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:

There are some forms where Drupal '#size' does not seem to work, why?!

I created a form a while back and included an entry like this:

  '#size' => 10

in several text fields of the form. Especially useful when you add a suffix:

  '#field_suffix' => 'Something'

But that would not do anything... I looked at the output of the form and it looked 100% correct. In other words, the input tag had its size="10" properly set. So the next step was to find whether some CSS code would be in the way.

You bet! The node.css file includes the following:

nice and ionice for Linux users

By default, a computer system gives each process the same priority level in regard to accessing your hard drive.

With newer versions of Linux, it is possible to use two other priorities: one where I/O is not primordial and thus you do not get it if anyone else wants it, and one where you want to work in realtime and have priority over anyone else.

This is achieved with the ionice command line (or corresponding kernel calls.)

This is particularly useful if you want to copy a partition to another and you know that it will take 20 minutes to copy everything... and thus the computer will be ...

/var is 99% full...

Problem

On Unix systems, you create partitions and assign them a folder such as /usr, /home, and /var. Many people like to put different things on different partitions. Very frankly, it is often complicated to do that, so if you don't have a real need, only break up the /home and /tmp folders from the rest. The /var is a good idea to break up if you use databases or very heavy logs. The /etc can be separate mainly for ease of backup.

Attacks by ZmEu or w00tw00t robots

Who is ZmEu?

An image showing Zmeu The name Zmeu (no capital E) is the name of a fantastic creature of Romania. There are so many stories that there isn't a clear understanding of what it is... but it is human like, can spit fire and wants to marry young women.

If you're wondering, it is generally a bad guy.

ZmEu Attack

Today, I noticed a lot of traffic on one of my servers. Looking into what was happening, I immediately found out that an attacker was looking for a loophole in that system. That attack was being performed from China.

I checked another server, and sure enough, that other server was ...

Trace PHP code with xdebug

xdebug

XDebug "logo" I'm very much working on Drupal and once in a while, I just have no clue what the code does... especially when there are callbacks that call callbacks in forever loops.

Multiple Adresses on the same Network Interface Card

Netplan Method

I think that the Netplan method is pretty explicit. The addresses option accepts an array of addresses with a mask (prefix length, really, which is mandatory; the "/24" in my example). So you do not have to duplicate the whole entry.

Here is an example:

network:
    version: 2
    renderer: networkd
    ethernets:
        eno1:
            addresses:
                - 192.168.1.2/24
                - 10.1.1.233/24
            dhcp4: false
            dhcp6: false
            optional: false
            gateway4: 192.168.1.1
            ...

Not too long ago, I accepted the update from Microsoft to go to MS-Windows 2000 SP4. Neat. Except that when I rebooted (I think the 2nd time, but not totally sure, my wife used the computer in between, it seems...) it could not load my profile anymore.

Problem

I worked on a project with many functions that access the database. These functions will generally have a Recordset variable. Yet, when I tried to run a script with the recordset declaration, it would fail with the error Undefined variable type.

  Dim rcd As Recordset

Since that definition was not required for the software to work, I ignored the error for a long time.

I worked on a site a week ago or so and checked it with IE 8 but not IE 7...

The customer then contacted me saying that some images were "completely" off. (about 30 pixels)

The image being off was actually centered. IE 7 and older does NOT properly reset the text-align CSS settings. So the parent setting leaks in the children instead of the chidren using the default as they should. So that one was easy, I just added a text-align: left; in the next <div> statement and got that to work right!

Closing a window from Flash

I had a little project which requirements was an Adobe Flash animation that calls a JavaScript function to close a browser window.

With the newest version of Internet Explorer, it will first ask you whether you want to let the script close your window... that's a problem when you'd like that process to be smooth (i.e. without user interaction.)

Unfreeze your Mouse when it Froze

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Main Menu

Problem

Who is ZmEu?

ZmEu Attack

xdebug

Netplan Method

Problem