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Security headers in your web site

You can scan your website here (don’t forget to check ‘hide result’): Then add the following code to your .htaccess or directly inside de server configuration file if you have access to it: Now it’s better:

Detect Active Directory users password expiration and send a reminder email

The following code must be executed as administrator on your active directory server:

expdp / impdp causes Oracle segmentation fault (core dumped)

This error is caused because of a malformed command line impdp / expdp. Also it depends on your oracle server version, in recent oracle servers you will probably have less problem with the pattern combination. For instance you have several… Continue Reading →

Rocky Linux: remove remi’s php package

CentOS-8 – AppStream Error: Failed to download metadata for repo ‘AppStream’: Cannot prepare internal mirrorlist: No URLs in mirrorlist

Solution to CentOS 8 AppStream Error As explained here, Centos mirrors have been migrated to Then the solution is: After this you can again use the yum command but you won’t received recent updates because Centos mirrors are not… Continue Reading →

Shell script function particularities: declare local variables, run in background, …

Run a function in background and get its process ID Instead of creating another script that you call from your primary script you can simply declare a function (inside your primary script or inside another file that you include), and… Continue Reading →

Install ansible 5 inside a python virtual environment with python 3.10.4

Note: The following commands are for RockyLinux, RedHat, CentOS, on other distros it will be almost the same. I’ve made the choice to connect to a user called ansible, and inside his home directory I’ve created a directory called ansible,… Continue Reading →

Python and virtual environments on Linux OS

Install python 3.10.4 from source on Rocky Linux or CentOS The following commands are executed as a root user. Virtual Python environment You can install several virtual python environments on your Linux OS. It will allow you to deploy a… Continue Reading →

Why CRLF on Linux can sometimes be displayed as ^M with line feed?

Firstly, it’s good to remember these following points: CR is for Carriage Return LF is for Line Feed On windows line endings are represented by CRLF (CR+LF) On Linux line endings are represented by LF In a shell script you… Continue Reading →

Chrome Refused to display ‘’ in a frame because it set ‘X-Frame-Options’ to ‘deny’.

In the DevTool of your web browser you have this kind of message because you’ve been to the url (or a completely different domain like that contains an HTML page which includes an iframe of This message… Continue Reading →

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