A Date and Time Processing tutorial in Ruby and a date Processing tutorial in ruby
The Time class is used in Ruby to represent the date and Time. It is based on the system date and time provided by the operating system. This type may not represent the date before or after January 1.
This tutorial will familiarize you with all important concepts of date and time.C
Analysis of Ruby source code layout and programming style, analysis of ruby source code Layout
Use the UTF-8 as the source file encoding.
Each indentation level uses two spaces (also known as soft tabs). Do not use hard tabs
# bad - four spaces def some_method do_something end # good def some_method do_something end
Use Unix-style line breaks. (* Users of BSD, Solaris, Linux, and OSX are covered
This blog provides an easy way for Elasticsearch to index multiple documents. The support of Bulk API can implement batch add, delete, update and so on once request. The bulk operation uses the UDP protocol, and UDP cannot ensure that data is not lost when communicating with the Elasticsearch server.First, Bulk APIWith the bulk command, the REST API _bulk ends with a bulk operation written in the JSON file,
Optimizing Queries with FiltersElasticsearch supports a variety of different types of queries, which you should all be familiar with. However, the query is not the only option when choosing which document should match successfully and which document should be presented to the user. ElasticSearch Query DSL allows the vast majority of queries that a user can use to have their own identities, which are also nested into the following query types:
immediately[[Email protected] ~]# [[email protected] ~]# source/etc/profile//Both of these effective methods you can use either [[email protected] ~]# [[Email ProtEcted] ~]#. /etc/profile[[email protected] ~]#Test if the environment variable is installed successfully[[email protected] ~]# Java-versionjava version "1.7.0_67" Java (TM) SE Runtime Environment (build 1.7.0_67-b01) Java HOTSPO T (TM) 64-bit Server VM (build 24.65-b04, Mixed mode)JDK Installation Complete ...Third, install elasticsea
Reference: http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/setup-repositories.htmlDownload and install the public Signing Key
rpm --import https://packages.elasticsearch.org/GPG-KEY-elasticsearch
Add the following in your/etc/yum.repos.d/directory with a file named (for example) Elasticsearch.repo
[elasticsearch-1.4]
This paper records the entire process of building elasticsearch clusters using Docker (the 2.1.2 examples used in this article), and process affinity is also applicable to elasticsearch2.x,5.x, and subsequent authors will continue to study es in depth, The next step is to make a retrofit test based on this cluster for source Elasticsearch (hereafter referred to as ES). 1. Environment Introduction
This paper
1. Preparatory workDownload Elasticsearch version number 2.3.4 https://www.elastic.co/downloads/past-releases/elasticsearch-2-3-4, download the package required to synchronize the database https:// codeload.github.com/jprante/elasticsearch-jdbc/tar.gz/2.3.4.0, download ik chinese word https://github.com/medcl/ Elasticsearch
There has been an interesting phenomenon in the IT community over the past few years. Many new technologies have emerged and embraced "big data" immediately. A little bit older technology will also add big data to their own features, to avoid falling too far, we see the different technologies of the marginal ambiguity. If you have search engines such as Elasticsearch or SOLR, they store JSON documents, MongoDB has JSON documents, or a bunch of JSON do
Example of writing code for exception handling in Ruby, and ruby Exception Handling
A single exception uses the fail keyword only when an exception is caught and thrown repeatedly (because you do not fail here, but are accurate and intentionally throw an exception ).
begin fail 'Oops' rescue => error raise if error.message != 'Oops' end
Do not specify an accurate RuntimeError for fail/raise.
# bad
Tutorial on interrupt and return in Ruby programming and tutorial on ruby programming usage
The use of the return, break, and next keywords involves the issue of jumping out of the scope. Their difference lies in the different scopes of different keywords jumping out, because there are code blocks, you need to pay special attention to them.ReturnCommon Methods
Generally, the return statement is the same as
Example parsing for Hook methods in Ruby and ruby hook instance Parsing
By using the Hook method, we can intervene in the life cycle of Ruby classes or modules, greatly improving programming flexibility.The following hook methods related to lifecycle are available:
Classes and modules
Class # inherited
Module # include
Module # prepended
Module # extend_
Let's get back to our jukebox for a moment (remember the jukebox ?). At some point
We'll be working on the code that handles the user interface-the buttons that people
Press to select songs and control the jukebox. We'll need to associate actions
Those buttons: press START and the music starts. It turns out that Ruby's blocks are
A convenient way to do this. Let's start by assuming that the people who made
Hardware implemented a Ruby extension that gi
1. Debug comment Print output debugRuby is an interpreted language, a script, and on Linux, scripts cannot be executed in three ways:1. Run the script with the interpreterInterpreter script FileThat is:Ruby script File2. Run the script directlyIn the script file, use the#! Script InterpreterDefine the script interpreter path, then grant the script execute permission, then run directly./script FileCan.3. Run the script inside the interpreter[Email protected]:/home/ywt/ror_tests/ruby_tests# irb
The example explains the Hook method in Ruby and adds a hook to the method call. The example explains ruby.
The Hook method is similar to the event-driven device. You can execute a specific callback function after a specific event occurs. This callback function is the hook method (more vividly described: The Hook method can be like a hook, hook up a specific event .), In Rails, The before \ after function i
Detailed description of the code block and parameter transfer in Ruby, detailed description of ruby code transfer
1. Block DeclarationAfter the function is called, the block declaration is enclosed by {...}, Or do. end encapsulation. {} Is generally used in single-line statements, and do... end is used in multi-line statements.
(1 .. 4). each {| v | print "# {v}"} # output 1 2 3 4
Blocks can contain paramet
The example parses the value types and constants in Ruby AND the ruby numerical constants.
Number)Integer)There are two types of integer types. If the value is within 31 characters (four bytes), it is a Fixnum instance. If the value is exceeded, it is a Bignum instance.The integer ranges from-230 to 230-1 or-262 to 262-1. Integers in this range are Fixnum-like objects, and integers out of this range are sto
Ruby class inheritance, abstract classes, class expansion, proxy class instances, ruby instances
Summarize the class extensions encountered in the work:
1. class inheritance:
When multiple classes share many methods, you can extract the public methods and inherit the required classes.
Example:
Copy codeThe Code is as follows:Class A DefP "it was"EndEnd
Class B End
Class C End
B. new. a # => "it was"C. new.
Methods (functions) in Ruby, ruby Functions
1. The method name and variable name naming rules in Ruby are the same (Start with a lower-case letter, and separate words with "_",), but you can add it behind the method name! (Major method) or? (Boolean return value ).
2. Use () for method parameters (),All parameters are local variables. You can set the default valu
Ruby implements batch code sharing by adding prefixes to files, and ruby Prefix code sharing
From the perspective of the designer, we get a large number of images, and the results are all file names such as 1.png and 2.png. We also need to convert these files into readable file names and do not want to modify them one by one, so we wrote a simple script, you can add prefixes to multiple files in batches. Yo
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