RHEL and CentOS 8+ ship 64-bit only by default. Some Windows applications require 32-bit Wine or run better under it. Since the distribution repositories don’t provide prebuilt 32-bit Wine, you’ll need to compile from source. The process requires building 64-bit Wine first, then 32-bit, then rebuilding 64-bit to establish proper cross-architecture linking. Install Build Dependencies…
View all virtual machines registered with VirtualBox: vboxmanage list vms Output example: “ubuntu-server” {a1b2c3d4-e5f6-7890-abcd-ef1234567890} “debian-test” {b2c3d4e5-f6a7-8901-bcde-f12345678901} “centos-prod” {d6c938d8-0bec-57f0-9fd3-8e395ba3d218} Each VM appears with its name and UUID. The UUID uniquely identifies the VM in VirtualBox’s database. List running VMs only See only active virtual machines: vboxmanage list runningvms This is useful when you have many VMs…
Gmail requires OAuth2 authentication for SMTP access — direct passwords have been disabled entirely. This is the only supported method for sending mail through Gmail in Thunderbird, whether you’re using a personal or Workspace account. OAuth2 Setup Open Thunderbird and go to Account Settings → Outgoing Server (SMTP). Click Add and configure these settings: Server…
RSA (Rivest–Shamir–Adleman) underpins SSH authentication, TLS certificates, code signing, and encryption across most Linux systems. OpenSSL is the standard tool for generating and managing these keys. Verify OpenSSL Installation OpenSSL is bundled with virtually all distributions. Check your version: openssl version If it’s missing: # Ubuntu/Debian sudo apt-get install openssl # RHEL/CentOS/Fedora sudo dnf install…
Thunderbird’s built-in calendar support (Lightning) handles local calendars, but you need two extensions to sync with Exchange Online: TbSync — manages cloud account synchronization for contacts, calendars, and tasks Provider for Exchange ActiveSync — adds ActiveSync protocol support to TbSync Install both from Thunderbird’s Add-ons Manager: Open Thunderbird and go to Menu → Add-ons and…
Cloud computing has fundamentally reshaped how organizations operate, shifting from on-premises infrastructure to distributed, internet-accessible systems. Rather than maintaining physical servers and data centers, companies now leverage cloud platforms where data storage, processing, and management occur across networked server clusters accessible via the internet. This shift has concrete implications for how work gets done, where…
SSH keys provide secure, password-less authentication to remote systems. Choosing the right algorithm matters for security, compatibility, and operational stability. Generate an Ed25519 Key Pair Ed25519 is the modern standard for SSH key generation. It offers stronger security properties than RSA, faster operations, and smaller key sizes. ssh-keygen -t ed25519 -C “your_email@example.com” You’ll be prompted…
You don’t need to fully extract a .tar archive just to read one file inside it. The tar command can stream individual files directly to stdout, which saves time and disk space—especially useful for large archives. Basic syntax tar -xOf archive.tar path/to/file.txt The flags break down as: -x: Extract mode -O: Write to stdout instead…
Wget is a reliable command-line tool for downloading entire websites for offline viewing, archival, or testing. It preserves the full site structure—HTML, images, CSS, JavaScript—and maintains the original directory layout. Basic Mirroring Command The core command to mirror a website: wget –mirror –convert-links –adjust-extension –page-requisites –no-parent https://example.com Flag Breakdown –mirror: Enables recursive downloading with time-stamping…
Linux Kernel 5.0 shipped in March 2019 as a symbolic milestone—the first major version bump from the 4.x series. The kernel project switched to semantic versioning at that point, so the jump to 5.0 was more about naming convention than revolutionary technical changes. That said, the release included several features and hardware improvements worth understanding,…
By default, rsync connects as your standard user. When you need to write to protected directories like /etc, /var/www, or other root-owned locations, use the –rsync-path option to invoke rsync with sudo privileges on the remote side. Basic syntax rsync -avz –rsync-path=”sudo rsync” local-file user@remote:/protected/path This tells the remote server to execute rsync under sudo….
Wayland screen recording has matured significantly. Here are the tools that actually work well in 2026, with their tradeoffs and setup. GNOME Built-in Screen Recording GNOME 40+ includes integrated screen recording on Wayland. Press Ctrl+Alt+Shift+R to start. A red dot appears in the top-right corner. Press the same shortcut again or click the indicator to…
Renaming a Git branch involves three steps: rename locally, push the new branch, and delete the old remote branch. How you do this depends on whether you’re working from the command line or your Git hosting platform’s UI. Rename the branch locally The simplest command renames a branch in your local repository: git branch -m…
Use the -d flag to run a container in the background and return terminal control immediately: docker run -d –name my-service my-image The container starts as a daemon process. Verify it’s running and check output: docker ps docker logs my-service Essential Configuration for Production Daemons A single -d flag isn’t enough for real workloads. Here’s…
Emoji rendering at incorrect sizes in Thunderbird usually comes down to font configuration. Unlike browsers that inherit system emoji rendering, Thunderbird manages its own font stack, which can drift out of sync with your system fonts or get corrupted in Thunderbird’s cache. Install a Color Emoji Font Start by ensuring you have a proper color…
GNOME’s natural scrolling setting can be frustrating — especially when the GUI option is missing or doesn’t apply to your mouse while leaving your touchpad alone. The issue usually comes down to your session type, GNOME version, and how input devices are registered on your system. Check your session type first Before troubleshooting, verify whether…
bbPress is WordPress’s standard forum plugin. When you need to modify how forum topics, replies, or other content displays, you’ll use WordPress filter hooks to intercept and transform the content before it reaches users. Common bbPress Content Filters Filtering Topic Content The bbp_get_topic_content filter runs after topic content is retrieved from the database but before…
The built-in pdb module is Python’s equivalent to gdb — a command-line debugger that lets you step through code, set breakpoints, inspect variables, and control execution flow. It’s essential for server-side debugging and situations where IDE graphical debuggers aren’t available. Starting a pdb Session Run a script through pdb directly: python -m pdb prog.py arg1…
iptables remains the standard firewall interface across most Linux distributions, though it’s technically a compatibility layer over nftables. Whether you’re managing legacy systems or prefer the familiar syntax, here’s what you need to know. Basic Command to Open a Port The fundamental syntax to allow inbound traffic on a specific port: sudo iptables -A INPUT…
Intercepting traffic before normal routing decisions requires understanding packet flow through iptables chains. If you need incoming packets to bypass the INPUT chain and process through FORWARD instead, you’ll use the PREROUTING chain with Destination NAT (DNAT). Packet Flow Through iptables When a packet arrives at your system, it traverses these chains in order: PREROUTING…