answersy.com Blog

• REPLACE(url, str2, str1), replace all the "https://" with "http://"
• SUBSTRING_INDEX(xxx, '/', 3), get everything before the 3rd '/'
• REPLACE(yyyy, str1, ''), remove 'http://'

DROP FUNCTION IF EXISTS getHostFromUrl;
CREATE FUNCTION getHostFromUrl (url text(1024)) RETURNS CHAR(255)
BEGIN
DECLARE str1 varchar(10);
DECLARE str2 varchar(10);
SET str1='http://';
SET str2='https://';
RETURN REPLACE(SUBSTRING_INDEX(REPLACE(url, str2, str1), '/', 3), str1, '');
END;

See official Mysql Reference http://dev.mysql.com/doc/refman/5.0/en/encryption-functions.html#function_md5

mysql> SELECT MD5('testing');

Step 1: Download the package

• You can find the official download Link at http://dev.mysql.com/downloads/
• For MySql 5.0: http://dev.mysql.com/downloads/mysql/5.0.html#downloads

Step 2: Install the Binary
shell> /usr/sbin/groupadd mysql
shell> /usr/sbin/useradd -g mysql mysql
shell> cd /usr/local
shell> gunzip < /PATH/TO/MYSQL-VERSION-OS.tar.gz | tar xvf -
shell> ln -s FULL-PATH-TO-MYSQL-VERSION-OS mysql
shell> cd mysql
shell> scripts/mysql_install_db --user=mysql
shell> chown -R root .
shell> chown -R mysql data
shell> chgrp -R mysql .
shell> bin/mysqld_safe --user=mysql & # start mysql daemon

Step 3: Post-installation
shell> su mysql
shell> mysql/scripts/mysql_install_db

shell> mysql -u root -p
mysql> use mysql
mysql> GRANT ALL PRIVILEGES ON *.* TO 'user'@'localhost' IDENTIFIED BY 'password' WITH GRANT OPTION;
mysql> set PASSWORD FOR 'user'@'localhost' = PASSWORD('password');
mysql> FLUSH PRIVILEGES;
mysql> select * from mysql.user;

mysql> create database db_name;
mysql> SHOW DATABASES;
mysql> use db_name;
mysql> SHOWTABLES;

From Interstate I-280 in Santa Clara, take exit El Monte/Moody Road and drive west on Moody Road. Pass the traffic light in front of Foothill College, and at a stop sign turn left to stay on Moody. Drive about 0.5 mile more, then turn left onto Rhus Ridge Road. Take another 0.2 mile on the narrow road, then bear right into the parking lot. This is the trailhead of Rhus Ridge Trail.

This 9.4 mile (round trip) hike to the top of Black Mountain has two quite different segments. The first mile, known as Rhus Ridge Trail is a bit steep.

As Rhus Ridge Trail zigzags uphill, the longest steep section starts form about 0.5 mile, and at 0.90 mile the trail crests, ends at a signed junction.

Turn right onto Black Mountain Trail. The initial stretch of Black Mountain Trail is a nicely graded footpath winding through woods and chaparral. The quite woods have a lot of creatures inside. Deers are very common in this area of the preserve except that they tend stay a little far away from human beings.

At about 3.2 miles, the trail steps out under a high-tension power line. You can hear clearly the noise on the power lines, as the electricity rushing though "under very high pressure."

Form there, the footpath widens to fire road width, and shoots nearly straight uphill, with little shade. Stay on the trail. After a brief downhill stretch, there are more steep sections, some of them quite rocky. Finally, at 4.4 miles, you'll reach a gate, with some telecoms base station nearby.

While you enjoy the accomplishment of an over 2300 foot climb all the way up the mountain, don't forget to enjoy the great view!

As a blogger, I am interested in how Google finds and indexes my blog.

Google's web search found my blog very quickly, even if no external incoming link was available. I would assume Google uses domain registration information to find new domains. Besides, since I have an AdSense account, it can be a plus.

Google Blog Search is an RSS-based. It extracts some basic entities like "update time" and "blogger name" from the RSS feed. Google's blog search might get feeds from its web search database. With some kind of filtering, these feeds are sent to a special RSS crawler. Google also uses ping service to track newly published blog posts.

As you can see from the figure below, my post was indexed within 7 minutes after it was on the web! But when I searched "answersy," this result did not show up. Only when I click on the "Last hour" link, was I able to see it.

Since wordpress ping tells Google when a blog was updated, Google blog search sends crawler right away to fetch the RSS. I looked at my access log, and confirmed that Google bot crawled my RSS in less than a minute. The mysterious part is Google's indexing turn -around time. To be able to serve the results in less than 10 minutes, Google must be keeping a relatively small database. As we know, a database can be optimized either for data manipulation or for query. Only when it is small, can it achieve good performance for both.

Another thing I noticed was Google did not fetch the post page itself. It only indexes the description in RSS.
I then do the query again and click the "Last hour" link, this time I got the following no result page!

My guess was that the previous result got pushed out from that small super-fast database, and it will take a while before it can be re-indexed by the main cluster :−)

Then I added THIS post and searched again. This time I saw THIS post itself while the previous one was still missing.

By any means, I have to say Google's crawler and indexer work really hard. In the meanwhile, I also found Google blog search is still not as good as I expected. It has some inconsistent behaviors from the view point of end users.

The screen command lets you start new terminals, detach them and bring them back later. So you do not need to worry about how to bring a process to background any more. Here, I will give a very brief introduction on it, which is good enough for one to see the beauty of it. If you want to learn more, do a search "screen man" on any search engine.

To start screen: enter screen -RD at Unix prompt.
To exit screen: you need to close all the terminals attach to it. Hit ctrl-d or enter exit for each terminal, screen will exit when the last terminal exits.

To detach screen (sent it to background): simply close the terminals window if you are using any ssh/telnet clients, or to do it explicitly by hitting ctrl-a then d.

To re-attach screen and bring you previous Unix session to foreground: enter screen -RD at Unix prompt. If you only have one screen running on the host, it will be brought to foreground right away. Otherwise, see below.
You can start multiple screens on one host, detach them to send them to background. When you enter screen -RD next time, screen will list all the detached ones, and you can choose to re-attach any one of them by screen -RD screen_name

EditPlus is a commercial text editor for Windows. It supports utf8 and many different encodings. Like most developer-oriented editors, it supports per-language syntax coloring. But it doesn't come with a Python module.

So I did a search with Yahoo using query "python syntax file for editplus" and found the first result very cool: http://adamv.com/dev/python/editplus/

What you need to do is to download the file python.stx and add it to EditPlus by choosing Document(M) -> Permanent Settings -> File Types -> Add(B)

For other language syntax highlighting in Editplus, you might want to consult this page http://www.editplus.com/javacpp.html.

Sometimes it can be annoying to have you laptop play a sudden sound when you reboot it. You might want to turn the greeting sounds off.

To do so, go to the Windows control panel, choose "Sounds and Audio Devices"

You will see the following window,

Select "Sounds" tab, and in the "Program events" list, select "Windows Logon" and/or "Windows Logoff", then pick the Sounds to be "(None)" to turn it off, or you might want to replace it with some other ones.

Oops, it did not work! You need to turn off sounds for "Exit Windows" and "Start Windows" also!

Now reboot you laptop, it should be silent now :−)

From Interstate I-280 in Santa Clara County, exit Page Mill Road, drive west on Page Mill about 7.5 miles, a large dirt parking lot is on the left of the road. This is the trailhead of Monte Bello open space preserve. Parking is available for more than 40 cars, and there is no entrance or parking fees. Maps are available at an information signboard.

It was drizzling when I started. As far as I remember, this was the first rain since summer. Tiny rain drops flied in the air as wind blew; I suddenly realized, north California's dry season was no longer around.

There are a lot of different trails. To be frank, I did't know which one is the best. So I randomly followed one: canyon trail.

The trail was not hard at all, but very delightful. Different views kept on shifting, grassland, oak trees, there was even a big pond on the side of the trail.

When I got to a sign saying that Black Mountain is only 0.2 miles away, I decided to head downhill.

Rain became heavier and fog in the woods became much closer and denser. I felt I was heading into a painting.

With no one around, I felt a little chilly. So I started to whistle. Apparently, I did have some companies near by. They seemed to be scared and started to run.

It only took them one minute to realize that I was just another nice peaceful visitor. Everyone calmed down and resumed his normal behaviors. It was as if a drop of color fell on the painting, and the painter skillfully made it a piece of fallen leaf on the ground.

It has cooled down for a while before I look back whereas the memory is still so vivid.

It was a not-so-typical hot dry day in the fall. When I took this picture, both my legs, calves and thighs got very bad cramps. I could not even stand up to get a better view. That was on the top of Half Dome, Yosemite. Several minutes ago, everyone said 'you are almost there' and I finally was there. That was about 5:30PM.

It took me more than half an hour to get down from the dome. Thanks god, my arms are still strong and functioning. When getting down with cables, arms mattered more. This picture was taken before the final spurt started. Looking back, I have to say it was a little too risky to try it given the cramps on my legs.

When I got here, my friends called 911 to ask for help. The ranger arrived in less than 20 minutes. He calmed me down and let me know the worst scenario would be to stay in his ranger station for a night. I had some drink and took a power bar given by him. Cramps seemed to be fading away. We started to head down. I guess the view was still as beautiful as we hiked up, but nobody seemed to have the mode to appreciate it. It was getting dark.

We went to the ranger's station. I was fed with some Gatorade and caned sardines. The ranger checked me up to make sure I could continue to hike down. He was a very nice guy!

It was fully dark when we got back to Nevada fall. Again, the above pictures were taken when I first came here in the afternoon. We spent about 4 hours to hike back to the trailhead. Many thanks to the friends' help, we finally made it safely!

That night was a new moon. On the way to trailhead, I looked up into the sky and was amazed by the Milky Way. Really could not remember when was the last time I saw that many stars together. I guess, they have always been there, but I simply could not see.