An example implementation of the self-pipe trick in Ruby, by Paul Annesley (found here: http://pastebin.com/1SZprwZm)
Further reading:
man 2 select
| A Tree is just a restricted form of a Graph. | |
| Trees have direction (parent / child relationships) and don't contain cycles. | |
| It has only one path between any two vertices | |
| They fit with in the category of Directed Acyclic Graphs (or a DAG). | |
| So Trees are DAGs with the restriction that a child can only have one parent. | |
| Directed Acyclic Graphs is a kind of directed graph that have no cycles. |
| { | |
| description = "Flutter on NixOS."; | |
| inputs = { | |
| # We disable this to use indirect nixpkgs from android-nixpkgs | |
| # nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable"; | |
| flake-utils.url = "github:numtide/flake-utils"; | |
| android-nixpkgs.url = "github:tadfisher/android-nixpkgs"; | |
| }; |
| #version: "3" | |
| # More info at https://github.com/pi-hole/docker-pi-hole/ and https://docs.pi-hole.net/ | |
| services: | |
| pihole: | |
| container_name: pihole | |
| image: pihole/pihole:latest | |
| network_mode: "host" | |
| # For DHCP it is recommended to remove these ports and instead add: network_mode: "host" | |
| environment: |
| xset r rate 250 60 | |
| setxkbmap -option caps:escape | |
| xbacklight -set 10 | |
| # paired with `Xft.dpi: 144` | |
| export GDK_DPI_SCALE=1.4 | |
| if [ -z "${XDG_RUNTIME_DIR}" ]; then | |
| export XDG_RUNTIME_DIR=/tmp/${USER}-runtime-dir | |
| if [ ! -d "${XDG_RUNTIME_DIR}" ]; then |
| import QRgen | |
| import QRgen/renderer | |
| import pkg/[pixie] | |
| import os | |
| # Create a new QR code | |
| let qr = newQR("https://github.com/aruZeta/QRgen", ecLevel=qrECH) | |
| # Generate the QR code |
| CREATE TABLE audit_log ( | |
| id SERIAL PRIMARY KEY, | |
| schema_name TEXT NOT NULL, | |
| table_name TEXT NOT NULL, | |
| operation CHAR(1) NOT NULL, | |
| new_data JSONB, | |
| old_data JSONB, | |
| changed_at TIMESTAMP NOT NULL, | |
| changed_by TEXT | |
| ); |
| { lib, ... }: | |
| rec { | |
| # Compute the fixed point of the given function `f`, which is usually an | |
| # attribute set that expects its final, non-recursive representation as an | |
| # argument: | |
| # | |
| # f = self: { foo = "foo"; bar = "bar"; foobar = self.foo + self.bar; } | |
| # | |
| # Nix evaluates this recursion until all references to `self` have been | |
| # resolved. At that point, the final result is returned and `f x = x` holds: |
| # args: | |
| # $1. server_name assuming SNI (eg. sub.domain.com) | |
| # $2. endpoint (eg. IP_ADDR:8443 or sub.domain.com:443) | |
| function tlscert-check() { | |
| echo | \ | |
| openssl s_client -servername $1 -connect $2 2>/dev/null | \ | |
| openssl x509 -text -noout | |
| } | |
| function tlscert-list-kube() { |