Documentation


Viewing posts for the category Omarine User's Manual

SELinux: xscreensaver-demo: Transitioning the file type

SELinux not only ensures the system securely against unauthorized access, but along with security policies also fixes software bugs, leads them in the right way in using resources and avoids conflicts. Xscreensaver-demo is a graphical tool used to set parameters for XScreenSaver. It creates ~/.xscreensaver configuration file and writes information into it

Scanning for viruses in the secure domain

Open source systems have begun to "get" the virus to care. The gdk-pixbuf software package has been identified by ClamAV antivirus software as virus infection since the releases after gdk-pixbuf-2.37:

Setting up security policy for xscreensaver-systemd

xscreensaver-systemd now belongs to the default installation of xscreensaver since xscreensaver-5.44. It works to lock the screen when the system goes into sleep mode.
However, the security rules for xscreensaver-systemd are not yet common, and we set it up in this article
We first declare the role group xscreensaver_systemd_roles, the type of domain and the type of the binary file

Counting the number of rows in the spreadsheet that meets a condition

Assuming you enter the products in the spreadsheet, each row is a product with a production date and product code. Given that the date data in column A, the product code in column B, cell D14 is used to count the number of products in a day, for example, October 12, 2019.
We can use a very simple but highly effective formula, an array formula - a situation using advanced SUM function. Select a representative cell with required date data, for example A7. The resulting formula in cell D14 is as follows

When to start the firewall?

This article is for those who want to learn the systemd units. The units need to work together and be started at the right time to ensure operational efficiency.

Firewalls are used to control incoming and outgoing packets, block unwanted packets from the outside and allow only certain applications to make new connections from the inside.

Thus the firewall must be running before any network is set up. The target identifying this point is network-pre.target, so we will start the firewall before network-pre.target.
network-pre.target is a passive unit, it only runs when another unit pulls it in. Here is the firewall service firewall.service



With Requires=network-pre.target, the target network-pre.target will be run



The firewall service is installed to be pulled in by the target network.target, a special unit that is started during boot which indicates network functionality is available



firewall.service is the common firewall service that is enabled by default. If you want to run a firewall on a specific network interface, for example wlp3s0, run the following commands as the root user