Traditionally, tools like strace used ptrace to monitor system calls. While effective for development debugging, ptrace stops the entire process for every syscall, causing 2-10x slowdown. This makes it unsuitable for production workloads where you need real-time visibility without tanking performance. Modern Linux offers significantly faster alternatives through eBPF (Extended Berkeley Packet Filter), which runs…
When you need additional swap space but all partitions are allocated, creating a swap file lets you add capacity without repartitioning. This is especially useful on systems with fixed disk layouts or cloud instances where you can’t modify the underlying disk structure. Creating the Swap File Start by allocating space. fallocate is the fastest option…
GNOME Evolution’s email address auto-completion works by querying your local address books and, optionally, external sources. Here’s how to get it working properly. Check Your Address Books Evolution pulls auto-completion suggestions from multiple sources: Personal address book (local contacts you’ve added) On This Computer (system-wide contacts) Synced contact sources (Google, CalDAV, CardDAV, LDAP) To see…
Retrieving hardware serial numbers is essential for inventory management, warranty tracking, and identifying physical servers across your infrastructure. The standard approach uses dmidecode, which reads the system’s DMI (Desktop Management Interface) data. Using dmidecode First, install the tool: sudo apt-get install dmidecode For Rocky Linux, RHEL, and derivatives: sudo dnf install dmidecode Then query the…
EncFS is a transparent encrypted filesystem that works well on Linux and macOS, but Windows doesn’t support it natively. If you’re migrating from Linux or need EncFS-specific functionality on Windows, you’ll need to either run it in a virtual machine or switch to Windows-native alternatives. Why EncFS Doesn’t Work on Windows EncFS relies on FUSE…
EncFS is a FUSE-based encrypted overlay filesystem that was once popular for transparent file encryption. However, its use on Android has become impractical due to Android’s security architecture. Here’s what you need to know in 2026. Why EncFS Doesn’t Work Well on Android Anymore Android’s evolution has made direct EncFS usage difficult: Scoped Storage (enforced…
When you need to break up a large gzip file into smaller chunks, you have several practical options depending on your constraints. Using zcat with split The most straightforward approach is to decompress the gzip file and split it simultaneously: zcat large_file.gz | split -b 100M – chunk_ gzip chunk_* This decompresses large_file.gz, pipes it…
Google Maps integration is straightforward, but the approach depends on whether you need an interactive map or a static image. Each has trade-offs worth understanding. Static Map Images For a simple, lightweight solution, use Google’s Static Maps API. This generates a single PNG image without requiring JavaScript or API interactions. <img src=”https://maps.googleapis.com/maps/api/staticmap?center=40.714728,-73.998672&zoom=12&size=600×400&key=YOUR_API_KEY” alt=”Map of New…
Go provides straightforward ways to write to standard output and standard error streams. Understanding when and how to use each is essential for building robust applications, especially in containerized and cloud environments where log separation matters. Using the fmt Package The fmt package is the most common approach for printing to STDOUT: package main import…
The standard way to get your running process’s PID in Go is through the os package: package main import ( “fmt” “os” ) func main() { pid := os.Getpid() fmt.Println(“Current PID:”, pid) } os.Getpid() returns an int representing the current process’s ID. This works across all platforms—Linux, macOS, Windows, and others. Getting the Parent Process…
Go’s os package provides a straightforward function to retrieve the system’s hostname: package main import ( “fmt” “os” ) func main() { hostname, err := os.Hostname() if err != nil { fmt.Println(“Error:”, err) return } fmt.Println(“Hostname:”, hostname) } The os.Hostname() function returns a string containing the hostname and an error value. Always check the error—it…
Retrieving the hostname of the machine running your script is essential for logging, node identification in distributed systems, monitoring, and conditional logic based on where code executes. Bash offers multiple approaches with different tradeoffs. Using the $HOSTNAME Variable The quickest method is the $HOSTNAME environment variable, which Bash sets at shell initialization: echo $HOSTNAME host01…
There are two primary ways to access environment variables in Java: System.getenv() for reading variables and System.getProperty() for reading system properties. They’re different things, so understanding which one you need matters. Reading Environment Variables with System.getenv() System.getenv() retrieves variables set in your shell or container environment: String javaHome = System.getenv(“JAVA_HOME”); System.out.println(“JAVA_HOME: ” + javaHome); To…
Use os.Getenv() to read an environment variable: package main import ( “fmt” “os” ) func main() { val := os.Getenv(“MY_VAR”) fmt.Println(val) } os.Getenv() returns an empty string if the variable doesn’t exist. This means you can’t distinguish between an unset variable and one explicitly set to an empty string. Checking if a variable exists To…
Disabling a user account is a common administrative task. Whether you’re offboarding an employee, removing an unused service account, or securing a compromised account, there are several approaches depending on your requirements. Lock the account with usermod The simplest method is to lock the password hash: sudo usermod -L username This prepends an exclamation mark…
Linux powers most of the cloud infrastructure, supercomputers, and embedded systems globally. The field itself spans kernel development, system administration, performance tuning, networking, and DevOps. Researching systems effectively requires understanding where to look, what tools matter, and how to validate your findings against real-world constraints. Start With the Right Foundation Before diving into specific research,…
VNC (Virtual Network Computing) provides a graphical remote desktop connection to Linux servers. It’s straightforward to set up and useful when you need GUI access to a headless or distant system. Installation On the server side, install a VNC server package. TigerVNC is the most reliable choice across distributions: Debian/Ubuntu: sudo apt install tigervnc-server tigervnc-common…
Modern Universal Windows Platform (UWP) apps store their data in protected user-specific directories. Understanding this structure is essential if you need to back up app settings, troubleshoot issues, or migrate data between systems. Default Data Location UWP app data lives here: C:\Users\<YourUsername>\AppData\Local\Packages\<AppPackageName>\ The <AppPackageName> is a unique identifier assigned by Windows—typically a long alphanumeric string…
iOS SSH clients have matured significantly, and if you need SOCKS proxy support, there are several solid options worth evaluating. The key difference from desktop clients is that iOS imposes sandbox restrictions, so dynamic forwarding requires apps built with that constraint in mind. vSSH vSSH remains one of the more capable SSH clients for iOS,…
You can retrieve detailed metadata about an S3 object using the aws s3api head-object command. This is useful when you need to check object properties, sizes, modification times, or custom metadata without downloading the entire file. Basic Usage The simplest form queries an object’s metadata: aws s3api head-object –bucket test-hkust –key dir2/fileupload/fb0c6353-a90c-4522-9355-7cd16cf756ff.file.txt This returns output…