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Ich konnte online kein einfaches Diagramm zum anschliessen finden, also habe ich schnell eins gezeichnet. Eine Tasterschaltung mit einer Lampe, einem Eltako S91-100 und beliebig vielen Tastern sieht wie folgt aus:

Der Eltako schaltet dann die Lampe bei jedem Tastimpuls (Tastendruck) zwischen dem ein- und dem ausgeschalteten Zustand hin und her.

Disclaimer: Ich bin keine Elektrikfachkraft und möchte hier niemanden auf dumme Ideen bringen. Strom im Haushalt ist gefährlich und kann bei mangelhafter Verdrahtung zu Bränden führen. Ich übernehme keine Verantwortung. Im Zweifel solltest du dir einen Elektriker organisieren.

The problem: Automations sometimes need to store the state of several entities at once and then restore all of them at a later point in time. An example of this is:

When I open my balcony door at night, I want the lights in my room to turn off. when I close the balcony door, I want the lights to be restored to the exact same state they were previously.

Sometimes you need to upgrade a server, but you also need to prevent apt from upgrading a specific package (eg. your node.js version). Many package-managers support this scenario under names like “version pinning” or “package holding”. This is how you prevent apt from upgrading a single package:

Dependencies

• Ubuntu 12.04 or newer
• apt

Pin a package to prevent it from being upgraded

sudo apt-mark hold $PACKAGE_NAME

Unpin a package to allow it being upgraded again

sudo apt-mark unhold $PACKAGE_NAME

Dependencies

• node.js and npm (obviously)
• jq
• xargs (may needs to be installed manually)

Update all dependencies to their latest version:

cat package.json | \
	jq -r '.dependencies | keys[]' | \
	xargs -I {} npm i -S {}@latest

Update all devDependencies to their latest version:

cat package.json | \
	jq -r '.devDependencies | keys[]' | \
	xargs -I {} npm i -S {}@latest

Alias the commands for easier reuse

To reuse the commands without having to remember them just put them into your .bashrc or .bash_profile file. Add this to the end of your bash configuration and restart your shell afterwards:

Today I learned how to count git commits in a repository by author name:

git shortlog -s -n --all --no-merges

Explanation:

• git shortlog: summarize git log output
• -s: only count commits
• -n: sort by commit number instead of author name
• --all: count commits in all branches
• --no-merges: exclude merge commits

If you want to include author emails add -e

Sources:

• https://git-scm.com/docs/git-shortlog
• https://git-scm.com/docs/git-log