Trevor Max zhao-ji

## gist:d22d71d336f82149b67f
private const double EARTH_RADIUS = 6378.137;
private static double rad(double d)
{
   return d * Math.PI / 180.0;
}
public static double GetDistance(double lat1, double lng1, double lat2, double lng2)
{
   double radLat1 = rad(lat1);
   double radLat2 = rad(lat2);
   double a = radLat1 - radLat2;

## latency.markdown

      
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                zhao-ji
                / latency.markdown
            
            
              Last active
              August 29, 2015 14:13
                — forked from hellerbarde/latency.markdown
            
          
    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

  
## viewport
 <!--在html代码的<head>...</head>中嵌入下面代码-->
<meta name="viewport"
content="
height = [pixel_value | device-height] ,
width = [pixel_value | device-width ] ,
initial-scale = 0.5 ,
minimum-scale = float_value ,
maximum-scale = float_value ,
user-scalable = [yes | no] ,
"

## gist:4c9c18428f30099b651f
class Num:
    '''output the nature number'''
    num = 0

    def next_num(self):
        yield self.num
        self.num += 1

## ros scripts
[admin@RouterOS] > /ip firewall layer7-protocol add name=example.com regexp=example.com
[admin@RouterOS] > /ip firewall mangle add chain=prerouting dst-address=10.0.0.254 layer7-protocol=example.com action=mark-connection new-connection-mark=example.com-forward protocol=tcp dst-port=53
[admin@RouterOS] > /ip firewall mangle add chain=prerouting dst-address=10.0.0.254 layer7-protocol=example.com action=mark-connection new-connection-mark=example.com-forward protocol=udp dst-port=53
[admin@RouterOS] > /ip firewall nat add action=dst-nat chain=dstnat connection-mark=example.com-forward to-addresses=10.0.1.11
[admin@RouterOS] > /ip firewall nat add action=masquerade chain=srcnat connection-mark=example.com-forward

## start-stop-example.sh
#!/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

## tun-ping-linux.py
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

## local mail server to test email
sudo python -m smtpd -c DebuggingServer -n localhost:25

## unshorten.py
# This is for Py2k.  For Py3k, use http.client and urllib.parse instead, and
# use // instead of / for the division
import httplib
import urlparse

def unshorten_url(url):
    parsed = urlparse.urlparse(url)
    h = httplib.HTTPConnection(parsed.netloc)
    resource = parsed.path
    if parsed.query != "":

## eslint.sh
npm i -g eslint-plugin-import eslint-plugin-jsx-a11y eslint-plugin-react
	private const double EARTH_RADIUS = 6378.137;
	private static double rad(double d)
	{
	return d * Math.PI / 180.0;
	}
	public static double GetDistance(double lat1, double lng1, double lat2, double lng2)
	{
	double radLat1 = rad(lat1);
	double radLat2 = rad(lat2);
	double a = radLat1 - radLat2;
	<!--在html代码的<head>...</head>中嵌入下面代码-->
	<meta name="viewport"
	content="
	height = [pixel_value \| device-height] ,
	width = [pixel_value \| device-width ] ,
	initial-scale = 0.5 ,
	minimum-scale = float_value ,
	maximum-scale = float_value ,
	user-scalable = [yes \| no] ,
	"
	class Num:
	'''output the nature number'''
	num = 0

	def next_num(self):
	yield self.num
	self.num += 1
	[admin@RouterOS] > /ip firewall layer7-protocol add name=example.com regexp=example.com
	[admin@RouterOS] > /ip firewall mangle add chain=prerouting dst-address=10.0.0.254 layer7-protocol=example.com action=mark-connection new-connection-mark=example.com-forward protocol=tcp dst-port=53
	[admin@RouterOS] > /ip firewall mangle add chain=prerouting dst-address=10.0.0.254 layer7-protocol=example.com action=mark-connection new-connection-mark=example.com-forward protocol=udp dst-port=53
	[admin@RouterOS] > /ip firewall nat add action=dst-nat chain=dstnat connection-mark=example.com-forward to-addresses=10.0.1.11
	[admin@RouterOS] > /ip firewall nat add action=masquerade chain=srcnat connection-mark=example.com-forward
	#!/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
	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
	# This is for Py2k. For Py3k, use http.client and urllib.parse instead, and
	# use // instead of / for the division
	import httplib
	import urlparse

	def unshorten_url(url):
	parsed = urlparse.urlparse(url)
	h = httplib.HTTPConnection(parsed.netloc)
	resource = parsed.path
	if parsed.query != "":