Answer:

To upgrade a single package, first need to perform an update first.

# sudo apt-get update

Then use the install sub command to perform an upgrade, e.g. apache2

#sudo apt-get install apache2

Answer:

Qt bindings to WebKit have been added since 4.4, so you can use PyQt to script the browser (Webkit based).

Firstly, make sure you have installed the need packages:

# sudo apt-get install libqt4-core libqt4-webkit python-qt4

Then you can write a simple script to test, e.g.

#!/usr/bin/env python

import sys
from PyQt4.QtCore import *
from PyQt4.QtGui import *
from PyQt4.QtWebKit import *

app = QApplication(sys.argv)

web = QWebView()
web.load(QUrl("http://www.google.com"))
web.show()

sys.exit(app.exec_())

Answer:

To remove ownloaded archive files from apt-get to save spaces, try the following command:

# sudo apt-get clean

So all the unneeded archive files will be removed.

Answer:

7zip is a well known compression program if you need a very small file size, i.e. high compression ratio.

To install under Ubuntu/Debian:

# sudo apt-get install p7zip

To compress a file

# p7zip test.txt

To decompress a file

# p7zip -d test.txt.7z

Answer:

To completely uninstall a package in Ubuntu/Debian, you can use the command below:

# sudo apt-get --purge remove PACKAGE

That's it.

Answer:

Add a User in Linux, just use the useradd command:

# sudo useradd -d /home/john -m john

The above command will create the user john and create a home directory which is at /home/john

Answer:

It is easy to use apt-get to install multiple softwares at the same time, without executing commands one by one.

E.g.

# sudo apt-get install curl wget lynx elinks

Answer:

In Ubuntu, the package index is managed by the Advanced Packaging Tool (APT).

The index of all the available packages from the repositories is defined in the file /etc/apt/sources.list file.

To update this package index, use the following command.

# sudo apt-get update

That is it.

Answer:

If you want to remove a package in Ubuntu, you can use apt-get remove, e.g.

# sudo apt-get remove php5

However, the config files will NOT be removed.

To remove the config files also, you can use apt-get purge, e.g.

# sudo apt-get purge php5

Answer:

To check which Apache modules are loaded, in RHEL/Fedora/CentOS, type

# httpd -M

In Debian/Ubuntu

# sudo apache2ctl -M