SEARCH KEYWORD -- Good code


  Install and setup Kafka on Windows

Kafka has become a very popular distributed message delivery service which decouples different services while making message delivery between service easy, fast and reliable. In this post, we will walk through how to install and set up Kafka on Windows. Pre-requisite Java Apache ZooKeeper Installation Go to Kafka's download link and download the latest stable release, we downloaded 2.2.0 as of this writing. After downloading, copy the installation file to some folder and unzip it.  Sinc...

   KAFKA,STREAM,USER GUIDE     2019-06-01 02:12:07

  Fix Permission Issue for iTerm2 to Access Application Support on MacOS

In case you have a new MacOS setup (especially on the newly released Apple M4 MacBook) and you are trying to install/launch iTerm2 on your system, you may encounter an error where it complains that you don't have enough permission to access Application Support, the error message would be like There was a problem finding or creating your application support directory. iTerm2 won't work very well until this problem is fixed. It should be at ~/Library/Application Support/iTerm2. The error was...

   FIX,MACOS,APPLICATION SUPPORT,ITERM2,PERMISSION ISSUE     2024-11-17 13:09:11

  Bug caused by using changeable value as the default in "python method overload"​

In python we can set the passed in parameter's default value to make the function has the same running feature as the method overload in Java. Define a function like this: def testFunction(self, param1, param2=None, param3=None): Normally we use "None" as the parameter's default value. We can also use str/bool as the default value, but is it OK we use empty list [] as its default value? This is our test program: """ A test program using empty list as the passed-in parameter's default value. ...

   PYTHON     2019-03-11 08:52:52

  Text editor vs IDE

A meaningless editor war Many people like to debate which editor is the best. The biggest controversy is between Emacs and vi. vi supporters like to say: "Look it's very fast to type in vi, our fingers no need to leave the keyboard, we even no need to use the up,down,left and right keys" Emacs supporters often downplayed this and said: "What's the use of typing fast if I just need to press one key and it equals to dozens keys you type in vi?"In fact, there is another group of people who like to ...

   Editor,IDE,Structured editor,vi     2013-05-20 12:03:39

  Write Your Own R Packages

Introduction A set of user-defined functions (UDF) or utility functions are helpful to simplify our code and avoid repeating the same typing for daily analysis work. Previously, I saved all my R functions to a single R file. Whenever I want to use them, I can simply source the R file to import all functions. This is a simple but not perfect approach, especially when I want to check the documentation of certain functions. It was quite annoying that you can’t just type ?func&n...

   DATA SCIENCE,R PROGRAMMING,DATA ENGINEERING     2019-10-19 07:20:52

  Encrypting and decrypting PGP file or text on MacOS

When doing data exchange among different parties, there is a frequent need of encrypting data or file and sending it to partner and asking partner to use corresponding key to decrypt the data or file. A famous way of exchanging data is using asymmetric keys where no secret key needs to be shared. One party can just use the public key shared by partner to encrypt the data and the other party uses the private key to decrypt the data. Today, we will introduce how to use PGP to encrypt and decrypt d...

   TUTORIAL,ENCRYPTION,DECRYPTION,PGP,GPG     2020-10-29 05:06:09

  Stub Mixlib::ShellOut and shell_out in Ruby unit testing

Unit testing is part of software development to ensure the tiny component of a function can work as designed. Different frameworks and tools can be used to run unit testing for different programming languages. In Ruby, one popular unit testing framework is Rspec, or Chefspec if you are writing Chef recipes. While writing Chef recipes, some low level commands(DOS commands or shell commands) need to be executed on the managed resource to perform actions or gather information. For example, lis...

   RUBY,UNIT TESTING,RSPEC,CHEFSPEC,SHELL_OUT     2016-11-11 00:14:46

  Use DTrace to diagnose gdb issues

A few days ago, I installed the newest 64-bit gdb program (version 7.7.1) on Solaris 10 (X86_64 platform) to debug programs. After playing with the gdb a day, I found 2 issues about gdb:(1) The "set follow-fork-mode child" command doesn't take effect. By default, after the parent process forks the child process, the gdb will track the parent process, so this command can make gdb begin to follow the child process. But this command works OK on Linux.(2) The gdb can't parse the 32-bit application c...

   DTrace, debug, gdb, UNIX     2014-06-28 05:11:20

  Computer skills one can learn within one day

Computer related technical skills are usually thought as complicated and difficult to understand. It's very difficult for one to get hands on one skill or master one skill. But if you really do want to learn something useful within one day, there are some good choices which will not take too long to get to know and use.. Version control:- Git, GitHub and SVN Regular expressions AWK sed Grep Learn how to do things with Vim that you never knew could be done. Set up a crawler that can scrape some ...

   Computer skills,Learn     2013-09-16 08:51:35

  Here is what XcodeGhost author says

The first compiler malware in iOS was disclosed by Chinese iOS developers on Wednesday(Beijing time). The name of this malware is XcodeGhost as described by Alibaba researchers who released the analysis of this malware.  The malicious code is located in a Mach-O object file that was repackaged into some versions of Xcode installers. These malicious installers were then uploaded to Baidu’s cloud file sharing service for used by Chinese iOS/OS X developers. Xcode is Apple’s offic...

   IOS,SECURITY,XCODEGHOST,APP STORE,APPLE     2015-09-18 20:51:38

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