debian.tips

curl

2026-07-05T00:00:00.000Z

80+ tested curl examples: GET/POST/PUT/DELETE, headers, auth, cookies, uploads, redirects, retries, and scripting.

find

2026-07-05T00:00:00.000Z

Tested find examples: name and type filters, size and age, permissions, -exec vs -delete, and safe scripting patterns.

grep

2026-07-05T00:00:00.000Z

80+ tested grep examples: recursive search, regex flavours, context lines, counting, scripting, and more.

sed

2026-07-05T00:00:00.000Z

Tested sed examples: substitution, addressing, deletion, in-place editing, and multi-command scripts.

tar

2026-07-05T00:00:00.000Z

Tested tar examples: create, list, and extract archives, choose a compression format, and verify integrity.

Exit codes and error handling

2026-07-05T00:00:00.000Z

How $?, PIPESTATUS, set -e, and pipefail combine to tell a script what actually succeeded or failed, and where each one falls short.

File permissions explained

2026-07-05T00:00:00.000Z

The rwx/owner-group-other model, numeric vs symbolic chmod, umask, and why setuid/setgid on directories behave differently than you'd expect.

Pipes and redirection

2026-07-05T00:00:00.000Z

How | connects commands together, and how >, >>, 2>&1, and <() route data to and from files, other commands, and each other.

Your first script

2026-07-05T00:00:00.000Z

Write, mark executable, and run your first bash script, plus what the shebang line and PATH lookup actually do.

Variables and quoting

2026-07-05T00:00:00.000Z

Why unquoted variables break bash scripts, when to use double vs single quotes, and how glob characters make it worse.

Conditionals and test

2026-07-05T00:00:00.000Z

The difference between [ and [[ in bash, why unquoted variables crash [ but not [[, and pattern matching with case.

Bulk rename a batch of files

2026-07-05T00:00:00.000Z

Rename many files at once with a plain bash loop, safely handling spaces and previewing changes before committing.

Copy files between two machines over SSH

2026-07-05T00:00:00.000Z

Transfer a file or directory tree between two machines with scp or rsync, and resume an interrupted transfer without starting over.

Find the largest files on disk

2026-07-05T00:00:00.000Z

Locate what's actually eating your disk space, from a whole filesystem down to one directory.

Find and kill whatever is using a port

2026-07-05T00:00:00.000Z

Identify the process bound to a TCP port that's refusing to let a service start, then stop it.

Monitor a log file in real time

2026-07-05T00:00:00.000Z

Watch a log file as new lines are written, filter it live, and keep watching across log rotation.

APT essentials

2026-07-05T00:00:00.000Z

The apt, apt-get, and dpkg commands that cover almost everything you'll do to manage packages on Debian, and how remove differs from purge.