Nicolas Mattia nmattia

Nix Flake MVP

Goals

To provide Nix repositories with an easy and standard way to reference other Nix repositories.
To allow such references to be queried and updated automatically.
To provide a replacement for nix-channel, NIX_PATH and Hydra

Custom format for displaying bytes as kb, mb, gb or tb.

Response to a few places on the internet: https://productforums.google.com/forum/#!topic/docs/x_T_N-yRUYg And here: https://stackoverflow.com/questions/1533811/how-can-i-format-bytes-a-cell-in-excel-as-kb-mb-gb-etc

Here is one that I have been using:

[<1000000]0.00," KB";[<1000000000]0.00,," MB";0.00,,," GB"

Nixpkgs pinning example

This is an example of how to pin the version of nixpkgs in a package repo. The goal is to improve reproducibility, make sure all the developers use the same version of nixpkgs and also allow to share binary caches.

Usage

Put all these files in a nixpkgs folder and then in other derivations, instead of import <nixpkgs> {} use import ./path/to/nixpkgs {}

Keeping nixpkgs up to date

Reddit discussion.

Disclaimer 1: Type classes are great but they are not the right tool for every job. Enjoy some balance and balance to your balance.

Disclaimer 2: I should tidy this up but probably won’t.

Disclaimer 3: Yeah called it, better to be realistic.

Type classes are a language of their own, this is an attempt to document features and give a name to them.

ANNOUNCEMENT

I have moved this over to the Tech Interview Cheat Sheet Repo and has been expanded and even has code challenges you can run and practice against!

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PROCESS STATE CODES

Here are the different values that the s, stat and state output specifiers (header "STAT" or "S") will display to describe the state of a process.

CODE	Meaning
D	Uninterruptible sleep (usually IO)
R	Running or runnable (on run queue)
S	Interruptible sleep (waiting for an event to complete)
T	Stopped, either by a job control signal or because it is being traced.
W	paging (not valid since the 2.6.xx kernel)

Each of these commands will run an ad hoc http static server in your current (or specified) directory, available at http://localhost:8000. Use this power wisely.

Discussion on reddit.

Python 2.x

$ python -m SimpleHTTPServer 8000

	{-# LANGUAGE MagicHash, UnboxedTuples #-}
	module Main(main) where

	import GHC.Exts ( addrToAny# )
	import GHC.Ptr ( Ptr(..) )
	import System.Info ( os, arch )
	import Encoding
	import ObjLink

	main :: IO ()

	{-
	Copyright (C) 2014 András Kovács

	Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

	The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOF

	# Ways to execute a shell script in Ruby
	# Example Script - Joseph Pecoraro

	cmd = "echo 'hi'" # Sample string that can be used

	# 1. Kernel#` - commonly called backticks - `cmd`
	# This is like many other languages, including bash, PHP, and Perl
	# Synchronous (blocking)
	# Returns the output of the shell command
	# Docs: http://ruby-doc.org/core/classes/Kernel.html#M001111