The most reliable way to get a file extension in Python is os.path.splitext(), which splits a filename into the base name and extension. For modern code, pathlib.Path provides a cleaner alternative. Using os.path.splitext() os.path.splitext() returns a tuple of (name, extension): import os name, ext = os.path.splitext(‘file.txt’) print(name) # ‘file’ print(ext) # ‘.txt’ This works with…
When working with file I/O in C on Linux, you’ll often need to convert between low-level file descriptors (returned by open(), socket(), etc.) and higher-level FILE pointers (returned by fopen()). This is common when integrating different libraries or mixing POSIX I/O with standard C I/O. Getting a FILE Pointer from a File Descriptor Use fdopen()…
Once your HP printer is working on a Linux system, enabling the scanner requires installing SANE (Scanner Access Now Easy) and HP-specific backends. If wireless connectivity is already established for printing, the scanner should be discoverable on the same network. Install Required Packages On Fedora: sudo dnf install sane-backends sane-backends-devel hplip hplip-common On Ubuntu/Debian: sudo…
Skype periodically fails to start with a “system is unavailable” error when it can’t read or write to the user’s temporary directory. This typically happens when the temp folder becomes corrupted, has permission issues, or contains orphaned Skype cache files that prevent proper initialization. Understand the Problem On Windows, each user account has a temporary…
When your C: drive fills up with user profile data, moving the entire user directory to another drive is a legitimate solution—but it requires careful execution and understanding of the tradeoffs involved. Why This Matters User profiles contain everything: Documents, Desktop, Downloads, AppData, and all application settings. On a full C: drive, this can easily…
VirtualBox on Fedora reports “The vboxdrv kernel module is not loaded” when you try to launch it, even though the virtualbox and kernel module packages are installed. This typically happens on systems with UEFI Secure Boot enabled, which requires kernel modules to be cryptographically signed. Check if the module is loaded First, verify whether the…
When you need to browse the web over SSH or in a headless environment, graphical browsers aren’t an option. Several terminal-based browsers exist that actually handle modern websites reasonably well, though with limitations around JavaScript and CSS. Lynx Lynx is the oldest and most established terminal browser, first released in 1992. It’s still actively maintained…
RPM Fusion provides packages that Fedora and RHEL can’t ship by default due to patent, licensing, or trademark restrictions. This includes multimedia codecs, proprietary drivers, and other software. Here’s how to enable it on RHEL 9 and Rocky Linux. Enable RPM Fusion Free and Non-Free # Enable EPEL first (required dependency) sudo dnf install epel-release…
The default dd command can feel sluggish because it uses a small block size (512 bytes) by default. You can dramatically improve throughput by increasing the bs (block size) parameter. Basic optimization Instead of: dd if=/dev/sda2 of=./sda2.bak Use: dd if=/dev/sda2 of=./sda2.bak bs=1M The bs parameter controls how much data dd reads and writes in each…
Attaching storage to a running Xen DomU without rebooting is straightforward using the xl toolstack. This is useful when you need to add capacity, attach backup storage, or provision new volumes without downtime. Basic Disk Attachment To attach a logical volume or physical disk to a running DomU, use xl block-attach on Dom0: xl block-attach…
When you SSH to a server and see the warning below, your SSH client has detected that the server’s host key doesn’t match what’s stored locally: @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY! Someone could be eavesdropping on you right now (man-in-the-middle attack)!…
[md] When you need to inspect what files a .deb package contains or will install, dpkg is your primary tool. This is useful for understanding package contents before installation, checking what files a package added to your system, or troubleshooting file conflicts. ## Listing Files in an Installed Package If the package is already installed…
When your host machine connects to the network via WiFi, giving QEMU guests network access requires a different approach than traditional bridged networking. Since wireless interfaces typically don’t support bridge mode, you’ll need to use NAT (Network Address Translation) or a tap device with masquerading. Understanding your options NAT mode is the simplest approach—the host…
When running Hadoop on systems with substantial memory, the default 1GB heap size is often inadequate. If you check running processes with ps aux and see -Xmx1000m, you’re working with the default configuration that doesn’t scale to modern hardware. Understanding Hadoop Heap Configuration Hadoop’s Java process memory is controlled by environment variables set in configuration…
When you start a QEMU guest without explicitly configuring VNC, the display server may not bind to an address your VNC client can reach. You’ll see an error like: vncviewer: ConnectToTcpAddr: connect: Connection refused Unable to connect to VNC server This happens because QEMU defaults to SDL display output and doesn’t automatically expose VNC to…
When you connect an iPhone or iPad to a computer and tap “Trust,” iOS stores a pairing record that allows that computer to communicate with the device without asking for permission again. If you want to revoke that trust relationship, you need to delete the pairing data on both the device and the computer. On…
The most straightforward way to identify which installed package provides a specific file is with dpkg: dpkg -S /path/to/the/file The -S flag searches for a filename pattern across all installed packages. This works for any file path in your system, whether it’s a binary, library, configuration file, or anything else. Searching for command binaries To…
UDP packet loss on Linux commonly stems from undersized kernel buffers. When packets arrive faster than the application can process them, the kernel drops excess datagrams silently. Unlike TCP, UDP offers no retransmission, so these losses are permanent. Proper buffer tuning is essential for DNS servers, NTP, monitoring systems, video streaming, and any high-throughput UDP…
You can fetch a webpage as if you’re requesting from a mobile device by setting curl’s User-Agent header to match a mobile browser. Remote servers use the User-Agent header to decide whether to serve mobile or desktop versions of pages. Basic syntax Use the -A (or –user-agent) flag to specify a mobile User-Agent string: curl…
If you’re running a dual-boot system with Windows, you’ll need to configure which operating system loads by default. The method depends on your Windows version and whether you’re using legacy BIOS or UEFI firmware. Windows 7 and Vista: System Properties Method For Windows 7 systems using the traditional boot manager: Open Control Panel and navigate…