Bash Startup

bash has a rather complicated way of working out which init files to read when it starts up. This is documented in the man page, but since that is 900 lines long, this page summarises how it works, so that you can find which file(s) to modify for the effect you want.

Login shell vs normal shell

First, you need to know whether your shell is a login shell or not. As the name suggests, a login shell is the one you get when you log in on the console. You can also obtain [continued…]

Performance Tuning

Simple performance tuning tips

 > I don't know if it is IO bound and don't really know how to test > such things. I just know access isn't as snappy as it used to be. 

When the system is running fast/normally you need to take a baseline. Look at top, see what your percentage system, user, idle and iowait is. These can be seen here:

 Cpu(s): 8.6% us, 0.3% sy, 0.0% ni, 90.5% id, 0.6% wa, 0.0% hi, 0.0% si

Mac Mini

Installing Linux & OSX on a MAC Mini System by Stephen Davies

This article is a result of my experiences and nothing else. There are probably better ways to do some things but I didn’t find them or failed to get them to work.

The task was to install both OSX & Linux on a Mac Mini system.

The Mini came with OSX 10.3 already installed as it was one I won on an Ebay auction. So, my first exercise was to remove the existing OSX installation and look at how [continued…]

DVD Authoring

The Topfield ‘Toppy’ TF5800PVRA is a freeview HD recorder with a USB interface. You can download the recordings (.rec files) to a PC and then burn them to a DVD after a bit of juggling. Here is a four step working solution after many false starts:

A) Translate the .rec file to something usable:

Use !ProjectX

  • Set the cut points to skip ads etc (CutControl tab)
  • Demux (click prepare button, tick demux box, press play button)
  • B) Re-multiplex in a way that dvdauthor can read

    Use mplex:

    • mplex -f8 -o tvprog.mpg tvprog.m2v tvprog.mp2

    C) Create menus [continued…]


    ffmpeg for 3gp on Ubuntu

    Here I will try and describe compiling ffmpeg for ubuntu to enable it to create 3gp files.

    OK, so I have a nice new Video phone. I want to be able to play, edit and create the videos. The format that the Sony Ericsson phone uses is 3gp. It turns out that ffmpeg can handle these, but no sound with the version that comes with ubuntu. Here is how I went about fixing this. Please remember that a lot of of this was discovered by Google, and not really my own work.

    The first thing [continued…]

    Debian Tips


    This is intended as an FAQ / Tips page to do with managing a Debian system. It’s a work in progress, so make sure that if you find something useful, and it is not listed, that you add it. I’ll get around to categorising this list, but these tips are answering a lot of questions that appear on the mailing list.

    Apt-get returns the error: “E: Dynamic MMap ran out of room”

    This is caused because the cache is too small to handle all of the packages in the flavour of Debian that you are using. [continued…]

    SEO Database Website

    Intended Audience

    In today’s fast paced world, the importance of Search Engine Optimisation and Usability has been thrust into the limelight. More and more companies and employers are hearing the buzz that is SEO, and want you to ensure them that their new website will deliver. They all want to be top of the search engines and we all know that that will rarely happen. There are however things we can do to help the issue and to make life a little easier for those lovable bots and spiders who crawl our pages.


    Whether you believe the fact that [continued…]

    Redundant Networks

    This page will describe how to set up Linux so that it works with redundant networks links to the local switch or pair of switches.

    Convert From Mbox To Maildir

    Converting from mbox to Maildir


    This article describes how to convert from mbox to Maildir format. Maildirs have quite a few advantages over mbox format, especially when you have a lot of users with large mailboxes. Another big advantage is that with dovecot and Maildirs, users can create sub-folders.

    These notes are specific to my situation. I wasn’t able to find a complete guide to doing this anywhere, so hopefully it’ll serve as a good guide to others. My system uses:

    • Debian GNU/Linux 3.1r2
    • dovecot (POP3 and IMAPS)
    • exim4 (exim4-daemon-heavy)
    • procmail (some users have a ~/.procmailrc and there’s [continued…]

    Password Policy

    Some Tips for Passwords and Logins


    • R : Root, user role
    • S : System Accounts
    • U : User Accounts

    In general order of increasing security.

    Do not send passwords in clear text over the network


    As a general rule no protocol that transmits unencrypted authentication data over a network should be used. Examples of insecure protocols are telnet, ftp and the r* tools. All modern Unix and Linux systems ship with secure alternatives as default, and either no longer contain or require manual intervention to enable legacy protocols.

    Where legacy applications demand use of insecure protocols, [continued…]