Different projects and languages have different indentation conventions. Rather than manually adjusting settings each time you switch contexts, you can define custom commands in Vim to toggle between common tab widths quickly. Using Custom Functions and Mappings Add these functions to your ~/.vimrc: function SetTab2() set shiftwidth=2 set tabstop=2 set softtabstop=2 echo “Set tab to…
If you already have PHP and nginx running on Rocky Linux 9 and need to add or update glibc, glibc-common, and GD libraries independently, you can do so safely without disrupting your existing installation. Understanding the dependencies glibc: The GNU C Library — the core runtime library for nearly all C programs on Linux glibc-common:…
The “invalid syntax, continuing…” warning from sysctl typically means your /etc/sysctl.conf file has a malformed line that the parser can’t understand. Here’s how to diagnose and fix it. Identifying the Problem When you run sysctl -p to load configuration from /etc/sysctl.conf, any syntax error will be printed with a line number: sysctl -p warning: /etc/sysctl.conf(44):…
Error handling is fundamental to Go development. Often you’ll need to convert an error to a string for logging, displaying to users, or including in API responses. Go provides several straightforward approaches. Using the Error() Method Every error in Go implements the error interface, which has a single method: Error() string. The simplest conversion is…
Sending output to stderr keeps error messages separate from normal program output, making it easier to redirect and filter logs in shell scripts and pipelines. Basic Approach with fmt The simplest method uses fmt.Fprintln() with os.Stderr: package main import ( “fmt” “os” ) func main() { fmt.Fprintln(os.Stderr, “This is an error message”) } This writes…
In Go, a string is a read-only slice of bytes, while a rune is an alias for int32 representing a Unicode code point. Understanding this distinction is essential when you need to work with individual characters, especially in multilingual text. Basic Conversion The simplest approach is direct type conversion: s := “Hello, 世界” runes :=…
Processing files line by line is a common task in Go. Here are the practical approaches, from simplest to most flexible. Using bufio.Scanner The most straightforward method uses bufio.Scanner, which handles line splitting automatically: package main import ( “bufio” “fmt” “log” “os” ) func main() { file, err := os.Open(“input.txt”) if err != nil {…
The traditional Node.js approach uses require(). Create a module that exports functions, then import them where needed. exporting functions (math.js): function add(a, b) { return a + b; } function subtract(a, b) { return a – b; } module.exports = { add, subtract }; importing in another file (app.js): const { add, subtract } =…
The kernel log buffer (dmesg) outputs timestamps in seconds since boot by default, making it difficult to correlate events with wall-clock time or other system logs. Here’s how to convert them to human-readable format. Using journalctl Instead of dmesg The modern approach is to use journalctl, which handles timestamp formatting automatically: journalctl -b This shows…
When you’re working in a Makefile, you often need to reference files relative to where the Makefile itself is located. This is especially useful for multi-directory projects or when your build system needs to know its own location. The Solution Make provides the MAKEFILE_LIST variable, which contains the names of all makefiles that have been…
Grep handles tab characters in a few different ways depending on your needs. Here’s what actually works. Using \t with extended regex The most straightforward approach uses grep’s extended regular expressions (-E flag): grep -E ‘\t’ filename.txt This matches any line containing a literal tab character. The \t escape sequence is interpreted as a tab…
Many Go functions accept an io.Reader interface. To pass a string to these functions, use strings.NewReader, which wraps the string without copying it—the data is read directly from the original string. Basic Usage import “strings” reader := strings.NewReader(“Hello, World!”) This creates an io.Reader that can be passed to any function expecting that interface. The reader…
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…
The Windows Start Menu pulls shortcuts from two key directories. Understanding where these files live is essential if you’re managing deployments, troubleshooting pinned apps, or automating setups. User-Specific Start Menu User-scoped shortcuts go here: C:\Users\<YourUsername>\AppData\Roaming\Microsoft\Windows\Start Menu\Programs This directory contains all the Start Menu shortcuts specific to your user account. Shortcuts you create or applications install…
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,…
SSH key management becomes critical when you’re handling multiple identities across different hosts. By default, ssh tries keys in a specific order, but you can explicitly configure which key to use for particular hosts through the SSH config file. Using ~/.ssh/config The cleanest approach is to define host-specific key configurations in ~/.ssh/config. This file lets…
Tethering your iPhone to your computer’s internet connection via USB is useful when you need a stable, low-power connection or want to avoid wireless overhead. This guide covers the practical setup on Windows and how to configure your iPhone to use your PC’s internet. Windows USB Tethering Setup On Windows 10/11: Install iTunes or Apple…
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…
Bash maintains a set of built-in options that control script behavior. You disable them using set +o followed by the option name, or with short flags like set +x. The Basic Syntax set +o option-name Or using short flag notation: set +x The + sign disables an option; – enables it. This works for both…
To check whether a function exists in Bash, use the type builtin with the -t option. This returns a string identifying what the name is: alias, keyword, function, builtin, or file. Basic Check The simplest approach: if [[ $(type -t f1) == “function” ]]; then echo “f1 is defined as a function” fi This works…