UNIX is an operating system. And your known equivalent is Windows or the Mac. You may even know about Linux. The purpose of an OS is to accommodate programs in order to get some work done. Editing pictures, browsing the web or serving data from a database. It is the thing that lets you operate […]

What is UNIX?

How to analyze suspicious email
Millions of emails are sent and received every day. Most of them are just junk. And many among those are potentially harmful. Phishing still is one of the most effective ways for malicious actors to penetrate into well secured networks. The weakest link, too often, is the human factor. Training can help mitigate this 24×7 […]

How to use Cloudflare’s Argo Tunnel service to publish a website on FreeBSD 12/13
What is the Cloudflare Argo Tunnel service? In short, a tunneled connection between a host and Cloudflare’s network. A longer depiction can be read in a blog entry of theirs, but I would put it as a secure way to connect the services you want to publish using their network as a shield. An example […]

How to load and unload kernel modules in Linux
Kernel modules permit enabling hardware features on a given system. For example, if we need to read from a particular filesystem from a hard drive, we need to load a particular kernel module. Or use a specific network card, a sound card or sound device, a video display, etc. This is mostly done automatically in […]

List of Speculative Execution Vulnerabilities
Vulnerability CVE Exploit name Public vulnerability name Firmware changes Spectre 2017-5753 Variant 1 Bounds Check Bypass (BCB) No Spectre 2017-5715 Variant 2 Branch Target Injection (BTI) Yes Meltdown 2017-5754 Variant 3 Rogue Data Cache Load (RDCL) No Spectre-NG 2018-3640 Variant 3a Rogue System Register Read (RSRE) Yes Spectre-NG 2018-3639 Variant 4 Speculative Store Bypass (SSB) […]

How to set the locale in FreeBSD
The locale is the character set that will be used. And it is very important to match the keyboard you are using. Mind this also matters if you are transferring data to other systems. Different standards as the ASCII, UTF’s and the ISO’s, to name a few, have been put in place through the years […]

How to use find in GNU/Linux and FreeBSD
How to use find is a very basic, but important, UNIX lesson. Find is a very useful command which can help us not just finding a particular file, but for examples files or directories matching certain criteria such as: size, permissions, type. The basic mode of operation for find is the following: find path criteria […]

The firewall
If you don’t know why you need a firewall it’s because you are not very tech savy. Don’t worry. You can discover by yourself why you need one. The router sitting in your house has one installed in it. And please don’t disable that by any mean. You can check why a firewall is important […]

Symbolic and Hard Links in UNIX and Linux
Symbolic and Hard Links are useful ways to reference to information on a disk, both found in UNIX and Linux systems. While they seem similar in the surface they are quite different in how they work and it what can be achieved when using them. If you find the articles in Adminbyaccident.com useful to you, […]

How to compile cloudflared in FreeBSD 13/14
I happen to self-host my websites using Cloudflare’s services (article 1, article 2). Since the FreeBSD port seems to be delaying its releases and Cloudflare’s policy on maintaining versions only considers 1 year old code, in an act of prevention I have learnt, and I am publishing, how to compile cloudflared in FreeBSD. Note: At […]
