The Ghost Operator's Signal
When you first see a file in Linux, the three-letter string that starts with -rw-r--r-- can look like an alien language.
It tells the system who can read, write, or execute that file. Don’t worry – it’s just a set of rules.
In this post we’ll break those rules down into bite-sized pieces and give you a handy cheat sheet for the most common chmod commands.
At Tom’s IT Cafe we break down the hard stuff so you can secure your
systems without getting lost in jargon. Below is a straight-ahead look
at what “in transit” and “in rest” mean, why they matter, and how to
implement them with the most common algorithms.
A firewall sits between your server and the outside world. It decides which network traffic is allowed to reach your machine and which should be dropped. Think of it as a bouncer at a club: only people on the guest list get in.
UFW, short for Uncomplicated Firewall, is Ubuntu’s front‑end to iptables. It lets you write rules with simple commands instead of juggling raw tables.
Every system admin has a moment when a simple “look at that file” turns
into a three-hour hunt for information. That’s where the old friends
grep, head, tail, cut, less and sed come in. They’re not
fancy new tools; they’re tried-and-true helpers that can save you hours
of repetitive work.
Want your blog reachable by anyone – both Tor users and regular browsers – without running two separate installations?
The trick is one code-base, two reverse proxies, and a single database. Below is a quick 400-500 word guide for Ubuntu/Debian that shows the minimal steps.
Want a private blog or small business site that nobody can reach unless they use the Tor Browser?
Below is a step-by-step guide that keeps the server lean, secure, and accessible only via an .onion address.
All commands are for Ubuntu/Debian; adjust paths if you’re on another distribution.
Tired of corporate servers watching every chat?
Host your own Matrix on Tor, no public IP, zero tracking.
By running Matrix over Tor, you eliminate exposure to public servers and keep your chats private.
This isn’t just another guide – it’s a battle‑tested recipe for keeping your Matrix chats private on Tor.
Continue reading “Private Matrix: Hosting a Synapse Server Over Tor (Modern Chat On The Dark Net)”
Systemd is the heartbeat of most modern Linux systems.
When you run:
sudo systemctl restart nginx
you trigger a full chain of actions – not a single binary reload.
Systemd reads unit definitions, resolves dependencies, checks targets, and updates logs.
Knowing what happens gives you clarity when a service misbehaves.
Continue reading “Systemd by Example: What Actually Happens When You Type systemctl restart nginx”You don’t need to fight systemd. You just need to understand its rhythm.
It usually arrives out of nowhere. A person claiming to work for a domain registration center or network authority says another company wants to register your brand name as several .cn domains – maybe example.cn, example.com.cn, example.net.cn, and so on.
Continue reading ““Someone’s Trying to Register Your .CN Domain!” – A Common Domain Scam”
Tom's IT Cafe 