git
Full git workflow — setup, staging, commits, branches, remotes, history, undo, and advanced operations.
commitbranchremoterebaseundo
shell scripting
Bash variables, loops, functions, arrays, I/O redirection, plus grep, sed, and awk for text processing.
bashgrepsedawkloops
powershell
Variables, control flow, functions, the object pipeline, file/process cmdlets, modules, and remoting.
cmdletspipelineobjectsremotingmodules
docker
Images, containers, exec, logs, networking, volumes, docker compose, and system cleanup commands.
imagescontainerscomposevolumesnetwork
python
General scripting reference — types, strings, lists, dicts, control flow, functions, classes, file I/O, and builtins.
scriptinglistsclassesfilesbuiltins
structured text
IEC 61131-3 ST for PLC programming — data types, variables, control flow, function blocks, timers, and counters.
IEC 61131PLCtimerscountersFB
real-time linux
PREEMPT_RT kernel, cyclictest, chrt/taskset, IRQ isolation, memory locking, ftrace, and rtla for deterministic systems.
schedulinglatencyirqftracePREEMPT_RT
modbus & opc ua
Function codes, register addressing, RTU/TCP framing, and OPC UA address-space, services, and security basics.
function codesregistersnodeidsubscriptionssecurity
systemd
Service control, unit file anatomy, journalctl log queries, timers, targets, and boot troubleshooting.
systemctljournalctltimersunit filestargets
html & css
Semantic markup, form validation, selectors, flexbox, grid layout, and custom properties (CSS variables).
semanticflexboxgridselectorscss vars
http & https
Methods, status codes, headers, TLS/HTTPS fundamentals, caching, and CORS.
status codesheaderstlscachingcors
sql
Queries, joins, aggregation, subqueries/CTEs, DDL, constraints, indexes, and transactions.
joinsaggregationsubqueriesconstraintstransactions
regex
Anchors, character classes, quantifiers, groups, lookaround, flags, and common real-world patterns.
anchorsquantifiersgroupslookaroundflags