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@zhao-ji
zhao-ji / JapaneseRegex.js
Created April 22, 2020 03:11 — forked from ryanmcgrath/JapaneseRegex.js
Regex to test for presence of Japanese characters
// REFERENCE UNICODE TABLES:
// http://www.rikai.com/library/kanjitables/kanji_codes.unicode.shtml
// http://www.tamasoft.co.jp/en/general-info/unicode.html
//
// TEST EDITOR:
// http://www.gethifi.com/tools/regex
//
// UNICODE RANGE : DESCRIPTION
//
// 3000-303F : punctuation
@zhao-ji
zhao-ji / tun-ping-linux.py
Created July 28, 2016 09:30 — forked from glacjay/tun-ping-linux.py
Reading/writing Linux's TUN/TAP device using Python.
import fcntl
import os
import struct
import subprocess
# Some constants used to ioctl the device file. I got them by a simple C
# program.
TUNSETIFF = 0x400454ca
TUNSETOWNER = TUNSETIFF + 2
@zhao-ji
zhao-ji / start-stop-example.sh
Created July 26, 2016 09:02 — forked from alobato/start-stop-example.sh
start-stop-example
#!/bin/sh
# Quick start-stop-daemon example, derived from Debian /etc/init.d/ssh
set -e
# Must be a valid filename
NAME=foo
PIDFILE=/var/run/$NAME.pid
#This is the command to be run, give the full pathname
DAEMON=/usr/local/bin/bar

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