Craig M craig-m-unsw

second ssh

run a second copy of sshd and enable root login without pam or password

cat << EOF > /etc/ssh/authorized_keys2
ssh-rsa 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 root@host
EOF

Directory structure for JavaScript/Node Projects

While the following structure is not an absolute requirement or enforced by the tools, it is a recommendation based on what the JavaScript and in particular Node community at large have been following by convention.

Beyond a suggested structure, no tooling recommendations, or sub-module structure is outlined here.

Directories

lib/ is intended for code that can run as-is
src/ is intended for code that needs to be manipulated before it can be used

Test VM

Use the chef bento project to build the Vagrant boxes.

Tested November 2023 on:

Ubuntu 22.04.3 LTS (Jammy Jellyfish)
Virtual Box 7.0.12 r159484 (Qt5.15.3)
Packer 1.9.4
Vagrant 2.4.0

These are some notes from reading Ian Lance Taylor's 20-part essay on linkers. Prettified version on gist.io.

I'm not going to describe the basics of what a linker does because I know already. I talk a little about linkers in How to call Rust from assembly, and I found this Beginner's guide to linkers pretty helpful. Parts [1] and [2] of the essay also discuss "what's a linker?".

How to read an executable

I used to think that executables were totally impenetrable. I'd compile a C program, and then that was it! I had a Magical Binary Executable that I could no longer read.

It is not so! Executable file formats are regular file formats that you can understand. I'll explain some simple tools to start! We'll working on Linux, with ELF binaries. (binaries are kind of the definition of platform-specific, so this is all platform-specific.)

Let's write a simple C program, hello.c:

#include

cross platform pwsh core

PowerShell is a task automation and configuration management program from Microsoft, consisting of a command-line shell and the associated scripting language. Initially a Windows component only, known as Windows PowerShell, it was made open-source and cross-platform on 18 August 2016 with the introduction of PowerShell Core

source: Wikipedia. PowerShell 7.2 runs on:

Windows (installed by default from Win8 onwards)
MacOS

	class Software {
	[string]$Name
	[string]$Id
	[string]$Version
	[string]$AvailableVersion
	}

	$upgradeResult = winget upgrade \| Out-String

	$lines = $upgradeResult.Split([Environment]::NewLine)

	<#
	name:
	WinGet-setup-apps.ps1
	desc:
	Install Winget + packages on Windows 11
	Based on these gists:
	- https://gist.github.com/crutkas/6c2096eae387e544bd05cde246f23901
	- https://gist.github.com/Codebytes/29bf18015f6e93fca9421df73c6e512c
	#>

	## Commonly used PSADT env variables
	$envCommonDesktop # C:\Users\Public\Desktop
	$envCommonStartMenuPrograms # C:\ProgramData\Microsoft\Windows\Start Menu\Programs
	$envProgramFiles # C:\Program Files
	$envProgramFilesX86 # C:\Program Files (x86)
	$envProgramData # c:\ProgramData
	$envUserDesktop # c:\Users\{user currently logged in}\Desktop
	$envUserStartMenuPrograms # c:\Users\{user currently logged in}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs
	$envSystemDrive # c:
	$envWinDir # c:\windows

	#!/usr/bin/env python3

	'''
	to run age-calc.py from docker:

	docker run -it --rm --name age-calc --mount type=bind,source="$(pwd)/age-calc.py",target=/app/age-calc.py \
	--network none python:3 python /app/age-calc.py 20/10/2010
	'''

	import sys