Wednesday, November 10, 2010

Add new rule to SpamAssassin

Add this lines to /etc/mail/spamassassin/

describe LOCAL_DEMONSTRATION_RULE This is a simple test rule

then you must restart the SpamAssassin Process:

/etc/init.d/psa-spamassassin restart

You can also add rule to each user in ~/.spamassassin/user_prefs

but remember that by default allow_user_rules is 0, and you must change
that to 1. Add this line to:


allow_user_rules 1

Don't forget to restart the SpamAssassin.

Friday, August 13, 2010

Likewise-Open: Authenticate a Linux machine to an Active Directory domain

To install the likewise-open package in Ubuntu, open a terminal prompt and enter:
sudo apt-get install likewise-open

Or you could download appropriate Script from here.

The main executable file of the likewise-open package is /usr/bin/domainjoin-cli, which is used to join your computer to the domain. Before you join a domain you will need to make sure you have:

  • Access to an Active Directory user with appropriate rights to join the domain.

  • The Fully Qualified Domain Name (FQDN) of the domain you want to join. If your AD domain does not match a valid domain such as, it is likely that it has the form of domainname.local.

  • DNS for the domain setup properly. In a production AD environment this should be the case. Proper Microsoft DNS is needed so that client workstations can determine the Active Directory domain is available.

To join a domain, from a terminal prompt enter:

sudo domainjoin-cli join Administrator

See here for more details.

Qmail & SpamAssassin - Change Default Rules Score

Under this directory:


edit user_prefs and add the new Score for desire rule:


score RDNS_NONE 5.0

that overrides the defualt score.

You can find all rules here:

Wednesday, June 2, 2010

Ubuntu - Convert jpg files to gif animator

Run this command:

convert -delay 10 -loop 0 *.jpg animation.gif

Monday, May 10, 2010

Chrooted SSH/SFTP

with these settings, works for me in Debian Lenny:

Be sure that this line in /etc/ssh/sshd_config exists:

Subsystem sftp internal-sftp

Chroot the user to his home:

ChrootDirectory %h

The owner of home must be root (mod 755).

These lines are important, otherwise the root user could not login into system:

Match User root
ChrootDirectory /

Restart the ssh process:

/etc/init.d/ssh restart

Thursday, April 8, 2010

Colored output in bash

Use escape sequences:

echo -e '\E[color1;color2mYour Text.'
(color1 is the foreground, color2 the background color)

Shell Scripting Syntax

  1. echo -e '\E[30m black \E[31mred \E[32mgreen \E[33myellow \E[34mblue \E[35mmagenta \E[36mcyan \E[37mwhite'
  2. echo -e '\E[30;41mblack on red'

Shell Scripting Syntax
  1. Color: Foreground: Background:
  2. ---------------------------------------------------------
  3. black 30 40
  4. red 31 41
  5. green 32 42
  6. yellow 33 43
  7. blue 34 44
  8. magenta 35 45
  9. cyan 36 46
  10. white 37 47

Monday, March 8, 2010

Tuesday, March 2, 2010

Ubuntu - If your desktop icons are disappeared, try this

Press Alt+F2 and type gconf-editor in window.

Then apps --> nautilus --> preferences

Make sure "show_desktop" is checked.

If it's checked then double click on it and hit ok.

Wednesday, February 24, 2010

Send test mail from command line with Sendmail

In shell run this command:

( echo subject: test; echo ) | sendmail -v -oi YOUR-EMAIL@ADDRESS.COM

MySQL - debian-sys-maint account

Find your debian-sys-maint password in /etc/mysql/debian.cnf.

Then use this command in Mysql shell:

GRANT ALL PRIVILEGES ON *.* TO 'debian-sys-maint'@'localhost' \

Replace PASSWORD with your debian-sys-maint password.

Backup and restore debian/ubuntu package selection

If you are running Debian and have lost track of which packages you are running, it could be useful to get a backup of your currently installed packages. You can get a list by running:

dpkg --get-selections > debianlist.txt

This will put the entire list in debianlist.txt. You could then install the same packages on a different computer with:

dpkg --set-selections < debianlist.txt

You should bear in mind that you would also need to copy over configuration files from /etc when copying your system to a new computer.

To actually install the selections, use:

apt-get -u dselect-upgrade


Tuesday, February 16, 2010

Convert a ssh-keygen to putty format using puttygen

First install putty-tools:

apt-get install putty-tools

then use this command to convert ssh-key:


Monday, January 25, 2010

How-To: Find missing packages in Debian

apt-file is a command line tool for searching packages in Debian/Ubuntu repositories.
Unlike apt-cache search, apt-file can find files in uninstalled or can list the content of uninstalled packages.

First, we will install the apt-file package:

apt-get install apt-file

then we need to update database:

apt-file update

now we can query the database for myfile:

apt-file search FILENAME