When you need to share work in progress or maintain a separate feature branch on a remote Git server, you’ll need to create a local branch and push it upstream. Here’s how to do it properly. Basic workflow The fundamental process involves three steps: Create a local branch and switch to it Make changes and…
Vim determines file types by extension to apply syntax highlighting and indentation. If you have custom file extensions that should be treated as C files, you need to configure Vim to recognize them. Using autocommand in .vimrc Add an autocommand to your ~/.vimrc: ” Treat .h and .c files in a custom directory as C…
When working with codebases that use non-standard file extensions for C source files, ctags won’t recognize them by default. You can configure it to treat files with custom extensions like .c0 or .puc as C source code. Using the langmap option The simplest approach is to add language mappings to your ctags configuration. Edit ~/.ctags…
When managing a Linux system remotely, you sometimes need to terminate all sessions for a specific user—whether they’re logged in locally at the console, via SSH, through X11 forwarding, VNC, or any other method. Here’s how to do it. Quick Answer To terminate all processes for a user named bob: killall -u bob This kills…
GIMP is the most full-featured image editor on Linux, but it can be overkill for quick edits. Several lighter alternatives provide essential editing features without the complexity or resource usage of GIMP. Pinta — Simple Paint.NET-Style Editor sudo dnf install pinta # Fedora sudo apt install pinta # Ubuntu Pinta provides a clean interface with…
When your iPhone completely freezes or becomes unresponsive, a force restart is usually the fastest way to get it working again. Unlike a regular restart, a force restart bypasses the normal shutdown process and forces the device to reboot immediately. Force Restart by iPhone Model The method depends on which iPhone you have. Apple changed…
Resizing a single image is straightforward, but processing dozens or hundreds requires automation. ImageMagick’s convert command (or the modern magick command) paired with a bash loop is the standard approach for batch image resizing on Linux. Using ImageMagick ImageMagick remains the most reliable tool for this task. Here’s a practical script to resize all images…
Adding a second metadata directory to your HDFS NameNode increases reliability by maintaining synchronized replicas of the namespace and transaction logs across separate disks. This guide walks through the process safely. Prerequisites and Planning Before starting, verify your current configuration and plan the new directory location: grep -A2 “dfs.namenode.name.dir” $HADOOP_HOME/etc/hadoop/hdfs-site.xml The new directory should be…
When running make recursively with $(MAKE) or make -C, you’ll see verbose messages like “Entering directory” and “Leaving directory” for each subdirectory. These messages clutter the build output and make it harder to spot actual errors. The Quick Fix Pass –no-print-directory to make: make –no-print-directory Or set it in your Makefile: .MAKEFLAGS: –no-print-directory Suppressing via…
Detecting whether an image is predominantly blank, black, or contains minimal content is useful for automated workflows like batch processing, quality control, or identifying failed captures. Here’s how to do it reliably on Linux. Using ImageMagick ImageMagick’s convert command (or magick in newer versions) can extract image statistics to determine if an image is nearly…
GNU Screen’s status bar (called the hardstatus line) displays useful information about your current session—which window you’re on, the time, hostname, and more. It’s especially helpful when you’re running multiple windows and need a quick visual reference without typing commands. Basic Status Bar Setup Add these lines to your ~/.screenrc: hardstatus alwayslastline hardstatus string ‘%{=…
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)!…
Converting a series of JPG images into a single PDF is useful for creating documents, presentations, or archiving scanned photos. Linux offers several tools for this task, each with different trade-offs between simplicity, quality preservation, and features. Using img2pdf (Recommended) For most cases, img2pdf is the best choice because it merges images without re-encoding or…
[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 managing HDFS clusters, you often need to verify the replication factor of specific files to ensure data redundancy meets your requirements. Here are the practical methods to check this. Using hdfs dfs -ls The most straightforward way is to list the file with hdfs dfs -ls: hdfs dfs -ls /usr/GroupStorage/data1/out.txt Output: -rw-r–r– 3 hadoop…
When you need to increase data redundancy or reduce storage overhead on a running HDFS cluster, you’ll often need to adjust the replication factor. Before making changes, understand that HDFS replication works differently than you might expect. How HDFS Replication Factor Works The replication factor in HDFS is determined at write time by the client,…
RTMP (Real Time Messaging Protocol) streams are still used for live broadcasts and on-demand video delivery, though less commonly than HLS or DASH. If you need to capture an RTMP stream, there are several solid tools available on Linux. Using ffmpeg (recommended) ffmpeg is the modern standard for working with RTMP streams. It’s widely available,…
Removing version control or build artifact directories across a large directory tree is a common sysadmin task. SVN directories (.svn), Git metadata (.git), or node modules (node_modules) often need to be purged before deployment or archiving. Using find with xargs The most efficient approach combines find with xargs: find ./ -name “.svn” -type d |…
Distribution repositories often lag behind Calibre’s latest releases. If your package manager shows an older version and you need current features or bug fixes, installing directly from the official installer is straightforward. Official installer method Calibre provides a dedicated Linux installer that works across distributions. This is the recommended approach for staying current: sudo -v…
HDFS snapshots provide a way to create read-only point-in-time copies of the filesystem or specific directories without duplicating data. Understanding their design helps you implement efficient backup strategies and recover from accidental deletions in production clusters. How HDFS Snapshots Work Snapshots in HDFS use copy-on-write semantics to avoid duplicating data. When you create a snapshot,…