Posting code to blogspot

I just found out how to post code snippets to blogspot

Use the (pre) & (code) tags to denote code segments (using normal html <> style tag brackets instead of the round ones used here)

(pre)(code)
Source code goes here
(/code)(/pre)


Once we replace the round tags we get output like this

Source code goes here

The End Of An Era

Sad news.

It seems the inmates have taken over the asylum over at my favourite tech news site, "The Register".

After nearly ten years of reading their site on a daily basis their horrendous new fixed width format is so utterly terrible that the site is no longer pleasant to read and I have to give up reading it.

They received a torrent of complaints to the comments section of their explanatory article entitled "OMFG what have you done?" and this is despite actively censoring many commenters. I myself was censored three times before I gave up and resorted to impotently whining about it on a blog that nobody reads. Other posters complained of the same censorship too, but maybe their moderators were so inundated with comments that many of them just fell into the bit-bucket at the end of the conveyer.

It doesn't matter anyway. It's their site, they can fcuk it up any way they please. It's hard to imagine why they would want to inflict such an appalling design on their readers but it seems they're quite willing to do so.

I have no idea what their motives are, other than change for change sake.

Idiots.

apt-get update GPG errors

I have a small network and I use apt-cacher as an apt proxy to save having to download the same thing multiple times. I also use an unofficial Ubuntu mirror that my ISP provides because I am on a capped plan and use of their repository does not count towards my downloads.

Unfortunately I have an occasional problem where aptitude decides that my GPG key is bad and I get errors like this on my local proxy;

W: A error occurred during the signature verification. The repository is not updated and the previous index files will be used.GPG error: http://apt-proxy hardy-backports Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key

Now, I'm not sure whether the problem is with my local proxy or the ISP's mirror but to fix it I need to issue the following command;

sudo apt-get update -o Acquire::BrokenProxy=true

Everything should be OK from there. If you still have problems, I have also sometimes found that if 'sudo apt-get update' fails, using 'sudo aptitude update' instead works.

I have no idea why.

Speeding up Firefox 3

1. Type “about:config” into the Firefox address bar and hit Enter.

2. Alter the following entries like so:

Set “network.http.pipelining” to “true”
Set “network.http.proxy.pipelining” to “true”
Set “network.http.pipelining.maxrequests” to "30"

3. Right-click within the browser and select New-> Integer.

Name it “nglayout.initialpaint.delay” and set its value to “0".

For more info check out this site.

Sharing a mouse and keyboard with Synergy

If, like me, you have two computers on your desk with two keyboards and two mice and find yourself occasionally typing something on the wrong computer or clicking with the wrong mouse then this tip is for you.

First you need to install synergy on both computers;

sudo apt-get install synergy

Then choose one of the two to be the "server". You will use the keyboard and mouse that is connected to this computer. In this example the two PC's are side by side.

You will only need a configuration file on the server PC. Create one;

sudo vi /etc/synergy.conf

# sample synergy configuration file
#
# comments begin with the # character and continue to the end of
# line. comments may appear anywhere the syntax permits.

section: screens
  server_pc:
  client_pc:
end
section: links
  server_pc:
     left = client_pc 
  client_pc:
     right = server_pc
end

Where server_pc and client_pc are the names of the two computers.

For example, my server PC is called "jupiter" and the client is called "saturn". The server is on the right (client on the left)

# sample synergy configuration file
#
# comments begin with the # character and continue to the end of
# line. comments may appear anywhere the syntax permits.

section: screens

  earth:
  saturn:

end

section: links
  earth:
     left = saturn 

  saturn:
     right = earth
end

You can test the the setup with these commands;

On the server:

synergys -f --config /etc/synergy.conf

On the client:

synergyc -f server_pc

To start synergy automatically when gnome starts;

sudo gedit /etc/gdm/Init/Default

Add these lines just before the "sysmodmap=/etc/X11/Xmodmap" line:

On the server:

SYNERGYS=`gdmwhich synergys`
if [ x$SYNERGYS != x ] ; then $SYNERGYS --config /etc/synergy.conf
fi

On the client;

SYNERGYC=`gdmwhich synergyc`
if [ x$SYNERGYC != x ] ; then $SYNERGYC server_pc
fi

This starts synergy at the gnome login screen. Once you log in gnome kills the server so you need to start it again for your user session;

sudo gedit /etc/gdm/PreSession/Default

Add the same lines this time just before the "XSETROOT=`gdmwhich xsetroot`" line;

On the server:

SYNERGYS=`gdmwhich synergys`
if [ x$SYNERGYS != x ] ; then $SYNERGYS --config /etc/synergy.conf
fi

On the client;

SYNERGYC=`gdmwhich synergyc`
if [ x$SYNERGYC != x ] ; then $SYNERGYC server_pc
fi

Once you restart gnome on both the PC's you should be able to move the mouse left and right between the two screens. Keyboard focus will follow the mouse pointer.

Dual-booting with Grub

On one of my PC's I still dual boot to Windows. Most of the online guides to dual booting instruct you to install Windows first and then install Linux and let Linux modify your boot sector accordingly.

I don't like doing it this way partly because I am an uber-geek and like to do stuff the hard way but also because i have a special setup whereby I can boot natively into Windows or I can boot the same Windows installation from within a vmware virtual machine which is neat. I might describe how to do that one day.

Anyway, to do this, Windows must be on its own separate drive and both Windows and Linux must use their own boot loaders and both must believe that they are booting from the primary hard disk.

To achieve this we must fool Windows into thinking that it is on the primary drive even tough it is on a secondary.

To do this we simply add the following stanza to /boot/grub/menu.lst

title Windows
map (hd0) (hd1)
map (hd1) (hd0)
rootnoverify (hd1,0)
chainloader +1

NOTE: The "map" lines have a 'space' between (hd0) (hd1). You will get "GRUB: Error 11: Unrecognized device string" error without that space.

If you want to hide/unhide partitions also add;
hide (hd0,0)
unhide (hd0,0)

Once you’ve made the change just update Grub with this command:

update-grub

When you reboot, you should see an option to boot Windows.

Notes:
For this to work, you must have a hard disk with a bootable, working copy of Windows on it. For example, install the HDD in your PC as the first drive (master) and install Windows. If it boots OK when you are done then remove the disk and install the one that has[will have] Ubuntu on it and set the Windows drive as slave. Modify grub as above and everything should be hunky-dory. (Disclaimer; If you muck any of this up it could render your PC unbootable and cause you much distress and possibly anger. It is your responsibility to ensure that you know what you are doing when mucking about inside your PC. For further info see this)

HOWTO: Mounting SSH directories

If you want to mount a directory on a remote PC then here is what you do.

Of course, to mount a folder via ssh the server must be running as a ssh server.

sudo apt-get install openssh-server

It is not necessary, but I strongly recommend that you set up passwordless ssh logins between the server and the client. The linked guide describes setting up SSH keys between two root users, so you do need to ensure that you configure things correctly for whatever pair of users you intend to use here.

From here on, all of the configuration we need to do is on the client.

1. Install SSHFS;

sudo apt-get install sshfs

2. Use the modprobe command to load fuse into the kernel;

sudo modprobe fuse

3. Set up the appropriate users & permissions;

sudo adduser username fuse
sudo chown root:fuse /dev/fuse
sudo chmod +x /bin/fusermount

If you've added yourself to the fuse user group, you need to logout and back in at this point.

To mount the home directory of "user";

sshfs user@host: mountpoint

Eg.

sshfs brett@server: ~/server_home

You can add a path after the colon.

Eg. to mount the "share" directory on the server (ie. /home/brett/share)

sshfs brett@server:/share ~/share

UPDATED: By default, only the user who has mounted the share has access to it. To allow access to root add the following option;

-o allow_root

For all users;

-o allow_other

To mount the share as read only;

-o ro

Eg. to mount the "share" directory on the server as read only and available to all users;

sshfs -o allow_other -o ro brett@server:/share ~/share

And that is all you need to do! Easy Peasy!