Tutorial by Examples: p

To declare exposed ports from a Dockerfile use the EXPOSE instruction: EXPOSE 8080 8082 Exposed ports setting can be overridden from the Docker commandline but it is a good practice to explicitly set them in the Dockerfile as it helps understand what an application does.

Group common operations Docker builds images as a collection of layers. Each layer can only add data, even if this data says that a file has been deleted. Every instruction creates a new layer. For example: RUN apt-get -qq update RUN apt-get -qq install some-package Has a couple of downsides: ...

_mycompletion() { local command_name="$1" # not used in this example local current_word="$2" local previous_word="$3" # not used in this example # COMPREPLY is an array which has to be filled with the possible completions # compgen is used to fi...

It is possible to save a Docker container's filesystem contents to a tarball archive file. This is useful in a pinch for moving container filesystems to different hosts, for example if a database container has important changes and it isn't otherwise possible to replicate those changes elsewhere. Pl...

RewriteEngine on RewriteCond %{HTTP_REFERER} !^$ RewriteCond %{HTTP_REFERER} !^http://(www\.)?yourdomain.com/.*$ [NC] RewriteRule \.(gif|jpg|css)$ - [F] This blocks all the links to '.gif', '.jpg' and '.css' files which are not from the domain name http://www.yourdomain.com. Display alterna...

import fileinput replacements = {'Search1': 'Replace1', 'Search2': 'Replace2'} for line in fileinput.input('filename.txt', inplace=True): for search_for in replacements: replace_with = replacements[search_for] line = line.replace(search_for, replace_with...

The method compareTo should be used to compare BigDecimals: BigDecimal a = new BigDecimal(5); a.compareTo(new BigDecimal(0)); // a is greater, returns 1 a.compareTo(new BigDecimal(5)); // a is equal, returns 0 a.compareTo(new BigDecimal(10)); // a is less, returns -1 Commonly you shou...

GCD provides mechanism for performing a loop, whereby the loops happen concurrently with respect to each other. This is very useful when performing a series of computationally expensive calculations. Consider this loop: for index in 0 ..< iterations { // Do something computationally expens...

Applying a function to a collection/stream and creating a new collection/stream is called a projection. /// Projection var newReleases = [ [ "id": 70111470, "title": "Die Hard", "boxart": "http://cdn-0.nflximg.com/images...

A HAVING clause filters the results of a GROUP BY expression. Note: The following examples are using the Library example database. Examples: Return all authors that wrote more than one book (live example). SELECT a.Id, a.Name, COUNT(*) BooksWritten FROM BooksAuthors ba INNER JOIN Aut...

PostgreSQL and SQLite To create a temporary table local to the session: CREATE TEMP TABLE MyTable(...); SQL Server To create a temporary table local to the session: CREATE TABLE #TempPhysical(...); To create a temporary table visible to everyone: CREATE TABLE ##TempPhysicalVisibleToEveryo...

Sometimes one wants to capture the records that have just been updated. CREATE TABLE #TempUpdated(ID INT) Update TableName SET Col1 = 42 OUTPUT inserted.ID INTO #TempUpdated WHERE Id > 50

When files are not available, the require family will throw a LoadError. This is an example which illustrates loading optional modules only if they exist. module TidBits @@unavailableModules = [] [ { name: 'CoreExtend', file: 'core_extend/lib/core_extend' } \ , { name: 'Fs' ...

The Kernel#load method will evaluate the code in the given file. The search path will be constructed as with require. It will re-evaluate that code on every subsequent call unlike require. There is no load_relative. load `somefile`

To get records having any of the given ids select * from products where id in (1,8,3) The query above is equal to select * from products where id = 1 or id = 8 or id = 3

DECLARE @DateFrom DATETIME = '2016-06-01 06:00' DECLARE @DateTo DATETIME = '2016-07-01 06:00' DECLARE @IntervalDays INT = 7 -- Transition Sequence = Rest & Relax into Day Shift into Night Shift -- RR (Rest & Relax) = 1 -- DS (Day Shift) = 2 -- NS (Night Shift) = 3 ;WITH roster AS ...

This function returns the floating-point remainder of the division of x/y. The returned value has the same sign as x. #include <math.h> /* for fmod() */ #include <stdio.h> /* for printf() */ int main(void) { double x = 10.0; double y = 5.1; double modulus = fmod(x,...

Whenever a template is called upon, the default data context of the template is implicitly gained from the caller as in example the childTemplate gains the data context of the parentTemplate i.e caller template <template name="parentTemplate"> {{#with someHelperGettingDataForPa...

Sometimes we would like to pass into the template a template type without fixing its values. This is what template template parameters are created for. Very simple template template parameter examples: template <class T> struct Tag1 { }; template <class T> struct Tag2 { }; templ...

Python classes support properties, which look like regular object variables, but with the possibility of attaching custom behavior and documentation. class MyClass(object): def __init__(self): self._my_string = "" @property def string(self): "&...