Google link converter

Links provided in the search results of Google look something like

http://www.google.co.uk/url?sa=t&source=web&cd=1&ved=0A&url=http%3A%2F%2Fabc.go.com%2F&rct=j&q=abc&ei=kuw&cad=rja

when the URL it links to is simply

http://abc.go.com/

This tool allows users to transform the former into the later for easier copying and pasting.

Apache ignoring mod_rewrite rules?

Then it is very likely in the site configuration file, usually at
/etc/apache/sites-available 
you have directives such as
AllowOverride None 
Change them to
AllowOverride All 
and try again.

Unique rows in vim

Simple! Just

:sort u

Sending UTF-8 mail with PHP

I was facing issues sending mail encoded as UTF-8 via PHP. In order to do it properly, you need to set UTF-8 as the encoding for the mail function (first line of code below). Then, mail can be sent (second line).

mb_internal_encoding("UTF-8");
mb_send_mail( 'myrecipient@wherever.com', 'Polite subject', $message, $headers );


Apache module modwsgi 3.3 on Ubuntu Lucid

A bit of library hell on Linux. I tried to install modwsgi on Ubuntu Lucid. I downloaded the Debian version. However,

root@virt251:/tmp# dpkg -i libapache2-mod-wsgi_3.3-2+b2_i386.deb 
...
dpkg: dependency problems prevent configuration of libapache2-mod-wsgi:
 libapache2-mod-wsgi depends on libpython2.7 (>= 2.7); however:
  Package libpython2.7 is not installed.
dpkg: error processing libapache2-mod-wsgi (--install):
 dependency problems - leaving unconfigured
Errors were encountered while processing:
 libapache2-mod-wsgi

You cannot install Python 2.7 (easily, at least) on Lucid, but you can install Python 3.1. Use apt-get and that will do the trick.

Automatic creation of regular expressions in different computing languages

Regular expressions are a powerful tool, albeit they can become difficult to build. This page, text2re, helps you build complex re's and provides code in a number of computing languages such as Python, Perl, etc.

Modifying Xubuntu application menu

One of the most disturbing features of my Xubuntu desktop is the apparent inability to modify the application menu. In particular, I had a huge settings submenu with duplicated entries: many already appeared in the system submenu.

So I edited the file /etc/xdg/menus/xfce-applications.menu and changed the section

    <Menu>
        <Name>Settings</Name>
        <Directory>xfce-settings.directory</Directory>
        <Include>
            <Category>Settings</Category>
        </Include>

        <Layout>
            <Filename>xfce-settings-manager.desktop</Filename>
            <Separator/>
            <Merge type="all"/>
        </Layout>

        <Menu>
            <Name>Screensavers</Name>
            <Directory>xfce-screensavers.directory</Directory>
            <Include>
                <Category>Screensaver</Category>
            </Include>
        </Menu>
    </Menu>

into

    <Menu>
        <Name>Settings</Name>
        <Directory>xfce-settings.directory</Directory>
        <Include>
            <Category>Settings</Category>
        </Include>
        <Exclude>
            <Or>
                <Category>System</Category>
            </Or>
        </Exclude>

        <Layout>
            <Filename>xfce-settings-manager.desktop</Filename>
            <Separator/>
            <Merge type="all"/>
        </Layout>

        <Menu>
            <Name>Screensavers</Name>
            <Directory>xfce-screensavers.directory</Directory>
            <Include>
                <Category>Screensaver</Category>
            </Include>
        </Menu>
    </Menu>

This is a simple example of what can be achieved if you (very carefully) edit the file.