dvliman

$: (Dollar Colon) is basically a shorthand version of $LOAD_PATH. $: contains an array of paths that your script will search through when using require.
$0 (Dollar Zero) contains the name of the ruby program being run. This is typically the script name.
$* (Dollar Splat) is basically shorthand for ARGV. $* contains the command line arguments that were passed to the script.
$? (Dollar Question Mark) returns the exit status of the last child process to finish.
$$ (Dollar Dollar) returns the process number of the program currently being ran.
$~ (Dollar Tilde) contains the MatchData from the previous successful pattern match.
$1, $2, $3, $4 etc represent the content of the previous successful pattern match.
$& (Dollar Ampersand) contains the matched string from the previous successful pattern match.
$+ (Dollar Plus) contains the last match from the previous successful pattern match.
$` (Dollar Backtick) contains the string before the actual matched string of the previous successful pattern match.

tsiege

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!






\

luca-m

# ----------------------------------------------------------------------
#	Radare2 
#		(Quick n'dirty) Cheat-Sheet
# 													lucam.ko@gmail.com
# ----------------------------------------------------------------------
# See http://radare.org/doc/html/contents.html for details
# ----------------------------------------------------------------------


# MISC

vasanthk

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

1. Clarify and agree on the scope of the system

• User cases (description of sequences of events that, taken together, lead to a system doing something useful)
  • Who is going to use it?
  • How are they going to use it?

subfuzion

Common Options

-#, --progress-bar Make curl display a simple progress bar instead of the more informational standard meter.

-b, --cookie <name=data> Supply cookie with request. If no =, then specifies the cookie file to use (see -c).

-c, --cookie-jar <file name> File to save response cookies to.

williballenthin

radare2

load without any analysis (file header at offset 0x0): r2 -n /path/to/file

• analyze all: aa
• show sections: iS
• list functions: afl
• list imports: ii
• list entrypoints: ie
• seek to function: s sym.main

P-A-R-U-S

/ Convert IPv4 range into CIDR
func iPv4RangeToCIDRRange(ipStart string, ipEnd string) (cidrs []string, err error) {

	cidr2mask := []uint32{
		0x00000000, 0x80000000, 0xC0000000,
		0xE0000000, 0xF0000000, 0xF8000000,
		0xFC000000, 0xFE000000, 0xFF000000,
		0xFF800000, 0xFFC00000, 0xFFE00000,
		0xFFF00000, 0xFFF80000, 0xFFFC0000,
		0xFFFE0000, 0xFFFF0000, 0xFFFF8000,

AndrewBestbier

provider "aws" {
  version = "~> 2.0"
  region  = "eu-west-2"
}

# Providing a reference to our default VPC
resource "aws_default_vpc" "default_vpc" {
}

# Providing a reference to our default subnets

josemarimanio

Installing pyenv on macOS for Zsh using Homebrew

Published May-13-2020

• Installation
• Basic Usage
• Virtualenv

yassineaboukir

#!/bin/bash

# Written by Frans Rosén (twitter.com/fransrosen)
_debug="$2" #turn on debug
_timeout="20"
#you need a valid key, since the errors happens after it validates that the key exist. we do not need the secret key, only access key
_aws_key="AKIA..."
H_ACCEPT="accept-language: en-US,en;q=0.9,sv;q=0.8,zh-TW;q=0.7,zh;q=0.6,fi;q=0.5,it;q=0.4,de;q=0.3"
H_AGENT="user-agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.146 Safari/537.36"