// it will remove all <!--[if ...]>....<![endif]--> comments
preg_replace('/<!--\[if[^\]]*]>.*?<!\[endif\]-->/i', '', $string);

or 

// it will remove all <!--[if ...]>.... --> comments
preg_replace('/<!--\[if[^\]]*]>.*?-->/i', '', $string);

sudo apt-get install enscript
enscript lorem.txt -o - | ps2pdf - lorem.pdf

There is also the unoconv, which converts between any document format that OpenOffice understands. It uses OpenOffice's UNO bindings for non-interactive conversion of documents.
Supported document formats include Open Document Format (.odt), MS Word (.doc), MS Office Open/MS OOXML (.xml), Portable Document Format (.pdf), HTML, XHTML, RTF, Docbook (.xml), and more.

Features:

Converts between different document formats that OpenOffice understands
OpenOffice can export to about 100 different document formats
Can be used for batch processing
Combines with asciidoc and docbook2odf/xhtml2odt to create PDF or Word (.doc) files
Can apply custom style templates during conversion (to enforce corporate identity)
Autostarts OpenOffice for processing if necessary
Can be used in a client/server environment to process documents centrally
Can influence OpenOffice filters during import and export
Supports OpenOffice on Linux, Windows and MacOSX

CLI instructions (these will take care of removing OpenOffice.org and installing LibreOffice):

Add the PPA and install LibreOffice:

sudo add-apt-repository ppa:libreoffice/ppa
sudo apt-get update
sudo apt-get install libreoffice

For GNOME integration (for people running default Ubuntu):

sudo apt-get install libreoffice-gnome

or for KDE Integration (for people running Kubuntu):

sudo apt-get install libreoffice-kde

As of Ubuntu 11.04, LibreOffice will replace by default OpenOffice.

sudo apt-get install tk8.5
sudo update-alternatives --config wish
# a list will show up and you need to type in the number that corresponds to tk8.5 (in my case was 3) then hit enter.

That's it. You can now reopen gitk and see the difference.

grep -r --line-number "string_you_search" path/where/to/look

Note the -r tells grep also to look into all subfolders recursively.

sudo mount -oloop Image.iso /mnt

Unfortunately if you want to play a game that needs the CD inside the drive, mounting using the mount tool won't make the CD available for the game (unless it didn't worked for me). So i looked around and found that CDEmu can do the job. To install on Ubuntu add the repos from ppa:cdemu/ppa them install:

sudo add-apt-repository ppa:cdemu/ppa
sudo apt-get update
sudo apt-get install gcdemu

This will install and applet which you can use with your Gnome panel, and all the other libs that it needs. In order for the applet to work you need to start the cdemud daemon, which depends on the vhba kernel module. To start those run:

sudo modprobe vhba; cdemud &

Now you can mount images using your CDEmu applet

Adobe® Flash® Player "Square" is a preview release that enables native 64-bit support on Linux, Mac OS, and Windows operating systems, as well as enhanced support for Microsoft Internet Explorer 9 beta.

I'm glad to see Adobe has is finally embracing the way it should the 64 bit Platform. This release is a milestone as far as i know, as is the first one that's released in the same time for win, mac and linux. I've put together a small tutorial on
how to install adobe flash player square on linux:

#!/bin/bash
# Script  created by
# Romeo-Adrian Cioaba romeo.cioaba@spotonearth.com

echo "Stopping any Firefox that might be running"
sudo killall -9 firefox

echo "Removing any other flash plugin previously installed:"
sudo apt-get remove -y --purge flashplugin-nonfree gnash gnash-common mozilla-plugin-gnash swfdec-mozilla libflashsupport nspluginwrapper
sudo rm -f /usr/lib/mozilla/plugins/*flash*
sudo rm -f ~/.mozilla/plugins/*flash*
sudo rm -f /usr/lib/firefox/plugins/*flash*
sudo rm -f /usr/lib/firefox-addons/plugins/*flash*
sudo rm -rfd /usr/lib/nspluginwrapper

echo "Installing Flash Player Square"
cd ~
# 64 bit
wget http://download.macromedia.com/pub/labs/flashplayer10/flashplayer_square_p1_64bit_linux_091510.tar.gz
tar zxvf flashplayer_square_p1_64bit_linux_091510.tar.gz
# 32 bit
# wget http://download.macromedia.com/pub/labs/flashplayer10/flashplayer_square_p1_32bit_linux_091510.tar.gz
# tar zxvf flashplayer_square_p1_32bit_linux_091510.tar.gz
sudo cp libflashplayer.so /usr/lib/mozilla/plugins/

echo "Linking the libraries so Firefox and apps depending on XULRunner (vuze, liferea, rsswol) can find it."
sudo ln -sf /usr/lib/mozilla/plugins/libflashplayer.so /usr/lib/firefox-addons/plugins/
sudo ln -sf /usr/lib/mozilla/plugins/libflashplayer.so  /usr/lib/xulrunner-addons/plugins/

# now doing some cleaning up:
sudo rm -rf libflashplayer.so
sudo rm -rf flashplayer_square_p1_64bit_linux_091510.tar.gz

To check if the install did it's job, you need to check about:plugins in your address bar. It should show you this for flash player:

Shockwave Flash

File: libflashplayer.so

Version:

Shockwave Flash 10.2 d161

As usual, I've wrapped everything mentioned before into a script to easily install flash player square on Linux

If this version doesn't work out that well for you, you can still check my other tutorial on how to install native 64bit flash player on Linux
Happy browsing!

So to recapitulate, I did the following (citing the other guys, thanks to atlasit, ajayksh and rune00):

1) write a list of the additional statuses that you want

2) download and open the file Magento\app\code\core\Mage\Sales\etc\config.xml
(do not upload it again as soon as you’re done, you need to place it into a different folder, see below)

3) find this code:

<pending translate="label"><label>Pending</label></pending>

and after that add your own new custom status

<my_new_custom_status translate="label"><label>My New Custom Status</label></my_new_custom_status>

4) Now find this code, a few lines below:

<states>
  <new translate="label">
    <label>New</label>
    <statuses>
      <pending/>
    </statuses>
  </new>

and under or above this block create a new block with your own custom status:

<states>

  <new translate="label">
    <label>New</label>
    <statuses>
      <pending/>
    </statuses>
  </new>

  <my_new_custom_status translate="label">
    <label>My New Custom Status</label>
    <statuses>
      <my_new_custom_status/>
    </statuses>
  </my_new_custom_status>

repeat this (step 3 and 4) for each new custom status

5) So that you can change your status from the admin interface back and forth
from any current status, you need to edit again each of the status code block
as follows.

change this

<new translate="label">
    <label>New</label>
    <statuses>
      <pending/>
    </statuses>
  </new>

to this

<new translate="label">
    <label>New</label>
    <statuses>
      <my_new_custom_status/>
      <pending/>
      <processing/>
      <holded/>
      <complete/>
      <closed/>
      <canceled/>
    </statuses>
    <visible_on_front/>
  </new>

you need to do this with all of the existing statuses and the new custom statuses that you’ve just created

so that these new statuses do not only become available and visible to the admin, but also to the customer
on his “my account” page (order history, current status), you need to make the new statues visible (thanks to rune00)
with the tag , as described above.

6) After you saved your changes, upload the new config.xml file to
/app/code/local/Mage/Sales/etc/ (you will need to create that folder structure)

7)Create a file named Mage_Sales.xml with the following content (thanks to atlasit)

<?xml version="1.0"?>
<config>
    <modules>
        <Mage_Sales>
            <active>true</active>
            <codePool>local</codePool>
        </Mage_Sales>
    </modules>
</config>

Upload it to /app/etc/modules/

that’s pretty much it.

If you got it running successfully as well, let us know so that it will help others as well.

You can install it easy:

sudo apt-get install ncdu

Issuing ncdu inside the folder you want to check will open a cool ncurses interface, really easy to use

The most popular disk image formats i've had to deal with are: iso (which Ubuntu handles by default perfectly), CloneCD/IMG (used by CloneCD), CUE/BIN, MDF (created by Alcohol 120%), NRG (Nero images) and last but not least DMG (format used mainly by Apple).

Since Linux handles very well .iso files, the idea is to convert any of the image types listed into iso and then the job is easy. For all of the formats there are tools to do just that. You can install them as follows:

sudo apt-get install ccd2iso bchunk mdf2iso nrg2iso dmg2img

Example usage:

# ccd
ccd2iso /path/to/example.img /path/to/example.iso
# bin/cue
bchunk /path/to/example.bin /path/to/example.cue /path/to/example.iso
# mdf
mdf2iso /path/to/example.mdf /path/to/example.iso
# nrg
nrg2iso /path/to/example.nrg /path/to/example.iso
# dmg
dmg2img filename.dmg

Some of those formats can be also mounted using the CLI:

# ccd/img
sudo mount -o loop example.img /media/example
# nrg
sudo mount -o loop,offset=307200 /path/to/example.nrg /media/example
# dmg
dmg2img /path/to/example.dmg /path/to/example.img
sudo modprobe hfsplus
sudo mount -t hfsplus -o loop example.img /media/example