Grazfather

Sending Ether Cheat Sheet

TLDR

🥇 Instead of sending Ether, use the withdrawal pattern

🥈 If you really need to send Ether, use a safe wrapper like OpenZeppelin's Address.sendValue(addr, amount)

🥉 If you really need to send Ether without dependencies, use (bool success, ) = addr.call{value: amount}("")

FWIW: I (@rondy) am not the creator of the content shared here, which is an excerpt from Edmond Lau's book. I simply copied and pasted it from another location and saved it as a personal note, before it gained popularity on news.ycombinator.com. Unfortunately, I cannot recall the exact origin of the original source, nor was I able to find the author's name, so I am can't provide the appropriate credits.

Effective Engineer - Notes

By Edmond Lau
Highly Recommended 👍
http://www.theeffectiveengineer.com/

What's an Effective Engineer?

openssl

Install

Install the OpenSSL on Debian based systems

sudo apt-get install openssl

Source: man syscall

Architecture calling conventions

Every architecture has its own way of invoking and passing arguments to the kernel. The details for various architectures are listed in the two tables below.

The first table lists the instruction used to transition to kernel mode, (which might not be the fastest or best way to transition to

NOTE: This is a question I found on StackOverflow which I’ve archived here, because the answer is so effing phenomenal.

Q: How can I make a chain of function decorators in Python?

If you are not into long explanations, see [Paolo Bergantino’s answer][2].

Locate the section for your github remote in the .git/config file. It looks like this:

[remote "origin"]
	fetch = +refs/heads/*:refs/remotes/origin/*
	url = [email protected]:joyent/node.git

Now add the line fetch = +refs/pull/*/head:refs/remotes/origin/pr/* to this section. Obviously, change the github url to match your project's URL. It ends up looking like this:

Fenced code blocks inside ordered and unordered lists

This is a numbered list.
I'm going to include a fenced code block as part of this bullet:
```
Code
More Code
```

	#!/usr/bin/env bb
	; =========================================================================== ;
	; FILE: hack-captive-portal.bb ;
	; USAGE: sudo bb hack-captive-portal.bb ;
	; ;
	; DESCRIPTION: This script helps to pass through the captive portals in ;
	; public Wi-Fi networks. It hijacks IP and MAC from somebody ;
	; who is already connected and authorized on captive portal. ;
	; Tested in Ubuntu 16.04 with different captive portals in ;
	; airports and hotels all over the world. ;

	# GIT heart FZF
	# -------------

	is_in_git_repo() {
	git rev-parse HEAD > /dev/null 2>&1
	}

	fzf-down() {
	fzf --height 50% --min-height 20 --border --bind ctrl-/:toggle-preview "$@"
	}

	#!C:\Python27\python.exe
	# The MIT License (MIT)
	#
	# Copyright © 2014-2016 Santoso Wijaya <[email protected]>
	#
	# 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, sub-license, and/or sell copies of the Software,