Finding large files is something you end up doing a lot — disk fills up, you need to track down what’s eating space, or you’re auditing a directory before archiving. The find command handles this cleanly. Basic usage Find all files larger than 500MB under the current directory: find . -type f -size +500M The…
When a disk fills up or you’re doing a cleanup pass, finding the biggest files quickly saves a lot of time. Here are the practical approaches on Linux. Top 10 largest files in the current directory du -ah –max-depth=1 | sort -rh | head -n 10 Breaking this down: du -ah shows sizes for all…
The default GNOME Settings application doesn’t expose font configuration options. You’ll need additional tools to customize system fonts, but you have several approaches depending on your GNOME version and preferences. Using GNOME Tweaks GNOME Tweaks (formerly gnome-tweak-tool) is the recommended graphical approach for font customization. Installation On Fedora/RHEL: sudo dnf install gnome-tweaks On Ubuntu/Debian: sudo…
GNOME Shell in GNOME 3 uses a specific font for the top bar, activities overview, and system notifications. You can customize these fonts using GNOME Tweaks or dconf to match your preferences. Using GNOME Tweaks (Recommended) # Install GNOME Tweaks sudo dnf install gnome-tweaks # Fedora sudo apt install gnome-tweaks # Ubuntu Open GNOME Tweaks…
Broken symbolic links accumulate over time and can cause confusion or errors when scripts rely on their targets. Identifying and cleaning them up is a regular maintenance task. Basic approach Use find with the -xtype l test to locate broken symlinks: find /path/to/directory -xtype l The -xtype l flag specifically matches symbolic links that point…
When managing user accounts on a cluster or application, you’ll often need to generate temporary passwords programmatically. Here’s a practical approach using Scala’s built-in utilities. Basic implementation with scala.util.Random For non-security-critical use cases, here’s a straightforward generator: def randomString(len: Int): String = { val rand = new scala.util.Random() val chars = “0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz” (0 until len).map(_…
The passwd command is the standard tool for changing your password on Linux systems. It works across all distributions and doesn’t require administrative privileges for changing your own password. Basic password change Log in to your Linux system and run: passwd You’ll be prompted for: Your current password (to verify your identity) Your new password…
A4-sized PDFs—particularly technical papers and academic documents—render poorly on Kindle devices. The small fonts become nearly unreadable, and Amazon’s “Send to Kindle” feature often destroys formatting in the process. You need a tool designed specifically for this workflow. Why Standard Conversion Fails Amazon’s email-to-Kindle conversion assumes reflowable text content. Technical papers with multi-column layouts, equations,…
Gnuplot can output directly to EPS (Encapsulated PostScript) format, which is useful for including plots in LaTeX documents and other publishing workflows. Direct EPS Output The simplest approach is to set the terminal to postscript with the eps option before plotting: set terminal postscript eps enhanced mono “Helvetica” 14 set output “my-plot.eps” plot sin(x) This…
Several tools can convert .doc and .docx files to PDF from the command line. Here’s what works in practice. LibreOffice (most common approach) The standard command is: libreoffice –headless –convert-to pdf –outdir /path/to/output/ /path/to/file.docx This works well on systems with X11 available. However, on truly headless servers, –headless doesn’t fully suppress X11 requirements—LibreOffice will still…
When you need to rsync against hosts behind NAT gateways or port-forwarded SSH services, the standard port 22 won’t work. The solution is the -e flag, which lets you specify a custom SSH command with your desired port. Basic usage Use -e to pass custom SSH arguments: rsync -avxP –delete -e “ssh -p 13022” username@example.com:/remote/path/…
GNOME 3 removed the GUI option for customizing window title fonts that existed in earlier versions. The setting is still configurable, but you’ll need to access it through command-line tools or configuration editors. Using gsettings (Command Line) The simplest approach is gsettings, which directly modifies the configuration: gsettings set org.gnome.desktop.wm.preferences titlebar-font ‘Sans Bold 10’ To…
You’ve accidentally broken a file and need to restore it from an earlier commit without touching anything else in your repository. Here’s how. Restore a file to a specific commit To restore my_file.name to its state at a specific commit: git checkout commit_sha1 my_file.name Replace commit_sha1 with the actual commit hash. You can find it…
When you work with multiple git servers or need different credentials for different hosts, SSH’s config file lets you specify which key to use for each server. This is cleaner than managing aliases or environment variables. Setting Up ~/.ssh/config Create or edit ~/.ssh/config and add entries for each server: Host git.example.org Port 22111 IdentityFile ~/.ssh/id_rsa.git.example.org…
By default, libvirt stores VM images as files in /var/lib/libvirt/images/. While functional, this approach limits flexibility. LVM (Logical Volume Management) provides better control over disk space, snapshots, and performance tuning. Using LVM volumes as libvirt storage pools lets you manage VM storage like block devices rather than files, giving you faster provisioning, atomic snapshots, and…
When your OCaml program crashes with Fatal error: Exception “Stack_overflow” but doesn’t tell you where the problem originated, you need to enable backtrace reporting. The process is straightforward but requires recompilation. Enable Debug Symbols and Backtraces First, recompile your program with the -g flag to include debug information: ocamlopt -g -o myprogram myprogram.ml If you’re…
sbt (Scala Build Tool) isn’t available in the default Fedora repositories, though Scala itself is. Here’s how to install it properly. Using the Official Repository The most reliable approach is to add sbt’s official repository to your system. This gives you automatic updates and avoids manual RPM downloads. Create the repository configuration file: sudo tee…
Linux systems can have multiple timer sources available, and the kernel selects one as the active clocksource. Understanding what’s available and how to view or change the current source is essential for performance tuning and troubleshooting timing-related issues. View the Current Timer Source Check which clocksource is currently in use: cat /sys/devices/system/clocksource/clocksource0/current_clocksource This will output…
utop is an improved OCaml REPL with line editing, history, context-sensitive completion, and syntax highlighting. While powerful, its key bindings differ from standard GNU readline, which can be jarring if you’re used to standard shell behavior. Getting the key bindings list The simplest way to see all available bindings is to run the #utop_bindings directive…
Trailing spaces and tabs at the end of lines are common annoyances in source code and configuration files. They’re invisible, waste space, and can cause issues with certain tools or version control systems. Here’s how to remove them efficiently. Using sed The most straightforward approach with sed: sed ‘s/[[:space:]]*$//’ your_file > your_file.tmp && mv your_file.tmp…