There are several ways to retrieve the hostname on a Linux system from Python. The choice depends on your use case and whether you need the simple hostname or the fully qualified domain name (FQDN). Using socket.gethostname() The simplest approach uses the socket module from the standard library: import socket hostname = socket.gethostname() print(hostname) This…
The most straightforward way to read an environment variable in Python is with os.getenv(): import os api_key = os.getenv(‘API_KEY’) print(api_key) If the variable doesn’t exist, getenv() returns None. You can provide a default value as a fallback: debug_mode = os.getenv(‘DEBUG’, ‘False’) port = os.getenv(‘PORT’, ‘8000’) For variables that must exist, use os.environ[] instead. This raises…
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…
There are several ways to get a file’s size without importing the os module. Each approach has different use cases depending on your needs. Using pathlib.Path The most straightforward approach uses pathlib, which is part of the standard library: from pathlib import Path file_path = Path(‘example.txt’) size = file_path.stat().st_size print(f”File size: {size} bytes”) This is…
The most straightforward approach is using ioutil.ReadFile() or the modern os.ReadFile() function, both of which return the entire file content as a byte slice that you can convert to a string. package main import ( “fmt” “os” ) func main() { content, err := os.ReadFile(“example.txt”) if err != nil { fmt.Println(“Error reading file:”, err) return…
EncFS provides an encrypted filesystem in user space — files are encrypted on the fly and stored in an existing directory. It’s lighter than LUKS and doesn’t require root access or dedicated partitions. Here’s how to set it up on CentOS 6. Install EncFS EncFS is available from the EPEL repository: # Enable EPEL sudo…
The most straightforward approach is os.access(), which tests whether the process has the requested access to a file: import os file_path = “example.txt” # Check if file is readable if os.access(file_path, os.R_OK): print(“File is readable”) # Check if file is writable if os.access(file_path, os.W_OK): print(“File is writable”) # Check if file exists and is executable…
Configuring multiple static IP addresses on a Xen VM is useful for hosting multiple services, SSL certificates, or failover scenarios. The approach depends on your underlying Linux distribution and whether you’re using traditional network configuration or modern network managers. Using ip Command for Immediate Changes The quickest way to add a secondary IP is with…
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:…
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…
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…
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 {…
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…
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…
Python provides several ways to check if files or directories exist, with different trade-offs depending on your use case. Using pathlib (recommended) The modern approach uses pathlib.Path, which is cleaner and more object-oriented: from pathlib import Path path = Path(‘/etc/passwd’) # Check if path exists (file or directory) if path.exists(): print(“Path exists”) # Check if…
When Linux fails to boot with the error message “sulogin: can not open password database” despite /etc/passwd and /etc/shadow appearing intact, SELinux is often the culprit. The files exist and have correct content, but SELinux context labels are missing or corrupted, preventing the login process from reading them. Diagnose the Problem Boot into the initramfs…
Webpages often render differently when printed than on screen. Firefox’s developer tools make it straightforward to preview and debug print stylesheets without wasting paper. Using the CSS Media Type Emulator The fastest way to test print styles in Firefox: Open DevTools with F12 Click the Inspector tab (usually open by default) Look for the “Emulate…
Writing a master thesis means protecting years of work. You need to handle three core concerns: preventing data loss from hardware failure or malware, ensuring 24/7 access to your work, and keeping it private until publication. The solution is version control with remote backup. Git provides local history and recovery, while a private remote repository…
Getting a file’s size is a common task in Python. There are several ways to do it, depending on what you need and how much detail you want about the file. Using os.path.getsize() The simplest approach is os.path.getsize(): import os file_path = ‘/path/to/your/file.txt’ size_bytes = os.path.getsize(file_path) print(f”File size: {size_bytes} bytes”) This returns the size in…
When you need to traverse a directory tree in Python, you have several options. The choice depends on whether you want recursive traversal, how you want to handle the results, and your Python version. Using os.walk() The os.walk() function is the classic approach for recursively iterating through directories. It yields tuples of (dirpath, dirnames, filenames)…