# Linux, Devops, Scripting, Cats and various things come to my mind
// also on this box: ./practice, ./tools and ./games
A test fails and you have no idea when it broke. This one-liner binary-searches your whole Git history and prints just the hash of the commit that did it.
cat git-find-the-first-bad-commit-with-a-one-liner.md →calltree reads a Bash project and prints which function calls which, in run order, with file:line and the control flow around every call. It follows source includes, draws graphs and GIFs, and ships an MCP server for Claude Code.
cat calltree-static-call-trees-for-bash.md →Every Greek receipt has carried a QR code since November 2023, and it holds the exact date and total. Here is a local tool that reads it from a phone photo, with OCR as the fallback: CLI, REST API and MCP server.
cat reading-greek-receipts-aade-qr-tesseract.md →Run Claude Code like a real engineering team: Opus as architect and senior, Sonnet as mid, Haiku as junior, failed tests climbing the ladder one level at a time, and a five-minute tool that staffs each project.
cat your-ai-needs-an-org-chart.md →By Konstantinos Patronas, kpatronas@gmail.com Every Linux admin has had this conversation: "The backup script works perfectly when I run it." "So why is last night's backup missing?" The script runs fine in…
cat cronman-stop-guessing-why-your-cron-job-didnt-run.md →ttl is a Rust traceroute/mtr replacement with ASN lookup, ECMP path discovery, PMTU detection, trace diffing and a headless Prometheus mode. Here is what it does and when it is worth using over mtr.
cat ttl-faster-mtr-diff-traceroutes-prometheus-metrics.md →One curl line that downloads a file only when the server has a newer one, and why -f, -R and friends are there.
cat curl-keep-a-local-copy-up-to-date.md →In Linux systems, empty directories often accumulate over time — leftovers from removed applications, failed builds, or cleanup scripts…
cat finding-empty-directories-in-linux-with-one-command.md →There’s a moment every Linux user hits sooner or later.
cat copy-a-directory-structure-transfer-nothing.md →When working in the terminal, backing up a file before editing it is a habit that saves time, nerves, and sometimes entire systems. There’s…
cat the-fastest-way-to-back-up-a-file-in-bash-youre-probably-not-using-it.md →
