Bollogs

CUPS 1.4.3 and printing that just won;t work

Had a problem today where I was trying to print from an Ubuntu machine with CUPS running locally and it just sat there in a 'Pending' state.

Eventually I tried to use the 'Resume Printer' action in the Printers section of http://localhost:631, but 'twas to no avail, principally because I had to log in .. and I wasn't in the group !

Adding myself to the group 'lpadmin' allowed me to resume, and all is well.

Apparently, CUPS gets the ache if there's an error (like the printer not being switched on) and this activity may need to be repeated regularly ... boo

VBox install for CENToS

These instructions helped a lot with resolving the KERN_DIR issue

Jailbreaking and Apple TV 2

I never thought I'd say it, but I love the Apple TV 2. I only really love it when it's dirty; when it's jailbroken and free to be used properly.

Here's how I JB'ed mine, using Windows;-

Ensure you have iTunes updated and ready BEFORE you start this

Plug your Apple TV in a couple of times via nice micro-USB cable to make sure the drivers are all loaded and ready

Download Seas0nPass from here

Run seasonpass, and follow the instructions ... it can take a long while to download the IPSW and build it

When instructed, plug the Apple TV 2 in, and put it into DFU mode

Try and load the IPSW you created

If you get a 21 error, it's because you didn't have the ATV in DFU mode

If you get 1600, 1601 or 1602 errors try a new cable

If you still get them, try this;-

Download sn0wbreeze 2.6 from here

Start it up, and instead of creating a new IPSW, just drop in the one that SeasonPass created (which will be in the Documents folder of your drive)

Let it run iReb

Then plug in the ATV and do the shift+restore option to pull in that IPSW once again

It seemed to me that the iReb action just did enough to get me over those 16xx errors; no idea why !

You're in !!!

Generate Java classes from XSDs usign Maven

Use this little snippet of configuration in a POM to get a task to use a XJC task within your Maven config




	org.codehaus.mojo
	jaxb2-maven-plugin
	1.3
	 
                 
                     
                         xjc
                     
                 
            
            
                 com.fatwire.rest.aviva.beans 
                 ${basedir}/src/main/jaxb
                 ${basedir}/src/main/resources

I'm using a whole new jaxb directory to store the generated files, just for safety.

Forgotten password for archiva

If you have forgotten the password for your archiva install, try this route;-

- Log in to archiva as the 'guest' user (blank password) and change the password to something else
- Shut down archiva
- Install SQuirreL and ensure you opt to have the Derby Embedded driver installed
- Start SQuirreL and configure the Derby Embedded driver

The Derby Embedded driver needs to have the following properties set;

- User name is 'sa', but password is blank
- On the Extra Classpath tab, add derby.jar
- the JDBC URL is in the form jdbc:derby://archiva/database

Once it is configured, test it and then log in (after creating an alias)

When connected, locate the 'SA' schema and expand it to find the 'JDOUSER' table.

Open the table and click on the 'Content' tab that appears. There may be many rows but you need to find the column for the Guest user's password and copy the contents into the same column on the admin row

Restart archiva

Log in, bob's your wotsit

DHCP fails to work for eth0 on Ubuntu 10.04

(FYI: Using a Dell Latitude E6400 with Ubuntu 10.04, patched to latest release (July 2010) with network manager doing the work for me)

Very strange problem, around not being able to get an IP address for a wired connection in the house (although wireless was fine).

Ran, dhclient and got this


Internet Systems Consortium DHCP Client V3.1.3
Copyright 2004-2009 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/

Listening on LPF/eth0/00:26:b9:a7:60:76
Sending on   LPF/eth0/00:26:b9:a7:60:76
Sending on   Socket/fallback
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 5
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 7
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 15
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 13
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 21
No DHCPOFFERS received.
No working leases in persistent database - sleeping.

so I logged into the router and discovered that although I had allocated a fixed IP address to my machine, the NAS I also have on the network (which does not have a fixed IP address), had stolen the address, which obviously caused the problems for my machine.

I deleted the old leases and took out the fixed allocation and then restarted network manager using


> sudo restart network-manager

and all was well !


> sudo dhclient eth0

There is already a pid file /var/run/dhclient.pid with pid 2863
killed old client process, removed PID file
Internet Systems Consortium DHCP Client V3.1.3
Copyright 2004-2009 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/

Listening on LPF/eth0/00:26:b9:a7:60:76
Sending on   LPF/eth0/00:26:b9:a7:60:76
Sending on   Socket/fallback
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 8
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 12
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 9
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 9
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 15
DHCPOFFER of 192.168.1.69 from 192.168.1.254
DHCPREQUEST of 192.168.1.69 on eth0 to 255.255.255.255 port 67
DHCPACK of 192.168.1.69 from 192.168.1.254
bound to 192.168.1.69 -- renewal in 33105 seconds.

JODE decompiler for Eclipse in Ubuntu

Great article here about setting up JODE for use within Eclipse.

I can't live without a Java decompiler !

Virtual Box and mounted drives

Having problems mounting a drive in VBox ? If it used to work and no longer does, try re-installing the Guest additions.

This article explains a little more, but to summarize, check that you have the vboxvfs available by typing

lsmod | grep vbox

also, consider using modprobe to bring it back if it went away ...

sudo modprobe vboxvfs load

Reinstalling Guest additions also fixed the problem I was having with the Host key needing to be pressed even when I have enabled the option to make it seamless.

Cancel an apt-get installation

run

sudo nautilus /var/cache/apt/archives/partial

then remove all files in that directory, but not the directory itself.

Then restart the apt-get operation

Maven - some stuff I learnt

How to set up your settings.xml so that it uses your local Archiva repository as first port of call ... here

If you want to use Maven in your build.xml, you need to do the following;-
- Add the maven-ant-tasks .. get them from here

- Add the following namespace to the tag like this ...

- Think about copying the required libs into a local lib directory prior to compilation like this ...

... note the use of the settingsFile attribute for using a local settings.xml

Synergy - share a mouse and keyboard across machines

This is awesome - Synergy here

and the Ubuntu client here, although using

apt-get install quicksynergy

gives you the binary, rather than having to compile it all

You can download a binary setup for Windows from the SF site

Set the windows machine as the client and connect the keyboard and mouse to the Linux box.

There's also a DMG for Apple machines as well

Works a treat !

ReadyNAS and shares in Windows

Using the NoSMBDisconnect addon from here seems to have helped with disconnection issues I had with Windows.

Previously I was getting a lot of� "The specified network name is no longer avaliable" messages, which is a little frustrating.

Cheeky script to create a SVN repository

$SVN_ROOT=/svn_location
$MY_SVN_USER=svnuser

mkdir $SVN_ROOT/$1
mkdir /tmp/$1
mkdir /tmp/$1/branches
mkdir /tmp/$1/tags
mkdir /tmp/$1/trunk
svnadmin create $SVN_ROOT/$1
svn import /tmp/$1 file://$SVN_ROOT/$1 -m "initial import for $1"
rm -rf /tmp/$1

sudo chown -R $MY_SVN_USER:$MY_SVN_USER $SVN_ROOT/$1
sudo chmod 2770 -R $SVN_ROOT/$1

Setting up subversion for access

Found this document (in an email thread) quite useful ...

and this one about users and passwords http://scorreiait.wordpress.com/2009/06/11/svnssh/

Find in unix

Still haven't found what you're looking for ?

Try this

Useful find sequences for Unix

Dumping a SQL Server table to SQL statements

This useful utility will extract the contents of tables in SQL Server and dump them to a file ... I've found it useful when I've been wanting to dump a subset of data from one environment to another ...

MS Database Publishing Wizard

Kudos to this blog entry for pointing me in the right direction !

Unknown Source shows up instead of line numbers in a Java stack trace

If you get a stack trace in a piece of code that is difficult to debug through Eclipse (or simialr) and you rely on the stack trace to tell you where an exception is occuring, you may sometimes see (Unknown Source) instead of a line number ... never fear, to get the line numbers to appear, make sure you switch the debugging information on for a class when it is compiled. i.e. don't specify the '-g:none' flag when compiling, or, in Ant, make sure you set the following attribute for the javac task;

Find out your user details in PHP

Use these lines to fidn out various information about your process in a PHP file;


echo 'Id: ' . getmyuid() . '
';
echo 'Gid: ' . getmygid() . '
';
echo nl2br(print_r(stat('index.php'), true));

often comes in handy when you're writing to a file in a Unix environment and it just won't work !

Smarty, Unix permissions, pain, woe, grief

As it says ...

had a custom function in Smarty called 'currency'

the owner of the directory was 'fred', the group was 'fred'. Cushty.

Kept getting this message;

Fatal error: Smarty error: [in school_search.tpl line 100]: [plugin] unknown tag - 'currency' (core.load_plugins.php, line 118) in /opt/lampp/lao/libs/Smarty.class.php on line 1095

Turns out the group and other permissions have to be set to 'r' as well ...

obvious to a Unix guru ! Less obvious to a pleb like me :-(

MDI MS-DOS

Some tools I have encountered lately that are a bit special ...

online regular expression checker

komodo open source IDE - source/text editor

console2 - an MDI MS-DOS console

foxit - PDF reader - 1000 x better than the adobe effort !

XMing and plink

Useful X Server here for Windows. Called Xming.

X Servers and the like are a mystery to me; all I know is that if I start the XMing server in Windows, then add it's program directory to my path, then go to a command prompt and type

plink.exe -pw my_secret_password -ssh -X username@machine_ip_or_name xcalc

then I can get an xcalc application running on my desktop

Now that's progress for you !

Eclipse says 'The type java.lang.Object cannot be resolved'

I created a new project in Eclipse today and added a class.

The

package statement had been underlined in red and gave me the The type java.lang.Object cannot be resolved error message .... turns out I needed to add a JRE to my project ... d'oh !

see here for more info



LAMPP/XAMPP and phpMyAdmin errors
Just installed XAMPP and got a problem when I went to click on the phpMyAdmin link in the menu

"please check errors given in your PHP and/or webserver log file and configure your PHP installation properly." 

turns out it's related to php not having access to the nominated directory (/tmp) where it likes to store its session information.

The resolution;

prompt> chmod 777 /tmp

simple !


Foreign Keys in MYSQL
I've been doing some work in my spare time on a PHP/MySQL site. 
I decided to be all proper and use foreign keys to make everything nice.

I set up a script and ran it and it kept failing with this;

ERROR 1005 (HY000) at line 88: Can't create table '.\database_name\table_name.frm' (errno: 150)

the script said this

,FOREIGN KEY (status_ID) REFERENCES Status(status_ID) ON DELETE NO ACTION ON UPDATE NO ACTION

ans both the status_ID in the table I was creating, and the status ID in the table I was referencing were INT NOT NULL, so I could not work out why it was happening ... until I realised that the key I was referencing was in fact INT UNSIGNED NOT NULL ... 

... and therein lies the difference ! Unsigned versus signed ... of course, if I had applied the 'make sure the columns are of EXACTLY the same datatype' rule, then this would never happen.

Smack on the wrist.


Turning off the beep on a Dell Latitude 620
If you've got a Dell Latitude 620 and that bloody annoying beep that occurs in a console window is cheesing you off, then hope is at hand ;

Turning off the beep on a Dell Latitude D620

1. Right-click on "My Computer", then click "Manage"
2. Click on "Device Manager"
3. Click on "View > Show hidden Devices"
4. Click on "Non-Plug and Play Drivers". Then right-click on "Beep" and choose "disable".
5. Restart


hoorah for  this man and his blog


Command prompts from Explorer in Windows
Oooh, this is 'andy 'arry .... http://www.petri.co.il/add_command_prom ... plorer.htm


SQLServer and the 10061 message
Every time I install SQLServer Express Edition 2005 I get a problem with the TCP/IP connectivity ..solution is in here http://blogs.msdn.com/sql_protocols/arc ... ed-it.aspx

you need to set a value for the TCP port in the IPAll section of the enabled TCP/IP connection option.

You can turn that on by starting the 'SQL Server Configuration Manager', selecting and expanding the SQL Server 2005 Network Connections tree and then selecting protocols for SQL Express ... phew !!!


Remote debugging of Tomcat using Eclipse
This is fairly easy, proving you know what to set up and where;

First, amend the Tomcat startup such that it will make use of JDPA. I edited my startup.bat file and put these three lines at the top, just below the rem statements

rem  *** Remove these for non-debug version
SET JPDA_TRANSPORT=dt_socket
SET JPDA_ADDRESS=8000
SET JPDA_SUSPEND=n 


then, at the bottom of that file, I amended the start command to teh following


call "%EXECUTABLE%" jpda start %CMD_LINE_ARGS%


where the jpda is a new addition. Of course, you could define that as an Env var and just set or unset it at the top.

Next, you need to configure a Remote Debug session with your project in Eclipse, like so ...



pressing Debug starts the session.


Parsing a DateTime into a Timestamp in Java
I needed to parse a datetime value, with or without the time portion, into a java.sql.Timestamp object. 
Initially, you need to populate a java.util.Date object.


boolean wasDateOnly = false;
Date dt = null;
SimpleDateFormat formatter[] = new SimpleDateFormat[]{
	new SimpleDateFormat("yyyy/mm/dd HH:mm:ss.SSS"),
	new SimpleDateFormat("yyyy/mm/dd HH:mm:ss"),
	new SimpleDateFormat("yyyy/mm/dd HH:mm"),
	new SimpleDateFormat("yyyy/mm/dd")
	}; 

for (int counter = 0; dt == null && counter < formatter.length; counter++) { 
	try {
		dt = formatter[counter].parse((String) value);
		if (counter == formatter.length - 1)
			wasDateOnly = true;
	} catch (ParseException e) {
	}
}

if (dt != null) {
	... do stuff with the dt object here ... like stuffing into a Calendar ...
}




Web safe colour picker
Take a look here  
grrr ... note spelling of colour on that page.