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@fogus
fogus / 0 - UNIX Fifth Edition
Created July 20, 2011 00:15
UNIX V5, OpenBSD, Plan 9, FreeBSD, and GNU coreutils implementations of echo.c
main(argc, argv)
int argc;
char *argv[];
{
int i;
argc--;
for(i=1; i<=argc; i++)
printf("%s%c", argv[i], i==argc? '\n': ' ');
}
@ryancdotorg
ryancdotorg / cryptroot.patch
Created December 25, 2011 02:43
patch to the cryptroot hook that comes with cryptsetup on debian/ubuntu
--- cryptroot.dist 2011-12-24 16:50:11.000000000 -0800
+++ cryptroot 2011-12-24 17:07:33.000000000 -0800
@@ -211,7 +211,7 @@
fi
# We have all the basic options, let's go trough them
- OPTIONS="target=$target,source=$source,key=$key"
+ OPTIONS="target=$target,source=$source"
local IFS=", "
unset HASH_FOUND
@austinmarton
austinmarton / sendRawEth.c
Created February 27, 2012 08:40
Send a raw Ethernet frame in Linux
/*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*/
#include <arpa/inet.h>
#include <linux/if_packet.h>
#include <stdio.h>
@jboner
jboner / latency.txt
Last active April 25, 2025 07:06
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
@hellerbarde
hellerbarde / latency.markdown
Created May 31, 2012 13:16 — forked from jboner/latency.txt
Latency numbers every programmer should know

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

@aspyct
aspyct / signal.c
Last active February 19, 2024 11:24
Unix signal handling example in C, SIGINT, SIGALRM, SIGHUP...
/**
* More info?
* [email protected]
* http://aspyct.org
*
* Hope it helps :)
*/
#include <stdio.h>
#include <stdlib.h>
@skyscribe
skyscribe / .gdbinit
Created October 30, 2012 03:04
GDB init file to print STL containers and data members
#
# STL GDB evaluators/views/utilities - 1.03
#
# The new GDB commands:
# are entirely non instrumental
# do not depend on any "inline"(s) - e.g. size(), [], etc
# are extremely tolerant to debugger settings
#
# This file should be "included" in .gdbinit as following:
# source stl-views.gdb or just paste it into your .gdbinit file
@naholyr
naholyr / _service.md
Created December 13, 2012 09:39
Sample /etc/init.d script

Sample service script for debianoids

Look at LSB init scripts for more information.

Usage

Copy to /etc/init.d:

# replace "$YOUR_SERVICE_NAME" with your service's name (whenever it's not enough obvious)
@vvuk
vvuk / install-ubuntu
Last active March 1, 2018 06:58
Install Ubuntu 13.04 on Chromebook
#!/bin/bash
#
# Version 0.2, for Ubuntu 13.04 (Raring)
#
# Based on Chrubuntu 34v87 script
BASE_IMAGE_FILE="http://mirrors.med.harvard.edu/ubuntu-cdimage/lubuntu/releases/13.04/release/lubuntu-13.04-preinstalled-desktop-armhf+ac100.tar.gz"
# fw_type will always be developer for Mario.
# Alex and ZGB need the developer BIOS installed though.
@pezz
pezz / crypto-pi-root.md
Last active December 17, 2020 15:40
Archlinux ARM encrypted root

Intro

Just some FYI, to get started:

  • I'm using a 16 GB Sandisk SD card.
  • I have a model B Pi, 512 MB RAM (not really relevant, thought I'd mention it).
  • Monitor and keyboard connected to the Pi itself, for now.
  • Network working, internet access.