Linux is a multi-user operating system where multiple users can run processes simultaneously. Groups provide a mechanism to efficiently manage permissions for collections of users without having to set individual permissions for each account. What are user groups? A user group is a collection of user accounts that can be assigned permissions as a unit….
The full URL is commonly needed for redirects, canonical link headers, or logging. While PHP superglobals provide the raw components, how you assemble them matters for security and reliability. Using $_SERVER Superglobals The most direct approach uses the $_SERVER array: $url = (isset($_SERVER[‘HTTPS’]) ? “https” : “http”) . “://$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]”; This reconstructs the scheme, host, and…
Securing your website with HTTPS is no longer optional—it’s essential for SEO, user trust, and browser compatibility. The good news: Let’s Encrypt provides free certificates, and the tooling has matured significantly. Using Certbot with Nginx or Apache The standard approach is Certbot, which automates certificate issuance and renewal: sudo certbot –nginx This automatically configures HTTPS…
RHEL-based distributions only provide 64-bit Wine packages in their standard repositories. Many Windows applications—especially legacy software—require 32-bit Wine. Building Wine from source is the most reliable approach to get a working 32-bit installation alongside 64-bit support. Prerequisites and Resource Requirements Building Wine requires significant resources: ~2GB temporary disk space, ~500MB installed Compilation takes 20-40 minutes…
Systemd replaced traditional init on most modern Linux distributions, shifting terminology from “runlevels” to “targets.” If you’re migrating from older systems, here’s the mapping: Runlevel Systemd Target Purpose 0 poweroff.target Shutdown 1 rescue.target Single-user mode 2, 3, 4 multi-user.target Multi-user, no GUI 5 graphical.target Multi-user with GUI 6 reboot.target Reboot The two targets you’ll use…
Open a terminal and connect to the server: ssh USER@HOST Replace USER with your username and HOST with the server’s hostname or IP address. On first connection, SSH will display the host key fingerprint: The authenticity of host ‘HOST (IP_ADDRESS)’ can’t be established. ECDSA key fingerprint is SHA256:xxxxxxxxxxxx. Are you sure you want to continue…
NetworkManager is the default network management tool on modern Fedora, RHEL, and CentOS systems. You can configure static IPs either through the CLI or by editing configuration files directly. This guide covers both approaches for Fedora 41+ and RHEL 9+. Identify your network interface Start by listing all available network interfaces: ip link show or…
Configuring an HP all-in-one printer’s scanner on Linux requires HPLIP (HP Linux Imaging and Printing) for device support and SANE (Scanner Access Now Easy) for scanning functionality. The main gotcha is that a working printer doesn’t guarantee a working scanner — they use different subsystems and need separate configuration. Installing Required Packages Start by installing…
When you repurpose disks from one RAID array to another system, Linux keeps the old RAID metadata intact as a safety measure. This prevents accidental data corruption, but it also blocks you from reusing the disk until the signatures are cleared. RAID metadata isn’t stored in one place — it’s scattered across the disk by…
SSH performance is constrained by cipher choice, especially for large file transfers over high-bandwidth links where CPU becomes the bottleneck. Selecting the right cipher, key exchange algorithm, and compression settings can yield substantial throughput improvements. Current Cipher Landscape Modern OpenSSH (7.4+) has deprecated or removed weak ciphers. Here’s what’s viable today: Secure and performant: chacha20-poly1305@openssh.com…
WordPress performance depends on three complementary caching layers: PHP bytecode caching (OPcache), page caching (WP Super Cache), and asset optimization (Autoptimize). Combined properly, they’ll cut your Time to First Byte in half and significantly improve Core Web Vitals. Enable OPcache in PHP OPcache caches compiled PHP bytecode in shared memory, eliminating parse and compile overhead…
Gitolite provides fine-grained access control over Git repositories without the overhead of a full-featured platform. It uses SSH keys for authentication and handles per-user, per-repository, and even per-branch permissions through a simple configuration file. This guide covers a working installation on modern Linux distributions. Prerequisites Server: Linux (Ubuntu 20.04 LTS or later, Debian 11+, RHEL/Rocky…
Self-hosting a photo gallery gives you control over your content. If you want to skip database management entirely, a handful of PHP solutions still work—though most are unmaintained. This post covers what’s still functional, where the limits are, and when you should choose something else instead. Static File-Based Gallery Scripts Single File PHP Gallery Status:…
Linux device names like /dev/sda and /dev/sdb are unreliable identifiers for physical hardware. They shift when you add, remove, or reseat drives, and there’s no guaranteed mapping between a SATA port and its device name. When a disk fails, you need to know exactly which physical slot to replace—guessing wrong takes down the wrong system….
Compressing HTTP responses with gzip reduces bandwidth usage and improves page load times. However, server-level compression should be your first choice—PHP-level compression is a workaround for constrained hosting environments. How GZIP Compression Works When a browser sends a request with Accept-Encoding: gzip in its headers, the server can compress the response body before transmission. The…
Insert the installation media and create a mount point: sudo mkdir -p /media/dvd sudo mount /dev/sr0 /media/dvd For a DVD image file instead of physical media: sudo mount -o loop /path/to/image.iso /media/dvd Verify the mount and check that packages exist: ls /media/dvd/Packages/ | head On systems with automatic mounting (systemd-based), the DVD may already be…
Emacs provides a built-in tutorial. Access it with: C-h t For structured learning, the GNU Emacs Manual (built-in via C-h i) is the most authoritative resource. The Emacs Wiki also maintains community-driven guides and examples. Emacs configuration Store your configuration in ~/.emacs.d/init.el rather than the legacy ~/.emacs file. This keeps your Emacs directory cleaner and…
Xen remains in production use across cloud providers (AWS EC2, Citrix Hypervisor) and large infrastructure deployments, though KVM has become the default hypervisor for most Linux distributions. This guide covers installing a Fedora Domain-U on a Xen Dom0 using PXE boot, applicable to current Fedora releases. Prerequisites A working Xen Dom0 installation LVM backing store…
Modern Fedora (29+) uses firewalld by default instead of the legacy iptables service. If you’re working with an older system or one configured for iptables, the concepts here still apply, but you should first check what’s actually managing your firewall: systemctl status firewalld systemctl status iptables If firewalld is active, use firewall-cmd instead. For iptables-based…
If your Linux machine is getting noticeably slower WiFi speeds than other devices on the same network, MTU (Maximum Transmission Unit) misconfiguration can be a culprit. While MTU tuning won’t be the answer in every case, it’s worth investigating if you’re seeing symptoms like high latency, dropped packets, or intermittent connection issues. Understanding MTU MTU…