In Ubuntu GNU/Linux there is an application called cryptsetup which will give necessary tools to do this. Therefore installcryptsetupapplication into your Live system.
apt-get install cryptsetup
Load necessary kernel modules to use cryptsetup
modprobe dm-crypt
Now let's create encrypted partitions.
cryptsetup -y --cipher aes-cbc-essiv:sha256 --key-size 256 luksFormat /dev/sdb2
On execution of the above command you will be prompted for a pass phrase. That pass phrase will be use to create necessary encryption keys to encrypt the partition. You may use different keys for different partitions.
cryptsetup -y --cipher aes-cbc-essiv:sha256 --key-size 256 luksFormat /dev/sdb6
After making partitions encrypted you should decrypt and mount those partitions to use them. The following command is used to open and mount LUKS encrypted partition.
cryptsetup luksOpen /dev/sdb2 enc_data
enc_data is the location where encrypted /dev/sdb2 should be mounted. You don't have to create mount points specifically. cryptsetup will do it for you. Newly created mount point can be located at /dev/mapper/ directory. Make sure you remember the corresponding pass phrase for encrypted partitions.
cryptsetup luksOpen /dev/sdb6 enc_root
Now create file systems in partitions using following commands.
mkfs.vfat /dev/sdb1
mkfs.ext3 /dev/mapper/enc_data
mkfs.ext2 /dev/sdb5
mkfs.ext3 /dev/mapper/enc_root
Now your pen drive is ready for installing Ubuntu GNU/Linux. Click on System -> Administration -> Install to begin Ubuntu installation. In the installation process make sure you partition disks manually. Below pictures show how I have allocated partitions for my installation. As you can see in the image, you should not format devices /dev/sdb6 and /dev/sdb7. Instead you should format decrypted devices of those which are located in /dev/mapper/.

At the final stage of your installation process you should give the installation location of grub as /dev/sdb by going into the advanced options.
After successful installation of Ubuntu GNU/Linux system you will be prompted to restart your machine. As we have some more things to do, you should chose to continue with the live CD system.
Making a swap partition to use with your newly installed system is bit different from others. If we create it using the above method then you will have to enter the password at the boot time for decrypting swap partition as well. It is embarrassing to enter too many passwords just to boot your system. So we will use a derived key from enc_root partition to decrypt our swap partition at boot time. It means that once root partition is decrypted the system will decrypt your swap partition seamlessly.
/lib/cryptsetup/scripts/decrypt_derived enc_root | cryptsetup luksFormat /dev/sdb7 --key-file -
Let's decrypt the partition.
/lib/cryptsetup/scripts/decrypt_derived enc_root | cryptsetup luksOpen /dev/sdb7 enc_swap --key-file -
Make it a swap partition.
mkswap /dev/mapper/enc_swap
Now we should make our installed system capable of decrypting our root partition. To do that first we have to chroot to the installed system. Use following commands to change your root.
mkdir /tmp/tmp/
mount /dev/mapper/enc_root /tmp/tmp/
mount /dev/sdb5 /tmp/tmp/boot
chroot /tmp/tmp/
mount -t proc proc /proc
mount -t sysfs sys /sys
Install required packages into the newly installed system.
apt-get update
apt-get install cryptsetup
Now we have to update initramfs with installed new modules. Edit /etc/initramfs-tools/modules and append following modules line by line.
aes-i586
sha256
dm-crypt
Edit /etc/crypttab file and add following lines.
enc_root /dev/sdb6 none luks,retry=1
enc_swap /dev/sdb7 enc_root luks,keyscript=/lib/cryptsetup/scripts/decrypt_derived,retry=1
Edit /etc/fstab and replace encrypted partitions UUID with it's real device name. My /etc/fstab file looks like this.

# /etc/fstab: static file system information.
#
# <file system> <mount point>   <type>  <options>               <dump>  <pass>
proc               /proc         proc    defaults                 0       0
# my root partition
/dev/mapper/enc_root /          ext3  relatime,errors=remount-ro  0        1
# my /boot partition /dev/sdb5
UUID=71500825-460e-4945-8634-04912c7b2999 /boot  ext2   relatime  0        2
# my swap partition
/dev/mapper/enc_swap swap       swap       sw                     0        0
/dev/scd0       /media/cdrom0   udf,iso9660 user,noauto,exec,utf8 0        0

Regenerate initram file
update-initramfs -k all -c
Now reboot the system and boot the system with using your pen drive. :-D