“Instead of spending the next 10 years trying to find a Flash implementation for Linux or OS X that doesn’t drain CPU cycles like there’s no tomorrow, NeoSmart Technologies has made an HTML5 viewer for YouTube videos. It loads YouTube videos in an HTML5 video container and streams (with skip/skim/pause/resume) against an MP4 resource, and an (optional) userscript file can update YouTube pages with the HTML5 viewer. The latest versions of Firefox, Chrome, and Safari are supported. Personally, I can’t wait until the major video sites default to HTML5 and we can finally say goodbye to Flash.”

from here

Optimize different GNOME applications to make it more faster and responsive.

So make your computer and other apps runs faster with this script :
For instance ,the gtk menu will be more responsives ( but you will clearly need to run the script after several apps install in this menu).

Requirements
This application requires GTK+ version 2.2.x.
About this version
Compatility update for lastest gnome and ubuntu.

take it here

Many of us are familiar with the use of Apache for hosting websites. It might not be the fastest webserver but it is extraordinarily popular, extremely flexible, and a great choice for most people. However there are times when it can struggle, and placing a proxy in front of it can be useful.

nginx is a very small, fast, and efficient HTTP server with a lot of built in smarts to allow it to work as a reverse proxy, and not just for HTTP, it also supports SMTP.

I’ve recently updated this site to change the way it works – as it has been struggling – and this brief introduction is mostly the documentation on the changes I made.

The site itself, like many, is made up of a mixture of static resources and dynamically generated content. In our case our dynamic content is produced a collection of Perl CGI scripts. The changes described in this brief introduction to using nginx would apply to any site that had a mixture of static & dynamic resources, so could apply equally well to a Ruby on Rails or PHP-based site.

Over the past couple of years I’ve noticed that Apache 2.x would perform well on an average day, but start to struggle and perform less well when under load. Apart from adding more memory to this host I wanted to change the setup to increase the number of connections and hits it could withstand.

My plan was:

• Leave Apache’s configuration as untouched as possible.
  • In case there were problems I wanted to be able to revert any changes easily.
• Leave Apache to serve all the dynamic content as it did currently.
• Place a dedicated smaller, faster, and simpler HTTP server to serve static resources.
  • With the expectation that this would leave Apache to handle the rest of the traffic which it would be able to do without being so distracted.

There are a several ways this plan could have been executed and the two most obvious were:

Shifting Resources Elsewhere

We could split the serving of static resources by moving them. For example rather than serving and hosting http://www.debian-administration.org/images/logo.png we could move that to a different domain, such as http://images.debian-administration.org/logo.png.

We could have created another sub-domain “static.” to host any other content, such as CSS and Javascript files.

This would allow us to easily configure a second webserver to handle the static content (perhaps on a different host, but most likely on the same one). The downside to this approach would be the required updates to our site code, templates, and other files.

Introduce A Proxy

To avoid moving resources around, and the overhead this would entail, the most simple solution would be to place a proxy in front of Apache. This would examine the incoming HTTP request and dispatch it to either:

• Apache if it were a request for /cgi-bin/
• Another dedicated server for all static resources (e.g. *.gif, *.png)

The decision to use nginx was pretty simple, there are a few different proxies out there which are well regarded (including pound which we’ve previously introduced for simple load-balancing). nginx looked like the most likely candidate because it focuses upon being both a fast HTTP server and a proxy.

By working as a proxy and a HTTP server this cuts down the software we must use. Had we chosen a dedicated proxy-only tool we’d have needed to have three servers running:

• The proxy to receive requests.
  • Apache2 for serving the dynamic content.
  • HTTP server for static content.

With nginx in place we have a simpler setup with only two servers running:

• nginx to accept requests and immediately serve static content.
  • Apache to receive the dynamic requests that nginx didn’t want to handle.

Installing nginx

The installation of nginx was as simple as we’d expect upon a Debian GNU/Linux host:

aptitude install nginx

Once installed the configuration files are all be located beneath the directory /etc/nginx. As with the Debian apache2 packages you’re expected to place sites you’d like to be enabled into configuration files beneath a sites-enabled directory.

We’ll not dwell on the nginx configuration files too much – the main one is /etc/nginx/nginx.conf and is pretty readable and sensible. The only change we need to make is to remove the file /etc/nginx/sites-enabled/default.

Configuring nginx & apache2

Configuring nginx itself is very simple, and our actual setup will consist of two parts:

• Configuring nginx to listen upon port 80, and forward some requests to Apache.
• Changing the Apache configuration so that it no longer listens upon *:80, instead another port will be used.

Our site is comprised of two virtual hosts our main main, and our planet. The latter site is by far the most simple one as it has no dynamic component to it, merely static files.

The setup of the static site consists of creating a configuration file for it at /etc/nginx/sites-available/planet.conf with the following content:

#<br />#  planet-debian-administration.org is 100% static, so nginx can<br /># serve it all directly.<br />#<br />server {<br />	listen :80;<br /><br />	server_name  planet.debian-administration.org;<br /><br />        access_log   /home/www/planet.debian-administration.org/logs/access.log;<br /><br />	root   /home/www/planet.debian-administration.org/htdocs/;<br />}<br />

This is sufficient for nginx to serve the virtual host planet.debian-administration.org from the directory /home/www/planet.debian-administration.org/htdocs – and log incoming requests to an appropriate file.

The dynamic handling of our main site is a little more complex. The contents of the /etc/nginx/sites-enabled/d-a.conf configuration file I came up with look like this:

#<br />#  This configuration file handles our main site - it attempts to<br /># serve content directly when it is static, and otherwise pass to<br /># an instance of Apache running upon 127.0.0.1:8080.<br />#<br />server {<br />	listen :80;<br /><br />	server_name  www.debian-administration.org debian-administration.org;<br />        access_log  /var/log/nginx/d-a.proxied.log;<br /><br />        #<br />        # Serve directly:  /images/ + /css/ + /js/<br />        #<br />	location ^~ /(images|css|js) {<br />		root   /home/www/www.debian-administration.org/htdocs/;<br />		access_log  /var/log/nginx/d-a.direct.log ;<br />	}<br /><br />	#<br />	# Serve directly: *.js, *.css, *.rdf,, *.xml, *.ico, & etc<br />	#<br />	location ~* \.(js|css|rdf|xml|ico|txt|gif|jpg|png|jpeg)$ {<br />		root   /home/www/www.debian-administration.org/htdocs/;<br />		access_log  /var/log/nginx/d-a.direct.log ;<br />	}<br /><br /><br />        #<br />        # Proxy all remaining content to Apache<br />        #<br />        location / {<br /><br />            proxy_pass         http://127.0.0.1:8080/;<br />            proxy_redirect     off;<br /><br />            proxy_set_header   Host             $host;<br />            proxy_set_header   X-Real-IP        $remote_addr;<br />            proxy_set_header   X-Forwarded-For  $proxy_add_x_forwarded_for;<br /><br />            client_max_body_size       10m;<br />            client_body_buffer_size    128k;<br /><br />            proxy_connect_timeout      90;<br />            proxy_send_timeout         90;<br />            proxy_read_timeout         90;<br /><br />            proxy_buffer_size          4k;<br />            proxy_buffers              4 32k;<br />            proxy_busy_buffers_size    64k;<br />            proxy_temp_file_write_size 64k;<br />        }<br />}<br />

This configuration file has several points of interest, but for full details you’ll need to consult the nginx documentation. The most obvious sections of interest are the rules which determine which content is handled directly by nginx.

You’ll see that we have two different rules:

• A rule which says anything beneath /images should be handled directly.
• Another rule which says regardless of location *.png will always be handled directly.

These rules might seem redundant but it is better to be explicit about our intentions. The rest of the file contains settings for the forwarding of all other requests to the local Apache instance – I made no changes to the sample configuration here.

The other point to note is that I log incoming requests to two files, depending on whether they were proxied to our Apache instance or handled directly. This isn’t really required but it gives an idea of which requests are going where.

With these two configuration files in place we’re almost done, we just need to ensure that Apache is no longer going to claim port 80 as its own. We do this by modifying /etc/apache2/ports.conf to read:

NameVirtualHost *:8080<br />Listen 8080<br /><br /><IfModule mod_ssl.c><br />    # SSL name based virtual hosts are not yet supported, therefore no<br />    # NameVirtualHost statement here<br />    Listen 443<br /></IfModule><br />

This will ensure that Apache binds to port 8080 and not port 80. We then make matching changes to our virtual host files. For example /etc/apache2/sites-enabled/debian-administration.org:

#  Debian Administration domain.<br />#<br /><VirtualHost *:8080><br />        ServerAdmin webmaster@debian-administration.org<br />        ServerName www.debian-administration.org<br />        DirectoryIndex index.cgi index.html<br /><br />        DocumentRoot /home/www/www.debian-administration.org/htdocs/<br />        ...<br />        ...<br />

With these changes in place we can switch to using our proxy:

/etc/init.d/apache2 stop<br />/etc/init.d/nginx start<br />/etc/init.d/apache2 start<br />

(We stop apache2 so that port 80 becomes available, then start nginx which will use that port, and finally restart apache2 so that it will be available on port 8080 such that nginx can talk to it.)

Note: In this example Apache is listening on port 8080 on all IPs rather than just 127.0.0.1:8080 – I later changed this.

Problems Experienced

Once deployed there were two problems which were initially apparent:

• Lack of IPv6 support.
• Incorrect IP addresses being logged.

Unfortunately the version of nginx available in the Lenny release of Debian did not contain any IPv6 support – which was a real shame as we’ve been running upon IPv6 for quite some time now. (About 3% of our visitors use native IPv6, including myself, and I didn’t want to lose them.)

The solution to the IPv6 problem was to backport the package available in Debian’s unstable distribution (a painless process). Once this was done the nginx configuration file could be updated to read:

  # Listen on both IPv6 & IPv4.<br />  listen [::]:80;<br />

The second problem was related to how Apache received all connections from the outside world via our local host via nginx. This meant it would believe each incoming request was made from the IP address 127.0.0.1.

Happily there was a very simple solution to this problem, the libapache2-mod-rpaf module for Apache 2.x which will allow the real IP address to be visible to our side, and the logfiles.

The RPAF module takes the IP address which initiated the original connection, and which nginx placed in a X-Forwarded-For header, and ensures this IP address is available to our dynamic scripts & apache logfiles.

Applying this solution was as simple as:

aptitude install libapache2-mod-rpaf<br />a2enmod rpaf<br />/etc/init.d/apache2 force-reload<br />

Once this was done our incoming connections were logged correctly, and our code would see the real IP address for each connection rather than the loopback address of the proxy host.

Potential Changes

As you can see from the posted configuration files all incoming requests on port 80 will be either handled directly or proxied – but I made no changes to the handling of port 443, or SSL requests.

We’ve offered SSL for a significant length of time but few visitors use it, so I elected to leave this setup as-is.

If the situation changes then nginx will be updated to proxy SSL requests too – it has support for this, as a perusal of the documentation will suggest.

So far it is too early to tell if this solution has increased our scalability, but I’m very optimistic. Resource usage has certainly fallen and the combination of nginx and apache is a good one that isn’t too complex.

from here

from here

This is my first post on Cheat sheets. Actually Cheat sheet is a concise set of notes used for quick reference. Cheat sheets will contain most of the shortcuts needed to program faster. And it is meant for newbie users who can’t remember the shortcuts or commands.

In this post , I have collected almost 27 Cheat sheets available for Linux users. These Cheat sheets will contain Linux command lines, Linux security, Linux administration, Gnome/KDE, sed/awk/vim, and distribution specific codes.

You may think that one cheat sheet is just enough for me , so why should I need to look at so many cheat sheets. According to me some cheat sheets may miss some points so its better to Look through all of them and then choose the top 5-10 you think will help you the most. After that you can Print them out and hang them on the wall around your desk for quick reference.

Unix/Linux Command Reference

THE ONE PAGE LINUX MANUAL

Treebeard’s Unix Cheat Sheet

Linux Shortcuts and Commands

The humble Linux cheat sheet

The Official Red Hat Linux Getting Started Guide

Evelyn’s LINUX Cheat Sheet

LINUX Cheat Sheet

Linux Security Quick Reference Guide

LINUX System Call Quick Reference

LINUX Admin Quick Reference

directory of Linux commands

Click on any of the 687 commands below to get a description and list of available options. All links in the command summaries point to the online version of the book on Safari Bookshelf.

Linux cheat sheet

Linux Command-Line Cheat Sheet

Linux Quick Reference Guide

Linux Commands – Ultimate Practical guide

Linux Cheat Sheet

Linux Cheat Sheet

Linux Cheat Sheet

Using Linux the CLI way – Cheat Sheet

ubuntu Reference Cheat Sheet

Debian GNU/Linux Reference Card

Gnome / KDE Keyboard Shortcuts

Tired of using your mouse so much? Did you know that both KDE and Gnome have keyboard shortcuts for just about everything you can do with a mouse? Here’s a list of the various shortcuts on both platforms.

Solaris Cheat Sheet

NetCat Cheat Sheet for Linux and Unix users

Solaris Handy commands

Unix Toolbox

I hope that these cheat sheets will definitely help you to remember some difficult commands for sure. If you have came across any other Linux or Unix cheat sheets then do let me know.

pdfedit
PDFedit is free and open source tool for manipulating PDF documents. You can use it to read, change and extract information from a PDF file.PDF Editor is run in english language by default, but by setting environment variable LANG before launching the program, you can tell PDF Editor to look for specific language file.

Howto install pdfedit in ubuntu / debian
open a terminal
$sudo apt-get install pdfedit ( or open synaptic package manager and search for pdfedit)

poppler-utils
poppler-utils is a package contains pdftops (PDF to PostScript converter), pdfinfo (PDF document information extractor), pdfimages (PDF image extractor), pdftohtml (PDF to HTML converter), pdftotext (PDF to text converter), and pdffonts (PDF font analyzer). After installation all the utilities can be used in command line.

Howto install poppler-utils in ubuntu / debian
open a terminal
$sudo apt-get install poppler-utils ( or open synaptic package manager and search for poppler-utils)

pdftk
Pdftk is pdf tool kit for doing everyday things with PDF documents. pdftk can be used for Merge PDF Documents, Split PDF Pages into a New Document, Encrypt Output as Desired
Fill PDF Forms with FDF Data or XFDF Data and/or Flatten Forms, Apply a Background
Attach Files to PDF Pages or the PDF Document, Unpack PDF Attachments, Burst a PDF Document into Single Pages, Repair Corrupted PDF (Where Possible).

Interface used is Command Line

Howto install pdftk in ubuntu / debian
open a terminal
$sudo apt-get install pdftk ( or open synaptic package manager and search for pdftk)

Eg:
Merge Two or More PDFs into a New Document
$ pdftk 1.pdf 2.pdf 3.pdf cat output 123.pdf

More Help Here

QPDF
QPDF is a command-line program that does structural, content-preserving transformations on PDF files. It could have been called something like pdf-to-pdf. QPDF is capable of creating web-optimized) files and encrypted files. QPDF also supports a special mode designed to allow you to edit the content of PDF files in a text editor.
Interface used is Command Line

Howto install qpdf in ubuntu / debian
open a terminal
$sudo apt-get install qpdf ( or open synaptic package manager and search for qpdf)

see more here

pdfsam
pdfsam is an open source tool designed to handle pdf files. Pdfsam basic is a simple tool designed to split and merge pdf files. It’s written in Java and it provides a Graphical interface (GUI) and a shell interface (Console). It’s platform independent and it runs on every platform where a Java Virtual Machine is available. It’s released in 2 versions.

split your pdf documents (into chapters, single pages, etc.). merge many pdf documents or subsections of them. extract sections of your document into a single pdf document. save and load your environment to automatize your recurrent jobs.

Howto install pdfsam in ubuntu / debian
open a terminal
$sudo apt-get install pdfsam ( or open synaptic package manager and search for pdfsam)

from here

How to patch KernelCheck

<code>cat PATCHNAME.patch | patch -p1</code>

<code>sudopatch -p1 <PATCHNAME.patch</code>

Firefox’s user interface is written using XUL and Javascript. The Gecko engine which renders the webpages also renders the user interface. This means you can enter chrome URLs into the Firefox address bar and do some really cool things.

I wouldn’t recommend trying out any of these “tricks” if you have any important websites open. Everything has been tested with Firefox 1.5 on Windows.

chrome://browser/content/browser.xul

This is awesome. Type this in the address bar and you can have a nested copy of Firefox running inside Firefox. You can even open up several tabs at this URL and have tabbed windows. You can even nest Firefox inside itself several times. Most things seem to work.

chrome://global/content/alerts/alert.xul

Notice: This will make your Firefox window disappear under the taskbar. Before loading this URL, make sure you have at least one other tab open. The Firefox window should do a crazy dance in the corner of the screen. If your Firefox window disappears, right click Firefox in the taskbar and select maximize. Press Control+W to stop Firefox from moving around.

chrome://browser/content/preferences/preferences.xul

Opens the Options window. In Firefox 1.0 use chrome://browser/content/pref/pref.xul

chrome://browser/content/bookmarks/bookmarksPanel.xul

Opens a list of your bookmarks.

chrome://browser/content/history/history-panel.xul

Opens a list of websites in your history.

chrome://global/content/console.xul

Opens the Javascript console.

chrome://mozapps/content/extensions/extensions.xul?type=extensions

Opens the Extensions window.

chrome://mozapps/content/extensions/extensions.xul

Opens the Themes window.

chrome://mozapps/content/profile/profileSelection.xul

Closes the current tab in Firefox; or the window if there is only one tab open.

chrome://global/content/finddialog.xul

Opens the old Firefox “Find” dialog (non functional)

chrome://global/content/printdialog.xul

Opens the Firefox Print dialog (non functional)

chrome://global/content/filepicker.xul

Seems to open a Linux style file picker on Windows for me. Non functional on Windows.

You can use the DOM Inspector and inspect windows to find cool URLs. Let me know if you find something neat.

from here

Open web pages or even hyperlinks in Google Chrome from Firefox itself.

If are using Firefox along side Google’s browser, this “Open in Google Chrome” extension might come handy – it lets you send web sites and links directly to Google Chrome from Firefox.

It can also be configured to always open certain web pages in Chrome – e.g. *google*, gmail, etc.

Install “Open in Google Chrome” for Firefox 3

Download open-in-google-chrome.xpi on to your desktop and then drag it inside Firefox 3 much like what you did for Send to Google Docs.

Restart Firefox. Then go to Tools -> Add-ons -> Options and browse for the chrome.exe file on your Vista / XP / Windows 2000 machine.

In Windows XP, Google Chrome installs under \Documents and Settings\<user>\Local Settings\Application Data\Google\Chrome\Application\ while in Windows Vista, Google Chrome installs in \Users\<user>\AppData\Local\Google\Chrome\Application\

The Google Chrome Firefox extension can also be configured to open a group of website(s) directly in Chrome even if you try accessing them from Firefox.

For instance, you may add “yahoo” to the list and any site that has yahoo in the URL would open in Chrome automatically. That includes “maps.yahoo.com”, “news.yahoo.com”, “yahoo.com” and even “bbc.com/news/yahoo-shares.html” so be careful while picking these wildcards.

Credits: Grayson Mixon wrote the excellent IE View Lite add-on based on the IE View of Paul Roub. I just made some very minor changes to Grayson’s code to make it work with Google Browser instead of Internet Explorer. Therefore all credits for the extension go to Grayson as it is entirely built upon his code-base.

from here

from here

Chrome is getting more and more popular and even if it doesn’t have all the features and extensions like Firefox It is very fast, slim and simple. Google made it open source (Chromium) and it is avalaible for Windows, Mac and Linux.

(Yep both the Pagerank extensions currently doesn’t works)

Now some useful customization to make Chrome better, in particular on Linux.

Install it via PPA

Chromium executable binaries are directly avalaible for Linux in DEB format, but if you use Ubuntu is better to install it via PPA. So you’ll keep Chromium updated easly.
Just add to the package manager this repository:

deb <a href="http://ppa.launchpad.net/chromium-daily/ppa/ubuntu">http://ppa.launchpad.net/chromium-daily/ppa/ubuntu</a> <span>karmic</span> main

Then import the key:

sudo apt-key adv <code>--</code>recv-keys <code>--</code>keyserver keyserver.ubuntu.com 0xfbef0d696de1c72ba5a835fe5a9bf3bb4e5e17b5

Use gtk theme

The default theme is nice and it could became even nicer enabling the gtk option. The gtk icons and colors will be inheredited and it will look like more integrated with the rest of the system.

Security & Privacy

Check in the options “save cookies only from visited sites”.

Smoothscroll

If you enable this extension the scrolling will be more smooth. [Download]

chromeTouch

This is another extension that improves the scrolling. On Firefox if you do the middle button click you can move quickly in the page, this is different, it is “kinetic scrolling” (like on iPhone) but the result is quite similar. My advice is to enable “Full dragging” and then to use shift+selection to select the text. [Download]

It is very useful to translate some paragraphs directly on the page. It could be in conflict with the extension above so check the shortcuts.

AdBlock+

It look like the NoScript plugin for Firefox to block javascript and advertising from unknown site, but it is still far from it. [Download]

Control the extensions

Type chrome://extensions/ and manage them. You don’t need to restart the browser just reload the page if you want to see the changes.

Shortcuts

You can zoom with ctrl+wheel and use the middle click on a tab to close it without looking for the cross.

Inspector

It is in some way similar to the Firebug plugin for Firefox, it permit you to debug the web pages.