The simplest way to see your commit history as a tree structure: git log –graph –oneline This produces a text-based graph showing branch relationships and merges with abbreviated commit hashes: * b5dc8b9 Merge branch ‘main’ into develop |\ | * 7514ef1 revised the README.md | * 6692428 align size to page for both shalloc and…
GDM (GNOME Display Manager) lets you control which users appear on the login screen. You have two main options: hide the entire user list or exclude specific users while keeping the list visible for others. Disable the user list entirely The most straightforward approach is to disable user listing completely. This forces everyone to type…
Chrome aggressively caches HTTP redirects—especially 301 (permanent) and 308 redirects—as a performance optimization. The cache persists across browser sessions, which causes real problems when you’ve updated redirect rules and need to test them immediately. Understanding Chrome’s Redirect Cache Behavior Chrome stores redirect information at the browser level, separate from typical page caches. This means: 301…
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…
WordPress sanitizes HTML in comments by default for security. The <pre> tag is stripped unless you explicitly whitelist it. Here’s how to enable it without compromising security. Using wp_allowed_post_html Filter The proper approach is to whitelist <pre> and related tags via the wp_allowed_post_html filter: function allow_pre_in_comments( $allowed ) { $allowed[‘pre’] = array(); $allowed[‘code’] = array(…
By default, crond sends email notifications whenever a cron job produces output or encounters an error. For high-volume cron jobs or systems without a mail server, you’ll want to disable these notifications. Redirect output to /dev/null The simplest approach is to discard all output from your job: 0 2 * * * /usr/local/bin/backup.sh > /dev/null…
Bash provides comparison operators for conditionals through the test command (aliased as [), the [[ ]] compound command, and the (( )) arithmetic command. Each has specific use cases and behavior differences worth understanding. String Comparisons String comparisons work with test/[ and [[ ]]: Operator Meaning -n STRING String length is nonzero (true if not…
The built-in etags command doesn’t recursively traverse directories by default, but generating TAGS files across your entire project is straightforward with the right tools and setup. Using ctags (Recommended) The simplest approach is ctags with the -e flag, which generates Emacs-compatible TAGS files: ctags -e -R . The -R flag enables recursive traversal. This works…
Aggregating multiple RSS feeds into a single source is essential for monitoring diverse content — whether tracking news, blogs, project updates, or monitoring systems. Here are the practical approaches with working examples for 2026. Self-Hosted Feed Readers Miniflux is the modern standard for self-hosted feed aggregation. Written in Go, it’s lightweight, actively maintained, and provides…
DVI (Device Independent) files are the output format from TeX and LaTeX compilers. While modern workflows typically generate PDF directly with pdflatex, you’ll still encounter DVI files in legacy documents, archived projects, and specific publishing pipelines that require intermediate processing. Viewing DVI Files Xdvi Xdvi is the most reliable dedicated DVI viewer and remains the…
When debugging a program or understanding what it actually touches on your filesystem, you need to see which files it opens. Two tools do this well: strace traces system calls in real time, while lsof inspects a running process without the overhead. Using strace to capture file operations The simplest approach is to run strace…
IEEE requires a specific format for web citations, and BibTeX handles this cleanly with the @online entry type. Here’s how to get it right. IEEE Web Citation Format IEEE specifies this pattern for online sources: [#] Initial(s). Surname, “Title [Online]. Available: URL. Accessed: Month Day, Year.” A complete example looks like: [1] J. Jones, “Networks…
When you install a JDK on Linux, you need to configure environment variables so your shell uses the correct Java binary and build tools can locate the installation. If you have multiple Java versions installed, proper configuration becomes essential. Why Set Java Environment Variables Setting JAVA_HOME and PATH ensures: Tools and applications can locate the…
Amazon S3 has a maximum object size of 5TB per object. This limit applies uniformly across all storage classes and regions — there are no exceptions or workarounds. Understanding the 5TB Ceiling The 5TB limit is a hard constraint at the API level. You cannot upload, copy, or restore an object larger than this. While…
The replication factor determines how many copies of each data block HDFS maintains across your cluster. The default is 3, which provides adequate fault tolerance for most deployments by surviving both node and rack failures simultaneously. Setting Cluster-Wide Default Replication To set the default replication factor for all new files, add the dfs.replication property to…
When using two-column layouts, the last page often ends with uneven column heights—one column noticeably longer than the other. This looks sloppy in formal documents. Two main packages solve this: balance and flushend. Using the balance package The balance package gives you explicit control over where balancing happens. Add to your preamble: \usepackage{balance} Then insert…
MPlayer is effectively unmaintained. If you’re starting fresh, use mpv — the actively maintained fork with better codec support, hardware acceleration, and improved filter performance. That said, if you’re working with existing MPlayer setups, you can still improve playback quality through filters. When to Use Filters vs. When to Switch Before spending time tuning MPlayer,…
MPlayer is largely obsolete, but if you’re maintaining legacy systems, you’ll need to know how to position windows. For new work, use mpv (MPlayer’s maintained fork) instead. Centering with MPlayer Add this to ~/.mplayer/config: geometry=50%:50% This centers the window by setting both X and Y to 50% of screen dimensions. Override at runtime: mplayer -geometry…
When you need to reach a server through one or more intermediate hosts, you can establish a direct connection without manually chaining SSH sessions. This is essential for accessing internal servers that aren’t directly reachable from your workstation. The scenario laptop —-> proxy —-> server You want to connect to server.example.com through proxy.example.com as if…
SSH is fast enough for most tasks, but when you’re transferring large files, running multiple commands, or managing hundreds of servers, every millisecond counts. Here’s how to squeeze real performance gains from SSH and SCP on Linux. Choose the Right Cipher Cipher selection has the biggest impact on throughput. Modern CPUs have AES-NI hardware acceleration,…