Welcome to The Linux Page

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This site is a collection of my own work with Linux. Certain things are easy, others take time to decipher and if I ever need to repeat the work (which usually happens!), then I need to remember everything by memory or... have a site with all the steps taken and to take again.

The following are my most recent posts:

X11 starts, but nothing appears on the screen...

Today I finally resolved a problem I had for a while on one of my computers.

When logging in using the normal lightdm X11 login screen, directly on the computer, I would get an error and absolutely no menu, no icons, no keyboard functionality, no unity, no nautilus... The only thing I had working was the background which gave me access to the settings, but nothing else. More or less, nothing useful.

I just had an idea and then I found a comment form a user on a forum who said that he just deleted his .config and .compiz directories and rebooted. After that it worked for him. It worked for me ...

Today I wanted to upgrade some packages that had security issues. Ubuntu (like Debian) provides the apt-get tool that allows you to do upgrades the easy way:

sudo apt-get upgrade

However, that upgrades all the packages present. In some cases, you may want to skip on some packages because you know they are not ready (i.e. your own packages).

In order to only upgrade security issues, you want to get a list of packages that are to be upgraded for security issues:

apt-get -s dist-upgrade | grep "^Inst" | grep -i securi

That apt-get command line lists all the packages ready for ...

Note: This bug is fixed in Ubuntu 16.04

Working on a website I have to convert invoices to PDF so end users have the ability to print and share the invoices from the website.

In order to do that, I generate an HTML page with the invoice which also gets displayed in the website, and then convert that HTML to PDF with xhtml2pdf. I use that tool instead of whtmltopdf because it does not require X11 to work. The other tool is said to require Qt and X11 and we do not want those things on our backend servers.

So... I upgraded to 14.04 and the tool stopped working with an ugly error:

...

As I upgrade to 14.04, I started seeing this error in my console:

no talloc stackframe at ../source3/param/loadparm.c:4864, leaking memory

Quite cryptic if you ask me, but the "leaking memory" did sound bad.

The error would in particular appear when I used sudo for whatever reason, for example:

sudo iptables -L -nvx

So... something to do with sudo?

I found the answer on the Ubuntu forum. The solution is to turn off a feature of samba. Run the samba setup tool in your console:

sudo pam-auth-update

That opens a curses window in your console. You should then see an option ...

Oka, so today I finally got the chance to upgrade to Ubuntu 14.04, hopefully soon to 14.10 too.

I have to say that in general, it looks like they've done a good job as things seem to work better...

However, the display setup got lost. My HP 2509m monitor is connected through a KVM and because of that, it does not always work as expected. That is, the nVidia card does not get to read the monitor information. It took me a while, but I found a way to fix the problem.

First of all I connected the monitor directly to my computer. That gave me the ability to change the resolution to 1920x1080 ...

I found a different way which is to use the:
Local Network or Host-only Network on your Virtual Machine

Today I did my first full install of Snap on a VM in my Ubuntu development system that runs VirtualBox.

This took me about 1h between getting all the files ready from our own APT repository, and then finding out all the setups needed (we have a few working installations, but we added all the necessary magic with time and did not clearly document all the steps yet... argh! so much to do!)

At some point, I wanted to setup the "domains" and "websites" tables on the VM. ...

Performance Monitor under MS-Windows

I recalled reading somewhere that you could see the performance of NVidia cards under MS-Windows. Looking around I could not really see how that would be done. Today, though, I found out that perfmon does it all!

To start perfmon, click on your Start button and enter perfmon and click Run. You may also start it from a command line although perfmon is a graphical tool.

Once in there, click on ":Performance Monitor", it should appear under Monitoring Tools.

That won't give you the GPU information though, not by default.

When you right click on the area with the graph, you see ...

I run a few Drupal website and once per hour I run the cron.php script. I do it only once per hour because nothing changes so often on my websites so it would require faster refreshes.

Once in a while (relatively rarely now) I get a list of errors from CRON saying that the checks failed. The errors look something like this:

HTTP/1.0 302 Found
Location: /cgi-bin/ipdiags.ha
Pragma: no-cache
Content-Type: text/html

<html><meta http-equiv=Refresh content=0;url=/cgi-bin/ipdiags.ha>
<body></body></html>

As you can see, this is a 302 so a temporary error. ...

Right Alt key not working at all, why?

It has been a while that my right Alt key acted as the Level3 key instead of a right Alt key. I never cared for the AltGr on my QUERTY keyboard, but it kept popping up as the Level3 key even though I clearly removed that option in the keyboard settings under /etc/default/keyboard

XKBMODEL="pc105"
XKBLAYOUT="us"
XKBVARIANT=""
#XKBOPTIONS="lv3:ralt_switch"
XKBOPTIONS="compose:caps"

I commented out the level3 definition and instead put "compose:caps" which makes my CAPS Lock key work as a compose key (i.e. if you press ...

I was ask by a customer to add line numbers to each entry in a table shown in an invoice.

The concept is pretty simple, but really, how do you do that properly in MS-Access?

Microsoft actually has a solution (see link below) and it comes down to writing a function that counts the number of items from that item's current position to the beginning of the table (i.e. going backward). It works, it is just really bad if you have very large invoices since it will tend to slow down as you start getting many items.

There is the function, we can see the counting in the do until near the end ...

Unfreeze your Mouse when it Froze

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