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@drbrain
drbrain / nightmares.rb
Last active July 25, 2017 17:40
A method that has a default argument that defines a method that contains a here-document
def a l = def b; <<-NIGHTMARES; end; puts send l; end
😱😱😱
NIGHTMARES
a
@dergachev
dergachev / squid-deb-proxy_on_docker.md
Last active May 25, 2023 03:55
Caching debian package installation with docker

TLDR: I now add the following snippet to all my Dockerfiles:

# If host is running squid-deb-proxy on port 8000, populate /etc/apt/apt.conf.d/30proxy
# By default, squid-deb-proxy 403s unknown sources, so apt shouldn't proxy ppa.launchpad.net
RUN route -n | awk '/^0.0.0.0/ {print $2}' > /tmp/host_ip.txt
RUN echo "HEAD /" | nc `cat /tmp/host_ip.txt` 8000 | grep squid-deb-proxy \
  && (echo "Acquire::http::Proxy \"http://$(cat /tmp/host_ip.txt):8000\";" > /etc/apt/apt.conf.d/30proxy) \
  && (echo "Acquire::http::Proxy::ppa.launchpad.net DIRECT;" >> /etc/apt/apt.conf.d/30proxy) \
  || echo "No squid-deb-proxy detected on docker host"
@wsargent
wsargent / docker_cheat.md
Last active August 31, 2023 12:10
Docker cheat sheet
@piscisaureus
piscisaureus / pr.md
Created August 13, 2012 16:12
Checkout github pull requests locally

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 = git@github.com: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:

@jboner
jboner / latency.txt
Last active May 15, 2024 13:22
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
@erikh
erikh / hack.sh
Created March 31, 2012 07:02 — forked from DAddYE/hack.sh
OSX For Hackers
#!/usr/bin/env sh
##
# This is script with usefull tips taken from:
# https://github.com/mathiasbynens/dotfiles/blob/master/.osx
#
# install it:
# curl -sL https://raw.github.com/gist/2108403/hack.sh | sh
#

Fibur

Fibur is a library that allows concurrency during Ruby I/O operations without needing to make use of callback systems. Traditionally in Ruby, to achieve concurrency during blocking I/O operations, programmers would make use of Fibers and callbacks. Fibur eliminates the need for wrapping your I/O calls with Fibers and a callback. It allows you to write your blocking I/O calls the way you normally would, and still have concurrent execution during those I/O calls.

Example

Say you have a method that fetches data from a network resource:

@kevsmith
kevsmith / gist:1473809
Created December 13, 2011 20:44
deadcode detecting escript
#!/usr/bin/env escript
%% -*- erlang -*-
%% Find unused exports in a given module
%% Example: deadcode mod_foo deps/foo/ebin deps/bar/ebin
%% Assumes this script is in a file named deadcode
main([Module0|Dirs]) ->
Module = list_to_atom(Module0),
{ok, _Pid} = xref:start(foo),
@vmg
vmg / sparc.c
Created November 15, 2011 23:03
Sparks in C
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <float.h>
int main
(int argc
,char *ac []){int i, count = argc - 1;
double * dvalues=malloc(01- 01+count*
sizeof(double)+1); double mi=DBL_MAX,ran=.0,ma =DBL_MIN,mo;for(i= 00; argc>1
&&i<count;i=i+8-7) {double val = atof(ac[i+1]) ;if(23&&val<mi)mi= val;if(val
@mikeyk
mikeyk / gist:1329319
Created October 31, 2011 22:56
Testing storage of millions of keys in Redis
#! /usr/bin/env python
import redis
import random
import pylibmc
import sys
r = redis.Redis(host = 'localhost', port = 6389)
mc = pylibmc.Client(['localhost:11222'])