Click to enlarge

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:

Readonly content cannot be changed. Libreoffice preventing edits...

Today I opened a document where I had to make a few edits and LibreOffice decided to tell me:

Readonly content cannot be changed.
No modifications will be accepted.

There is a screenshot of that message:

Error message: Readonly content cannot be changed. No modifications will be accepted.

The error may be justified, I do not know, but apparently not too many people know how to unlock a document. I found pages and pages that tell people to check the read/write protection of the file, as if a read-only file on disk could not be updated in the editor... (yes! you cannot write it back, but you can edit it and do a Save As ...)

One person, though, had the correct answer to ...

Somehow my NVG 510 broadband light started blinking red a couple of time in the last few days. I've been wondering why and I think I have the answer now.

In most cases it may just be that the broadband signal disappears for too long and the modem disconnects.

However, in my case, I think it was because they made an upgrade (a push!) on the modem because a few things do not work as expected anymore. (i.e. I cannot access the nsh shell anymore...)

Whenever software is upgraded, the likelyhood that you have to reset the whole thing is very high. I had to restart twice and even after that, ...

I have used several different software to gain remote access to other's computers.

With a Unix system, it's easy. You use ssh and you can do everything you want (although some people just cannot handle a console, I'm fine with such, but ssh allows you to access X-Windows if you'd like with the -X command line option.)

With MS-Windows, since that system is just a desktop application, you need a special tool in order to achieve that feat. Most of them are for money or make use of things that do not work under Linux. Yet, there is one that I like, it is called TeamViewer. It was ...

The select() Unix command allows you to wait on an event on a set of file descriptions, in most cases, sockets.

The select() function accepts the following parameters:

Largest file descriptor + 1
An fd_set of file descriptors to listen to for read
An fd_set of file descriptors to listen to for write
An fd_set of file descriptors to listen to for special events (i.e. closed on the other end)
A timeout structure

The fd_set pointers are all optional. Actually, if all are set to NULL, select() waits for the specified timeout and then returns. Similarly, the ...

One thing that I find annoying in gvim is the foldcolumn parameter which is not reset once you are done with a diff process.

Of course, gVIM does not really know when you are done diff-ing, so its behavior makes sense... only it is still annoying.

To remove the fold (2 gray columns on the left used to hide areas that match in each file) you simply have to set the foldcolumn parameter to zero:

:set foldcolumn=0

Just in case, you enter a diff from within vim by loading two files, then using;

:diffsplit #

The diffsplit can specify any buffer number, I use the # as the other buffer (the ...

HTML background that fits the screen

You can actually define an image or a background (with CSS) that fits the area in which is it shown.

For a simple image use a width of 100%, then the browser computes the height for you.

  <div class="header"><img src="images/background.png" width="100%"></div>

This code will make the image width match the width of the <div> tag. Assuming the <div> tag fits the screen width, it will show in the full width, stretching as required.

When trying to do that with a background image in CSS, you want to use the background-size parameter ...

Useful online network tools

I'm starting this page and hope to think about it again at a later time when I find additional tools... but as I have network problems I often need these types of services to make sure I can get the information I need.

For more Network stuff, click on the Network tag!

What is your IP address?

Check your current IP address from your browser:

http://alexis.m2osw.com/nvg510/my-ip.php [Super clean version!]

https://www.whatismyip.com/ [More advance and with ads...]

What is my DNS?

This one is for people who setup a DNS to make sure that it can accessed from all over the world. It ...

Working on a PHP application setup, I stumble upon a problem. Going to the installation page, I got the dreadful error:

Forbidden

You don't have permission to access <root-path>/admin/install on this server.

Looking at the error logs, the only thing reported was:

client denied by server configuration

The fact is that Apache does not tell you which setting actually forbids the access. I guess that's because once it gets checked by Apache, it is a blend of all the settings and not a tree being followed.

Looking a round, and since I already had that error not too long ...

I work with Apache a lot. It is a really good web server that has many options and features. Unfortunately, maybe it has too many of them!

I ran in a problem where a notification from one server to another would fail with the following error:

[Fri Oct 11 19:43:50 2013] [error] [client 162.226.130.121] client denied by server configuration: <path to file>

Looking at the error, I was first thinking that my script was generating the error. The fact is that my script does not generate error 403. It has a 400 and 500 but not 403.

So looking at the error I thought, maybe that's an ...

Full Update

Once in a while, I update my policy file because tripwire tends to checks EVERYTHING and many things are being updated on a constant basis (such as the letsencrypt files which appear under /etc/letsencrypt/..., which should use /var/lib/letsencrypt/..., but I digress here...)

So as a result I have to update the file and to do so I edit my twpol.txt file and then run the following three commands to update the database:

sudo twadmin --create-polfile --cfgfile tw.cfg --site-keyfile site.key twpol.txt
sudo rm /var/lib/tripwire/hostname.twd
sudo tripwire --init

The ...

Unfreeze your Mouse when it Froze

Thank you for visiting my website.

Main Menu

Welcome to The Linux Page

What is your IP address?

What is my DNS?

Forbidden

Full Update