Category: UNIX Commands

Solved – error while loading shared libraries: libpangox-1.0.so.0: Anydesk on Ubuntu 22.04 LTS

Resolve the “libpangox-1.0.so.0” shared library error in Anydesk on Ubuntu 22.04 LTS with this easy step-by-step fix and download instructions.

After successfully upgrading from Ubuntu 20.04 LTS to 22.04 LTS, most of the applications are working perfectly. But, some of the applications behave unusually. Such as, I tried to run the Anydesk application, but it doesn’t launch/start. when I checked the status service, the AnyDesk service was failed and the reason for failing is mentioned in the below error message,

anydesk: error while loading shared libraries: libpangox-1.0.so.0: cannot open shared object file: No such file or directory

What is libpangox library?

libpangox-1.0.so.0 is a library used for text layout and rendering the text. Most of the work on Pango-1.0 was done using the GTK+ widget toolkit as a test platform.

Install the library

So, I ran the command to install it using the apt as follows,

sudo apt install libpangox-1.0-0

But, it gives me the following error,

Package libpangox-1.0-0 is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or is only available from another source

So, from that we can understand that, libpangox-1.0.so.0 can’t be installed from apt or apt-get. We need to install it manually.

Use the following steps to install libpangox-1.0.so.0 manually,

Step 1. Download the libpangox-1.0 package

You need to manually download the .deb file using wget to any location,

wget http://ftp.us.debian.org/debian/pool/main/p/pangox-compat/libpangox-1.0-0_0.0.2-5.1_amd64.deb

Step2: Install the package using apt

Install the downloaded .deb file using apt command as follows,

sudo apt install ./libpangox-1.0-0_0.0.2-5.1_amd64.deb

Step3: Restart the AnyDesk service

After successful installation, restart the anydesk service.

sudo service anydesk restart

After these steps, if you check the AnyDesk service status, it will show active (running).

Setup and use a virtual python environment in Ubuntu

With virtualenvwrapper (user-friendly wrappers for the functionality of virtualenv)

Install virtualenv

Install virtualenv with

sudo apt-get install virtualenv

(for Ubuntu 14.04 (trusty) install python-virtualenv)

Install virtualenvwrapper

The reason we are also installing virtualenvwrapper is that it offers nice and simple commands to manage your virtual environments. There are two ways to install virtualenvwrapper:

As Ubuntu package (from Ubuntu 16.04)

Run sudo apt install virtualenvwrapper then run echo "source /usr/share/virtualenvwrapper/virtualenvwrapper.sh" >> ~/.bashrc

Using pip

  1. Install and/or update pip

    Install pip for Python 2 with
    sudo apt-get install python-pip

    or for Python 3
    sudo apt-get install python3-pip

    (if you use Python 3, you may need to use pip3 instead of pip in the rest of this guide).

    Optional (but recommended): 
    Turn on bash autocomplete for pip Run
    pip completion --bash >> ~/.bashrc

    and run 

    source ~/.bashrc 

    to enable.
  2. Install virtualenvwrapper Because we want to avoid sudo pip we install virtualenvwrapper locally (by default under ~/.local) with:
    pip install --user virtualenvwrapper

    and

    echo "export VIRTUALENVWRAPPER_PYTHON=/usr/bin/python3" >> ~/.bashrc
  3. Source virtualenvwrapper in .bashrc

    echo "source ~/.local/bin/virtualenvwrapper.sh" >> ~/.bashrc

Setup virtualenv and virtualenvwrapper:

First, we export the WORKON_HOME variable which contains the directory in which our virtual environments are to be stored. Let’s make this ~/.virtualenvs

export WORKON_HOME=~/.virtualenvs

now also create this directory

mkdir $WORKON_HOME

and put this export in our ~/.bashrc file so this variable gets automatically defined

echo "export WORKON_HOME=$WORKON_HOME" >> ~/.bashrc

We can also add some extra tricks like the following, which makes sure that if pip creates an extra virtual environment, it is also placed in our WORKON_HOME directory:

echo "export PIP_VIRTUALENV_BASE=$WORKON_HOME" >> ~/.bashrc

Source ~/.bashrc to load the changes

source ~/.bashrc

Test if it works

Now we create our first virtual environment. The -p argument is optional, it is used to set the Python version to use; it can also be python3 for example.

mkvirtualenv -p python2.7 test

You will see that the environment will be set up, and your prompt now includes the name of your active environment in parentheses. Also if you now run

python -c "import sys; print sys.path"

you should see a lot of /home/user/.virtualenv/... because it now doesn’t use your system site packages.

You can deactivate your environment by running

deactivate

and if you want to work on it again, simply type

workon test

Finally, if you want to delete your environment, type

rmvirtualenv test

Enjoy!

Auto-Start Tomcat on Ubuntu Boot Using systemd

Learn how to configure Apache Tomcat to start automatically on system boot in Ubuntu using systemd service units. A complete step-by-step guide.

Apache Tomcat is not configured with autostart by default in Ubuntu. So, custom init script is required to configure Tomcat for autostart on startup.

Create the init script in /etc/init.d/tomcat8 with the contents as per below.

Init script contents:

#!/bin/bash

### BEGIN INIT INFO
# Provides:        tomcat8
# Required-Start:  $network
# Required-Stop:   $network
# Default-Start:   2 3 4 5
# Default-Stop:    0 1 6
# Short-Description: Start/Stop Tomcat server
### END INIT INFO

PATH=/sbin:/bin:/usr/sbin:/usr/bin

start() {
 sh {tomcat_root}/bin/startup.sh
}

stop() {
 sh {tomcat_root}/bin/shutdown.sh
}

case $1 in
  start|stop) $1;;
  restart) stop; start;;
  *) echo "Run as $0 <start|stop|restart>"; exit 1;;
esac

Note: Please change {tomcat_root} with your Tomcat installation folder path.

Change its permissions and add the correct symlinks automatically:

chmod 755 /etc/init.d/tomcat8
update-rc.d tomcat8 defaults

And from now on it will be automatically started and shut down upon entering the appropriate run levels.

It could be also controlled with just use following commands like Apache

service tomcat8 <stop|start|restart>

Using above process any server script can be created and configured to start on startup.

Access shell with SSH on cPanel server from Linux

Discover an effective way to set PostgreSQL schemas using PHP PDO when the SET search_path approach fails. Learn best practices for schema-based architecture.

Some of the important server related problems will be solved only using shell access to the server. To access the cPanel server shell using SSH, there must be an SSH client installed on PC. Most of the Linux distros include SSH client software by default. If it is not installed, then it can be easily installed with following commands,

For Ubuntu: apt-get install openssh-client
For CentOS: yum install openssh-clients

After installation, follow these steps to access the cPanel shell with SSH from Linux:

  1. Login to cPanel and go to Security > SSH/Shell Access to generate SSH key pair.
  2. Click Manage SSH Keys > Generate a New Key. You should use a password to protect the key. You will be asked the password each time you use the key.
  3. In Public Keys section click ‘Manage Authorization’ and ‘Authorize’
  4. In Private Keys section click, Vew/Download then download the key (id_dsa or id_rsa) to your PC.
  5. Save it to ~/.ssh directory on your Linux machine under a meaningful name to not overwrite your existing keys for example id_dsa.myjavahost
  6. Now make sure permissions are correct on the key (one-time task) and connect:
    mypc:~$ chmod 600 .ssh/id_dsa
    mypc:~$ ssh -p1033 -i .ssh/id_dsa yourusername@yourservername
    Enter passphrase for key '.ssh/id_dsa':
  1. Provide the password for the key, set up in step #2

You should be logged in by now.

Fix: phpMyAdmin Gives 404 Error in Localhost

Troubleshooting guide to fix the 404 error when accessing phpMyAdmin on localhost. Learn common causes and step-by-step solutions for Apache and Nginx servers.

To run phpmyadmin without getting 404 error, configure apache.conf for phpmyadmin.

gksu gedit /etc/apache2/apache2.conf

Then add the following line to the end of the file.

Include /etc/phpmyadmin/apache.conf

And restart apache

/etc/init.d/apache2 restart

Please read this section in Ubuntu wiki describes the 404 error problem for phpmyadmin.