Utilizing Off Time in Internet Radio

Airtime Image from Wikipedia

No one likes a silence when tuning to a radio station, and for a radio manager its tough to have 24*7 programmes, in case you are running an Internet Radio Station using Airtime you probably would be programming your shows and in Offtime your radio is always silent i would suggest you to play some random tracks in this Offtime and also include a track which tells when your station plays live so here is how to achieve this

  1. Put some MP3 files in a folder of your server, please also record a message with the showtimings etc or what ever you want this folder may contain any number of files which you want to play in off time (Folder used in the below script /store00/rand)
  2. Edit /usr/lib/airtime/pypo/bin/liquidsoap_scripts/ls_script.liq (below is the patch) the modified lines are in bold

@@ -150,14 +150,14 @@
 #                "read_stop_all",
 #                fun (s) -> begin log("dynamic_source.read_stop") destroy_dynamic_source_all() end)

-default = amplify(id="silence_src", 0.00001, noise())
+#default = amplify(id="silence_src", 0.00001, noise())
 ref_off_air_meta = ref off_air_meta
 if !ref_off_air_meta == "" then
     ref_off_air_meta := "Airtime - offline"
-default = rewrite_metadata([("title", !ref_off_air_meta)], default)
-ignore(output.dummy(default, fallible=true))
+#default = rewrite_metadata([("title", !ref_off_air_meta)], default)
+#ignore(output.dummy(default, fallible=true))
+default = playlist(mode='random', "/store00/rand/")
 master_dj_enabled = ref false
 live_dj_enabled = ref false
 scheduled_play_enabled = ref false

Once you have modifed you are good to go restart the services, upon restarting you will listem random tracks in offtime from the folder you have set in the script.

Tested on Airtime 2.5.1, do listem to VMOU's stream @ http://vmou.ac.in/stream

Resize Multiple Images


I am sure you would have come to a situation when you would have to resize multiple images say you copied 200 images from your Digital Camera and now need to upload them and need to resize them all, now doing this using GIMP would take ages here is a easy way.

Step 1) Install ImageMagick

sudo apt-get install imagemagick

Step 2) Change to the Directory where all Images are Present

Step 3)

a) If you need to reduce images to a specific Percentage

mogrify -resize 20% -format jpg *

b) If you need to reduce to Specific Width & Height

mogrify -resize 800x600 -format jpg *

c) If you need to reduce to Specific Width

mogrify -resize 1024x -format jpg *

Further Reading Click Here !!!

Drush & Dreamhost

Its been more than a year since i am using Dreamhost, The basic package is not too great but is cheap and the support is responsive.

Drush or the Drupal Shell is one of the most powerful tools to use when you are working with Drupal. DreamHost provides php5 but uses php4 as the default for the php command line and in that case drush wont work, so here is a 3 step guide to setup drush on your dreamhost account.

  1. Download & Extract Drush some where on your home folder
  2. Add the following lines to .bash_profile using your favorite editor.

    export PATH=/usr/local/php5/bin/:$PATH
    alias drush='/home/username/drush/drush'

    replace the path of drush as per your preferences :)
  3. Their is no Step 3, Login again and use Drush


For Using Drush Command Line tool you will need to enable SSH on your DreamHost Account.

Connecting via SSH

$ ssh username@domain.com

Editing .bash_profile

$ vi .bash_profile

path to ,bash_profile would be /home/username/.bash_profile

Happy Drush :)

Using SQL * Plus on Command Line in Ubuntu

This blog post is an HowTo "Setup SQL*Plus to work on BASH" The commands illustrated in this howto are tested on Ubuntu 9.10 with Oracle Database 10g Express Edition Release - Production Installed.

What is SQL * Plus ?

SQL*Plus is a command line SQL and PL/SQL language interface and reporting tool that ships with the Oracle Database Client and Server software. It can be used interactively or driven from scripts. SQL*Plus is frequently used by DBAs and Developers to interact with the Oracle database.


Oracle Database 10g Express Edition Release Installed

Once you have Oracle 10g Installed successfully you can go to

Applications > Oracle Database 10g Express Edition > Run SQL Command Line

and successfully run all your SQL PL/SQL easily but using SQL*Plus directly on BASH is the real fun, Below are the steps which will enable you to use SQL*Plus on BASH

2) set ORACLE_HOME/bin in $PATH

The above 2 steps can be performed by adding the following lines to .bashrc

export ORACLE_HOME=/usr/lib/oracle/xe/app/oracle/product/10.2.0/server/

The above 2 Steps are sufficient to use SQL*Plus on Command Line once you have done the steps execute

$ sqlplus user/password@database

In the default install XE would be used as database.

Issues while using the default or only the above method

  • SQL*Plus does not support the Up/Down Arrow command scroll under linux environment which in itself is the biggest problem.
  • Default Editor is not Set which will confuse you while executing ED.
  • Various Other Environment variables are not set

Resolving the above mentioned issues

  • Install rlwrap this will enable the Up/Down Scroll function
    $ sudo apt-get install rlwrap
    now connect to oracle using
    $ rlwrap sqlplus user/password@database
    You will find that Up/Down Scroll is now enabled.
  • Set the most common Environment Variables

    $ rlwrap sqlplus user/password@database
    SQL*Plus: Release - Production on Sun Feb 28 23:53:15 2010
    Copyright (c) 1982, 2005, Oracle. All rights reserved.
    Connected to:
    Oracle Database 10g Express Edition Release - Production
    SQL> SET EDITFILE "afiedt.buf"

    This will set the default editor as VIM, Default Edit File as afiedt.buf LINESIZE as 132 & will mark SERVEROUTUT as ON
    various other variables can also be set similar commands on the SQL prompt

Refer SQL*Plus FAQ's for more information.

4 Steps to add Ubuntu Systems to Active Directory Setup

The IT environment today in any organization is a sort of a mixture where many different Operating Systems are used, and Windows Active Domain Controller exists in majority of such organization.

Below is a 4 step How to on "Connecting Linux (Ubuntu) Systems to Active Directory Setup"

1) Update the Software Repositories

sudo apt-get update

2) Install Required Packages (likewise-open)

sudo apt-get install likewise-open

3) Join The Domain using Domain Administrator Account, replace Administrator with Domain Administrator Username and fqdn..domain with the Fully Qualified Domain Name

sudo domainjoin-cli join fqdn.domain Administrator

4) Update the Startup Scripts

sudo update-rc.d likewise-open defaults
sudo /etc/init.d/likewise-open start

Thats it !! you have now joined the Domain, Log Off or preferably Restart the Machine.

Now you can login using Active Directory Credentials remember appending DOMAIN\ before your username

User Name to Login : DOMAIN\username
Password: domainpassword

This will also create a home Directory for Domain Users under /home/DOMAIN

Restrict Multiple Logins in Domain (AD)

I have always asked this question to my colleagues as to "How do i restrict Multiple Logins in an Active Directory Setup"

So here is the answer

Create a file when a user login and check for such file each time the login request is received  if file exists logoff, if file is not present Login and create the file. Its that simple

Below is the step by step process to achieve this using Group Policy


  1. Windows 2003 AD is being used
  2. //<server>/logon is shared and write access is given to everyone

The Steps

Step 1) Create 2 batch files in C:\WINDOWS\SYSVOL\sysvol\domain.name\scripts\logon

File 1: login.bat

If Exist \\server\logons\%username%.txt Goto notlogon
Echo %username% logged in from %computername% > \\server\logons\%username%.txt
Echo %username% logged in from %computername% > \\server\logons\%computername%.txt
Goto end

File 2: logout.bat

If Not Exist \\server\logons\%computername%.txt goto notlogon
Del \\server\logons\%username%.txt
Del \\server\logons\%computername%.txt
Goto end

Step 2) Modify Group Policy

Edit the Group Policy related to the OU where you want to disable multiple logins, In Group Policy Object Editor locate to

User Configuration > Windows Settings > Scripts (Logon/Logoff)

Add the login.bat created earlier in Logon and logout.bat in Logoff

Adding Login Script on Group Policy

thats it now when you login a file would be created in //<server>/logon with the username and computername of the loggedin user and he/she will not be able to login to other computer and once he logoff these would be automatically deleted and the user will be allowed to login on any Client.

This was simple

Key Based Authorization with SSH

Using remote shells is all time favourite but remembering those many passwords is a pain so here are the steps to login using SSH without putting a password :)


1. Create a public ssh key, if you haven’t one already. Look at ~/.ssh. If you see a file named id_dsa.pub then you obviously already have a public key. If not, simply create one.

ssh-keygen -t dsa should do the trick. Please note that there are other types of keys, e.g. RSA instead of DSA.

2. Make sure your .ssh dir is not publically writable

    # chmod 700 ~/.ssh

3. Get your public ssh key on the server you want to login automatically.
    #scp ~/.ssh/id_dsa.pub remoteuser@example.com

4. Append the contents of your public key to the ~/.ssh/authorized_keys and remove it.

Important: This must be done on the server you just copied your public key to. Otherwise you wouldn’t have had to copy it on your server. Simply issue something like


    # cat id_dsa.pub >> .ssh/authorized_keys while at your home directory.


5. Instead of steps 3 and 4, you can issue something like this:
    # cat ~/.ssh/id_dsa.pub | ssh -l remoteuser remoteserver.com 'cat >> ~/.ssh/authorized_keys'

   6. Remove your public key from the home directory on the server.

   7. And you are in

    # ssh -l remoteuser example.com
    # ssh remoteuser@example.com


 without getting asked for a password.

Configuring Apache with SSL

Apache is the most common web server used now a days, you would have already configured apache many times by now but what about configuring it with SSL i.e. using apache to service on the https protocol, i assume you have already configured the basic apache server and have also enabled the SSL module, if not refer to my previous post on Configuring Apache Web server.

The following post is an extremely simplified step by step guide to configure SSL in apache using Self Signed Certificates you can also use a real certificate issued by a CA if you have it


1) Apache with SSL module enabled
2) openssl installed

Step 1) Generate a Private Key

We will use the openssl toolkit for generating a RSA Private Key and Certificate Signing Request, as the first step generate the key the command below will create a 1024bit key using 3des

abhishek@kashipur.in:~$ openssl genrsa -des3 -out server.key 1024
Generating RSA private key, 1024 bit long modulus
unable to write 'random state'
e is 65537 (0x10001)
Enter pass phrase for server.key:
Verifying - Enter pass phrase for server.key:

Step 2) Generate a CSR (Certificate Signing Request)

Once the key is generated you will need to make a CSR or Certificate Signing Request, using the following command you can generate a CSR in this process you would be asked to enter various parameters as shown below

abhishek@kashipur.in:~$ openssl req -new -key server.key -out server.csr

Enter pass phrase for server.key:
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter '.', the field will be left blank.
Country Name (2 letter code) [AU]:IN
State or Province Name (full name) [Some-State]:UK
Locality Name (eg, city) []:Kashipur
Organization Name (eg, company) [Internet Widgits Pty Ltd]:Kashipur Networks
Organizational Unit Name (eg, section) []:
Common Name (eg, YOUR name) []:kashipur.net
Email Address []:abhishek at kashipur dot net

Please enter the following 'extra' attributes
to be sent with your certificate request
A challenge password []:
An optional company name []:

Step 3) Remove Pass phrase from Key

This is completely an optional step if you skip this you will have to run to the server as and when the server restarts to enter the pass phase :) , use the following commands to get rid of this problem

abhishek@kashipur.in:~$ cp server.key server.key.org
abhishek@kashipur.in:~$ openssl rsa -in server.key.org -out server.key

Enter pass phrase for server.key.org:
writing RSA key

Step 4) Generating a Self-Signed Certificate

Once you have your Key and CSR ready its time to generate the Certificate use the following command to generate a certificate

abhishek@kashipur.in:~$ openssl x509 -req -days 365 -in server.csr -signkey server.key -out server.crt

Signature ok
subject=/C=IN/ST=UK/L=Kashipur/O=Kashipur Networks/CN=kashipur.net/emailAddress=abhishek at kashipur dot net
Getting Private key

Step 5) Copy Certificate and Key to Apache Folder

After following the steps above you would have the following files generated

abhishek@kashipur.in:~$ ls -l

-rw-r--r-- 1 abhishek abhishek 952 2009-06-12 14:30 server.crt
-rw-r--r-- 1 abhishek abhishek 704 2009-06-12 14:27 server.csr
-rw-r--r-- 1 abhishek abhishek 887 2009-06-12 14:29 server.key
-rw-r--r-- 1 abhishek abhishek 963 2009-06-12 14:28 server.key.org

Copy the crt and key file to a preferable location inside the apache configuration folder generally /etc/apache2/cert using the following command

abhishek@kashipur.in:~$ cp server.crt server.key /etc/apache2/cert

Step 6) Configure Apache with SSL

Once you have your Certificate and Key copied, modify your httpd.conf to reflect the following

SSLEngine on
SSLCertificateFile /etc/apache2/cert/server.crt
SSLCertificateKeyFile /etc/apache2/cert/server.key
SetEnvIf User-Agent ".*MSIE.*" nokeepalive ssl-unclean-shutdown
CustomLog logs/ssl_request_log \
"%t %h %{SSL_PROTOCOL}x %{SSL_CIPHER}x \"%r\" %b"

Ensure apache is listening to Port 443 if not add the Listen Directive. After making these changes preferable verify the configuration file using the following command

abhishek@kashipur.in:~$ apache2ctl configtest
Syntax OK

Once you see Syntax OK you are ready to use https.

Step 7) Restart Apache and test

To apply the configuration changed you need to restart apache which can be done using the following command

root@kashipur.in:~# service apache2 restart


root@kashipur.in:~# service httpd restart (in many cases)

Once you restart test it by appending https:// to the URL

Happy HTTPS :)

Configuring BSNL EVDO Modem in Debian GNU/Linux

EVDO DeviceI recently shifted to Debian GNU/Linux (Lenny), and the first task included configuring my Internet Connection, i use BSNL EVDO Modem to connect to the internet which is not recognized my default in Debian so following is the process by which i configured my BSNL EVDO in Debian

Step 1) Checked for Modem, Vendor and Product ID

$ cat /proc/bus/usb/devices

You will find many entires in this just check for your modem entry in my case i found

T:  Bus=01 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#=  4 Spd=12  MxCh= 0
D:  Ver= 1.10 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
P:  Vendor=19d2 ProdID=fffe Rev= 0.00
S:  Manufacturer=ZTE, Incorporated
S:  Product=ZTE CDMA Tech

by this i know the following information


Step 2) Detect modem (as root user)

# modprobe usbserial vendor=0x1952 product=0xfffe

Note : appending "0x" before Vendor and ProdID is a must

Step 3) Replug The Modem

Check if its detected using dmesg

# dmesg

[   14.280399] usbcore: registered new interface driver usbserial
[   14.280399] usbserial: USB Serial support registered for generic
[   14.280399] usbserial_generic 1-1:1.0: generic converter detected
[   14.280399] usb 1-1: generic converter now attached to ttyUSB0
[   14.280399] usbserial_generic 1-1:1.1: generic converter detected
[   14.280399] usb 1-1: generic converter now attached to ttyUSB1
[   14.280399] usbserial_generic 1-1:1.2: generic converter detected
[   14.280399] usb 1-1: generic converter now attached to ttyUSB2
[   14.280399] usbserial_generic 1-1:1.3: generic converter detected
[   14.280399] usb 1-1: generic converter now attached to ttyUSB3
[   14.280399] usbcore: registered new interface driver usbserial_generic
[   14.280399] usbserial: USB Serial Driver core

from this you come to know that your modem Device is ttyUSB0

Step 4) Install wvdial

# apt-get install wvdial

Step 5) Configure wvdial

edit the wvidal configuration file (/etc/wvdial.conf) below is my wvdial.conf this should work for you aswell

# gedit /etc/wvdial.com

[Dialer Defaults]
Modem = /dev/ttyUSB0
Init1 = ATZ
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
Stupid Mode = on
Modem Type = Analog Modem
Phone = #777
ISDN = 0
Username = cdma
Password = cdma
Baud = 9600

Step 6) Connect :)

# wvdial

hey you are now connected.....

Step 7) Adding the Modem Detection @ startup

edit /etc/modules and add the following

usbserial vendor=0x1952 product=0xfffe

# gedit /etc/modules (add the above line)

Notes : wvdial runs as a super user to enable this for normal user you need to edit user permissions.

G2Image in Drupal using TinyMCE with WYSIWYG API

UPDATE: This post is quite old now and wont work with the latest version of WYSIWYG API, will try to update this soon.

Gallery2 is one of the best galleries available which could be integrated with Drupal easily you would have read my post on integrating it earlier, after you have integrated it the bigger question is how get those images into your content or nodes so this posts answers it, after reading this post you would be able to integrate Gallery2 with your WYSIWYG (TinyMCE) Editor.


The Steps

  1. Extract G2 Image Application in $DRUPAL_HOME/sites/all/modules/wysiwyg/tinymce/jscripts/tiny_mce/plugins/
  2. Open Gallery Setting in Web Browser from $SITENAME/admin/settings/gallery/g2image and enable G2Image for TimyMCE as shown in the image below
    gallery settings
  3. Once you have selected the Mode as TinyMCE add the following code in %drupal%sites/all/modules/wysiwyg/editors/tinymce.inc (function wysiwyg_tinymce_plugins($editor))

    'G2Image' => array(
            'path' => $editor['library path'] .'/plugins/G2Image',
            'buttons' => array('G2Image' => t('G2Image')),
            'internal' => TRUE,
            'load' => TRUE,

  4. Now enable G2Image button for TinyMCE from the editor profile at "admin/settings/wysiwyg/profile/edit/2"
  5. Thats it select G2Image button in TinyMCE

    it will popup a Galley as shown below for you to select images and insert them directly in your posts :)

    gallery Pop Up