Today's Question:  What does your personal desk look like?        GIVE A SHOUT

SEARCH KEYWORD -- delete file

  Learn Emacs: Keyboard Macros

An emacs keyboard macro is just a recording of user input into emacs, which means that most anything you can do in emacs can be recorded as a macro. Read that again. Pretty powerful.Here’s how it works. To start recording, typeC-x (and input the commands in your macro. Then typeC-x )to stop recording. Then typeC-x eto apply the macro once, orC-u 0 C-x eto apply the macro until the bell rings or end of buffer is reachedKeep in mind that you must not ring the bell when defining a keyboard m...

   Emac,Macro,Code,Example     2011-11-10 10:45:47

  SQL Grammar Summary

整理了一下，希望对大家有用SQL语句大全  --语 句 功 能--数据操作SELECT --从数据库表中检索数据行和列INSERT --向数据库表添加新数据行DELETE --从数据库表中删除数据行UPDATE --更新数据库表中的æ...

   SQL,Query,Summary,Select,Update,Delete,I     2011-05-20 12:04:55

  How Kafka achieves high throughput low latency

Kafka is a message streaming system with high throughput and low latency. It is widely adopted in lots of big companies. A well configured Kafka cluster can achieve super high throughput with millions of concurrent writes. How Kafka can achieve this? This post will try to explain some technologies used by Kafka. Page cache + Disk sequential write Every time when Kafka receives a record, it will write it to disk file eventually. But if it writes to disk every time it receives a record, it would ...

   BIG DATA,KAFKA     2019-03-08 09:42:57

  About JavaScript source map

Last week jQuery 1.9 was released. This is the last release before jQuery 2.0. It adds many new functions, one of them is the source map. By accessing http://ajax.googleapis.com/ajax/libs/jquery/1.9.0/jquery.min.js , you can scroll to the last line and you will see below line : 　//@ sourceMappingURL=jquery.min.map This is source map, it is a separate file and it is put at the same directory as the source file. You can click here and see what it looks like. It's an very useful functio...

   Source map, JavaScript, jQuery     2013-02-01 07:06:44

  Generate certificate from cert file in Java

A certificate is often used to prove the identity of a server. The certificate will contain information such as the subject and issuer of the certificate. It will also contain the validation date of the certificate. A certificate is often exported to an external cert file which is transferred over the internet. We will often see its use in SSL communication which provides secure communication between two entities. In this post, we will show how to read the data from an external certificate file ...

   PKCS12,CertificateFactory,Example,Java,X509     2015-06-08 06:47:05

  Bill Gates : Ctrl+Alt+Del was a mistake

Microsoft chairman Bill Gates admitted that Ctrl+Alt+Del command was a mistake when he was in a fund raising campaign at Harvard University last week. This command was initially designed to reboot the system. David Rubenstein, the Harvard fund raising campaign chairman, asked Bill Gates : "Why when I turn on my software or computer do I need to have my three fingers to press control,alt and delete? Whose idea was that?" The answer given by Bill Gates is : "Basically because when you turn your co...

   Bill Gates,Ctrl-Alt-Del,Mistake     2013-09-26 23:28:37

  Run JavaScript in GoLang

In some cases, there might be some JavaScript code needs to be ran in a GoLang project. Fortunately, there are a few libraries which support running JavaScript in GoLang. The most famous one would be v8. This is a Go API for the famous v8 JavaScript engine originally developed for the Chrominum project and the foundation of NodeJS. In this post, we will show some simple steps to get v8 working in a GoLang program on MacOS. First you need to install the package so that you can import it. Run...

   GOLANG,JAVASCRIPT,V8     2019-05-16 07:40:38

  Why would I learn C++11, having known C and C++?

I am a programmer in C and C++, although I don't stick to either language and write a mixture of the two. Sometimes having code in classes, possibly with operator overloading, or templates and the oh so great STL is obviously a better way. Sometimes use of a simple C function pointer is much much more readable and clear. So I find beauty and practicality in both languages. I don't want to get into the discussion of "If you mix them and compile with a C++ compiler, it's not a mix ...

   C++11,New feature,Study     2012-03-16 08:44:38

  bash network interface

Some of us may have seen /dev/tcp/<host>/<port> before, is this a special file system implemented in some BSD kernel? Because there is no /dev/tcp in Linux. Actually, this one is implemented in bash. We no need to rely on wget,nc to do network connection. It's very easy to use this interface: bash-4.2$ cat </dev/tcp/time.nist.gov/13 56188 12-09-18 15:34:26 50 0 0 733.5 UTC(NIST) * bash-4.2$ exec 3<>/dev/tcp/www.w3.org/80 bash-4.2$ echo -e "GET / HTTP/1.0\n\n" >&3 b...

   Bash,Network interface,/dev/tcp     2013-07-20 00:57:52

  Convert time to Unix time

Unix time is defined as the number of seconds that have elapsed since midnight Coordinated Universal Time (UTC), 1 January 1970,not counting leap seconds. It is used widely in Unix-like and many other operating systems and file formats. It is neither a linear representation of time nor a true representation of UTC. Unix time may be checked on some Unix systems by typing date +%s on the command line. Sometimes it's a bit difficult to compare times stored in different applications or systems with ...

   UNIX time, Oracle DATE, conversion, timestamp     2013-01-19 09:04:17

RECENT