Sunday, November 23, 2008

Is my computer 64-bit support?

Well, one thing is when we're talking about 64bits system, actually we are talking about 2 separate things: 64-bit hardware support and 64-bit OS support.

In my understanding, if you can see 4GB or more memory in your system profile, then you have a 64-bit computer. (Whatever OS you use, there should be some system utils can help you to monitor the system status in runtime, e.g., system monitor for mac/u*x/, task manager for Windowz, etc.)

You may not really feel how 64-bit benefits you. But at least it's compatible with most of your current applications so you don't need to pay extra money to get the 64-bit edition for them.

Want to know more about 64-bit? Take a few minutes to read the following links:
- What kind of performance increase can I expect in going from 32-bit to 64-bit Stata?
- First Look: Leopard first looks: 64-bit support
- Is Leopard truly 64-bit?

Saturday, November 22, 2008

JDK 6 for Mac doesn't have Console support?

I just downloaded and installed JDK6 form here (http://support.apple.com/kb/HT1856). But look like there isn't the lib java.io.Console since the code "import java.io.Console;" will cause a compiler error, "cannot find symbol". That's strange.

Tested on a Linux box and it's good. So I suppose this "Java for Mac OS X 10.5 Update 1 adds support for Java SE 6" (This update provides Java SE 6 version 1.6.0_05.) is not a full version. If it's tailored, how could it comply with the license? Maybe I missed something here...

Wednesday, November 05, 2008

HTTP Protocol: Method OPTIONS?

Well, the method OPTIONS defined in HTTP RFC[1] is required to be implemented for all web servers. [2]

But when I test it with my local apache server and the bckids.info server, something looks interesting...

1. Trying http/1.0 shows the methods allowed together with error 501.

calvin:~ cxl$ telnet localhost 80
Trying ::1...
Connected to localhost.
Escape character is '^]'.
options * http/1.0

HTTP/1.1 501 Method Not Implemented
Date: Wed, 05 Nov 2008 22:26:33 GMT
Server: Apache/2.2.9 (Unix) mod_ssl/2.2.9 OpenSSL/0.9.7l DAV/2 PHP/5.2.6
Allow: GET,HEAD,POST,OPTIONS,TRACE
Content-Length: 209
Connection: close
Content-Type: text/html; charset=iso-8859-1


2. Trying http/1.1 shows error 400: Bad Request.

calvin:~ cxl$ telnet localhost 80
Trying ::1...
Connected to localhost.
Escape character is '^]'.
options * http/1.1

HTTP/1.1 400 Bad Request
Date: Wed, 05 Nov 2008 22:26:06 GMT
Server: Apache/2.2.9 (Unix) mod_ssl/2.2.9 OpenSSL/0.9.7l DAV/2 PHP/5.2.6
Content-Length: 226
Connection: close
Content-Type: text/html; charset=iso-8859-1


[1] http://www.w3.org/Protocols/rfc2616/rfc2616-sec5.html#sec5.1.1
[2] http://en.wikipedia.org/wiki/HTTP