Tag: Unix

Inspecting Processes with ps

Process selection, custom output, state codes, and portability across Unix systems

Migrating from GNU stow to chezmoi

Why I swapped GNU stow's symlink farm for chezmoi: one command to bootstrap a Mac with Homebrew packages and macOS settings, a small daily sync loop, and agent skills shared between Claude Code and Codex.

Background jobs and inherited file descriptors

Why & backgrounds execution but doesn't stop output from flooding your terminal.

waving goodbye to windows - part 1

Okay, so the title might be a little misleading. I waved goodbye to Windows in favor of Linux (obligatory "I use Arch, btw") some time ago. Given that my personal laptop's hardware was of the 2016 era, I just couldn't run Windows very well any longer. Not that I wanted to anyway. I opted for an Arch-based distribution called CachyOS, set it up once, and didn't fiddle with it at all. It worked great! But as the aging hardware continued to cause problems, it became apparent that it was time to mov...

I kind of like rebasing

Master git rebase for cleaner commit history. Learn interactive rebasing, squashing commits, and rebasing feature branches onto main with practical examples.

Dynamic shell variables

Learn variable indirection in Bash with ${!var} syntax. Build context-aware configs, function dispatch, and dynamic variable name resolution.

Running only a single instance of a process

Prevent multiple script instances with file locking. Use flock in Bash, fcntl in Python, and syscall.Flock in Go for single-instance processes.

SSH saga

Complete SSH setup guide: key pairs, authorized_keys, sshd_config, ssh_config, known_hosts, agent forwarding, and hardening for secure remote access.

Discovering direnv

Automate environment variables per directory with direnv. Load .envrc files on entry, unload on exit. Integrate with Python venv and uv workflow.

Bash namerefs for dynamic variable referencing

Master Bash namerefs with declare -n to create dynamic variable references. Build generic functions for arrays and associative arrays without eval.

Shell redirection syntax soup

Complete guide to Bash redirection. Master stdout, stderr, pipes, tee, file descriptors, and shorthand syntax with practical examples for every case.

Beyond Ctrl-C: The dark corners of Unix signal handling

An introduction to signals: a written version of my talk at RustConf 2023.

HTTP requests via /dev/tcp

Make raw HTTP requests with Bash's /dev/tcp file descriptor. Build health check scripts without curl or wget using TCP socket connections.

The *nix install command

Replace mkdir, cp, and chmod with a single install command. Copy files, create directories, and set permissions in one step with GNU coreutils.

Here-doc headache

Avoid here-doc pitfalls when running remote commands via SSH. Learn variable expansion gotchas and simpler alternatives for deployment scripts.

I kind of like rebasing

Master git rebase for cleaner commit history. Learn interactive rebasing, squashing commits, and rebasing feature branches onto main with practical examples.

sudo embrace

Microsoft’s decision to introduce sudo for Windows is strangely symbolic of how influential UNIX has been even on non-UNIX ecosystems.

Pesky little scripts

Organize custom scripts with comma-prefixed naming. Improve tab completion and eliminate clutter by prefixing script names with special characters.

Remembrance of computers past

I reminisce about the computers of my youth.

Making Way For Wayland

With recent moves made by prominent players, Wayland seems closer than ever to being the ultimate path for Linux users—but, let’s be honest, X11 will never truly die.

Dotfile stewardship for the indolent

Manage dotfiles across devices with GNU Stow. Symlink configuration files from git repo to home directory with simple, idempotent commands.

Using DNS record to share text data

Share data via DNS TXT records using dig and base64 encoding. Learn limitations, security concerns, and practical use cases for DNS tunneling.

Unix-style pipelining with Python's subprocess module

Build Unix-style command pipelines in Python using subprocess.run with stdout piping for efficient process chaining and output capture.

Implementing a simple traceroute clone in Python

Build a traceroute clone in Python using UDP and ICMP sockets to trace network packet routes and measure hop latency with TTL manipulation.

Fixed-time job scheduling with UNIX 'at' command

Schedule one-time commands with UNIX at command. Learn job queuing, remote scheduling via HTTP API, and managing atd/atrun daemons.

Associative arrays in Bash

Learn how to use associative arrays in Bash to create key-value pairs, mimic dictionaries, and manage complex data structures in shell scripts.

Process substitution in Bash

Use process substitution <() to treat command output as files in Bash. Compare directories, process data, and avoid temporary files with this technique.

Dynamic menu with select statement in Bash

Build interactive CLI menus with Bash select statement. Create user-friendly command-line tools with option selection and function dispatch.

Simple terminal text formatting with tput

Format terminal output with tput instead of ANSI codes. Set colors, bold text, underlines, and backgrounds with simple commands in shell scripts.

Tinkering with Unix domain sockets

Build Unix domain socket servers and clients with Python and socat. Access Docker API via UDS, create HTTP servers, and optimize inter-process communication.

Colon command in shell scripts

Use the colon : command as a no-op in Bash scripts for cleaner debug output with -x flag. Alternative to echo for section markers and comments.

Auditing commit messages on GitHub

Automate commit message validation with GitHub Actions. Enforce refs and closes patterns to maintain clean Git history and link commits to issues.

To quote or not to quote

Master shell quoting rules: single vs double quotes, backticks vs $(). Learn when to quote variables to prevent spaces and special characters from breaking commands.

Returning values from a shell function

Understand how return values work in Bash functions. Learn exit codes, status evaluation patterns, and proper boolean returns with true/false commands.

Distil git logs attached to a single file

View git commit history for a single file with git log --follow. Learn to track multiple files with xargs and concatenate their commit logs.

Health check a server with 'nohup $(cmd) &'

Run background health checks in CI with nohup and ampersand. Test server readiness with retry loops and automatic cleanup on success or failure.

Don't add extensions to shell executables

Why executable scripts shouldn't have extensions. Learn GitHub's scripts-to-rule-them-all pattern for language-agnostic project automation.

Use 'command -v' over 'which' to find a program's executable

Replace which with command -v for POSIX-compliant executable lookup. Learn why command -v is the portable alternative for finding program paths.

Use curly braces while pasting shell commands

Prevent shell commands from executing immediately when pasting. Use curly braces to safely paste multi-line commands with hidden newline characters.

Use strict mode while running bash scripts

Enable Bash strict mode with set -euo pipefail to catch errors early. Exit on failures, treat unset variables as errors, and handle pipeline failures properly.

Pipelines and your Unix toolbox

Go and UNIX files

The UNIX operating system

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