mrietveld

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

mrietveld

StackExchange (Apple): Rebuild partition table on external HDD - not writable
StackExchange (Apple): Partition map rebuild

Handy commands (as root, of course)

• diskutil unmountDisk /dev/disk2
• Remove the EFI partition:
  • gpt remove -i 1 /dev/disk2
• Destroy and recreate an empt partition table:
• sudo gpt destroy /dev/disk2

mrietveld

#!/usr/bin/perl 

use Cwd;
use Time::Local;
use Getopt::Std;
use POSIX 'strftime';

our($opt_h, $opt_p, $opt_r, $opt_s, $opt_u, $opt_v, $opt_O, $opt_P, $opt_U, $opt_S, $opt_a );
getopts('hpr:s:uvO:U:P:a');

mrietveld

Building a scheme first and then crafting a cryptographic model in which the scheme can be proved secure can result in schemes whose security breaks down in practice.

-- Breaking Web Applications Built On Top of Encrypted Data by Grubbs, P; Mcpherson, R; Naveed, M [2016]

mrietveld

What I currently use

Updated: 2021-10-06

OS

• OS X
  • HomeBrew: package manager
    • with Cask
• iTerm2

mrietveld

#!/usr/bin/perl

# This file takes 2 arguments when run: 
# -p <POMFILE>
# -v <VERSION>
#
# The <POMFILE> argument is the path to a pom.xml file whose version should be changed
# The <VERSION> argument is the new version that should replaced the existing version
#

mrietveld

#!/usr/bin/perl 

use Cwd;
use Time::Local;
use Getopt::Std;

getopts('s:f:a:h');

if( $opt_h ) { 
  die( "skip:  -s\n"